Pyoderma gangrenosum–like ulceration of the lower extremity secondary to sunitinib therapy: a case report

Sunitinib is a multi-targeted receptor tyrosine kinase inhibitor used for the treatment of multiple different types of malignancies. Serious grade 3–4 adverse events occur in <10% of the patient population and usually improve with dose reduction. One of the more rarely reported side effects of sunitinib therapy is the development of pyoderma gangrenosum–like ulcerations in the lower extremities. These pyoderma gangrenosum–like ulcerations are difficult to treat and distinguish from similar-appearing dermatological diagnoses. We present a patient with refractory lung carcinoma and a past medical history of squamous cell carcinoma of the lower extremity, who developed a non-healing ulceration at the previous site of her skin cancer while undergoing therapy with sunitinib. At the time of the initial evaluation, the ulceration mimicked recurrent squamous cell carcinoma, posing a diagnostic challenge. Histopathological findings showed epidermal hyperplasia, ulceration, and dense acute inflammation. Despite meticulous wound care and treatment of infection, the ulcer only improved with cessation of sunitinib.