A bimodal analysis of clinical phenotypes and eosinophilic responses as prognostic indicators in gastrointestinal basidiobolomycosis.

OBJECTIVES

Gastrointestinal basidiobolomycosis (GIB) is an emerging infection caused by Basidiobolus ranarum (Entomophthorales), typically producing chronic granulomatous inflammation in immunocompetent hosts and remains under-recognized in endemic regions. We compared pediatric and adult disease trajectories and assessed whether absolute eosinophil count (AEC) is associated with outcome.

METHODS

We conducted a 10-year (2015-2024) single-center retrospective observational study at The Royal Hospital, Muscat, Oman, including 13 patients with GIB diagnosed primarily by characteristic histopathology, including the Splendore-Hoeppli phenomenon with eosinophil-rich inflammation, supported by clinical and radiologic findings; patients were stratified into pediatric (n = 7; mean age ∼4 years) and adult (n = 6; mean age ∼55 years) cohorts.

RESULTS

Children most often presented with fever and abdominal pain, whereas adults more commonly presented with weight loss, constipation, and/or an abdominal mass (malignancy-mimicking phenotype); mean AEC was significantly higher in children than adults (4.44 × 10⁹/L vs 1.85 × 10⁹/L, P = 0.035), and was the only laboratory parameter to differ significantly between groups. Mortality occurred only in adults (33.3% (2/6)); fatal cases demonstrated a blunted eosinophilic response (mean AEC ∼0.9 × 10⁹/L) compared to survivors (reported mean AEC ∼4.5 × 10⁹/L).

CONCLUSION

GIB demonstrates a bimodal clinical phenotype with adult-predominant mortality, and lower AEC may signal worse prognosis, warranting validation in larger multicenter cohorts.