Autopsy Findings in a Case of Lomentospora prolificans Fungemia in Myelodysplastic Syndrome

Background Lomentospora prolificans is a soil‐, plant‐, or animal‐borne mold that can affect immunocompromised hosts. Most L. prolificans infections are identifiable in the bloodstream. L. prolificans fungemia has never been reported in an autopsy. Case Report We treated a 79‐year‐old man with myelodysplastic syndrome (MDS), MDS‐EB‐1 subtype. Due to his high‐risk MDS status, the patient was monitored in an outpatient setting. He developed bronchopneumonia and was hospitalized for treatment. He was empirically treated with meropenem and vancomycin, which did not improve the patient’s symptoms or clinical data. We diagnosed the patient with bronchitis obliterans organizing pneumonia because the culture report of the lavage fluid obtained through bronchofiberscopy (BFS) was negative. We administered methylprednisolone (mPSL) at 500 mg/day for 3 days mini‐pulse therapy on Day 10, followed by high‐dose mPSL. The patient’s condition improved slightly but worsened again during the corticosteroid tapering process. A second BFS was performed on Day 28, which detected L . prolificans on lavage culture. We treated the patient with voriconazole as per the literature, but it did not improve the condition, and on Day 46, the patient died of multiple organ failure due to L . prolificans fungemia. An autopsy revealed macroscopically white nodules and foci of fungal mass abscess pathologically in systemic tissues, including the lung, heart, kidney, thyroid gland, and peritoneum. Discussion Diagnosing the rare invasive infection caused by L. prolificans in immunosuppressed patients with hematologic malignancies is difficult. This case report will contribute to our understanding the pathogenesis of fatal L. prolificans fungemia.