Splenic Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma: A Case Report with Imaging Features and Comprehensive Literature Review

Splenic Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma: A Case Report with Imaging Features and Comprehensive Literature Review | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Splenic Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma: A Case Report with Imaging Features and Comprehensive Literature Review Shuxu Zhu, Ruimiao Shang, Xiaoying Tao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6379371/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Follicular dendritic cell sarcoma (FDCS) is an exceptionally rare malignant neoplasm originating from follicular dendritic cells of the immune system. A distinct histological subtype, designated as inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS), exhibits morphological overlap with inflammatory pseudotumors and represents an even more uncommon clinical entity. We presented a case of IPT-like FDCS and conducted a systematic literature review. This case provides critical insights into the multimodal imaging characteristics for this rare malignancy. Case Presentation We present a case of a 50-year-old asymptomatic male with an incidentally detected splenic mass during routine health screening. Ultrasound showed a hypoechoic mass in spleen with well-defined borders. Magnetic resonance (MRI) revealed a mass with slightly hyperintense signals both on T1-weighted and T2-weighted images. The mass showed a progressive inhomogeneous enhancement. Finally The patient underwent splenectomy, with histopathological and immunohistochemical confirmation of IPT-like FDCS. Conclusions Splenic IPT-FDCS is characterized by nonspecific or subclinical presentations, rendering non-invasive imaging modalities crucial for diagnostic confirmation. Progressive enhancement and a arc-shaped hypointense peripheral rim observed on T2-weighted image are important imaging features of IPT-FDCS. inflammatory pseudotumor follicular dendritic cell sarcoma spleen image features Figures Figure 1 Figure 2 Figure 3 Background Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) usually occurs in the liver and spleen, and to a lesser extent in the gastrointestinal tract, pancreas and other organs [ 1 , 2 ] . IPT-like FDCS is more common in female, with an average age of 56.5 years [ 3 ] . Due to its atypical imaging presentation, IPT-like FDCS is easily misdiagnosed as hemangioma, inflammatory pseudotumour or other conditions. IPT-like FDCS was found for the first time in our hospital, this article describes the discovery, diagnosis and treatment of this disease in the context of the literature. Case presentation A 50-year-old male patient presented to our hospital because of a physical examination which revealed splenic occupancy on 2023-10-14, complaining of no symptoms and no other medical history. Ultrasound revealed a mass of approximately 48 × 48 mm in size at the lower pole of the spleen, with well-defined borders, and the colour Doppler examination revealed that blood flow signals were visible within the mass (Fig. 1 ). A magnetic resonance (MRI) was performed, revealed a mass within the spleen demonstrating slightly hyperintense signals both on T1-weighted and T2-weighted images, measuring approximately 57 × 54 mm. There was a progressive inhomogeneous enhancement of the lesion (Fig. 2 ). On the fourth day of hospitalization, laparoscopic splenectomy was successfully performed. During the operation, a round solid tumor was seen in the lower pole of spleen, incision of the tumor showed that the section was fish-like. Patient recovered smoothly after the surgery, and was discharged. Immunohistopathological results showed that: CD21(+), CD23(+), CD35(+), Bcl-2(-), Bcl-6(-), CD10(-), CD68(+), CD138(+), CD3(-), CD30(-), CD43(+), CD38(+), CD34(-) ,Ki-67(20%+). In situ hybridization showed EBER was positive(Fig. 3 ). Discusioon Follicular dendritic cell sarcoma (FDCS) is a rare mesenchymal neoplasm arising from follicular dendritic cells of the lymphoid tissue. Initially described in 1986 [ 4 ] , this entity gained further recognition in 1996 when a morphologically distinct variant resembling inflammatory pseudotumor was reported, with proposed etiological links to Epstein-Barr virus (EBV) infection [ 5 ] . The term "inflammatory pseudotumor-like follicular dendritic cell sarcoma" was subsequently formalized by Cheuk et al. in 2001 to characterize this clinicopathological subtype [ 6 ] . Clinically, IPT-like FDCS typically follows an indolent course, with the majority of patients remaining asymptomatic at presentation. Non-specific symptoms such as localized pain or abdominal distension are observed in a minority of cases, often correlating with tumor size or anatomical involvement [ 7 ] . Several studies have demonstrated an association between inflammatory IPT-like FDCS and Epstein-Barr virus (EBV), with latent membrane protein 1 detected in the majority of IPT-like FDCS cases [ 8 ] . Epstein-Barr virus-encoded small RNA (EBER) in situ hybridization holds significant value in the definitive diagnosis of this condition [ 9 ] . The sonographic features of splenic IPT-FDCS vary depending on the size of the mass. When the mass is small, the mass appears as a well-defined and uniform hypoechoic lesion,and no blood flow signals are observed. When the mass is large, the mass may demonstrate heterogeneous echogenicity with either well-defined or ill-defined margins, and blood flow signals can be detected [ 10 ] .The research on contrast-enhanced ultrasound (CEUS) features of IPT-FDCS remains limited. In the study by Xu L et al., the mass demonstrated mild, rapid, and heterogeneous enhancement