Fatal Fungal Peritonitis Caused by <i>Aspergillus udagawae</i>: An Autopsy Case Report

A 56-year-old man with chronic progressive pulmonary aspergillosis due to multidrug-resistant Aspergillus udagawae presented with acute abdominal pain. Computed tomography revealed rupture of an intra-abdominal abscess with ascites. Despite emergency surgery for peritonitis, he died on day 5. Autopsy showed numerous fungal abscesses with direct invasion and hematogenous spread from the lungs to the peritoneum. A genetic analysis confirmed A. udagawae. This represents the first autopsy-proven case of fatal fungal peritonitis secondary to invasive pulmonary aspergillosis caused by A. udagawae, highlighting the importance of molecular identification in treatment-refractory Aspergillus infections.