An Autopsy Case of Anaplastic Pancreatic Cancer Complicated by Refractory Eosinophilic Peritonitis.

Tumor-associated blood eosinophilia (TABE) and tumor-associated tissue eosinophilia (TATE) are rare in solid cancers, and reports of eosinophilic peritonitis in these cases are extremely limited. We present the case of a 68-year-old man with pancreatic and lung cancer who developed severe eosinophilia and eosinophilic peritonitis. Despite corticosteroid therapy, refractory ascites led to a decline in performance status. An autopsy confirmed undifferentiated pancreatic adenocarcinoma with TABE, TATE, and lung cancer. This case underscores the diagnostic challenges of multiple primary malignancies with eosinophilia and highlights the need for individualized management strategies for tumor-associated eosinophilic disorders.