Solitary synchronous metastatic gastric cancer arising from t1b renal cell carcinoma: a case report and systematic review

Abstract

Metastasis to the stomach from renal cell carcinoma (RCC) is extremely rare. Usually, gastric metastasis seems to be a late event in patients with RCC and is accompanied by disseminated tumor spread to other organs. Solitary synchronous gastric metastasis from small, localized RCC has rarely been reported. We report a case of 79-year-old man with synchronous gastric metastasis presenting with a single erosive lesion from pT1 RCC. The patient underwent radical nephrectomy and endoscopic resection for metastatic gastric cancer. The resected specimen showed an ill-defined tumor, approximately 0.6 cm long, with a clear resection margin. The morphologic features of the tumor cells were consistent with those of metastatic RCC of the clear cell type. At 6 months's follow-up, the patient did not show local recurrence or additional metastasis on upper endoscopy and computed tomography scan.

Keywords: Carcinoma; Neoplasm metastasis; Renal cell; Stomach neoplasms.

Fig. 1

Upper endoscopy showing an erosive lesion approximately 0.6 cm long in the anterior wall of the gastric mid-body.

Fig. 2

(A) Computed tomography showing a hypervascular mass (arrow) approximately 5 cm long and bilobular in shape in the right kidney. (B, C) Positron emission tomography showing an isometabolic mass (arrow, maxSUV 2.7) in the right kidney. maxSUV, maximum standardized uptake value.

Fig. 3

Pathology findings for the tumor of the right kidney. The tumor was 5.2×3.8×3.5 cm in size, located in the lower pole (arrow), and confined to the renal parenchyma. Thus, lymphovascular invasion and tumor emboli in the renal vein were absent in the tumor. The Fuhrman nuclear grade was 2/4. Inset: The tumor cells had clear cytoplasm and round nuclei, typical of renal cell carcinoma of the clear cell type (H&E stain, ×400).

Fig. 4

Endoscopic resection of the metastatic lesion of the stomach. (A) Marking associated with soft coagulation. (B) Snaring after precutting with a needle knife and partial submucosal dissection with an IT-knife after the injection of a saline-epinephrine solution into the submucosa. (C) Ulcer after endoscopic resection. (D) Grossly resected specimen.

Fig. 5

Microscopic features of the resected specimen showing the characteristics of a metastatic gastric tumor arising from renal cell carcinoma (RCC). (A) The poorly defined tumor, approximately 0.6 cm long, was located in the submucosa, extended to the lamina propria (arrow), and did not involve the deep resection margins (H&E stain, ×40). (B) The morphologic features of the tumor cells were consistent with the features of metastatic RCC of the clear cell type (H&E stain, ×400).