An autopsy case of Clostridium perfringens peritonitis on CAPD related to malignant mesothelioma

A 74-year-old man with nephrosclerosis had been treated with CAPD since 2007, until he passed away in 2011. He was admitted to our hospital three times in June, July, and November 2010 due to bacterial peritonitis. In each episode, he responded to antibiotic treatment. In January 2011, he was again admitted to the hospital due to peritonitis. Abdominal CT showed a tumor mass in the upper pole of the spleen and multiple intra-abdominal nodules. Despite highly suspected malignancy, a biopsy was not performed due to his poor state. In March 2011, he was admitted to the hospital again (his fifth hospital admission) due to peritonitis. His clinical condition deteriorated progressively and he passed away on the day of admission. Clostridium perfringens and Streptococcus mitis were identified as the pathogens of the peritonitis by culture of CAPD fluid. The result of the autopsy proved that multiple intra-abdominal nodules were the peritoneal seeding of malignant mesothelioma. Although bacterial peritonitis was ultimately the cause of his death, malignant mesothelioma may be considered as the proximate cause of the peritonitis. Herewith, we present this case as an interesting and rare case in terms of the pathogenesis.