Pleural involvement and dyspnea as primary presentations of an occult gastric cancer: a case report

Herein, we reported a case of malignant pleural effusion as the initial metastatic presentation of occult gastric cancer in a 52-year-old diabetic woman. This is the first report of gastric cancer metastasized to pleura as a primary presentation. The pathologic results of adenocarcinoma pleural specimens were indicative of an undifferentiated cancer. Based on the results of immunohistochemistry, we suggested the metastasis of gastric cancer. For patients with such distinct clinical presentations, it would be suitable to study gastric cancer as one of the probable primary sites.