progressing from the periphery toward the center during the CEUS examination [ 11 ] . Splenic hemangioma typically present as well-defined hypoechoic or hyperechoic lesions on conventional ultrasound, with contrast-enhanced ultrasound (CEUS) demonstrating peripheral nodular enhancement, so splenic hemangioma should be included in the differential diagnosis of IPT-FDCS [ 12 ] . Splenic IPT-FDCS manifests as a hypodense lesion with either well-demarcated or indistinct borders on Computed Tomography (CT) [ 13 ] . Notably, the contrast enhancement patterns of IPT-FDCS in the liver and spleen differ significantly. Hepatic tumors exhibit mild arterial-phase enhancement with subsequent attenuation reduction during the portal venous and delayed phases, demonstrating a density marginally lower than that of the surrounding hepatic parenchyma. In contrast, the solid components of splenic tumors display mild persistent enhancement, while central regions with liquefactive necrosis remain non-enhancing [ 11 ] . Hepatic IPT-FDCS typically demonstrates hypointensity on T1-weighted image and hyperintensity on T2-weighted image. In contrast, splenic tumors more frequently exhibit isointense or hyperintensity on T1-weighted image and mild hypointensity on T2-weighted image, with heterogeneous internal signal intensity owing to fibrous scarring and vascular components. The solid portions display mild progressive enhancement, while central liquefactive or necrotic areas demonstrate no significant enhancement [ 14 , 15 ] .However, in our case, the tumor demonstrated a mildly hyperintense signal on T2-weighted image. This variation in T2-weighted image may be associated with the the degree and distribution of inflammatory cells and proliferating capillaries within the tumor [ 16 ] . Furthermore, the T2-weighted image revealed an arc-shaped hypointense rim at the tumor periphery, which exhibited mild enhancement in the delayed phase. This radiological feature could potentially correlate with the vascular distribution within the tumor's pseudocapsule. Splenic IPT-FDCS requires differentiation from inflammatory pseudotumor, hemangioma, and splenic lymphoma on MRI scans. Inflammatory pseudotumor of the spleen may present with slightly hypointense signals on T1-weighted image and slightly hyperintense signals on T2-weighted image, along with peripheral rim-like enhancement at arterial phase [ 17 ] . Splenic lymphoma is often associated with splenomegaly and enlarged retroperitoneal lymph nodes, typically demonstrating homogeneous enhancement of the tumor parenchyma [ 18 ] . Splenic hemangioma exhibits markedly hyperintense signals on T2-weighted image and shows gradual centripetal enhancement during contrast-enhanced phases [ 19 ] . Histologically, inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) shares overlapping features with inflammatory pseudotumor. Microscopically, the neoplastic cells exhibit spindle-to-oval morphology and are organized in fascicular, whorl or storiform pattern [ 20 ] . A defining histopathological distinction from classical FDCS is the prominent mixed inflammatory infiltrate (lymphocytes, plasma cells, and histiocytes) permeating the tumor microenvironment in IPT-like FDCS. Notably, the occasional presence of binucleated or multinucleated Reed-Sternberg-like cells may create diagnostic ambiguity, necessitating differentiation from Hodgkin lymphoma [ 9 ] . Immunohistochemically, CD21, CD23, and CD35 serve as cornerstone markers for confirming follicular dendritic cell lineage, as endorsed by current diagnostic guidelines [ 21 ] . Studies consistently demonstrated the expression of all three markers (CD21, CD23, and CD35) in most cases. Compared to FDCS, the IPT-like FDCS demonstrates reduced invasiveness and improved clinical outcomes [ 22 ] . This subtype typically follows an indolent disease course, with complete surgical resection remaining the standard therapeutic approach for localized lesions. Current evidence regarding adjuvant radiotherapy and chemotherapy remains inconclusive, as their efficacy in IPT-like FDCS management continues to be debated [ 23 , 24 ] . Furthermore, emerging data suggest limited responsiveness to contemporary immunotherapeutic regimens in this tumor subtype [ 25 ] . Notably, longitudinal studies reveal post-treatment recurrence and metastasis rates of 28% and 27% respectively, underscoring the need for vigilant long-term surveillance [ 26 ] . Conclusion Overall, IPT-like FDCS is a rare malignant tumour, often characterised by an absence of distinctive clinical manifestations. Its radiological features are varied, with progressive enhancement on both CT and MRI being among its defining characteristics. The arc-shaped hypointense rim on T2-weighted image may be helpful for the diagnosis of IPT-FDCS. EBV positivity also plays a crucial role in the differential diagnosis of the disease. Abbreviations FDCS Follicular dendritic cell sarcoma IPT-like FDCS inflammatory pseudotumor-like follicular dendritic cell sarcoma EBV Epstein-Barr virus EBER Epstein-Barr virus-encoded small RNA CEUS contrast-enhanced ultrasound CT Computed Tomography Declarations Author contributions Co-first authors: Shuxu Zhu and Ruimiao Shang. Xiaoying Tao contributed to the design of the study and revised the manuscript. Ruimiao Shang collected data and prepared pictures. Shuxu Zhu analyzed the data and wrote the first draft. All authors reviewed the manuscript. Funding None. Data availability All data generated or analyzed during this study are included in the manuscript. Further enquiries can be directed to the corresponding author. Ethics approval and consent to participate This study was approved by Jinhua Central Hospital Medical Ethics Review Committee. All the human data was in accordance with the Declaration of Helsinki principles, and written informed consent for study participation from this patient was obtained. Consent for publication Informed consent was obtained from the patient. Competing interests The authors declare no conflict of interest financial or otherwise. References He H, Xue Q, Tan F, Yang L, Wang X, Gao Y, et al. A rare case of primary pulmonary inflammatory pseudotumor-like follicular dendritic cell sarcoma successfully treated by lobectomy. Annals Translational Med. 2021;9(1):77. https://doi.org/10.21037/atm-20-4965 . Chen Y, Shi H, Li H, Zhen T, Han A. Clinicopathological features of inflammatory pseudotumour-like follicular dendritic cell tumour of the abdomen. Histopathology. 