Isolated Acute Appendicitis Caused by Aspergillus in a Patient Who Underwent Lung Transplantation: A Case Report

Invasive aspergillosis is an important cause of morbidity and mortality in patients who have undergone lung transplantation. Aspergillus infections usually involve the respiratory tract, with vascular invasion and subsequent dissemination. However, acute appendicitis associated with localized aspergillosis is rare, especially among patients who have undergone prophylaxis with voriconazole. We present a case of primary Aspergillus appendicitis diagnosed by histologic examination in a patient who underwent lung transplantation. A 51-year-old woman with dermatomyositis underwent lung transplantation for acute interstitial pneumonitis. According to our institution's protocol, the patient was treated with immunosuppressive therapy and prophylaxis with voriconazole, ganciclovir, and trimethoprim sulfamethoxazole during the post-transplantation period. Twenty-eight days after transplantation, the patient developed mild abdominal pain and paralytic ileus. There was no apparent infection sign. Abdominal computerized tomography indicated a wall defect of the appendix with multifocal fluid collection, mesenteric leave thickening, and pneumoperitoneum. These findings were consistent with perforated appendicitis, and the patient underwent an appendectomy. The histopathology examination of the resected appendix showed inflammation and abscess. Periodic acid-Schiff-positive and Grocott-Gomori methenamine silver-positive fungal hyphae with acute-angle branching were observed, demonstrating muscular invasion. A galactomannan antigen test obtained on the same day had negative results. The trough level of voriconazole was well maintained and was subsequently adjusted through monitoring of circulating drug concentration. Simultaneously, other potential sites of disseminated Aspergillus were considered and examined, but no other site of systemic Aspergillus infection was detected. Voriconazole treatment was maintained for 3 months, and no aspergillosis relapse or other invasive fungal infections were observed.