A Case of Primary Malignant Peritoneal Mesothelioma

Primary malignant mesothelioma (MPM) is a rare malignancy that arises from the epithelial cells that line visceral cavities. The primary pleural presentation is known as the most commonly seen presentation and is best recognized clinically. Less commonly, mesothelioma can arise from epithelial cells lining other visceral cavities, including the peritoneum and pericardium. Primary peritoneal presentations are often difficult to diagnose due to vague symptoms such as abdominal distention, anorexia, and diffuse pain. These symptoms overlap with those of many more common gastrointestinal conditions, often leading to delayed diagnosis. We report a male in his 40s with a past medical history of hypertension and diabetes mellitus type 2 who presented to the emergency room with non-specific abdominal complaints. He had a history of longstanding work on demolition sites. Treatment was initiated following studies that tested positive for H. pylori infection. A CT scan of the abdomen revealed nodular fat stranding of the omentum, with several confluent peritoneal nodules and small-volume ascites. An omental biopsy showed tumor cells positive for markers indicative of epithelioid-type malignant mesothelioma, with the peritoneum identified as the primary site. A key piece of this patient's case was long-standing exposure to demolition sites and asbestos. Asbestos exposure is a well-documented risk factor for the development of mesothelioma. This history was obtained but did not aid in guiding diagnostic practices due to overlapping symptomatology. The discovery of an H. pylori infection may have delayed the diagnosis of primary malignant peritoneal mesothelioma (PMPM) and its appropriate treatment, as H. pylori is a much more common condition.