Derm Dx: Non-healing ulcer associated with leukemia

A 56-year-old female undergoing chemotherapy for acute myelogenous leukemia is admitted to the hospital with a small purulent ulceration. General surgery services debrides the lesion, and broad-spectrum antibiotics are started, but the ulceration continues to expand rapidly.

Two more debridements are performed and antibiotic coverage is broadened. Despite these measures, the ulceration continues to expand, and the patient complains ...