Desquamation Interstitial Pneumonia Presenting as a Solid Mass in the Lung: a Case Report.

Desquamation Interstitial Pneumonia Presenting as a Solid Mass in the Lung: a Case Report. | 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 Desquamation Interstitial Pneumonia Presenting as a Solid Mass in the Lung: a Case Report. Wen Luo, Wanyu Wang, Yonghong Shi, Fang Lu, Yihua Lin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-955264/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: Desquamation interstitial pneumonia (DIP) is a rare type of idiopathic interstitial pneumonia. High resolution computed tomography (HRCT) shows ground glass opacities without the peripheral reticular opacities characteristic of usual interstitial pneumonia (UIP). Here we report a case of DIP presenting as a solid mass in the lung, which is rarely described in the literature. Case presentation: A 77-year-old man presented with dry cough and dyspnea on exertion for one month was admitted to our hospital. The lung CT scan showed there was a pulmonary mass in right lower lung and the patient was scheduled for surgery. He was a sculpture artist, non-smoker and the previous medical history included only mandatory spondylitis without other connective tissue diseases. Nine days post-last CT, the FDG PET/CT demonstrated the mass in the right lower lung was significantly hypermetabolic (SUV value=8.9) but inflammatory exudate could be observed around the mass. We gave antibiotics and performed CT-guided percutaneous lung biopsy. The result showed that there were a large number of macrophages in the alveolar cavity, alveolar epithelial type II cells hyperplasia in some areas and chronic inflammation was noted in the interstitium. Then the desquamative interstitial pneumonia was diagnosed. We gave the patient glucocorticoid therapy, then the patient's symptoms disappeared gradually and the lung CT showed that the pulmonary mass was disappeared. Conclusions: Our report illustrates the rare presentation of DIP. Furthermore, for the pulmonary mass, even if appeared hypermetabolic on PET/CT, it is still necessary to make a definite pathological diagnosis before operation, so as to reduce the damage to patients. Pathology Critical Care & Emergency Medicine Desquamation interstitial pneumonia solid mass case report Figures Figure 1 Figure 2 Background Desquamation interstitial pneumonia (DIP) is a rare type of idiopathic interstitial pneumonia and the incidence only accounts for about 10–17%[1]. The vast majority (>90 percent) of patients with DIP are smokers, a small percentage of cases are associated with rheumatic diseases[2]. High resolution computed tomography (HRCT) shows ground glass opacities without the peripheral reticular opacities characteristic of usual interstitial pneumonia (UIP)[3]. Here we report a case of DIP presenting as a solid mass in the lung. Case Report A 77-year-old man presented with dry cough and dyspnea on exertion for one month was admitted to our hospital. The lung CT scan showed there was a pulmonary mass in right lower lung and the patient was scheduled for surgery. He was a sculpture artist and non-smoker. The previous medical history included only mandatory spondylitis without other connective tissue diseases. His admitted physical examinations revealed vital signs were within normal limits. There were no cyanosis on lips, no clubbing and no superficial swollen lymph node being palpable. Breath sounds were decreased on the right lower side. Physical examinations of cardiovascular system and abdomen were normal. Blood chemistry showed almost normal white cell count, procalcitonin (PCT) and C-reactive protein (CRP). Erythrocyte sedimentation rate was 77 mm/1st h. The human leukocyte antigen-B27 (HLA-B27) antibody was mildly elevated. Among the autoimmune disease markers (C3, C4, rheumatoid factor, antinuclear antibody, anti- neutrophil cytoplasmic antibodies, anti-cardiolipin antibody, anti-dsDNA, anti-Sm, anti-SSA, anti-SSB, anti SCL-70, anti Jo-1, and anti-RNP/Sm antibodies) and immunoglobulin G, A, and M were all normal. Tumor markers (CA199, f-PSA, ProGRP, PSA, CEA, SCC, CYFRA21-1, CA242, CA125, NSE, CA153, CA724, CA50) were