Diagnostic Cytopathology最新文献

{"title":"The Milan System SUMP Category: 5-Year Diagnostic Performance","authors":"Henri Lagerstam,&nbsp;Erkka Tommola,&nbsp;David Kalfert,&nbsp;Saara Kares,&nbsp;Heini Huhtala,&nbsp;Ivana Kholová","doi":"10.1002/dc.25482","DOIUrl":"10.1002/dc.25482","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Salivary gland neoplasms are heterogeneous, with wide cytomorphological overlap. Neoplasms categorized in the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) as salivary gland neoplasms of uncertain malignant potential (SUMP) reflect this diagnostic challenge.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>All salivary gland fine-needle aspirations (SG-FNA) diagnosed at Fimlab Laboratories over a 5-year period (January 1, 2018–December 31, 2022) that were classified as SUMP were included. Follow-ups were reviewed until May 31, 2024. The SUMP cases were classified into cytomorphological subtypes. The risk of malignancy (ROM), risk of neoplasm, and median timelines of the pathology laboratory workflow and patient management were calculated. In addition, separate analyses of the impact of age and sex were performed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 1157 SG-FNAs were diagnosed over a 5-year period. Of these, 100 SG-FNAs from 52 females and 33 males were classified as SUMP. A total of 69 (69.0%) SUMP cases underwent histological verification. The ROM was 23.2% for all surgical follow-ups, 35.0% for the oncocytic/oncocytoid subtype, and 18.4% for the basaloid subtype. For the male and female groups, the ROMs were 26.9% and 16.2% for all surgical follow-ups, 40.0% and 14.3% for the oncocytic/oncocytoid subtype, and 18.8% and 16.7% for the basaloid subtype, respectively.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The 5-year analysis of SUMP category performance showed a lower ROM in our practice than the MSRSGC reference value. The oncocytic/oncocytoid subtype presented a higher ROM than the basaloid subtype. The ROMs were highest in the male population and in the age group of 30–69 years.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 8","pages":"370-381"},"PeriodicalIF":1.0,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dc.25482","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143978492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mucocyte-Rich/Extracellular Mucin-Poor Salivary Duct Carcinoma: An Unusual Morphological Variant Mimicking Mucoepidermoid Carcinoma","authors":"Azadeh Samiei,&nbsp;Harvey Cramer,&nbsp;Sheila Segura,&nbsp;Hector Mesa,&nbsp;Tieying Hou,&nbsp;Dongwei Zhang","doi":"10.1002/dc.25483","DOIUrl":"10.1002/dc.25483","url":null,"abstract":"<div>\u0000 \u0000 <p>Salivary duct carcinoma (SDC) is an aggressive malignancy of the salivary gland. The rare mucin-rich variant is characterized by the presence of nests of malignant cells floating in pools of extracellular mucin. We present an unusual case of SDC with abundant mucocytes but complete absence of extracellular mucin, initially misdiagnosed as mucoepidermoid carcinoma (MEC) on fine needle aspiration (FNA). The patient, an 85-year-old woman, presented with a 3.2 cm heterogeneous, partially cystic, right parotid mass causing facial nerve paralysis. FNA revealed mixed pleomorphic and hyperchromatic epithelial cells with abundant mucocytes. The tumor cells were focally positive for p63 and androgen receptor (AR). The patient was diagnosed with intermediate-grade MEC. Subsequent parotidectomy revealed high-grade duct-forming carcinoma with extensive perineural invasion, frequent mitosis, and comedonecrosis arising from a pleomorphic adenoma. This was remarkable for numerous mucocytes and the absence of extracellular mucin. Immunohistochemically, the tumor cells expressed AR, CK7, GATA3, and GCDFP-15, confirming the diagnosis of SDC. Whole exome sequencing revealed <i>RAD50</i> p.Lys973Arg and <i>POLE</i> p.Arg52Trp mutations, suggesting that the DNA damage repair pathway was affected. Given the potential for variability in individual marker expression, including aberrant phenotypes, such as p63-positive SDC or AR-positive MEC, employing a comprehensive panel of markers for accurate diagnosis is crucial. Markers such as GATA3 and GCDFP-15 can be useful in detecting highly aggressive SDC.