Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine carcinoma of the skin that shows locoregional or distant metastasis. Metastasis of MCC to body cavity effusion is extremely rare; only three cases have been reported so far. Metastatic MCC in effusion cytology shows small blue round cells with fine stippled chromatin like other small blue round cell tumors such as small cell lung carcinoma or lymphoma. The diagnosis of metastatic MCC can grant patients good chances at recently advanced therapeutic options. Here, we present a case of metastatic MCC to pleural effusion with characteristic single file-like pattern.
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Merkel cell carcinoma presenting as a malignant pleural effusion post‐COVID‐19 hospitalization: A case report and literature review Joel Lanceta, Mesut Toprak, Oana C. Rosca Diagnostic Cytopathology.2022;[Epub] CrossRef
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Derrame pleural por carcinoma de células de Merkel María J. Soler-Sempere, María O. Alvárez-Fernández, Isabel Padilla-Navas, María Cabezas-Macián, Jose F. Sánchez-Hernández, Eduardo García-Pachón Archivos de Bronconeumología.2021; 57(11): 715. CrossRef
A rare case of pleural localisation of both metastatic Merkel cell carcinoma and chronic lymphocytic leukaemia Elise Kaspi, Shirley Fritz, Julien Colle, Florent Amatore, Diane Frankel, Patrice Roll Cytopathology.2021; 32(3): 367. CrossRef
Merkel cell carcinoma with pleural effusion María J. Soler-Sempere, María O. Alvárez-Fernández, Isabel Padilla-Navas, María Cabezas-Macián, Jose F. Sánchez-Hernández, Eduardo García-Pachón Archivos de Bronconeumología (English Edition).2021; 57(11): 715. CrossRef
Merkel cell carcinoma (MCC) is an uncommon but potentially aggressive neuroendocrine carcinoma of the skin. It typically develops on sun-exposed areas of the head and neck, particularly the eyelid, periorbital region, and extremities. We report a case of unusually located MCC, presenting as a conjunctival mass, which has only been reported once in the English literature. An 83-year-old male presented with a 0.8 x 0.7 cm sized mass protruding from the lower fornix of the right conjunctiva. The mass was excised.
The tumor was located in the submucosa without connection to the overlying mucosa. Light microscopic findings showed a carcinoma with undifferentiated small round cells and the presence of cytokeratin (CK AE1/3, CK7) and neuroendocrine markers. We established a diagnosis of MCC. As reported in the literature, the majority of MCCs are positive for CK20 but negative for CK7. But, this case showed an uncommon cytokeratin immunohistochemical profile of positive for CK7 and negative for CK20, suggesting a new immunophenotypic MCC variant.