2016;68(6):858–65. https://doi.org/10.1111/his.12851 . Fu LY, Jiang JL, Liu M, Li JJ, Liu KP, Zhu HT. Surgical treatment of liver inflammatory pseudotumor-like follicular dendritic cell sarcoma: A case report. World J Gastrointest Oncol. 2022;14(11):2288–94. https://doi.org/10.4251/wjgo.v14.i11.2288 . Monda L, Warnke R, Rosai J. A primary lymph node malignancy with features suggestive of dendritic reticulum cell differentiation. A report of 4 cases. Am j pathol. 1986;122(3):562–72. Shek TW, Ho FC, Ng IO, Chan AC, Ma L, Srivastava G. Follicular dendritic cell tumor of the liver. Evidence for an Epstein-Barr virus-related clonal proliferation of follicular dendritic cells. Am j surg pathol. 1996;20(3):313–24. https://doi.org/10.1097/00000478-199603000-00008 . Cheuk W, Chan JK, Shek TW, Chang JH, Tsou MH, Yuen NW, et al. Inflammatory pseudotumor-like follicular dendritic cell tumor: a distinctive low-grade malignant intra-abdominal neoplasm with consistent Epstein-Barr virus association. Am j surg pathol. 2001 Jun;25(6):721–31. https://doi.org/10.1097/00000478-200106000-00003 . Zhao M, Du X, OuYang B, Li M, Yang H. Inflammatory pseudotumor-like follicular dendritic cell sarcoma mimicking a colonic polyp. J Gastrointest Surg. 2021;25(9):2429–30. https://doi.org/10.1007/s11605-021-04961-y . Selves J, Meggetto F, Brousset P, Voigt JJ, Pradère B, Grasset D, et al. Inflammatory pseudotumor of the liver. Evidence for follicular dendritic reticulum cell proliferation associated with clonal Epstein-Barr virus. Am j surg pathol. 1996;20(6):747–53. https://doi.org/10.1097/00000478-199606000-00013 . Jin J, Zhu X, Wan Y, Shi Y. Epstein-barr virus (EBV)-positive inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) presenting as thrombocytopenia: A case report and literature review. Heliyon. 2024;10(12):e32997. https://doi.org/10.1016/j.heliyon.2024.e32997 . Xue N, Xue X, Sheng C, Lu M, Wang Y, Zhang S, Xu Y. Imaging features of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen. Annals Palliat Med. 2021;10(12):12140–8. https://doi.org/10.21037/apm-21-2776 . Xu L, Ge R, Gao S. Imaging features and radiologic-pathologic correlations of inflammatory pseudotumor-like follicular dendritic cell sarcoma. BMC Med Imaging. 2021;21(1):52. https://doi.org/10.1186/s12880-021-00584-6 . Schwarze V, Lindner F, Marschner C, Negrão de Figueiredo G, Rübenthaler J, Clevert DA. Single-center study: The diagnostic performance of contrast-enhanced ultrasound (CEUS) for assessing focal splenic lesions compared to CT and MRI. Clin Hemorheol Microcirc. 2019;73(1):65–71. https://doi.org/10.3233/CH-199204 . Liu C, Li YY, Zhu XD, Xiang XL. CT and MRI characteristics of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen: a report of 11 patients with pathological correlation. Abdom radiol. 2024 Dec;11. https://doi.org/10.1007/s00261-024-04736-4 . Zhang J, He L, Ma X, Wang J, Qiu Y, Jiang L. Imaging findings of inflammatory pseudotumor–like follicular dendritic cell sarcoma of the spleen: A case report and literature review. Oncol Lett. 2022;24(5):399. https://doi.org/10.3892/ol.2022.13519 . Chen F, Li J, Xie P. Imaging and pathological comparison of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen: A case report and literature review. Front Surg. 2022;9:973106. https://doi.org/10.3389/fsurg.2022.973106 . Vardas K, Manganas D, Papadimitriou G, Kalatzis V, Kyriakopoulos G, Chantziara M, et al. Splenic Inflammatory Pseudotumor-Like Follicular Dendritic Cell Tumor. Case Rep Oncol. 2014;7(2):410–6. https://doi.org/10.1159/000365000 . Park JY, Choi MS, Lim Y-S, Park JW, Kim SU, Min YW, et al. Clinical Features, Image Findings, and Prognosis of Inflammatory Pseudotumor of the Liver: A Multicenter Experience of 45 Cases. Gut Liver. 2014;8(1):58–63. https://doi.org/10.5009/gnl.2014.8.1.58 . Li M, Zhang L, Wu N, Huang W, Lv N. Imaging Findings of Primary Splenic Lymphoma: A Review of 17 Cases in Which Diagnosis Was Made at Splenectomy. PLoS ONE. 2013;8(11):e80264. https://doi.org/10.1371/journal.pone.0080264 . Chen Y, Shi H, Li H, Zhen T, Han A. Clinicopathological features of inflammatory pseudotumour-like follicular dendritic cell tumour of the abdomen. Histopathology. 2016;68(6):858–65. https://doi.org/10.1111/his.12851 . Chen YR, Lee CL, Lee YC, Chang KC. Inflammatory pseudotumour-like follicular dendritic cell tumour of the colon with plasmacytosis mimicking EBV-positive lymphoproliferative disorder. Pathology. 2020;52(4):484–8. https://doi.org/10.1016/j.pathol.2020.02.010 . Yan S, Yue Z, Zhang P, Yuan L, Wang H, Yin F, et al. Case report: Hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma: a rare case and review of the literature. Front Med. 2023;10:1192998. https://doi.org/10.3389/fmed.2023.1192998 . Ge R, Liu C, Yin X, Chen J, Zhou X, Huang C, et al. Clinicopathologic characteristics of inflammatory pseudotumor-like follicular dendritic cell sarcoma. Int J Clin Exp Pathol. 