Cutaneous metastatic rectal carcinoma masquerading as herpes zoster.

A 78-year-old female with locally recurrent rectal carcinoma and hepatic metastases presented with new skin lesions. She had multiple painful skin lesions over her groin area initially treated as contact dermatitis. The lesions continued to spread to include the lower abdomen and developed a zosteriform appearance. She was referred to dermatology, where shave biopsies revealed metastatic rectal carcinoma. This case is unique as the patient had rapidly growing zosteriform cutaneous metastases from rectal carcinoma, which has rarely been reported. Physicians providing care to patients with a history of cancer should maintain a high clinical suspicion for cutaneous metastases in patients with new or evolving skin conditions.