Disseminated Mucormycosis with Characteristic Gastric Ulcers and Extensive Intravascular Invasion after ABO-Incompatible Living-Donor Liver Transplantation: A Case Report.

INTRODUCTION: Mucormycosis is a life-threatening invasive fungal infection that occurs mainly in patients who are immunocompromised. Here, we report a case of mucormycosis with characteristic gastric ulcers and severe vascular invasion after ABO-incompatible living-donor liver transplantation.

CASE PRESENTATION: A male patient in his 50s with decompensated cirrhosis due to metabolic dysfunction-associated steatohepatitis underwent an ABO-incompatible living-donor liver transplantation. Rituximab (375 mg/m2) was administered 14 days before transplantation, and tacrolimus (1 mg/day) and mycophenolate mofetil (500 mg/day) were initiated 7 days before surgery. Plasma exchange was performed the day before transplantation. Postoperatively, tacrolimus, mycophenolate mofetil, and methylprednisolone were continued as immunosuppressants, and micafungin was administered as antifungal prophylaxis. The postoperative course was complicated by sepsis due to infectious enteritis, which required broad-spectrum antibiotics. Two episodes of T cell-mediated rejection occurred, both treated with steroid pulse therapy. On POD 39, esophagogastroduodenoscopy was performed for persistent anemia and bloody drainage from the nasogastric tube. Multiple extensive gastric ulcers surrounded by dark brown mucosa were observed. Biopsy specimens revealed broad aseptate hyphae with wide-angle branching, consistent with mucormycosis. Rhizopus microsporus, the causative organism of mucormycosis, was isolated from gastric juice culture, confirming the diagnosis. Contrast-enhanced CT demonstrated poor enhancement of the gastric wall and multiple pulmonary nodules, suggesting disseminated fungal infection. Intravenous liposomal amphotericin B was initiated; however, on POD 56, the patient developed septic shock and died of multiple organ failure on POD 63. Autopsy revealed mucormycosis in the stomach, lungs, adrenal glands, thyroid gland, and kidneys. Cobblestone-like fungal masses were identified along the thoracic aortic intima, indicating extensive vascular invasion.

CONCLUSIONS: This case represents a breakthrough mucormycosis infection that developed despite antifungal prophylaxis. The disease manifested as characteristic gastric ulcerations and extensive vascular invasion, leading to fatal outcomes despite liposomal amphotericin B therapy. Necrotic gastric ulcers and positive gastric juice cultures provide critical diagnostic clues. In highly immunosuppressed liver transplant recipients, atypical gastric findings should raise suspicion for mucormycosis, and early systemic evaluation is essential to improve otherwise poor prognoses.