Zosteriform inflammatory metastatic carcinoma

A 57-year-old man presented with chest wall lesions and swelling of his left arm. The rapid onset of vesicular lesions in a dermatomal distribution resulted in an initial diagnosis of herpes zoster. Cutaneous biopsy revealed adenocarcinoma and further evaluation revealed a primary source of pulmonary adenocarcinoma. Lymphatic spread of tumor cells is the most likely source of the zosteriform skin lesions, but other possibilities are discussed.