only SCCA 12.6 ng/ml (range, 0-2.5 ng/mL). Pulmonary function tests showed that the patient had mild restrictive ventilatory dysfunction and mild diffusion dysfunction. Nine days post-last CT, the FDG PET/CT demonstrated the mass in the right lower lung was significantly hypermetabolic (SUV value=8.9) but inflammatory exudate could be observed around the mass. We gave antibiotics and performed PET/CT-guided percutaneous lung biopsy. The result showed that there were a large number of macrophages in the alveolar cavity, alveolar epithelial type II cells hyperplasia in some areas and chronic inflammation was noted in the interstitium (see Figure 2). Then the desquamative interstitial pneumonia was diagnosed. Methylprednisolone intravenous drip of 40 mg per day for 2 weeks were performed. After that, the treatment was converted to 40 mg of oral prednisone per day. The patient's symptoms disappeared gradually and the lung CT showed that the pulmonary mass was decreased in size (see Figure 1). The patient’s symptoms were resolved, and he was discharged with 40 mg of oral prednisone per day. The dose of prednisone was reduced by 5 mg weekly until to 20 mg. Then the dose was reduced by 5 mg monthly until to 10 mg and maintained for three months. The total course of treatment was half a year. The lung mass significant shrink was observed after discharged about one month and eventually disappeared. (see Figure 1). Discussion The exact etiology of the DIP is uncertain but 58-91% of DIP cases are linked with cigarette smoking[4, 5]. In addition, the DIP may be associated with harmful irritating substances from environmental/occupational (such as asbestos, talc, graphite, silica and aluminum), systemic disease virus infection and drugs [6, 7]. The main histopathological feature of DIP is a large number of macrophages in alveoli, which were usually diffusely distributed throughout the pulmonary acini within alveoli, and proliferation of pneumocytes over the course of alveolar septa [8]. Although there may be mild infiltration of inflammatory cells in the alveolar septum, the alveolar structure generally remained normal. The infiltrating inflammatory cells include a small number of eosinophils, accompanied by fibroblast proliferation. The rare changes are mild fibrosis, but severe fibrosis and honeycomb like lesions are very rare. Pathological diagnosis is the "gold standard" for the diagnosis of DIP. Methods of lung biopsy included transbronchial lung biopsy (TBLB), CT-guided percutaneous needle biopsy, transbronchial cryobiopsy and surgical lung biopsy. Lung specimens from TBLB are too small, which can't fully reflect the scope and degree of lung lesions and satisfy the diagnosis of interstitial lung disease. The specimens from surgical lung biopsy can meet the diagnostic requirements of interstitial lung disease, but the surgical lung biopsy is costly and traumatic, which is not easy for patients to accept. Transbronchial cryobiopsy or CT-guided percutaneous lung biopsies have fewer healthcare costs, fewer traumatic, and the specimens can meet the diagnostic requirements of interstitial lung disease, which is easy for patients to accept. This patient underwent percutaneous lung biopsy and the result showed that there were a large number of macrophages in the alveolar cavity and chronic inflammation was noted in the interstitium, so it could be diagnosed as DIP. At the same time, the patient had no history of smoking or second-hand smoke, which was rare in the literature. The patient was a sculptor. Because the environmental or occupational exposure may be one of an etiological risk factors, it is speculated that dust inhalation may be one of the inducing factors in this case. However, because the specimens were relatively small, it was impossible to know whether there was dust deposition in other lesions regions. The special feature of this case was lung CT, which showed a single solid mass in the right lower lung, and then rapidly progressed with peripheral infection. However, the typical imaging manifestation of DIP is diffuse ground glass shadow in both lungs, which is located under the pleura. The lower lung is more than the upper