Incidental Cutaneous Mucormycosis on a Previous Surgical Flap on the Scalp

Summary: Introduction: Mucormycosis is a rare yet life-threatening fungal infection, with mortality rates approaching 80% if not identified and treated before dissemination. Immunocompromised individuals, such as those with neutropenia, prolonged corticosteroid use, disease-modifying antirheumatic therapy, solid organ transplantation, HIV, or other immunosuppressive conditions, are at heightened risk. Case Report: A 60-year-old male diabetic patient with a history of rheumatoid arthritis managed with methotrexate, hydroxychloroquine, and prednisone, which was later switched to rituximab due to osteopenia, and who had been treated for squamous cell carcinoma of the scalp with MOHS surgery, presented to our clinic with focal ulceration along the flap distant from the original primary tumor. A biopsy of the ulceration demonstrated hollow, nonseptate, irregular, angioinvasive fungal hyphae, consistent with a Mucorales infection. Necrotic adipocytes with absent nuclei and finely granular, basophilic cytoplasmic changes were also noted. The patient was admited for urgent surgical debridement and intravenous antifungal therapy. Conclusion: This case highlights the importance of maintaining a high index of suspicion for rare opportunistic infections like mucormycosis, particularly in patients on immunosuppressive therapies. Prompt recognition and treatment are critical to improving outcomes in these life-threatening cases.