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Malignant melanoma with clinical and histologic features of Merkel cell carcinoma
Dermatology Publications and Presentations
  • Nancy S. House, Pennsylvania State University
  • Fred G. Fedok, Pennsylvania State University
  • Mary E. Maloney, University of Massachusetts Medical School
  • Klaus F. Helm, Pennsylvania State University
UMMS Affiliation
Department of Medicine, Division of Dermatology
Publication Date
Document Type
Antibodies, Monoclonal; Carcinoma, Merkel Cell; Cheek; Diagnosis, Differential; Humans; Male; Melanocytes; Melanoma; Microscopy, Electron; Middle Aged; S100 Proteins; Skin Neoplasms; Staining and Labeling
We describe a patient with malignant melanoma that resembled a Merkel cell carcinoma both clinically and histologically. Immunohistochemical studies showed focally positive staining with S-100 protein and strongly positive staining with HMB-45. Ultrastructural study confirmed the diagnosis by demonstrating premelanosomes and melanosomes. Although the tumor appeared to be clinically unimpressive, it was a deep melanoma with a Breslow level of 3.8 mm that necessitated aggressive treatment. Small cell melanoma must be considered in the differential diagnosis of small cell tumors, which also includes lymphoma, eccrine carcinoma, squamous cell carcinoma, and Merkel cell carcinoma. The diagnosis of amelanotic melanoma, including the small cell variant, may require electron microscopic studies.
DOI of Published Version

J Am Acad Dermatol. 1994 Nov;31(5 Pt 2):839-42. doi:10.1016/S0190-9622(94)70241-1


At the time of publication, Mary E. Maloney was not yet affiliated with the University of Massachusetts Medical School.

Related Resources
Link to Article in PubMed
PubMed ID
Citation Information
Nancy S. House, Fred G. Fedok, Mary E. Maloney and Klaus F. Helm. "Malignant melanoma with clinical and histologic features of Merkel cell carcinoma" Vol. 31 Iss. 5 Pt 2 (1994) ISSN: 0190-9622 (Linking)
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