2014;7(5):2421–9. Saygin C, Uzunaslan D, Ozguroglu M, Senocak M, Tuzuner N. Dendritic cell sarcoma: a pooled analysis including 462 cases with presentation of our case series. Crit Rev Oncol Hematol. 2013;88(2):253–71. https://doi.org/10.1016/j.critrevonc.2013.05.006 . Ding F, Wang C, Xu C, Tang H. Case report: Hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma: A rare case and minireview of the literature. Front Med. 2022;9:1002324. https://doi.org/10.3389/fmed.2022.1002324 . Resnick KA, Monroe C, Siddiqi I, Tam E. Case report: Splenic inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS): a trial of immunotherapy and review of the literature. Front Oncol. 2024;14:1360726. https://doi.org/10.3389/fonc.2024.1360726 . Zhang BX, Chen ZH, Liu Y, Zeng YJ, Li YC. Inflammatory pseudotumor-like follicular dendritic cell sarcoma: A brief report of two cases. World J Gastrointest Oncol. 2019;11(12):1231–9. https://doi.org/10.4251/wjgo.v11.i12.1231 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6379371","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":455991414,"identity":"140f7fea-98b9-4a3a-8a8e-e868f5a530a7","order_by":0,"name":"Shuxu Zhu","email":"","orcid":"","institution":"Affiliated Jinhua Hospital Zhejiang University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Shuxu","middleName":"","lastName":"Zhu","suffix":""},{"id":455991415,"identity":"4d0a9682-ab93-41f5-945e-8a5869c02d9b","order_by":1,"name":"Ruimiao Shang","email":"","orcid":"","institution":"Affiliated Jinhua Hospital Zhejiang University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Ruimiao","middleName":"","lastName":"Shang","suffix":""},{"id":455991416,"identity":"bbf7f0cf-f778-481c-b306-23b93858b17b","order_by":2,"name":"Xiaoying Tao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2klEQVRIiWNgGAWjYHAC9h8fKmzq+dkbGx98IEY9DxBLzjiTliDZc7jZcAaxWqR52w4nGNxIb5PmIEaLvUSOgeHMtrQ8hpsPG6QZGOzkdBsI2cJzxiDhwzmbYsbZiQ3GBQzJxmYHCGlh7zE4OKMsjbFZOrEheQbDgcRtBLUw8xg287AdZmyTPNhwmIcoLew9xsw8bYcTeyQYG5uJ03LmWBkjMJCNJXgSmxlnGBDhF/YZydsYgFEpZ3/8+HNgnNrJEdTCwMBhgMQxwKkMxZ4HRCkbBaNgFIyCEQwAYSVFexhen34AAAAASUVORK5CYII=","orcid":"","institution":"Affiliated Jinhua Hospital Zhejiang University School of Medicine","correspondingAuthor":true,"prefix":"","firstName":"Xiaoying","middleName":"","lastName":"Tao","suffix":""}],"badges":[],"createdAt":"2025-04-05 02:23:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6379371/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6379371/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":82891650,"identity":"94d3143e-0e30-482a-a308-3ff64cf42e19","added_by":"auto","created_at":"2025-05-16 12:13:50","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":288125,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA \u003c/strong\u003eUltrasound revealed a hypoechoic mass of approximately 48 × 48mm in size at the lower pole of the spleen, with well-defined borders. \u003cstrong\u003eB \u003c/strong\u003eThe colour Doppler revealed that blood flow signals were visible within the mass\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6379371/v1/e150211aaae35c2387c4e5e3.png"},{"id":82889407,"identity":"484a9e72-4059-4afa-9ff7-4e252cf5e038","added_by":"auto","created_at":"2025-05-16 12:05:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":328311,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA, B \u003c/strong\u003eMRI revealed a mass within the spleen demonstrating slightly hyperintense signals both on T1-weighted and T2-weighted images. C, D There was a progressive inhomogeneous enhancement of the lesion\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6379371/v1/f1c800490bebaa13c8e57a33.png"},{"id":82889409,"identity":"e193b15f-9359-4d51-97da-705567500c6f","added_by":"auto","created_at":"2025-05-16 12:05:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":601051,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA \u003c/strong\u003eThe tumor cells were spindle-shaped and scattered in the background of chronic inflammation, (HE 20x) B The nuclear chromatin was slightly vacuolar and some nucleoli could be seen: EBER(+) , (HE 20x)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6379371/v1/8c19dab5da88f07ea9bc0f12.png"},{"id":85945387,"identity":"06483211-83ff-4dbc-a7d7-4410c5aee83c","added_by":"auto","created_at":"2025-07-03 12:38:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1785952,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6379371/v1/526b76ab-1f24-4216-a71b-7f93694ec905.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Splenic Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma: A Case Report with Imaging Features and Comprehensive Literature Review","fulltext":[{"header":"Background","content":"\u003cp\u003eInflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) usually occurs in the liver and spleen, and to a lesser extent in the gastrointestinal tract, pancreas and other organs\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. IPT-like FDCS is more common in female, with an average age of 56.5 years\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Due to its atypical imaging presentation, IPT-like FDCS is easily misdiagnosed as hemangioma, inflammatory pseudotumour or other conditions. IPT-like FDCS was found for the first time in our hospital, this article describes the discovery, diagnosis and treatment of this disease in the context of the literature.