Peritoneal mesothelioma is the second most common form of mesothelioma, appearing in 20% of all cases. The disease typically presents as a diffuse malignancy that can spread throughout large areas of the peritoneum. In its advanced stages, the disease can infiltrate the outer layers of the GI tract, as well as metastasize to abdominal organs, but the first indication of the disease as a metastatic event is quite rare. Researchers from Italy have recently published an article in the International Journal of Surgical Pathology where they describe a case report of a 64 year-old man who presented with gastric metastases as the first sign of peritoneal mesothelioma.

The authors describe this as the first such case report in the literature on mesothelioma.

Case Report

The authors describe a 64 year-old man who presented with abdominal pain and distension, with corresponding ascites and significant weight loss within the year. At time of presentation, he has awaiting a liver transplant due to liver cirrhosis and suffered from esophageal varices as well. His physicians first assumed a bacterial infection was the cause of the abdominal pain, but the standard treatments were not effective. After serum markers returned negative, the patient underwent an esophageal gastric endoscopy, which revealed a lesion in the antral mucosa, which is a lining of a specific area (gastric antrum) in the stomach. A biopsy of the lesion was performed and subsequent analysis showed peritoneal mesothelioma, epithelial sub-type. After these results were returned, a high resolution abdominal CT showed thickening of the parietal pleura. The patient was treated with single-agent pemetrexed(Alimta) and was still alive 7 months after diagnosis.

Conclusion

The authors report their article as the first description of a case of gastric metastasis as the first indication of peritoneal mesothelioma. In the disease’s later stages, metastases to abdominal organs are common, but the authors describe discovering peritoneal mesothelioma during an endoscopic GI biopsy as “exceptionally rare.” Because of this, they note serious diagnostic challenges to the clinician who encounters such a case.

Labels: mesothelioma, peritonealmesothelioma