Primary cutaneous neuroendocrine (Merkel cell or trabecular carcinoma) tumour of the skin: a radioresponsive tumour.

Four patients with primary neuroendocrine carcinoma of the skin (Merkel cell or trabecular carcinoma) are reported to document their response to radiotheraphy. In three patients there was complete response following radiation treatment, with no local recurrence, whilst the other patient died later with distant metastases. In one patient, post-operative irradiation after excision of an involved local node prevented the growth of further tumour in this nodal group but the unirradiated primary site recurred after initial wide local excision only. This rare tumour appears to be radioresponsive, and although more clinical data are required, we would advocate a wider study of radiotherapy to the primary lesion after biopsy or excision biopsy, in association with prophylactic nodal irradiation. These tumours occur predominantly in elderly people in whom the avoidance of extensive surgery is particularly desirable.