</p>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 8","pages":"E149-E154"},"PeriodicalIF":1.0,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143985432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identifying HHV-6 Induced Cytopathic Effects in Bronchoalveolar Lavage Fluid Preparations to Enhance Care in Immunocompromised Patients","authors":"Komal Ijaz,&nbsp;Gloria Hopkins Sura","doi":"10.1002/dc.25481","DOIUrl":"10.1002/dc.25481","url":null,"abstract":"<div>\u0000 \u0000 <p>Human Herpesvirus 6 (HHV-6) is a ubiquitous virus that remains latent after primary infection but can reactivate in immunocompromised patients, leading to severe complications. Early detection of HHV-6 in respiratory samples is critical for timely intervention. We describe a 61-year-old immunocompromised woman who presented with pneumonitis and encephalopathy. Initial testing confirmed COVID-19, and worsening respiratory symptoms prompted bronchoalveolar lavage (BAL). Cytologic analysis of the BAL revealed epithelial cells with viral cytopathic effects, including multinucleation, chromatin margination, and nuclear inclusions. Plasma polymerase chain reaction (PCR) detected a high HHV-6 viral load, confirming HHV-6 pneumonitis and encephalitis. Despite antiviral treatment with Foscarnet and Ganciclovir, the patient's condition deteriorated, ultimately leading to her passing. This case highlights the importance of recognizing differential diagnoses of cytopathic effects in BAL specimens. Pathologists are crucial in identifying viral, infectious, or inflammatory conditions in BAL fluid, aiding in prompt diagnosis and management to improve patient care and prevent severe outcomes.</p>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 7","pages":"357-360"},"PeriodicalIF":1.0,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143971611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sporadic Burkitt Lymphoma Presenting as Peritoneal Lymphomatosis—A Case Report","authors":"Pritika Kushwaha,&nbsp;Meeta Singh,&nbsp;Deepika Rana,&nbsp;Radhika Batra,&nbsp;Alpana Manchanda,&nbsp;Shyama Jain","doi":"10.1002/dc.25478","DOIUrl":"10.1002/dc.25478","url":null,"abstract":"<div>\u0000 \u0000 <p>Peritoneal lymphomatosis is an extremely rare presentation of lymphoma, and Burkitt lymphoma is one of the infrequent types to present as peritoneal lymphomatosis. We report a case of Burkitt lymphoma in a 7-year-old child, with diffuse involvement of the omentum and peritoneum, with a homogenous mass in the abdomen along with ascites and bilateral hydronephrosis. Cytological examination of ascitic fluid, along with flow cytometry immunophenotyping, was used to confirm the diagnosis.</p>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 8","pages":"E144-E148"},"PeriodicalIF":1.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143972629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnosis of Pediatric Myositis Ossificans Based on Cytomorphology and Molecular Analysis From FNAB Sample: A Case Report","authors":"Živa Ledinek,&nbsp;Milica Stefanović,&nbsp;Blaž Mavčič,&nbsp;Maja Česen Mazić,&nbsp;Ana Gazikalović,&nbsp;Daja Šekoranja,&nbsp;Simona Miceska,&nbsp;Veronika Kloboves Prevodnik","doi":"10.1002/dc.25477","DOIUrl":"10.1002/dc.25477","url":null,"abstract":"<p>Myositis ossificans (MO) is a benign soft tissue lesion, characterized by ectopic ossification due to inappropriate fibroblast differentiation, most commonly affecting skeletal muscles. It often occurs in young adults after muscle trauma, predominantly in male patients and very rarely in children. We describe the case of a previously healthy 3-year-old boy who developed a lesion in his deltoid muscle after vaccination against tick-borne encephalitis. During an MRI scan, performed under general anesthesia, fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB) were performed. While the CNB sample resulted in a non-diagnostic finding, the FNAB sample showed cytomorphology consistent with the diagnosis of MO. A molecular analysis performed on the FNAB sample confirmed the presence of <i>COL1A1::USP6</i> fusion, which is considered diagnostic for MO in the appropriate clinical context. The boy was then referred to the orthopedic surgeon. Extracorporeal shock-wave therapy was chosen as the first-line treatment, but as it was too painful, the lesion was surgically removed, and histopathologic evaluation confirmed the diagnosis. Although rare in children, the diagnosis of MO should be considered in soft tissue lesions after trauma. We present the first pediatric case of MO diagnosed by FNAB and propose that FNAB, as a minimally invasive diagnostic procedure, is a suitable diagnostic approach, especially when molecular testing is available to confirm the diagnosis.</p>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 7","pages":"E138-E143"},"PeriodicalIF":1.