Primary cutaneous neuroendocrine (Merkel cell) carcinoma in association with squamous- and basal-cell carcinoma

The co-existence of squamous-cell carcinoma (SCC) and neuroendocrine (Merkel cell) carcinoma (NEC) of the skin has been well documented in several patients. The concurrent development of NEC and basal-cell carcinoma (BCC) in the same cutaneous lesion, on the other hand, has not been reported. We describe a 68-year-old man presenting with NEC, SCC, and BCC arising at the same site in retroauricular skin. Cells of NEC and SCC showed an intermingled pattern of growth, whereas those of BCC were "embedded" among those of the other two tumors. Immunohistochemical stains were consistent with the histopathologic diagnosis. We believe that this is the first report of the association of NEC, SCC, and BCC in the same skin lesion.