lung, and some are accompanied by linear opacities and reticulation in the base [9]. Honeycomb appearance is uncommon. Therefore, the imaging findings of this case were different from the typical imaging findings of DIP, which were rarely reported in the literature. These imaging findings were often misdiagnosed as pulmonary malignant tumor because of PETCT demonstrated hypermetabolism and the patients were usually treated by surgery. Therefore, for the pulmonary mass, even if PETCT indicates hypermetabolic lesions and highly suspected tumor, the pathological diagnosis of preoperative mass is still very important to avoid irreversible damage to patients. The main treatment is to quit smoking and glucocorticoid therapy and some cases become spontaneous remission after quitting smoking. Glucocorticoids have been reported to be beneficial in case series, although improvement may be temporary [3]. Environmental/occupational factors are also suspicious etiology of DIP [6, 7]. That DIP improved in two cases after leaving the workplace without steroid treatment was reported by Lougheed et al [7]. Therefore, It is reasonable to terminate any possible environmental risk factors. Initial glucocorticoid therapy consists of 40-60 mg/day for 6 weeks, then decreased gradually and stopped within 6-9 months. Glucocorticoid therapy of this case: intravenous methylprednisolone 40mg for 2 weeks, oral prednisone 40mg for 3 weeks, and then decrease 5 mg weekly until to 20 mg. Then the dose was reduced by 5 mg monthly until to 10 mg and maintained for three months. The total course of treatment was half a year. The case clinical symptoms and radiology were significant improvement after steroid treatment. Conclusions The imaging findings of such a case are rarely described in the literature. There is no smoking history and it is easy to be misdiagnosed as tumor. However, all of these clinical characteristics mentioned above are uncommon. Therefore, we still know little about this rare interstitial lung disease, and we still need more clinical cases, more complete clinical imaging and pathology to enrich our understanding of the disease. At the same time, for the pulmonary mass, even if appeared hypermetabolic on PET-CT, it is still necessary to make a definite pathological diagnosis before operation, so as to reduce the damage to patients. Abbreviations DIP: Desquamation interstitial pneumonia; HRCT: High resolution computed tomography; UIP: usual interstitial pneumonia; PCT: procalcitonin; CRP: and C-reactive protein; HLA-B27: human leukocyte antigen-B27; TBLB: transbronchial lung biopsy; Declarations Acknowledgment The authors thank the patient and her partner for allowing them to publish his story. Authors’ contributions LYH designed the study and revised the manuscript. LW conducted clinical data collection and analysis and drafted the manuscript. WWY, SYH and LF conducted clinical data collection and analysis. The authors read and approved the final manuscript. Funding This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Availability of data and materials All data and material were presented in this published article. Ethics approval and consent to participate Not applicable Consent for publication Written informed consent was obtained from the patient for publication. All authors are in agreement for the publication of the study. Competing interests The authors declare that they have no competing interests. References Costabel U, King TE: International consensus statement on idiopathic pulmonary fibrosis . The European respiratory journal 2001, 17 (2):163-167. Carrington CB, Gaensler EA, Coutu RE, FitzGerald MX, Gupta RG: Natural history and treated course of usual and desquamative interstitial pneumonia . N Engl J Med 1978, 298 (15):801-809. Akira M, Yamamoto S, Hara H, Sakatani M, Ueda E: Serial computed tomographic evaluation in desquamative interstitial pneumonia . Thorax 1997, 52 (4):333-337. Bradley B, Branley HM, Egan JJ, Greaves MS, Hansell DM, Harrison NK, Hirani N, Hubbard R, Lake F, Millar AB et al : Interstitial lung disease guideline: the British Thoracic Society in collaboration with the Thoracic Society of Australia and New Zealand and the Irish Thoracic Society . Thorax 2008, 63 Suppl 5 :v1-58. Wells AU, Nicholson AG, Hansell DM: Challenges in pulmonary fibrosis. 