Merkel cell carcinoma
Merkel cell carcinoma is a rare epidermal neoplasm with neuroendocrine differentiation, possibly of a cell type found in the hair follicle thought to contribute to skin endocrine and mechanoreceptor function. First described by Cyril Toker in 1972 who described it as a trabecular carcinoma (hence sometimes known as Toker tumour, but not to be confused with Toker cells).
There is an association with a recently discovered polyomavirus, named Merkel cell (polyoma) virus, which integrates into the host cell DNA. This is consistent with the observation that the tumour is more common in immunosuppressed individuals.
On immunohistology, they can be reactive to:
- ↑ Toker C. Trabecular carcinoma of the skin. Archives of dermatology. 1972 Jan; 105(1):107-10.
- ↑ Feng H, Shuda M, Chang Y, Moore PS. Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science (New York, N.Y.). 2008 Feb 22; 319(5866):1096-100.(Link to article – subscription may be required.)
- ↑ Requena L, Jaqueti G, Rütten A, Mentzel T, Kutzner H. Merkel cell carcinoma within follicular cysts: report of two cases. Journal of cutaneous pathology. 2008 Dec; 35(12):1127-33.