Merkel cell carcinoma: management of primary, recurrent and metastatic disease. A clinicopathological study of 17 patients.

The clinicopathology of Merkel cell carcinoma (MC) has been evaluated in 17 patients, and its outcome and clinical management in 14 of these. The histopathologic diagnosis was confirmed by electronmicroscopy and/or immunohistopathology. The location of the primary lesions demonstrated a predilection for the skin of the face and the extremities. The primary treatment usually consisted of a wide excision only. Four out of five patients with MC of the face suffered from local and/or nodal relapses, in contrast to only one out of seven patients with primary lesion on the extremities. The three patients treated for local recurrences and/or regional node metastases were alive and disease-free 22-72 months after recurrences. Three patients developed distant metastases. Two of these died within 4 months after initial diagnosis. One patient completely responded to chemotherapy. The high frequency of local recurrences would justify an excision with generous margins, except when the tumour is close to a vital structure. Radiotherapy could in these cases obviate the necessity for extensive operations. If the primary lesion is located on an extremity, regional lymphadenectomy seems only to be necessary whenever nodal involvement is suspected. Node dissection is also recommended for suspected nodes in the face or on the neck, but the guidelines for elective node dissections in these sites are not obvious since the results of salvage therapy were excellent and the location of relapses unpredictable.