Endoscopically observable white nodule caused by distal intramural lymphatic spread of rectal cancer: a case report

This report describes a case of rectal cancer with endoscopically observable white nodules caused by distal intramural lymphatic spread. A 57-year-old female presented to our hospital with frequent diarrhea and hemorrhoids. Computed tomography showed bilateral ovarian masses and three hepatic tumors diagnosed as rectal cancer metastases, and also showed multiple lymph node involvement. The patient was preoperatively diagnosed with stage IV rectal cancer. Colonoscopy demonstrated that primary rectal cancer existed 15 cm from the anal verge and that there were multiple white small nodules on the anal side of the primary tumor extending to the dentate line. Biopsies of the white spots were performed, and they were identified as adenocarcinoma. The patient underwent Hartmann's procedure because of the locally advanced primary tumor. The white nodules were ultimately diagnosed as being caused by intramural lymphatic spreading because lymphatic permeation was strongly positive at the surrounding area. Small white nodules near a primary rectal cancer should be suspected of being intramural spreading. Endoscopic detection of white nodules may be useful for the diagnosis of distal intramural spread.