Fig. 1

Timeline. The patient’s course included a long history of graft versus host disease (GVHD) requiring immunosuppression. When the peripheral neuropathy from tacrolimus became too severe, the tacrolimus was stopped and prednisone tapered. Around the same time, the patient experienced worsening oral ulceration and pain. Initial biopsy of her oral lesions showed squamous cell carcinoma (SCC) in the left buccal tissue and GVHD in the inferior labium. It was not until full resection of the buccal SCC that herpes simplex virus-1 was identified on microscopic examination of the surgical specimen. GVHD graft versus host disease. SCC squamous cell carcinoma