Clinical-pathological review of 14 cases of merkel cell carcinoma

Abstract

Merkel cell carcinoma (MCC) is a rare, primary, cutaneous, neuroendocrine skin tumour that occurs commonly in the head, neck or extremities of elderly white people. Fourteen cases of MCC in the Hamilton Regional Cancer Centre between 1992 and 2000 have been reviewed. Seven cases required a panel of immunohistochemical markers and two cases required electron microscopy for confirmation. Seven men and seven women were treated, and ranged from 67 to 96 years of age (mean 77.7 years). The primary tumour was located in the head and neck in seven patients (50%), in the extremities in four patients (29%) and on the trunk in two patients (14%). One patient had an unknown primary tumour location. Ten patients had stage Ia disease at presentation, three had stage Ib disease, and one presented with stage II disease. Primary treatment consisted of wide local excision in nine patients, wide local excision and radiotherapy in four patients and radiotherapy only in one patient. Seven patients had recurrence, five were disease free up to their most recent follow-up, one died of unrelated causes, and one was lost to follow-up after primary treatment. Of the seven patients with recurrence, two had local recurrence, two had lymph node recurrence and three developed metastases. Disease-free intervals were 69% and 50% for six-month and one-year follow-up, respectively. No difference in outcome was observed between stage Ia and Ib disease. The patient with stage II disease at presentation developed metastases. Longer duration of disease before presentation had a higher incidence of recurrence with distant metastases. Extremity lesions had the best prognosis associated with disease-free interval. Early management with excision and radiotherapy improved the disease-free interval.