[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-405632-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-405632-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","merkel-cell-carcinoma-epidemiology-clinical-features-diagnosis-and-treatment-of-a-rare-disease-continuing-medical-education","Merkel cell carcinoma: epidemiology, clinical features, diagnosis and treatment of a rare disease - Continuing Medical Education","","Merkel cell carcinoma is a rare, aggressive skin cancer with neuroendocrine differentiation. Risk factors include sun exposure, advanced age, immunosuppression (e.g., transplant recipients, lymphoproliferative neoplasms, and HIV), and Merkel cell polyomavirus infection. Clinical diagnosis is uncommon, so histopathology and immunohistochemistry are typically required. Localized disease is managed with complete surgical excision and appropriate margins; occult lymph-node metastasis is common, supporting sentinel lymph node biopsy.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/merkel-cell-carcinoma-epidemiology-clinical-features-diagnosis-and-treatment-of-a-rare-disease-continuing-medical-education/405632/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/merkel-cell-carcinoma-epidemiology-clinical-features-diagnosis-and-treatment-of-a-rare-disease-continuing-medical-education/405632.png","ImageObject",300,407,{"name":42,"@type":43},"Riley","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-31","2026-09-28",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",8,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What are the main risk factors for Merkel cell carcinoma?","Question",{"text":63,"@type":64},"Key risk factors include sun exposure, advanced age, immunosuppression (such as transplant recipients, lymphoproliferative neoplasms, and HIV), and Merkel cell polyomavirus infection.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"Why is Merkel cell carcinoma rarely diagnosed clinically?",{"text":68,"@type":64},"The diagnosis is rarely made based on clinical appearance alone, so histopathology and immunohistochemistry are usually necessary to confirm the tumor.",{"name":70,"@type":61,"acceptedAnswer":71},"How is Merkel cell carcinoma treated when there is no evidence of metastasis?",{"text":72,"@type":64},"Primary tumors without metastases are treated with complete surgical excision using appropriate surgical margins, and adjuvant radiotherapy is used postoperatively to improve local tumor control.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},405632,1790763342,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,106,110,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":107,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":108,"slug":109},7,40,"healthcare",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},"Research & Report",30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":107,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":123,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":143,"read_time":144,"preview_page_count":4},1374391975076,"https://ap-avatar.wpscdn.com/avatar/14000253ca4ec9f6853?x-image-process=image/resize,m_fixed,w_180,h_180&k=1783305029341752051","CONTINUING MEDICAL EDUCATION  \nMerkel cell carcinoma: epidemiology, clinical features, diagnosis and treatment of a rare disease􀀂  \nStella Meireles Siqueira  a,∗ , Gabriella Campos-do-Carmo  b, Alexssandra Lima Siqueira dos Santos  a, Cícero Martins  c, Andreia Cristina de Melo  a  \na Division of Clinical Research, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil b Gávea Medical Center, Rio de Janeiro, RJ, Brazil  \nc Oncology Service, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil  \nReceived 28 July 2022; accepted 16 September 2022 Available online 2 March 2023  \nKEYWORDS  \nCarcinoma, Merkel cell;  \nImmune checkpoint inhibitors; Merkel cell polyomavirus; Skin neoplasms  \nAbstract Merkel cell carcinoma is a rare skin cancer with neuroendocrine differentiation. The risk factors include sun exposure, advanced age, immunosuppression (such as transplant recipients, patients with lymphoproliferative neoplasms, or patients with HIV), and Merkel cell polyomavirus infection. Clinically, Merkel cell carcinoma appears as a cutaneous or subcutaneous plaque or nodule, but this tumor diagnosis is rarely made clinically. Therefore, histopathology and immunohistochemistry are usually necessary. Primary tumors without evidence of metastases are treated with complete surgical excision and appropriate surgical margins. The presence of occult metastasis in a lymph node is frequent and a sentinel lymph node biopsy should be performed. Postoperative adjuvant radiotherapy increases local tumor control. Recently, agents that block the PD-1/PD-L1 pathway have shown objective and durable tumor regression in patients with advanced solid malignancies. The first anti-PD-L1 antibody used in patients with Merkel cell carcinoma was avelumab, but pembrolizumab and nivolumabhave also shown efficacy. This article describes the current state of knowledge of the epidemiology, diagnosis, and staging of Merkel cell carcinoma, as well as new strategies for its systemic treatment.  \n© 2023 Sociedade Brasileira de Dermatologia. Published by Elsevier Espaa, S.L.U. This is an open access article under the CC BY license ([http://creativecommons.org/licenses/by/4.0/](http://creativecommons.org/licenses/by/4.0/) ).  \n􀀂 Study conducted at the Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil.  \n∗ Corresponding author.  \nE-mail: [stellamsiqueira@gmail.com](stellamsiqueira@gmail.com) (S.M. Siqueira).  \n[https://doi.org/10.1016/j.abd.2022.09.003](https://doi.org/10.1016/j.abd.2022.09.003)  \n0365-0596/© 2023 Sociedade Brasileira de Dermatologia. Published by Elsevier Espaa, S.L.U. This is an open access article under the CC BY license ([http://creativecommons.org/licenses/by/4.0/](http://creativecommons.org/licenses/by/4.0/)).  \nIntroduction  \nMerkel Cell Carcinoma (MCC) is an unusual and aggressive type of skin cancer with neuroendocrine origin,1 and was first described in 1972 by Toker as a trabecular skin carcinoma.2 Since then, understanding of its pathophysiology, outcomes and management have improved, especially after immunotherapies. Also known as primary cutaneous neuroendocrine carcinoma, MCC shares features with Merkel cells of the skin, justifying its nomenclature.3  \nEpidemiology  \nThe incidence rate of MCC varies in different regions of the world. In the European Union, between 1995 and 2002, its annual incidence rate was 0.13 per 100,000 inhabitants, but higher in groups aged 65 years or older.4 In the United States, the incidence rate was 0.79 per 100,000 inhabitants in 2011.5 In 2013, Paulson et al. reported that the absolute number of MCC in the United States was 2488 cases, which corresponds to an incidence rate similar to 0.7 per 100,000 person-years.6  \nA higher incidence of MCC was observed in an Australian study, with a rate of 1.6 per 100,000 inhabitants in the state of Queensland between 2006 and 2010, more frequent in males (2.5 per 100,000) than in females (0.9 per 100,000) and with an average life expectancy of 75.5 years for men","cbCaiuPEuiNeQehP","https://ap.wps.com/l/cbCaiuPEuiNeQehP","pdf",1850828,"English","# Introduction\n# Epidemiology\n# Risk factors","[{\"question\":\"What are the main risk factors for Merkel cell carcinoma?\",\"answer\":\"Key risk factors include sun exposure, advanced age, immunosuppression (such as transplant recipients, lymphoproliferative neoplasms, and HIV), and Merkel cell polyomavirus infection.\"},{\"question\":\"Why is Merkel cell carcinoma rarely diagnosed clinically?\",\"answer\":\"The diagnosis is rarely made based on clinical appearance alone, so histopathology and immunohistochemistry are usually necessary to confirm the tumor.\"},{\"question\":\"How is Merkel cell carcinoma treated when there is no evidence of metastasis?\",\"answer\":\"Primary tumors without metastases are treated with complete surgical excision using appropriate surgical margins, and adjuvant radiotherapy is used postoperatively to improve local tumor control.\"}]","Merkel cell carcinoma: epidemiology, clinical features, diagnosis and treatment of a rare disease - Continuing Medical Education | PDF",1790561188,25]