Perivascular Epithelioid Cell Tumor in the Stomach

Perivascular epithelioid cell tumors or PEComas can arise in any location in the body. However, a limited number of cases of gastric PEComa have been reported. We present two cases of gastric PEComas. The first case involved a 62-year-old woman who presented with a 4.2 cm gastric subepithelial mass in the prepyloric antrum, and the second case involved a 67-year-old man with a 5.0 cm mass slightly below the gastroesophageal junction. Microscopic examination revealed that both tumors were composed of perivascular epithelioid cells that were immunoreactive for melanocytic and smooth muscle markers. Prior to surgery, the clinical impression of both tumors was gastrointestinal stromal tumor (GIST), and the second case was erroneously diagnosed as GIST even after microscopic examination. Although gastric PEComa is a very rare neoplasm, it should be considered in the differential diagnosis of gastric submucosal lesions.

Malignant Perivascular Epithelioid Cell Tumor (PEComa) Arising in the Omentum with Metastatic Peritoneal Seeding: A Case Report / 대한내과학회지

The World Health Organization (WHO) defines a perivascular epithelioid cell tumor (PEComa) as a mesenchymal neoplasia composed of perivascular epithelioid cells with characteristic morphological and immunohistochemical features. They are rarely malignant. Indeed, only a few cases have been reported in the English literature, and this is the first case of PEComa reported in Korea. A 64-year-old man presented with an abdominal mass and peritoneal seeding. The patient underwent mass excision with descending colon resection and anastomosis. The primary mass and peritoneal seeding was diagnosed as a PEComa histopathologically. Seven months later, he developed liver metastasis and aggravated peritoneal seeding. Here, we report a case of malignant PEComa of the omentum.