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dc.25477","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143976691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thyroid Infiltration by Chronic Lymphocytic Leukemia: A Rare Case Report With Cytological and Flow Cytometry Findings","authors":"Nursinem Alkan Vurğun,&nbsp;Nagihan Yalçın,&nbsp;Nilay Şen Türk,&nbsp;Semin Melahat Fenkci,&nbsp;Gülsüm Akgün Çağlıyan","doi":"10.1002/dc.25476","DOIUrl":"10.1002/dc.25476","url":null,"abstract":"<div>\u0000 \u0000 <p>Primary and secondary involvement of the thyroid gland by CLL has been reported as extremely rare in the literature. Fine-needle aspiration cytology is one of the primary diagnostic procedures for determining the nature of suspicious thyroid nodules. Clinical information is particularly important during cytomorphological evaluation, especially in patients with a history of hematological malignancy. We report a case of a 58-year-old woman diagnosed with CLL, presenting with thyroid gland involvement 8 years after the initial diagnosis. Fine-needle aspiration cytology revealed an infiltrative cellular smear with coarse chromatin and monomorphic cells displaying a tortoise shell pattern within a colloid-containing background. Diagnostic confirmation was achieved through flow cytometric analysis of the aspirated fluid material. In patients with a history of hematologic malignancy, careful evaluation is required when a lymphocytic background is observed in aspirations, and additional methods should be employed if necessary. Distinguishing between primary and secondary lymphomas of the thyroid gland is clinically significant, as their treatment and prognosis differ substantially.</p>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 7","pages":"E133-E137"},"PeriodicalIF":1.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143973534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytologic Diagnosis of Lymphomatoid Granulomatosis, A Case Report and Review of the Literature","authors":"Mohamed Eltahir,&nbsp;Javeryah Safi,&nbsp;Brant G. Wang","doi":"10.1002/dc.25475","DOIUrl":"10.1002/dc.25475","url":null,"abstract":"<div>\u0000 \u0000 <p>Lymphomatoid granulomatosis (LYG) is a rare EBV-driven, extra-nodal, angiocentric, and angio-destructive lymphoproliferative disorder. The lungs are the most common site of involvement. We describe a case of LYG where the diagnosis was established based on fine needle aspiration. The case is of a 58-year-old female with a history of endometrial carcinoma, who presented with right upper lobe and right middle lobe pulmonary nodules which were identified on a surveillance computed tomography (CT) scan of the chest. The patient underwent an endobronchial ultrasound-guided fine needle aspiration, and a cytologic examination showed mixed inflammatory infiltrate with histiocyte and small lymphocyte predominance and scattered large atypical cells. Immunohistochemical analysis showed that the large atypical cells were positive for CD30, PAX5, and MUM1. In situ hybridization for Epstein–Barr virus-encoded RNA was found to be positive in the atypical cells. The patient was started on treatment with peginterferon alfa-2a. We also discuss the differential diagnosis of LYG and review the available literature.</p>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 7","pages":"E127-E132"},"PeriodicalIF":1.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143957970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic Utility of Clusterin in Fine Needle Aspiration Biopsy and Core Biopsies of Hepatocellular Carcinoma","authors":"Bhawana Dhiman,&nbsp;Reetu Kundu,&nbsp;Radhika Srinivasan,&nbsp;Suvradeep Mitra,&nbsp;Naveen Kalra,&nbsp;Madhumita Premkumar,&nbsp;Ajay Kumar Duseja","doi":"10.1002/dc.25473","DOIUrl":"10.1002/dc.25473","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Several immunohistochemical markers are available for demonstrating hepatocytic differentiation, thereby confirming the diagnosis of hepatocellular carcinoma (HCC). Clusterin is a new marker of malignant hepatocytes, not evaluated in fine needle aspiration biopsy (FNAB) samples. Hence, we evaluated its diagnostic utility in FNAB cell blocks (CB) and core biopsy samples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A total of 47 cases of HCC diagnosed on FNAB with CB (41)/core biopsy (6) were retrieved. For comparison, CB from metastatic adenocarcinoma (15) and cases with incidental benign hepatocytes (12) were included. Immunohistochemistry (IHC) for clusterin was performed and the 3 groups were compared to derive its sensitivity and specificity. Canalicular expression was considered positive for hepatocytic differentiation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The cohort comprised 47 cases of HCC, with 43 (91.5%) male and 4 (8.5%) female patients with an age range of 20–78 years. On clusterin IHC, benign hepatocytes showed a track-like canalicular pattern whereas in HCC, typical enhanced canalicular positivity (3+ intensity) was seen in 32/47 (68%) cases, 17 of which additionally showed cytoplasmic positivity. Only cytoplasmic positivity was noted in 7 HCC cases and was considered negative. All cases of well differentiated (6/6), 67.6% (25/37) of moderately differentiated, and 25% (1/4) of poorly differentiated HCC showed enhanced canalicular positivity, whereas metastatic adenocarcinoma showed cytoplasmic (2/15) or nucleocytoplasmic (1/15) positivity only.