A Rare Case of Granular Cell Myoblastoma of the Breast in a Young Woman: Diagnostic Challenges and Imaging Findings

A Rare Case of Granular Cell Myoblastoma of the Breast in a Young Woman: Diagnostic Challenges and Imaging Findings | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 12 November 2025 V1 Latest version Share on A Rare Case of Granular Cell Myoblastoma of the Breast in a Young Woman: Diagnostic Challenges and Imaging Findings Authors : Maurizio Lelario , Umberto Tupputi 0000-0002-0384-5864 , Claudia Rutigliano , Francesca Anna Carpagnano , Rosanna Nenna , Alessio Sciacqua 0009-0007-9118-0893 , Daniela Erriquez , and Giuseppe Guglielmi 0000-0002-4325-8330 [email protected] Authors Info & Affiliations https://doi.org/10.22541/au.176296493.33619965/v1 183 views 151 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Background and Clinical Significance : Granular cell tumor (GCT), also known as Abrikossoff tumor, is a rare, typically benign neoplasm of Schwannian origin. Although these tumors can occur in various locations, breast involvement is uncommon, accounting for up to 15% of cases. Case Presentation : We report the case of a 23-year-old female Case Report A Rare Case of Granular Cell Myoblastoma of the Breast in a Young Woman: Diagnostic Challenges and Imaging Findings Maurizio Lelario 1 , Umberto Tupputi 2 , Claudia Rutigliano 2 , Francesca Anna Carpagnano 1 , Rosanna Nenna 3 , Alessio Sciacqua 4 , Daniela Erriquez 1 , Giuseppe Guglielmi 4,5* 1 Senology Unit, ‘ ‘Dimiccoli’ ’ Hospital, Viale Ippocrate 15, 70051, Barletta (BT), Italy 2 Radiology Unit, “L. Bonomo” Hospital, Viale Istria, 70031 Andria (BT), Italy 3 Patholoy Unit, “L. Bonomo” Hospital, Viale Istria, 70031 Andria (BT), Italy 4 Department of Clinical and Experimental Medicine, Foggia University School of Medicine, Viale L. Pinto 1, 71121 Foggia, Italy. 5 Radiology Unit, “Dimiccoli” Hospital, Viale Ippocrate 15, 70051, Barletta (BT), Italy. * Correspondence: [email protected] Abstract Background and Clinical Significance : Granular cell tumor (GCT), also known as Abrikossoff tumor, is a rare, typically benign neoplasm of Schwannian origin. Although these tumors can occur in various locations, breast involvement is uncommon, accounting for up to 15% of cases. Case Presentation : We report the case of a 23-year-old female who presented with a firm, non-tender, 1 cm palpable lump in the upper outer quadrant of the left breast, detected during routine examination without skin changes or axillary lymphadenopathy. Ultrasound imaging revealed a hypoechoic, well-defined nodule, while MRI demonstrated minimal contrast enhancement, supporting a benign process despite features that may mimic malignancy. A core needle biopsy showed a proliferation of polygonal cells with abundant granular eosinophilic cytoplasm, mild nuclear pleomorphism, and low mitotic activity (Ki-67 ≤2%). Immunohistochemical analysis confirmed the diagnosis with strong positivity for S100, SOX10, and vimentin, and negativity for carcinoma-associated markers. Key clinical message : Breast granular cell tumors, though rare and often mimicking carcinoma on imaging, require histopathological and immunohistochemical confirmation to avoid overtreatment. They should be considered in differential diagnosis even in young patients. Keywords: Granular cell tumor, Abrikossoff tumor, Breast neoplasm, Immunohistochemistry, Diagnostic challenges, Schwann cell origin, Breast imaging, Ultrasound, Magnetic resonance imaging (MRI), Core needle biopsy. 1. Introduction and Clinical Significance Granular cell tumors (GCTs) are uncommon soft tissue neoplasms of Schwannian origin, first described by Abrikossoff in 1926 [1]. Although these tumors most frequently arise in the head and neck region, especially the tongue, they may occur in various anatomical sites, including the breast [1,7]. Breast involvement is rare, and GCTs can mimic malignant lesions both clinically and radiologically [2,4]. This similarity often poses a diagnostic challenge that may lead to unnecessary aggressive treatment if misinterpreted [2,4]. The purpose of this case report is to describe a rare presentation of a granular cell tumor of the breast in a young woman, emphasizing the role of imaging, histopathology, and immunohistochemistry in reaching the correct diagnosis [1,3]. 