Metastatic zosteriform squamous cell carcinoma in an immunocompetent patient.

BACKGROUND Although described in several reports of internal malignancies metastasizing to the skin, zosteriform metastases have been reported in only two cases of cutaneous squamous cell carcinoma (SCC). In both of these reports, the patients were immunosuppressed related to renal transplantation. OBJECTIVE We present a case of an immunocompetent patient with zosteriform metastases originating from a recurrent cutaneous SCC. The lesions were present along the maxillary division of the trigeminal nerve. METHODS Biopsies from eight lesions were studied using hematoxylin and eosin (H&E) and with immunohistochemistry. RESULTS Neural involvement was detected in H&E preparations before and during excision of the metastatic nodules by Mohs micrographic surgery. The tumor cells reacted with antikeratin antibodies. The patient has had no evidence of recurrence or metastases 30 months following surgery. CONCLUSION To our knowledge, this is the first case of cutaneous SCC with zosteriform metastases in a patient with an intact immune system. SCC should be included in the differential diagnosis of lesions presenting in a dermatomal distribution.