Cokeromyces recurvatus Incidentally Found in a Patient with Gastric Outlet Obstruction

Isolation of Cokeromyces recurvatus, a dimorphic mucormycete fungus, from clinical specimens poses a diagnostic challenge to physicians and laboratorians as this organism may represent a rare colonizer or true pathogen. Here, we report a case of Cokeromyces recurvatus present in a circumferential duodenal lesion. The patient is a 64-year-old with no past medical history, admitted with a three-week history of left upper quadrant abdominal pain. Computerized tomography scan identified duodenitis with significant gastric outlet obstruction, confirmed by the presence of a partially obstructing non-bleeding duodenal ulcer on upper endoscopy. Histology showed variably sized spherical structures without nuclei, reproductive tracts, or alimentary tracts. Small, clustered spherules representing putative endospores were observed within the larger structures and in the exudate. Based on the histology, the differential included Coccidioides spp, Emmonsia spp, or Chrysosporium spp. Additionally, gastric biopsies revealed concurrent Helicobacter pylori gastritis. The fungus was identified as C. recurvatus by broad-range fungal polymerase chain reaction performed on formalin-fixed paraffin-embedded biopsy tissue, as well as morphology and DNA sequencing of the cultured isolate. The fungus had low MICs to all major antifungal classes; however, in the context of the Helicobacter pylori infection, the patient was only treated with amoxicillin and clarithromycin with improvement in his symptoms before hospital discharge. Only three cases of Cokeromyces recurvatus isolated from the GI tract have been reported; this case highlights a unique clinical presentation in the small bowel in a patient without underlying medical conditions.