Clinical consequences of delayed recognition of gastrointestinal basidiobolomycosis: a case series

Gastrointestinal basidiobolomycosis (GIB) is a rare infection that often mimics colorectal malignancy or inflammatory bowel disease, leading to delayed diagnosis. A 20-year-old man presented with acute right iliac fossa pain and imaging suggestive of a cecal carcinoma with hepatic metastases. Colonoscopy showed a large fungating cecal mass, and biopsies demonstrated necrotizing granulomatous inflammation with broad pauciseptate hyphae compatible with basidiobolomycosis. A 14-year-old girl had mucous diarrhea, significant weight loss and was labeled as ulcerative colitis despite non-diagnostic histology, then developed mesalazine-related hypokalemia with cardiac arrest. Abdominal magnetic resonance imaging at a tertiary centre showed severe rectosigmoid colitis with peritoneal disease, and omental biopsy confirmed GIB. Both patients were treated with prolonged voriconazole. The first had complete clinical and radiologic resolution of colonic and hepatic disease without surgery. The second had marked regression of rectosigmoid and peritoneal disease, with later radiologic recurrence of pelvic disease despite ongoing therapy, but remains clinically stable under multidisciplinary follow-up. This series highlights GIB as an important differential diagnosis for refractory colitis in immunocompetent patients and supports the use of voriconazole as an organ-sparing option when the diagnosis is made before complications develop.