High‐risk cutaneous squamous cell carcinoma in a Japanese allogeneic bone marrow transplant recipient on long‐term voriconazole

Cutaneous squamous cell carcinomas arise as secondary cancers in hematopoietic stem cell transplant survivors. They have been documented primarily in Western cohorts and relatively little is known about their occurrence in Asian hematopoietic stem cell transplant recipients, with no reports of squamous cell carcinomas with high‐risk features in Asian patients. We describe a case of a cutaneous squamous cell carcinoma with high‐risk features on the scalp of a Japanese bone marrow transplant recipient approximately 6.5 years post‐transplant, who was on long‐term voriconazole. The history of a photodistributed erythema followed by the appearance of multiple actinic keratoses and solar lentigines, together with the rarity of cutaneous squamous cell carcinomas in Asian hematopoietic stem cell transplant cohorts revealed in our literature review, suggest that voriconazole use contributed to the development of high‐risk squamous cell carcinoma in our patient.