4: smoking-induced diffuse interstitial lung diseases . Thorax 2007, 62 (10):904-910. Diken Ö E, Şengül A, Beyan AC, Ayten Ö, Mutlu LC, Okutan O: Desquamative interstitial pneumonia: Risk factors, laboratory and bronchoalveolar lavage findings, radiological and histopathological examination, clinical features, treatment and prognosis . Experimental and therapeutic medicine 2019, 17 (1):587-595. Lougheed MD, Roos JO, Waddell WR, Munt PW: Desquamative interstitial pneumonitis and diffuse alveolar damage in textile workers. Potential role of mycotoxins . Chest 1995, 108 (5):1196-1200. American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001 . Am J Respir Crit Care Med 2002, 165 (2):277-304. Sverzellati N, Lynch DA, Hansell DM, Johkoh T, King TE, Jr., Travis WD: American Thoracic Society-European Respiratory Society Classification of the Idiopathic Interstitial Pneumonias: Advances in Knowledge since 2002 . Radiographics : a review publication of the Radiological Society of North America, Inc 2015, 35 (7):1849-1871. Supplementary Files CAREchecklistEnglish2013.pdf 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-955264","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":55460847,"identity":"c3a2c1f4-72d8-4a6f-9477-0b06398cabdf","order_by":0,"name":"Wen Luo","email":"","orcid":"","institution":"The First Affiliated Hospital of Xiamen University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Wen","middleName":"","lastName":"Luo","suffix":""},{"id":55460848,"identity":"2f19a0f5-c4ed-4af7-9b83-0c13921298c1","order_by":1,"name":"Wanyu Wang","email":"","orcid":"","institution":"the first affiliated hospital of Xiamen University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Wanyu","middleName":"","lastName":"Wang","suffix":""},{"id":55460849,"identity":"335c10f6-7468-4573-b4cd-7f37c3148f65","order_by":2,"name":"Yonghong Shi","email":"","orcid":"","institution":"The First Affiliated Hospital of Xiamen University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yonghong","middleName":"","lastName":"Shi","suffix":""},{"id":55460850,"identity":"8580617a-7036-441d-bef5-69da202189c4","order_by":3,"name":"Fang Lu","email":"","orcid":"","institution":"The First Affiliated Hospital of Xiamen University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Fang","middleName":"","lastName":"Lu","suffix":""},{"id":55460851,"identity":"69e399e5-1480-4806-b721-dbea25774d6f","order_by":4,"name":"Yihua Lin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0ElEQVRIiWNgGAWjYDACZh4QaQEiGR8kVNQQrUUCRDIbPDhzjBhrIFpABJvkwxZmwhoMjvMek/jBICFjLpGdVpHYwMbA396dgF/LYb40yR6gwyx7zm67kbhDhkHizNkNBLTwmAE9IsFjcLwXqOUMG4OBRC5hLZJ/QFoO824rSGxjJk6LNMwWBqK0SB7mMbaWAWk5c3azRMKZYzwE/cJ3/ozhzTcMNvYGN3I3fvxRUSPH396LX4vCASDB+A8hwINXOQjINxBUMgpGwSgYBSMeAABsVUE04FlSHAAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-1599-471X","institution":"The First Affiliated Hospital of Xiamen University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Yihua","middleName":"","lastName":"Lin","suffix":""}],"badges":[],"createdAt":"2021-10-04 11:05:37","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-955264/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-955264/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":14286051,"identity":"02a00df2-5640-4062-8f86-f16bfaa84faf","added_by":"auto","created_at":"2021-10-06 12:39:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":5849310,"visible":true,"origin":"","legend":"The patient's symptoms disappeared gradually and the lung CT showed that the pulmonary mass was decreased in size ","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-955264/v1/e75ede6ef205f98ad149df70.png"},{"id":14286050,"identity":"e00f94d3-d0ca-4603-ab30-66025b0ecede","added_by":"auto","created_at":"2021-10-06 12:39:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":2948373,"visible":true,"origin":"","legend":"The result showed that there were a large number of macrophages in the alveolar cavity, alveolar epithelial type II cells hyperplasia in some areas and chronic inflammation