A Case of Spontaneous Regression of Sigmoid Colon Cancer after Local Injection for Non-lifting Sign Evaluation

Abstract

A 63-year-old woman presented to our hospital due to sigmoid colon cancer detected by a colonoscopy. The tumor was 0-Isp lesion measuring 20 mm in diameter. Endoscopic submucosal dissection was planned and the glycerol with epinephrine and indigocarmine was locally injected just under the tumor. However, the non-lifting sign was seen and the patient was considered to be a candidate for surgery. Therefore, laparoscope assisted sigmoid colectomy with lymph node dissection was performed. The resected specimen only showed ulcer scar and tumorous lesion was absent. Histological examination revealed no cancer cells. The mechanism of spontaneous regression of the tumor in our case was speculated that separation between the normal and cancer tissues due to the injection, and the ischemic change due to vasoconstriction effect of epinephrine resulted in necrosis, sloughing ulcer and scar formation of cancer cells.

We must keep in mind that preoperative endoscopic treatment like in our case can lead to spontaneous regression of the tumor.