2. Case Presentation A 24-year-old female presented to our operative unit for evaluation of a palpable lump in the upper outer quadrant of her left breast. She reported noticing the mass approximately three weeks prior to presentation. The patient described the lump as firm and non-tender, and she denied any associated symptoms such as skin changes, nipple discharge, or axillary discomfort. Her personal and family histories were unremarkable, with no prior breast-related issues. On physical examination, a discrete, mobile nodule measuring about 1 cm in diameter was identified. The lesion appeared well-circumscribed, and there were no signs of skin retraction or regional lymphadenopathy. A comprehensive imaging work-up was initiated. High-resolution ultrasound revealed an oval, hypoechoic nodule with not well-defined margins, no envelope, without significant peripheral vascularization (Figure 1). Fig.1 : A) Ultrasound reveales hypoechoic nodule with not well-defined margins and no envelope. B) The Doppler shows no significant peripheral vascularization, making it challenging to differentiate from a malignant breast lesion. Magnetic resonance imaging (MRI) further characterized the lesion, demonstrating minimal contrast enhancement, findings that reinforced the benign nature of the mass (Figure 2). Fig.2: MRI findings of granular cell tumour (GCT) of the breast. A) T2 weighted MR image shows a round mass with irregular margins presenting with low signal intensity. B) axial contrast enhanced T1 weighted MR image shows the heterogeneously low enhancing mass. To establish a definitive diagnosis, a core needle biopsy was performed under ultrasound guidance. Histopathological evaluation with hematoxylin-eosin staining, and immunohistochemical studies (including markers like CD68) is essential to distinguish benign GCTs from malignant lesions. Histopathological evaluation of the biopsy specimen revealed a well-demarcated proliferation of polygonal cells with abundant granular eosinophilic cytoplasm, mild nuclear pleomorphism, and a low mitotic index (Ki-67 ≤2%). Immunohistochemical studies showed strong positivity for S100, SOX10, and vimentin, while markers typically associated with carcinoma were negative [1,5,9] (Figure 3). These combined findings confirmed the diagnosis of a granular cell tumor of the breast. Fig.3: A) S-100 The staining highlights positive activity within the granular cells, emphasizing the cytoplasmic granularity at 10x magnification. Fig.3: B) Hematoxylin-Eosin staining on paraffin-embedded sections reveals a non-capsulated nodule characterized by the proliferation of cells with small nuclei and ample granulomatous cytoplasm at 40X magnification. Fig.3: C) Tumor cells display CD68 immunoreactivity, as evidenced by immunohistochemistry at a magnification of 10x. 3. Discussion Breast granular cell tumors (GCTs) are rare neoplasms that present a significant diagnostic challenge due to their clinical and radiological similarities with malignant lesions [2,4,8]. Radiologically, GCTs may appear as small, hypoechoic nodules with well-defined margins, as observed on ultrasound in our case, or they may occasionally display spiculated or indistinct borders that closely mimic carcinoma on both ultrasound and MRI [8]. Such overlapping imaging features often lead to a high clinical suspicion for malignancy, underscoring the need for further histopathological confirmation. Histopathological evaluation remains the definitive method for diagnosis. GCTs are characterized by a proliferation of large, polygonal cells with abundant granular eosinophilic cytoplasm and minimal nuclear atypia [1,2]. In our case, the low mitotic index (Ki-67 ≤2%) supported the benign nature of the lesion. Immunohistochemical analysis is pivotal; the tumor cells typically express markers such as S100, SOX10, and vimentin, findings that are consistent with a Schwann cell origin [1,5,9]. The immunoprofile in our patient, with strong positivity for these markers and negativity for carcinoma-associated antigens, was crucial in confirming the diagnosis. It is noteworthy that breast GCTs are more commonly reported in middle-aged women [4,6,7]. The occurrence of this tumor in a 23-year-old patient is particularly unusual, highlighting the importance of including GCT in the differential diagnosis of breast lesions across all age groups. Differential diagnoses include invasive carcinoma, myofibroblastoma, and other benign or malignant soft tissue tumors; however, the integration of clinical examination, imaging, and immunohistochemical findings facilitates accurate diagnosis and prevents overtreatment. The standard treatment for benign GCTs is complete surgical excision with negative margins. Although recurrence is rare following adequate resection, regular follow-up is recommended to monitor for any potential recurrence [2,3]. This case underscores the importance of a multidisciplinary approach, combining clinical, radiological, and pathological assessments, to avoid misdiagnosis and unnecessary aggressive interventions. Overall, our case contributes to the literature by illustrating the diagnostic process and management of a rare benign breast GCT in a young patient, emphasizing that age alone should not preclude consideration of this entity in the differential diagnosis of breast masses. 