An 80-year-old white woman presented with an asymptomatic white patch affecting the tongue of 1 month’s duration. She had a 15-year history of oral lichen planus (OLP) managed with betamethasone dipropionate, 0.05%, gel twice daily and clotrimazole troches, 10 mg, 3 times daily as needed for symptomatic OLP flares. Medical history revealed stage 1A mycosis fungoides/cutaneous T-cell lymphoma affecting the right calf and left thigh managed primarily with halobetasol, 0.05%, cream owing to intolerance of narrowband UV-B therapy and mechlorethamine, 0.016%, gel. Immunosuppression or history of infectious diseases, including human immunodeficiency virus (HIV), was not reported. A 1.5 × 1.0-cm nonremovable white, plaquelike lesion was observed on the left lateral tongue (Figure 1A). Biopsy specimens were obtained with a 3-mm punch instrument at 3 different sites, which demonstrated similar microscopic findings (Figure 1B and C).