(a) Biopsy of the lesion showed nests and cords of uniform basophilic cells with high nuclear:cytoplasmic ratios and abundant mitoses that were infiltrating through the dermis. (b) large necrotic, hemorrhagic, ulcerated multilobulated tumor, (c) 5 mm papule
A 79-year-old Caucasian man developed a nodular skin lesion noted on his right forearm. Biopsy of the lesion showed nests and cords of uniform basophilic cells with high nuclear:cytoplasmic ratios and abundant mitoses that were infiltrating through the dermis (figure A; courtesy of Dr. Frederic Askin). Immunostains were positive for cytokeratin (CK) 20 in a dot-like cytoplasmic pattern and negative for thyroid transcription factor-1 (TTF-1).
The patient underwent repeat surgical excision to obtain negative margins and there was no evidence of distant metastases on imaging. Due to the patient’s poor performance status, a decision was made not to pursue adjuvant therapy with radiation or chemotherapy. About three months after resection of the right forearm lesion there was clinical evidence of local tumour recurrence. The lesion grew rapidly in a multinodular pattern and was erythematous to violaceous with a shiny surface. Focal areas of necrosis which oozed blood were present (figure B). Several months later a new lesion developed in the area of the right shoulder that closely resembled the initial lesion in appearance (figure C; arrow). The patient’s clinical condition deteriorated rapidly, and he died within fourteen months with the diagnosis of Merkel cell carcinoma.
