An Ulcerated Plaque in a Gay Man.

A 28-year-old homosexual man presented to our outpatient department with a solitary 2.0 × 1.5-cm ulcerated nodule on the forehead that had been present for 4 months (Fig 1). He denied any systemic symptoms such as weight loss, fevers, headaches, or visual disturbances. On examination, the nodule appeared translucent and clinically resembled a basal cell carcinoma with superficial telangiectases and rolled edges. His history included inflammatory bowel disease, anal condyloma, intravenous drug abuse, positive serologic results for the human immunodeficiency virus, and previously treated Pneumocystis carinii pneumonia. A "touch" preparation from the deep surface of a skin biopsy specimen taken from the nodule was stained with india ink and is shown in Fig 2. What is your diagnosis? Clinicians, local and regional societies, and residents and fellows in dermatology are invited to submit quiz cases to this section. Cases should follow the established pattern and be submitted.