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 50-year-old male patient presented to our hospital because of a physical examination which revealed splenic occupancy on 2023-10-14, complaining of no symptoms and no other medical history. Ultrasound revealed a mass of approximately 48 \u0026times; 48 mm in size at the lower pole of the spleen, with well-defined borders, and the colour Doppler examination revealed that blood flow signals were visible within the mass (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). A magnetic resonance (MRI) was performed, revealed a mass within the spleen demonstrating slightly hyperintense signals both on T1-weighted and T2-weighted images, measuring approximately 57 \u0026times; 54 mm. There was a progressive inhomogeneous enhancement of the lesion (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOn the fourth day of hospitalization, laparoscopic splenectomy was successfully performed. During the operation, a round solid tumor was seen in the lower pole of spleen, incision of the tumor showed that the section was fish-like. Patient recovered smoothly after the surgery, and was discharged. Immunohistopathological results showed that: CD21(+), CD23(+), CD35(+), Bcl-2(-), Bcl-6(-), CD10(-), CD68(+), CD138(+), CD3(-), CD30(-), CD43(+), CD38(+), CD34(-) ,Ki-67(20%+). In situ hybridization showed EBER was positive(Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e "},{"header":"Discusioon","content":"\u003cp\u003eFollicular dendritic cell sarcoma (FDCS) is a rare mesenchymal neoplasm arising from follicular dendritic cells of the lymphoid tissue. Initially described in 1986 \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e, this entity gained further recognition in 1996 when a morphologically distinct variant resembling inflammatory pseudotumor was reported, with proposed etiological links to Epstein-Barr virus (EBV) infection \u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. The term \"inflammatory pseudotumor-like follicular dendritic cell sarcoma\" was subsequently formalized by Cheuk et al. in 2001 to characterize this clinicopathological subtype \u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Clinically, IPT-like FDCS typically follows an indolent course, with the majority of patients remaining asymptomatic at presentation. Non-specific symptoms such as localized pain or abdominal distension are observed in a minority of cases, often correlating with tumor size or anatomical involvement\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSeveral studies have demonstrated an association between inflammatory IPT-like FDCS and Epstein-Barr virus (EBV), with latent membrane protein 1 detected in the majority of IPT-like FDCS cases\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Epstein-Barr virus-encoded small RNA (EBER) in situ hybridization holds significant value in the definitive diagnosis of this condition\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe sonographic features of splenic IPT-FDCS vary depending on the size of the mass. When the mass is small, the mass appears as a well-defined and uniform hypoechoic lesion,and no blood flow signals are observed. When the mass is large, the mass may demonstrate heterogeneous echogenicity with either well-defined or ill-defined margins, and blood flow signals can be detected\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e.The research on contrast-enhanced ultrasound (CEUS) features of IPT-FDCS remains limited. In the study by Xu L et al., the mass demonstrated mild, rapid, and heterogeneous enhancement progressing from the periphery toward the center during the CEUS examination\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Splenic hemangioma typically present as well-defined hypoechoic or hyperechoic lesions on conventional ultrasound, with contrast-enhanced ultrasound (CEUS) demonstrating peripheral nodular enhancement, so splenic hemangioma should be included in the differential diagnosis of IPT-FDCS\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSplenic IPT-FDCS manifests as a hypodense lesion with either well-demarcated or indistinct borders on Computed Tomography (CT)\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Notably, the contrast enhancement patterns of IPT-FDCS in the liver and spleen differ significantly. Hepatic tumors exhibit mild arterial-phase enhancement with subsequent attenuation reduction during the portal venous and delayed phases, demonstrating a density marginally lower than that of the surrounding hepatic parenchyma. In contrast, the solid components of splenic tumors display mild persistent enhancement, while central regions with liquefactive necrosis remain non-enhancing \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eHepatic IPT-FDCS typically demonstrates hypointensity on T1-weighted image and hyperintensity on T2-weighted image. In contrast, splenic tumors more frequently exhibit isointense or hyperintensity on T1-weighted image and mild hypointensity on T2-weighted image, with heterogeneous internal signal intensity owing to fibrous scarring and vascular components. The solid portions display mild progressive enhancement, while central liquefactive or necrotic areas demonstrate no significant enhancement \u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e.However, in our case, the tumor demonstrated a mildly hyperintense signal on T2-weighted image. This variation in T2-weighted image may be associated with the the degree and distribution of inflammatory cells and proliferating capillaries within the tumor\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. Furthermore, the T2-weighted image revealed an arc-shaped hypointense rim at the tumor periphery, which exhibited mild enhancement in the delayed phase. This radiological feature could potentially correlate with the vascular distribution within the tumor's pseudocapsule.