TY - JOUR T1 - Merkel cell carcinoma can be distinguished from metastatic small cell carcinoma using antibodies to cytokeratin 20 and thyroid transcription factor 1 JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 727 LP - 729 VL - 54 IS - 9 AU - S N Leech AU - A J O Kolar AU - P D Barrett AU - S A Sinclair AU - N Leonard Y1 - 2001/09/01 UR - http://jcp.bmj.com/content/54/9/727.abstract N2 - Aim—To investigate whether immunohistochemical staining for cytokeratin 20 (CK20) and thyroid transcription factor 1 (TTF-1) is useful in distinguishing Merkel cell carcinomas (MCCs) from metastatic small cell carcinomas (SCCs). Methods—Eleven cases of MCC and 10 of lung SCC were stained for CK20 and TTF-1. Results—Ten of 11 MCCs stained with the antibody to CK20. None was positive for TTF-1. No SCC stained with anti-CK20 and all stained strongly with anti-TTF-1. Conclusions—The use of both anti-CK20 and anti-TTF-1 can reliably distinguish between MCC and metastatic SCC, thus avoiding the need for a detailed clinical investigation of patients with MCC in whom metastatic SCC must be excluded. ER -