was noted in the interstitium ","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-955264/v1/c11d5256ae9e548a4ab73123.png"},{"id":14565447,"identity":"85de4dc9-a542-4b54-8471-8ef1300ee803","added_by":"auto","created_at":"2021-10-15 22:08:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2275683,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-955264/v1/85bcdeb8-981a-4e5b-acf2-8ab472f56488.pdf"},{"id":14286052,"identity":"ecfe0224-2b0c-4cdd-a4c4-d5756f150bda","added_by":"auto","created_at":"2021-10-06 12:39:47","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":648807,"visible":true,"origin":"","legend":"","description":"","filename":"CAREchecklistEnglish2013.pdf","url":"https://assets-eu.researchsquare.com/files/rs-955264/v1/3104905f9b786517cb6fdec2.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eDesquamation Interstitial Pneumonia Presenting as a Solid Mass in the Lung: a Case Report.\u003c/p\u003e","fulltext":[{"header":"Background","content":"\u003cp\u003eDesquamation interstitial pneumonia (DIP) is a rare type of idiopathic interstitial pneumonia and the incidence only accounts for about 10\u0026ndash;17%[1]. The vast majority (\u0026gt;90 percent) of patients with DIP are smokers, a small percentage of cases are associated with rheumatic diseases[2]. High resolution computed tomography (HRCT) shows ground glass opacities without the peripheral reticular opacities characteristic of usual interstitial pneumonia (UIP)[3]. Here we report a case of DIP presenting as a solid mass in the lung.\u003c/p\u003e"},{"header":"Case Report","content":"\u003cp\u003eA 77-year-old man presented with dry cough and dyspnea on exertion for one month was admitted to our hospital. The lung CT scan showed there was a pulmonary mass in right lower lung and the patient was scheduled for surgery. He was a sculpture artist and non-smoker. The previous medical history included only mandatory spondylitis without other connective tissue diseases. His admitted physical examinations revealed vital signs were within normal limits. There were no cyanosis on lips, no clubbing and no superficial swollen lymph node being palpable. Breath sounds were decreased on the right lower side. Physical examinations of cardiovascular system and abdomen were normal. Blood chemistry showed almost normal white cell count, procalcitonin (PCT) and C-reactive protein (CRP). Erythrocyte sedimentation rate was 77 mm/1st h. The human leukocyte antigen-B27 (HLA-B27) antibody was mildly elevated. Among the autoimmune disease markers (C3, C4, rheumatoid factor, antinuclear antibody, anti- neutrophil cytoplasmic antibodies, anti-cardiolipin antibody, anti-dsDNA, anti-Sm, anti-SSA, anti-SSB, anti SCL-70, anti Jo-1, and anti-RNP/Sm antibodies) and immunoglobulin G, A, and M were all normal. Tumor markers (CA199, f-PSA, ProGRP, PSA, CEA, SCC, CYFRA21-1, CA242, CA125, NSE, CA153, CA724, CA50) were only SCCA 12.6 ng/ml (range, 0-2.5 ng/mL). Pulmonary function tests showed that the patient had mild restrictive ventilatory dysfunction and mild diffusion dysfunction. Nine days post-last CT, the FDG PET/CT demonstrated the mass in the right lower lung was significantly hypermetabolic (SUV value=8.9) but inflammatory exudate could be observed around the mass. We gave antibiotics and performed PET/CT-guided percutaneous lung biopsy. The result showed that there were a large number of macrophages in the alveolar cavity, alveolar epithelial type II cells hyperplasia in some areas and chronic inflammation was noted in the interstitium (see Figure 2). Then the desquamative interstitial pneumonia was diagnosed. Methylprednisolone intravenous drip of 40 mg per day for 2 weeks were performed. After that, the treatment was converted to 40 mg of oral prednisone per day. The patient\u0026apos;s symptoms disappeared gradually and the lung CT showed that the pulmonary mass was decreased in size (see Figure 1). The patient\u0026rsquo;s symptoms were resolved, and he was discharged with 40 mg of oral prednisone per day. The dose of prednisone was reduced by 5 mg weekly until to 20 mg. Then the dose was reduced by 5 mg monthly until to 10 mg and maintained for three months. The total course