title: Merkel cell carcinoma.
abstract: A 92-year-old man presented for evaluation with a 1-month history of a rapidly growing asymptomatic pink nodule on his forearm. Biopsy results of the lesion demonstrated pathology consistent with Merkel cell carcinoma (MCC). Immunohistochemical studies displayed positive cytoplasmic staining for cytokeratin AE1/AE3, positive dot-like perinuclear staining for cytokeratin-20, diffuse cytoplasmic staining for neuron specific enolase, and no significant staining for S-100. Subsequent positron emission tomography did not reveal evidence of metastatic disease. Wide excision of the lesion was performed along with a sentinel node biopsy of his left axilla. The sentinel nodes were negative for MCC. Adjuvant radiation treatment of the tumor site was provided because the pathologist noted MCC within 2 mm of the deep margin.
authors.forename: Ardalan
authors.initials: A
authors.lastname: Minokadeh
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Wulkan
authors.forename: Kenneth
authors.initials: K
authors.lastname: Beer
authors.forename: Jill S
authors.initials: JS
authors.lastname: Waibel
mesh_terms: D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis* / Q000378:metabolism / Q000532:radiotherapy / Q000601:surgery; D005153:Facial Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000532:radiotherapy / Q000601:surgery; D005542:Forearm; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis; D018714:Radiotherapy, Adjuvant; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000532:radiotherapy / Q000601:surgery