Subcutaneous Basidiobolomycosis Masquerading as Cellulitis on the Forearm of an Elderly Woman.

Subcutaneous basidiobolomycosis is a rare chronic granulomatous infection, typically affecting skin and soft tissues of immunocompetent individuals in tropical and subtropical regions. We report a case of an elderly woman presenting with an indurated, progressively enlarging swelling on her distal forearm, initially resembling cellulitis. Despite multiple antibiotic courses and incision procedures, there was no improvement. Biopsy revealed hyperplastic squamous epithelium with granulomas and large aseptate hyphal structures, confirming basidiobolomycosis. The patient was treated with oral itraconazole, leading to significant resolution of the swelling within 3 months. This case highlights the atypical presentation of basidiobolomycosis in an elderly patient and emphasizes the importance of considering this diagnosis in subcutaneous swellings, especially in tropical climates. The case also underscores the challenges in diagnosing this condition, particularly when cultures are negative, and the need for further research to improve diagnostic methods.