of treatment was half a year. The lung mass significant shrink was observed after discharged about one month and eventually disappeared. (see Figure 1). \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe exact etiology of the DIP is uncertain but 58-91% of DIP cases are linked with cigarette smoking[4, 5]. In addition, the DIP may be associated with harmful irritating substances from environmental/occupational (such as asbestos, talc, graphite, silica and aluminum), systemic disease virus infection and drugs [6, 7]. The main histopathological feature of DIP is a large number of macrophages in alveoli, which were usually diffusely distributed throughout the pulmonary acini within alveoli, and proliferation of pneumocytes over the course of alveolar septa [8]. Although there may be mild infiltration of inflammatory cells in the alveolar septum, the alveolar structure generally remained normal. The infiltrating inflammatory cells include a small number of eosinophils, accompanied by fibroblast proliferation. The rare changes are mild fibrosis, but severe fibrosis and honeycomb like lesions are very rare.\u003c/p\u003e\n\u003cp\u003ePathological diagnosis is the \u0026quot;gold standard\u0026quot; for the diagnosis of DIP. Methods of lung biopsy included transbronchial lung biopsy (TBLB), CT-guided percutaneous needle biopsy, transbronchial cryobiopsy and surgical lung biopsy. Lung specimens from TBLB are too small, which can\u0026apos;t fully reflect the scope and degree of lung lesions and satisfy the diagnosis of interstitial lung disease. The specimens from surgical lung biopsy can meet the diagnostic requirements of interstitial lung disease, but the surgical lung biopsy is costly and traumatic, which is not easy for patients to accept. Transbronchial cryobiopsy or CT-guided percutaneous lung biopsies have fewer healthcare costs, fewer traumatic, and the specimens can meet the diagnostic requirements of interstitial lung disease, which is easy for patients to accept. This patient underwent percutaneous lung biopsy and the result showed that there were a large number of macrophages in the alveolar cavity and chronic inflammation was noted in the interstitium, so it could be diagnosed as DIP. At the same time, the patient had no history of smoking or second-hand smoke, which was rare in the literature. The patient was a sculptor. Because the environmental or occupational exposure may be one of an etiological risk factors, it is speculated that dust inhalation may be one of the inducing factors in this case. However, because the specimens were relatively small, it was impossible to know whether there was dust deposition in other lesions regions.\u003c/p\u003e\n\u003cp\u003eThe special feature of this case was lung CT, which showed a single solid mass in the right lower lung, and then rapidly progressed with peripheral infection. However, the typical imaging manifestation of DIP is diffuse ground glass shadow in both lungs, which is located under the pleura. The lower lung is more than the upper lung, and some are accompanied by linear opacities and reticulation in the base [9]. Honeycomb appearance is uncommon. Therefore, the imaging findings of this case were different from the typical imaging findings of DIP, which were rarely reported in the literature. These imaging findings were often misdiagnosed as pulmonary malignant tumor because of PETCT demonstrated hypermetabolism and the patients were usually treated by surgery. Therefore, for the pulmonary mass, even if PETCT indicates hypermetabolic lesions and highly suspected tumor, the pathological diagnosis of preoperative mass is still very important to avoid irreversible damage to patients.