Cutaneous Mucormycosis Involving a Colostomy Site

Summary: Cutaneous mucormycosis, or zygomycosis, is a rare, deadly fungal infection that requires prompt recognition and treatment for optimal survival chances. Infection may be primary due to direct inoculation (e.g., surgery or trauma) or secondary from dissemination. Although most frequently associated with diabetes and/or neutropenia, infections in renal failure, malnutrition, HIV, trauma, iatrogenic immunosuppression, and post-surgical patients are increasingly recognized. Treatment typically requires aggressive antifungals combined with surgical debridement and is associated with high mortality. We present a 53-year-old male with history of congestive heart failure, alcoholic cirrhosis, and recent left hemicolectomy for moderately differentiated adenocarcinoma of the sigmoid colon complicated by acute kidney injury, anastomotic leak, and colostomy placement. On physical exam, he was found to have violaceus patches around the colostomy site associated with a well-defined peristomal deep ulcer filled with fibrinous material. A punch biopsy from the ulcer edge was performed which revealed a dermal infiltrate of neutrophils, plasma cells, and histiocytes with bile deposition. Broad, hyaline pauci-septate hyphae with right angle branching which highlight with PAS and GMS were identified in the dermis. Angioinvasion was not identified. Given the clinical and histologic findings, mucormycosis was diagnosed. Fungal cultures were taken and found to be negative. The patient was treated with IV posacanazole but was surgical debridement was not possible due to his medical comorbidities. The patient deteriorated suffering multiorgan failure and died subsequently. This case represents an unusual location for cutaneous mucormycosis involving a colostomy site which, if disseminated, could have contributed to our patient's death.