4. Conclusions Granular cell tumors of the breast, although rare, should be considered in the differential diagnosis of breast masses regardless of patient age. This case emphasizes that even in young patients, such as our 23-year-old, a multidisciplinary diagnostic approach, including detailed imaging, histopathological evaluation, and immunohistochemical studies, is essential to distinguish benign GCTs from malignant lesions. Accurate diagnosis prevents unnecessary aggressive treatment and supports appropriate management through complete surgical excision with negative margins. Regular follow-up remains important to detect any recurrence, ensuring optimal patient outcomes. Author contribution Maurizio Lelario : conceptualization, investigation, methodology, writing - original draft. Umberto Tupputi : data curation, investigation, validation. Claudia Rutigliano : data curation, validation. Francesca Anna Carpagnano : data curation, validation. Rosanna Nenna : data curation, validation. Alessio Sciacqua : writing - review and editing. Daniela Erriquez : supervision, visualization. Giuseppe Guglielmi : resources, supervision, writing - review and editing. Funding This research received no external funding. Institutional Review Board Statement Ethical review and approval were waived for this study due to its retrospective model and the informed consent obtained from the participant as part of the standard care in the University Hospital. Informed Consent Statement Written informed consent was obtained from the patient for his data and images to be used in this study and published in this journal. The patients understood that their anonymity would be preserved, and no identifiable information would be disclosed. Conflicts of Interest None of the authors have any conflicts of interest to declare. References 1. Yan J. Granular cell tumor of the breast: A case report and review of literature. World J Clin Cases 2023; 11(33):8044-8049. 2. Fanburg-Smith JC, Meis-Kindblom JM, Fante R, Kindblom LG. Malignant granular cell tumor of soft tissue: diagnostic criteria and clinicopathologic correlation. Am J Surg Pathol. 1998;22(7):779-794. 3. Brown H, Weinberg ES, Adams EM, et al. Granular cell tumors: A comprehensive review of a rare neoplasm. J Clin Oncol. 2022;40:3035. 4. Khansarinia S, Tumeh PC, et al. Granular cell tumor of the breast: a rare neoplasm mimicking carcinoma. Breast J. 2021;27(6):497-504. 5. Youssef MM, Reis-Filho JS, et al. The molecular and genetic basis of granular cell tumors. Nat Rev Cancer. 2020;20(3):187-200. 6. Gropper AB, Lin SJ, et al. Granular cell tumors of the breast: a comprehensive review. Ann Surg Oncol. 2018;25(9):2715-2722. 7. Taylor HB, Helwig EB. Granular cell tumor: A study of 110 cases. Am J Clin Pathol. 1962;38(4):429-437. 8. Takamura M, Itoh Y, et al. Imaging characteristics of granular cell tumors: A review. Eur J Radiol. 2019;112:150-157. 9. Renno HC, Suster S, et al. Granular cell tumor of the breast: radiologic-pathologic correlation. Arch Pathol Lab Med. 2016;140(3):234-239. Information & Authors Information Version history V1 Version 1 12 November 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Keyword radiology & imaging Authors Affiliations Maurizio Lelario Ospedale Monsignor Dimiccoli View all articles by this author Umberto Tupputi 0000-0002-0384-5864 Ospedale Lorenzo Bonomo View all articles by this author Claudia Rutigliano Ospedale Lorenzo Bonomo View all articles by this author Francesca Anna Carpagnano Ospedale Monsignor Dimiccoli View all articles by this author Rosanna Nenna Ospedale Lorenzo Bonomo View all articles by this author Alessio Sciacqua 0009-0007-9118-0893 Universita degli Studi di Foggia Dipartimento di Medicina Clinica e Sperimentale View all articles by this author Daniela Erriquez Ospedale Monsignor Dimiccoli View all articles by this author Giuseppe Guglielmi 0000-0002-4325-8330 [email protected] Ospedale Monsignor Dimiccoli View all articles by this author Metrics & Citations Metrics Article Usage 183 views 151 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Maurizio Lelario, Umberto Tupputi, Claudia Rutigliano, et al. 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