\u003c/p\u003e\n\u003cp\u003eThe main treatment is to quit smoking and glucocorticoid therapy and some cases become spontaneous remission after quitting smoking. Glucocorticoids have been reported to be beneficial in case series, although improvement may be temporary [3]. Environmental/occupational factors are also suspicious etiology of DIP [6, 7]. That DIP improved in two cases after leaving the workplace without steroid treatment was reported by Lougheed et al [7]. Therefore, It is reasonable to terminate any possible environmental risk factors. Initial glucocorticoid therapy consists of 40-60 mg/day for 6 weeks, then decreased gradually and stopped within 6-9 months. Glucocorticoid therapy of this case: intravenous methylprednisolone 40mg for 2 weeks, oral prednisone 40mg for 3 weeks, and then decrease 5 mg weekly until to 20 mg. Then the dose was reduced by 5 mg monthly until to 10 mg and maintained for three months. The total course of treatment was half a year. The case clinical symptoms and radiology were significant improvement after steroid treatment.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe imaging findings of such a case are rarely described in the literature. There is no smoking history and it is easy to be misdiagnosed as tumor. However, all of these clinical characteristics mentioned above are uncommon. Therefore, we still know little about this rare interstitial lung disease, and we still need more clinical cases, more complete clinical imaging and pathology to enrich our understanding of the disease. At the same time, for the pulmonary mass, even if appeared hypermetabolic on PET-CT, it is still necessary to make a definite pathological diagnosis before operation, so as to reduce the damage to patients.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eDIP: Desquamation interstitial pneumonia; HRCT: High resolution computed tomography; UIP: usual interstitial pneumonia; PCT: procalcitonin; CRP: and C-reactive protein; HLA-B27: human leukocyte antigen-B27; TBLB: transbronchial lung biopsy;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank the patient and her partner for allowing them to publish his story.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLYH designed the study and revised the manuscript. LW conducted clinical data collection and analysis and drafted the manuscript. WWY, SYH and LF conducted clinical data collection and analysis. The authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data and material were presented in this published article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for publication. All authors are in agreement for the publication of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eCostabel U, King TE: \u003cstrong\u003eInternational consensus statement on idiopathic pulmonary fibrosis\u003c/strong\u003e. \u003cem\u003eThe European respiratory journal\u0026nbsp;\u003c/em\u003e2001, \u003cstrong\u003e17\u003c/strong\u003e(2):163-167.\u003c/li\u003e\n \u003cli\u003eCarrington CB, Gaensler EA, Coutu RE, FitzGerald MX, Gupta RG: \u003cstrong\u003eNatural history and treated course of usual and desquamative interstitial pneumonia\u003c/strong\u003e. \u003cem\u003eN Engl J Med\u0026nbsp;\u003c/em\u003e1978, \u003cstrong\u003e298\u003c/strong\u003e(15):801-809.\u003c/li\u003e\n \u003cli\u003eAkira M, Yamamoto S, Hara H, Sakatani M, Ueda E: \u003cstrong\u003eSerial computed tomographic evaluation in desquamative interstitial pneumonia\u003c/strong\u003e. \u003cem\u003eThorax\u0026nbsp;\u003c/em\u003e1997, \u003cstrong\u003e52\u003c/strong\u003e(4):333-337.\u003c/li\u003e\n \u003cli\u003eBradley B, Branley HM, Egan JJ, Greaves MS, Hansell DM, Harrison NK, Hirani N, Hubbard R, Lake F, Millar AB\u003cem\u003e\u0026nbsp;et al\u003c/em\u003e: \u003cstrong\u003eInterstitial lung disease guideline: the British Thoracic Society in collaboration with the Thoracic Society of Australia and New Zealand and the Irish Thoracic Society\u003c/strong\u003e. \u003cem\u003eThorax\u0026nbsp;\u003c/em\u003e2008, \u003cstrong\u003e63 Suppl 5\u003c/strong\u003e:v1-58.\u003c/li\u003e\n \u003cli\u003eWells AU, Nicholson AG, Hansell DM: \u003cstrong\u003eChallenges in pulmonary fibrosis. 4: smoking-induced diffuse interstitial lung diseases\u003c/strong\u003e. \u003cem\u003eThorax\u0026nbsp;\u003c/em\u003e2007, \u003cstrong\u003e62\u003c/strong\u003e(10):904-910.\u003c/li\u003e\n \u003cli\u003eDiken \u0026Ouml; E, Şeng\u0026uuml;l A, Beyan AC, Ayten \u0026Ouml;, Mutlu LC, Okutan O: \u003cstrong\u003eDesquamative interstitial pneumonia: Risk factors, laboratory and bronchoalveolar lavage findings, radiological and histopathological examination, clinical features, treatment and prognosis\u003c/strong\u003e. \u003cem\u003eExperimental and therapeutic medicine\u0026nbsp;\u003c/em\u003e2019, \u003cstrong\u003e17\u003c/strong\u003e(1):587-595.