An 89-year-old woman was pointed out to have anemia for a routine blood examination by her family doctor and was referred to our gastroenterological department for further examination. Colonoscopy showed a type Ⅰ tumor in the transverse colon and insertion of fiber across the tumor was difficult. On contrast enema using gastrographin, a crab's claw-like appearance was found. CT after contrast enema revealed a tumor, 5 cm in diameter with pseudokidney sign near the hepatic flexure of the transverse colon. Pathological examination of biopsy specimen proved the tumor to be a poorly differentiated adenocarcinoma. Thus, she was diagnosed with intussusception due to transverse colon cancer and we performed partial resection of the transverse colon without regional lymphadenectomy. Final pathological diagnosis of the tumor was undifferentiated carcinoma and tumor stage was pT3pN0cM0, pStage Ⅱa. She was discharged 13 days after surgery and alive without tumor recurrence at 7 months after surgery, not undergoing adjuvant chemotherapy.