Although endometriosis is a common disease in women of reproductive age, rectal endometriosis is rare and lymph node involvement by endometriosis is considered uncommon. We report a 37-year-old woman who had irregular lower abdominal pain and changes in bowel habits. She was operated on with suspected rectal cancer, but the histological diagnosis was rectal endometriosis with lymph node involvement. In women who suffer from digestive complaints, endometriosis should be considered in differential diagnosis. Rectal endometriosis has the ability to invade adjacent tissue as true malignant tumors. Therefore, lymph node involvement should be considered in rectal endometriosis.

© 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.