Recently, we have most of the patients with multiple myomas to take magnetic resonance imaging(MRI) routinely for preoperative evaluation. But, It is the first time in years we found other diseases besides myomas incidentally on MRI scan. The case report is described of a of a 35year-old female, nullipara, who came to outpatient department of our hospital with the chief complaint of heavy menstrual bleeding, dysmenorrhea. And she had multilpe myoma up to 5cm found two years ago. We performed preoperative magnetic resonance imaging(MRI) scan to evaluate myoma, but sigmoid colon cancer is confirmed on MRI, so she is transferred to general surgery part. A computed tomography scan, positron emission tomography-computed tomography(PET-CT) scan and colonoscopy demonstrated colon cancer and biopsy confirmed adenocarcinoma. She had laparoscopic anterior resection and adjuvant chemotherapy. We are planning myomectomy after stabilized her state.