Incidental Merkel cell carcinoma in a cutaneous horn: a case report.

Brian A. Schick; Joshua S. Tobe; Mariamma G. Joseph; Tyler B. Rouse; Manal Y. Gabril

doi:10.5826/dpc.0501a08

Incidental Merkel cell carcinoma in a cutaneous horn: a case report.

Authors

Brian A. Schick Department of Pathology, London Health Sciences Centre and Western University, London, Ontario, Canada
Joshua S. Tobe Schulich School of Medicine & Dentistry and Western University, London, Ontario, Canada
Mariamma G. Joseph Department of Pathology, London Health Sciences Centre and Western University, London, Ontario, Canada
Tyler B. Rouse Department of Pathology, Huron Perth Healthcare Alliance, Stratford General Hospital, Stratford, Ontario, Canada
Manal Y. Gabril Department of Pathology, London Health Sciences Centre and Western University, London, Ontario, Canada

Keywords:

Merkel cell carcinoma, squamous cell carcinoma, cutaneous horn

Abstract

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine malignancy, which usually presents as an asymptomatic, rapidly growing, firm nodule on sun-damaged skin. We present a 93-year-old female who presented with a “cutaneous horn” on the face. On excision, histologic examination revealed a combined squamous cell carcinoma in situ with underlying MCC. Merkel cell polyomavirus immunohistochemistry was negative in this lesion. This case report highlights the significant association between MCC and squamous cell carcinoma and the uncommon clinical presentation of this combined tumor in the form of a cutaneous horn.