Answer of Dermatopathology Case 53
Immunohistochemistry: Cytokeratin20 Merkel Cell Carcinoma Visit: Dermatopathology site Visit: Pathology of Merkel Cell Carcinoma Abstract: New insights into merkel cell carcinoma. Adv Anat Pathol. 2010 May;17(3):155-61. Merkel cell carcinoma (MCC) is a rare aggressive cutaneous malignancy of the elderly and immunocompromised populations. The clinical presentation of MCC is nonspecific, with the majority of cases presenting as localized skin involvement. Histologically and immunophenotypically, MCC is defined by both neuroendocrine and epithelial differentiation. Recently, the Merkel cell polyomavirus has been implicated in the pathogenesis of MCC. In addition, there have been numerous studies evaluating the histologic and immunohistochemical characteristics of MCC as they relate to diagnosis and prognosis. The purpose of this paper is to review the most salient and clinically relevant updates in the pathogenesis and histologic features of MCC. Specific attention is given to the clinic