A Case of Gastric Metastasis of Renal Cell Carcinoma Resected by Endoscopic Submucosal Dissection After Endoscopic Follow‐up of Morphological Changes

A 62‐year‐old man underwent partial nephrectomy for right renal cell carcinoma (RCC). Four years later, esophagogastroduodenoscopy revealed gastric mucosal redness with a smooth surface. Two more years later, the red lesion showed a morphological change to a reddish elevation, which prompted a biopsy. Histopathological examination led to the diagnosis of gastric metastasis of RCC. As the tumor resided within the submucosa and no other organ metastasis was found after nephrectomy by that time, endoscopic submucosal dissection (ESD) was performed and successfully resected. No evidence of local recurrence was noted for 7 years after ESD. Topical resection, such as ESD, can be considered an option to treat the gastric metastasis of RCC for which there are no established treatment guidelines. In this case report, we aimed to investigate a rare case of gastric metastasis of RCC, which was monitored endoscopically, showing morphological changes over several years, and was successfully resected by ESD.