[A Case of Suspected Lynch Syndrome Due to Radical Resection for Descending Colon Cancer and Renal Pelvic Cancer].

A 60-year-old woman was admitted on account of presenting with bloody stools. She had a history of endometrial cancer surgery. Family history revealed 3 colorectal cancer cases among the first or second relatives. Colonoscopy and contrast- enhanced computed tomography revealed descending colon cancer and left renal pelvic cancer. We performed partial resection of the descending/transverse colon with D3 lymph node dissection and total resection of the left kidney and ureter with curative intent. Postoperative pathological diagnosis revealed descending colon cancer(pT4bN0M1c, pStage Ⅳc)and left renal pelvic cancer (T1N0M0, Stage Ⅰ). In this case, Lynch syndrome was suspected based on the family history and medical history. The clinical findings were consistent with Amsterdam Criteria Ⅱ. The microsatellite instability(MSI)test result was MSI-H and the BRAF genetic test result showed a wild type. Immunohistochemical staining of descending colon cancer tissue showed loss of expression of MSH2 and MSH6 proteins. Genetic counseling was provided because Lynch syndrome was strongly suspected. Capecitabine plus oxaliplatin therapy was performed for 6 months for descending colon cancer. Nine months postoperatively, the patient remained recurrence-free for both colon cancer and renal pelvic cancer. We report a case of suspected Lynch syndrome triggered by double cancer of the descending colon and renal pelvis.