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>IHC for clusterin with enhanced canalicular pattern of expression revealed 68% sensitivity and 100% specificity for HCC, aiding its distinction from metastatic adenocarcinoma and benign hepatocytes in FNAB samples, thereby confirming its diagnostic utility.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 8","pages":"363-369"},"PeriodicalIF":1.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143802740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Testing Using ThyGeNEXT/ThyraMIR in Thyroid Nodules With Indeterminate Cytology: A Single Medical Institute Experience","authors":"Zhongbo Yang,&nbsp;Komal Ijaz,&nbsp;Magda Esebua","doi":"10.1002/dc.25474","DOIUrl":"10.1002/dc.25474","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Up to 30% of thyroid nodules, by fine needle aspiration (FNA), have indeterminate cytology, including Bethesda III (atypia of undetermined significance [AUS]), IV (follicular neoplasm/suspicious for follicular neoplasm [FN/SFN]), and V (suspicious for malignancy). Molecular testing is utilized for further risk stratification of these indeterminate thyroid nodules. A multiplatform test (MPTX), one of the commercially offered molecular tests, combines next-generation sequencing panel (ThyGeNEXT) with microRNA expression classifier (ThyraMIR) to help with risk stratification. This study aimed to evaluate the performance of MPTX in cytologically indeterminate thyroid nodules in real-world experience.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>All cases with indeterminate thyroid FNA results and corresponding MPTX test results in a period of 5 years were searched and retrieved. Subsequent clinical or surgical follow-up information was obtained. Molecular test results were compared to the histologic diagnoses. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated accordingly.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 106 cases were identified in the search, including 89 Bethesda III and 17 Bethesda IV. Overall MPTX results were negative in 59 cases, positive in 36 cases, and nondiagnostic in 11 cases. Only 17% of cases with negative molecular results had surgery, whereas 86% of those with positive molecular results had surgical follow-up. The false negative rate and false positive rate based on cytologic-histologic correlation (CHC) alone were 70% and 29%, respectively. In addition, based on both surgical and clinical follow-up data, the MPTX tests had an overall sensitivity of 76%, specificity of 75%, NPV of 83%, and PPV of 67%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study showed that more than half (56%) of the thyroid nodules with indeterminate cytology had benign molecular results by MPTX testing. The MPTX test showed moderate to high NPV and moderate PPV, suggesting that the MPTX test can be useful as an ancillary study to further risk-stratify cytologically indeterminate thyroid nodules. It is critical, however, to know the limitations of this assay, and the molecular results should be considered in correlation with clinical and radiologic findings.</p>\u0000 </section>\u0000 </div>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 7","pages":"351-356"},"PeriodicalIF":1.0,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143794789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pleural Metastasis of Merkel Cell Carcinoma","authors":"Sina Maghsoudlou,&nbsp;Marc Pusztaszeri,&nbsp;Mauro Saieg","doi":"10.1002/dc.25472","DOIUrl":"10.1002/dc.25472","url":null,"abstract":"<p>Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin cancer, often challenging to diagnose due to its morphological resemblance to other malignancies. Diagnosis is typically confirmed by immunohistochemistry (IHC), with most cases being positive for both neuroendocrine and epithelial markers, particularly the characteristic dot-like cytoplasmic pattern seen with Cytokeratin 20 (CK20). This case report describes a 68-year-old male with MCC originating in the left elbow, who developed pleural metastasis 10 months after initial diagnosis and 4 months following a pathologic complete response. IHC analysis confirmed MCC in the pleural fluid with positive markers including: CK20, chromogranin, synaptophysin, MCC polyomavirus, and SATB2, the latter emerging as a valuable adjunct in distinguishing MCC from other neuroendocrine tumors.</p>","PeriodicalId":11349,"journal":{"name":"Diagnostic Cytopathology","volume":"53 6","pages":"308-311"},"PeriodicalIF":1.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dc.25472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}