\u003c/p\u003e \u003cp\u003eSplenic IPT-FDCS requires differentiation from inflammatory pseudotumor, hemangioma, and splenic lymphoma on MRI scans. Inflammatory pseudotumor of the spleen may present with slightly hypointense signals on T1-weighted image and slightly hyperintense signals on T2-weighted image, along with peripheral rim-like enhancement at arterial phase\u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. Splenic lymphoma is often associated with splenomegaly and enlarged retroperitoneal lymph nodes, typically demonstrating homogeneous enhancement of the tumor parenchyma\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. Splenic hemangioma exhibits markedly hyperintense signals on T2-weighted image and shows gradual centripetal enhancement during contrast-enhanced phases\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eHistologically, inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) shares overlapping features with inflammatory pseudotumor. Microscopically, the neoplastic cells exhibit spindle-to-oval morphology and are organized in fascicular, whorl or storiform pattern\u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e. A defining histopathological distinction from classical FDCS is the prominent mixed inflammatory infiltrate (lymphocytes, plasma cells, and histiocytes) permeating the tumor microenvironment in IPT-like FDCS. Notably, the occasional presence of binucleated or multinucleated Reed-Sternberg-like cells may create diagnostic ambiguity, necessitating differentiation from Hodgkin lymphoma\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. Immunohistochemically, CD21, CD23, and CD35 serve as cornerstone markers for confirming follicular dendritic cell lineage, as endorsed by current diagnostic guidelines \u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. Studies consistently demonstrated the expression of all three markers (CD21, CD23, and CD35) in most cases.\u003c/p\u003e \u003cp\u003eCompared to FDCS, the IPT-like FDCS demonstrates reduced invasiveness and improved clinical outcomes\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. This subtype typically follows an indolent disease course, with complete surgical resection remaining the standard therapeutic approach for localized lesions. Current evidence regarding adjuvant radiotherapy and chemotherapy remains inconclusive, as their efficacy in IPT-like FDCS management continues to be debated \u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Furthermore, emerging data suggest limited responsiveness to contemporary immunotherapeutic regimens in this tumor subtype \u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. Notably, longitudinal studies reveal post-treatment recurrence and metastasis rates of 28% and 27% respectively, underscoring the need for vigilant long-term surveillance \u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOverall, IPT-like FDCS is a rare malignant tumour, often characterised by an absence of distinctive clinical manifestations. Its radiological features are varied, with progressive enhancement on both CT and MRI being among its defining characteristics. The arc-shaped hypointense rim on T2-weighted image may be helpful for the diagnosis of IPT-FDCS. EBV positivity also plays a crucial role in the differential diagnosis of the disease.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFDCS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFollicular dendritic cell sarcoma\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIPT-like FDCS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einflammatory pseudotumor-like follicular dendritic cell sarcoma\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEBV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEpstein-Barr virus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEBER\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEpstein-Barr virus-encoded small RNA\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCEUS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econtrast-enhanced ultrasound\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed Tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCo-first authors: Shuxu Zhu and Ruimiao Shang. Xiaoying Tao contributed to the design of the study and revised the manuscript.\u0026nbsp;Ruimiao Shang collected data and prepared pictures. Shuxu Zhu analyzed the data and wrote the first draft. All authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in the manuscript. Further enquiries can be directed to the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by Jinhua Central Hospital Medical Ethics Review Committee. All the human data was in accordance with the Declaration of Helsinki principles, and written informed consent for study participation from this patient was obtained.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from the patient.\u003c/p\u003e\n\u003ch3\u003eCompeting interests\u003c/h3\u003e\n\u003cp\u003eThe authors declare no conflict of interest financial or otherwise.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHe H, Xue Q, Tan F, Yang L, Wang X, Gao Y, et al. A rare case of primary pulmonary inflammatory pseudotumor-like follicular dendritic cell sarcoma successfully treated by lobectomy. Annals Translational Med. 2021;9(1):77. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.21037/atm-20-4965\u003c/span\u003e\u003cspan address=\"10.21037/atm-20-4965\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen Y, Shi H, Li H, Zhen T, Han A. Clinicopathological features of inflammatory pseudotumour-like follicular dendritic cell tumour of the abdomen. Histopathology. 2016;68(6):858\u0026ndash;65. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/his.12851\u003c/span\u003e\u003cspan address=\"10.1111/his.12851\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFu LY, Jiang JL, Liu M, Li JJ, Liu KP, Zhu HT. Surgical treatment of liver inflammatory pseudotumor-like follicular dendritic cell sarcoma: A case report. World J Gastrointest Oncol. 