MRI features of pyoderma gangrenosum in a diabetic patient with ulcerative colitis: A case report and review of the literature.

Pyoderma gangrenosum (PG) is a rare noninfectious skin condition which clinical picture can overlap with that of the diabetic foot. Meticulous physical examination along with biopsy and magnetic resonance imaging (MRI) can make the distinction easier, saving the patients from undergoing a debilitating intervention. We report a case of pathologically proven PG in the right ankle region of a 55-year old male with known uncontrolled diabetes mellitus and inflammatory bowel disease. Radiographs revealed increased soft tissue density overlying the lateral melleolus of the right ankle. MRI showed a well-defined soft tissue mass with heterogeneously intrinsically high signal intensity on T1- and on T2-weighted images, and heterogeneous peripheral enhancement on fat-suppressed, contrast-enhanced T1-weighted images. Histologically, diffuse neutrophilic infiltrate throughout the dermis was present without micro-organisms. This is the first report of MRI findings of PG in the ankle. We also summarize the findings of previously reported cases of PG.