Diffuse peritoneal mesothelioma presenting with the appearance of mesenteric panniculitis: A case report.

Diffuse peritoneal mesothelioma (DPM) is a rare and aggressive malignancy of the peritoneum. Early symptoms are non-specific and the condition is liable to misdiagnosis. In the present case, a 54-year-old man was misdiagnosed between April 2020 and October 2021 with mesenteric panniculitis. The patient later presented with a 2-month history of persistent upper-middle abdominal pain and weight loss in April 2022. A laparoscopic biopsy was performed and the sample was positive for Wilms tumor protein, Hector Battifora mesothelial-1 and podoplanin. Therefore, a diagnosis of DPM was made. A total of six cycles of pemetrexed-cisplatin chemotherapy were given and elicited a partial response. The disease progressed and intraperitoneal bevacizumab-cisplatin therapy was administered, which was ineffective. The patient died 13 months post-diagnosis. DPM often has a similar presentation to benign conditions, such as mesenteric panniculitis. Correct diagnosis is facilitated by an awareness of occupational exposure risk, such as that of asphalt exposure for the present case, and early histopathological evaluation. The prognosis for DPM remains poor despite multimodal therapy, and novel therapeutic strategies are needed.