Metastatic Pulmonary Adenocarcinoma Deposit Arising Within a Cutaneous Basal Cell Carcinoma: A Case Report

Skin metastases are rare complications of internal malignancies, and most commonly arise from primary lung carcinoma (Brownstein and Helwig in Arch Dermatol 105:82–68, 1972). Metastatic cutaneous lesions have not previously been documented to arise within other skin tumours. We report our experience of a solitary pulmonary adenocarcinoma metastasis that arose within a pre-existing basal cell carcinoma in a patient with undiagnosed lung cancer. Immunohistochemistry was invaluable in confirming both the metastatic nature of the secondary skin lesion and its site of origin.