Abstract
Hidradenocarcinoma is a locally aggressive malignancy of the sweat glands, most commonly found on the head, neck, and upper body. Although rare, it has been seen in patients with hidradenitis supparativa, who have an increased risk of non-melanoma skin cancers. Ustekinumab, a biologic agent used to treat inflammatory bowel disease, has been associated with development of cancer in some patients. We present a case of a 36-year-old female with hidradenitis supparativa and Crohn's disease who developed hidradenocarcinoma in setting of ustekinumab use, demonstrating the need for further study of the relationship between biologic therapy and malignancy.