2022;14(11):2288\u0026ndash;94. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4251/wjgo.v14.i11.2288\u003c/span\u003e\u003cspan address=\"10.4251/wjgo.v14.i11.2288\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMonda L, Warnke R, Rosai J. A primary lymph node malignancy with features suggestive of dendritic reticulum cell differentiation. A report of 4 cases. Am j pathol. 1986;122(3):562\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShek TW, Ho FC, Ng IO, Chan AC, Ma L, Srivastava G. Follicular dendritic cell tumor of the liver. Evidence for an Epstein-Barr virus-related clonal proliferation of follicular dendritic cells. Am j surg pathol. 1996;20(3):313\u0026ndash;24. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1097/00000478-199603000-00008\u003c/span\u003e\u003cspan address=\"10.1097/00000478-199603000-00008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheuk W, Chan JK, Shek TW, Chang JH, Tsou MH, Yuen NW, et al. Inflammatory pseudotumor-like follicular dendritic cell tumor: a distinctive low-grade malignant intra-abdominal neoplasm with consistent Epstein-Barr virus association. Am j surg pathol. 2001 Jun;25(6):721\u0026ndash;31. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1097/00000478-200106000-00003\u003c/span\u003e\u003cspan address=\"10.1097/00000478-200106000-00003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao M, Du X, OuYang B, Li M, Yang H. Inflammatory pseudotumor-like follicular dendritic cell sarcoma mimicking a colonic polyp. J Gastrointest Surg. 2021;25(9):2429\u0026ndash;30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11605-021-04961-y\u003c/span\u003e\u003cspan address=\"10.1007/s11605-021-04961-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSelves J, Meggetto F, Brousset P, Voigt JJ, Prad\u0026egrave;re B, Grasset D, et al. Inflammatory pseudotumor of the liver. Evidence for follicular dendritic reticulum cell proliferation associated with clonal Epstein-Barr virus. Am j surg pathol. 1996;20(6):747\u0026ndash;53. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1097/00000478-199606000-00013\u003c/span\u003e\u003cspan address=\"10.1097/00000478-199606000-00013\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJin J, Zhu X, Wan Y, Shi Y. Epstein-barr virus (EBV)-positive inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) presenting as thrombocytopenia: A case report and literature review. Heliyon. 2024;10(12):e32997. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.heliyon.2024.e32997\u003c/span\u003e\u003cspan address=\"10.1016/j.heliyon.2024.e32997\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXue N, Xue X, Sheng C, Lu M, Wang Y, Zhang S, Xu Y. Imaging features of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen. Annals Palliat Med. 2021;10(12):12140\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.21037/apm-21-2776\u003c/span\u003e\u003cspan address=\"10.21037/apm-21-2776\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu L, Ge R, Gao S. Imaging features and radiologic-pathologic correlations of inflammatory pseudotumor-like follicular dendritic cell sarcoma. BMC Med Imaging. 2021;21(1):52. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12880-021-00584-6\u003c/span\u003e\u003cspan address=\"10.1186/s12880-021-00584-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchwarze V, Lindner F, Marschner C, Negr\u0026atilde;o de Figueiredo G, R\u0026uuml;benthaler J, Clevert DA. Single-center study: The diagnostic performance of contrast-enhanced ultrasound (CEUS) for assessing focal splenic lesions compared to CT and MRI. Clin Hemorheol Microcirc. 2019;73(1):65\u0026ndash;71. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3233/CH-199204\u003c/span\u003e\u003cspan address=\"10.3233/CH-199204\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu C, Li YY, Zhu XD, Xiang XL. CT and MRI characteristics of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen: a report of 11 patients with pathological correlation. Abdom radiol. 2024 Dec;11. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00261-024-04736-4\u003c/span\u003e\u003cspan address=\"10.1007/s00261-024-04736-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang J, He L, Ma X, Wang J, Qiu Y, Jiang L. Imaging findings of inflammatory pseudotumor\u0026ndash;like follicular dendritic cell sarcoma of the spleen: A case report and literature review. Oncol Lett. 2022;24(5):399. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3892/ol.2022.13519\u003c/span\u003e\u003cspan address=\"10.3892/ol.2022.13519\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen F, Li J, Xie P. Imaging and pathological comparison of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen: A case report and literature review. Front Surg. 2022;9:973106. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fsurg.2022.973106\u003c/span\u003e\u003cspan address=\"10.3389/fsurg.2022.973106\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVardas K, Manganas D, Papadimitriou G, Kalatzis V, Kyriakopoulos G, Chantziara M, et al. Splenic Inflammatory Pseudotumor-Like Follicular Dendritic Cell Tumor. Case Rep Oncol. 2014;7(2):410\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1159/000365000\u003c/span\u003e\u003cspan address=\"10.1159/000365000\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark JY, Choi MS, Lim Y-S, Park JW, Kim SU, Min YW, et al. Clinical Features, Image Findings, and Prognosis of Inflammatory Pseudotumor of the Liver: A Multicenter Experience of 45 Cases. Gut Liver. 2014;8(1):58\u0026ndash;63. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.5009/gnl.2014.8.1.58\u003c/span\u003e\u003cspan address=\"10.5009/gnl.2014.8.1.58\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi M, Zhang L, Wu N, Huang W, Lv N. Imaging Findings of Primary Splenic Lymphoma: A Review of 17 Cases in Which Diagnosis Was Made at Splenectomy. PLoS ONE. 2013;8(11):e80264. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1371/journal.pone.0080264\u003c/span\u003e\u003cspan address=\"10.1371/journal.pone.0080264\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen Y, Shi H, Li H, Zhen T, Han A. Clinicopathological features of inflammatory pseudotumour-like follicular dendritic cell tumour of the abdomen. Histopathology. 2016;68(6):858\u0026ndash;65. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/his.12851\u003c/span\u003e\u003cspan address=\"10.1111/his.12851\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen YR, Lee CL, Lee YC, Chang KC. Inflammatory pseudotumour-like follicular dendritic cell tumour of the colon with plasmacytosis mimicking EBV-positive lymphoproliferative disorder. Pathology. 2020;52(4):484\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.pathol.2020.02.010\u003c/span\u003e\u003cspan address=\"10.1016/j.pathol.2020.02.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYan S, Yue Z, Zhang P, Yuan L, Wang H, Yin F, et al. Case report: Hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma: a rare case and review of the literature. Front Med. 2023;10:1192998. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fmed.2023.1192998\u003c/span\u003e\u003cspan address=\"10.3389/fmed.2023.1192998\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGe R, Liu C, Yin X, Chen J, Zhou X, Huang C, et al. Clinicopathologic characteristics of inflammatory pseudotumor-like follicular dendritic cell sarcoma. Int J Clin Exp Pathol. 2014;7(5):2421\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaygin C, Uzunaslan D, Ozguroglu M, Senocak M, Tuzuner N. Dendritic cell sarcoma: a pooled analysis including 462 cases with presentation of our case series. Crit Rev Oncol Hematol. 2013;88(2):253\u0026ndash;71. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.critrevonc.2013.05.006\u003c/span\u003e\u003cspan address=\"10.1016/j.critrevonc.2013.05.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDing F, Wang C, Xu C, Tang H. Case report: Hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma: A rare case and minireview of the literature. Front Med. 2022;9:1002324. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fmed.2022.1002324\u003c/span\u003e\u003cspan address=\"10.3389/fmed.2022.1002324\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eResnick KA, Monroe C, Siddiqi I, Tam E. Case report: Splenic inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS): a trial of immunotherapy and review of the literature. Front Oncol. 2024;14:1360726. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fonc.2024.1360726\u003c/span\u003e\u003cspan address=\"10.3389/fonc.2024.1360726\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang BX, Chen ZH, Liu Y, Zeng YJ, Li YC. Inflammatory pseudotumor-like follicular dendritic cell sarcoma: A brief report of two cases. World J Gastrointest Oncol. 2019;11(12):1231\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4251/wjgo.v11.i12.1231\u003c/span\u003e\u003cspan address=\"10.4251/wjgo.v11.i12.1231\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"inflammatory pseudotumor, follicular dendritic cell sarcoma, spleen, image features","lastPublishedDoi":"10.21203/rs.3.rs-6379371/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6379371/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eFollicular dendritic cell sarcoma (FDCS) is an exceptionally rare malignant neoplasm originating from follicular dendritic cells of the immune system. A distinct histological subtype, designated as inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS), exhibits morphological overlap with inflammatory pseudotumors and represents an even more uncommon clinical entity. We presented a case of IPT-like FDCS and conducted a systematic literature review. This case provides critical insights into the multimodal imaging characteristics for this rare malignancy.\u003c/p\u003e\u003ch2\u003eCase Presentation\u003c/h2\u003e \u003cp\u003eWe present a case of a 50-year-old asymptomatic male with an incidentally detected splenic mass during routine health screening. Ultrasound showed a hypoechoic mass in spleen with well-defined borders. Magnetic resonance (MRI) revealed a mass with slightly hyperintense signals both on T1-weighted and T2-weighted images. The mass showed a progressive inhomogeneous enhancement. Finally The patient underwent splenectomy, with histopathological and immunohistochemical confirmation of IPT-like FDCS.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eSplenic IPT-FDCS is characterized by nonspecific or subclinical presentations, rendering non-invasive imaging modalities crucial for diagnostic confirmation. Progressive enhancement and a arc-shaped hypointense peripheral rim observed on T2-weighted image are important imaging features of IPT-FDCS.\u003c/p\u003e","manuscriptTitle":"Splenic Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma: A Case Report with Imaging Features and Comprehensive Literature Review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-16 12:05:46","doi":"10.21203/rs.3.rs-6379371/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3846209d-78e0-48a1-a6bf-662c020041a1","owner":[],"postedDate":"May 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-07-03T12:38:12+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-16 12:05:46","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6379371","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6379371","identity":"rs-6379371","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}