Merkel cell carcinoma: a clinicopathological study of 34 patients

Background: Merkel cell carcinoma (MCC) is a rare cutaneous malignant tumour. Its natural course is fast progression of the primary tumour and rapid regional metastasis. Methods: The pathological archives of Helsinki University Hospital and Vaasa Central Hospital were reviewed from 1987 to 2001. Specimens were re-evaluated by two pathologists and size was measured from primary tumours. Multivariate analysis was performed for age, sex, primary tumour size, and method of initial surgery, development of metastatic disease and development of local recurrence. Overall survival (OS) was calculated by the Kaplan–Meier method. Results: Of 34 patients, 12 male and 22 female patients, are reported. Their median age was 76.4 years. Half of the primaries were located in the head and neck region. All patients were treated surgically. The mean OS was 2.7 years by the Kaplan–Meier method. The 2-year survival rate was 65% and 5-year rate was 50%. The mean OS for tumour size >2 cm was 1.7 years and for tumour size ≤2 cm 4.48. Poor prognostic factors for OS were: male sex, size of the primary tumour (>2 cm) and metastatic dissemination. A favourable prognosis seemed to correlate to more aggressive surgical management as use of primary excision with split skin graft or reconstruction with a local flap. Conclusion: MCC affects the elderly patients. In this study, female patients predominated. Primary tumour size >2 cm predicts poorer outcome of the disease. A wide surgical excision is recommended for the primary treatment of MCC.