Rationale: Mucormycosis is a rare opportunistic fungal infection with poor prognosis. The incidence of mucormycosis has been increasing, and it is a threat to immunocompromised hosts. We present a case of gastric mucormycosis complicated by a gastropleural fistula during immunosuppressive treatment for adult-onset Still disease (AOSD).
Patient concerns: An 82-year-old woman diagnosed with AOSD who developed gastric ulcers during the administration of an immunosuppressive therapy with corticosteroids, cyclosporine, and tocilizumab complained of melena and epigastralgia. Esophagogastroduodenoscopy showed multiple ulcers covered with grayish or greenish exudates.
Diagnoses: The patient diagnosed with mucormycosis based on culture and biopsy of the ulcers, which showed nonseptate hyphae branching at wide angles. Mucor indicus was identified using polymerase chain reaction.
Interventions and outcomes: Although liposomal amphotericin B was administered, gastric mucormycosis was found to be complicated by a gastropleural fistula. The patient died because of pneumonia due to cytomegalovirus infection, and autopsy revealed the presence of Mucorales around the fistula connecting the stomach and diaphragm.
Lessons: Gastric mucormycosis is refractory to treatment and fatal. Surgical resection, if possible, along with antifungal drugs can result in better outcomes.