\u003c/li\u003e\n \u003cli\u003eLougheed MD, Roos JO, Waddell WR, Munt PW: \u003cstrong\u003eDesquamative interstitial pneumonitis and diffuse alveolar damage in textile workers. Potential role of mycotoxins\u003c/strong\u003e. \u003cem\u003eChest\u0026nbsp;\u003c/em\u003e1995, \u003cstrong\u003e108\u003c/strong\u003e(5):1196-1200.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAmerican Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001\u003c/strong\u003e. \u003cem\u003eAm J Respir Crit Care Med\u0026nbsp;\u003c/em\u003e2002, \u003cstrong\u003e165\u003c/strong\u003e(2):277-304.\u003c/li\u003e\n \u003cli\u003eSverzellati N, Lynch DA, Hansell DM, Johkoh T, King TE, Jr., Travis WD: \u003cstrong\u003eAmerican Thoracic Society-European Respiratory Society Classification of the Idiopathic Interstitial Pneumonias: Advances in Knowledge since 2002\u003c/strong\u003e. \u003cem\u003eRadiographics : a review publication of the Radiological Society of North America, Inc\u0026nbsp;\u003c/em\u003e2015, \u003cstrong\u003e35\u003c/strong\u003e(7):1849-1871.\u003c/li\u003e\n\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":"Desquamation interstitial pneumonia, solid mass, case report","lastPublishedDoi":"10.21203/rs.3.rs-955264/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-955264/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Desquamation interstitial pneumonia (DIP) is a rare type of idiopathic interstitial pneumonia. High resolution computed tomography (HRCT) shows ground glass opacities without the peripheral reticular opacities characteristic of usual interstitial pneumonia (UIP). Here we report a case of DIP presenting as a solid mass in the lung, which is rarely described in the literature.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eCase presentation: \u003c/strong\u003eA 77-year-old man presented with dry cough and dyspnea on exertion for one month was admitted to our hospital. The lung CT scan showed there was a pulmonary mass in right lower lung and the patient was scheduled for surgery. He was a sculpture artist, non-smoker and the previous medical history included only mandatory spondylitis without other connective tissue diseases. Nine days post-last CT, the FDG PET/CT demonstrated the mass in the right lower lung was significantly hypermetabolic (SUV value=8.9) but inflammatory exudate could be observed around the mass. We gave antibiotics and performed CT-guided percutaneous lung biopsy. The result showed that there were a large number of macrophages in the alveolar cavity, alveolar epithelial type II cells hyperplasia in some areas and chronic inflammation was noted in the interstitium. Then the desquamative interstitial pneumonia was diagnosed. We gave the patient glucocorticoid therapy, then the patient's symptoms disappeared gradually and the lung CT showed that the pulmonary mass was disappeared.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003eOur report illustrates the rare presentation of DIP. Furthermore, for the pulmonary mass, even if appeared hypermetabolic on PET/CT, it is still necessary to make a definite pathological diagnosis before operation, so as to reduce the damage to patients.\u003c/p\u003e","manuscriptTitle":"Desquamation Interstitial Pneumonia Presenting as a Solid Mass in the Lung: a Case Report.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-10-06 12:39:45","doi":"10.21203/rs.3.rs-955264/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":"254157c2-3b21-4930-a465-730cc13afb89","owner":[],"postedDate":"October 6th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":7667000,"name":"Pathology"},{"id":7667001,"name":"Critical Care \u0026 Emergency Medicine"}],"tags":[],"updatedAt":"2021-10-15T22:08:54+00:00","versionOfRecord":[],"versionCreatedAt":"2021-10-06 12:39:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-955264","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-955264","identity":"rs-955264","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}