2022 Volume 71 Issue 1 Pages 153-158
We report a case of endometrioid cancer arising from cecal endometriosis. A 30-year-old woman frequently visited our hospital for abdominal pain for 10 years. Her blood carbohydrate antigen 125 (CA125) level and medical histories were regularly examined because her mother had uterine cancer and her sister had ovarian cancer. Although a rectal echo observation was made, no obvious organic changes were observed. She was admitted to our hospital complaining of abdominal pain that had persisted for a few days. A target sign in the ascending colon was confirmed by abdominal ultrasonography and abdominal CT examination, and intussusception was noted. Moreover, a laparoscopic tumor was found during the reduction operation, and the ileocecal mass and the diverticulum of the sigmoid colon were excised. The histopathological diagnosis was endometriosis-associated intestinal tumor (EAIT) arising from the endometriosis of the cecum, and the histologic type was endometrioid cancer (Grade 2). Given her family history, breast and ovarian cancers were suspected, and genetic tests were recommended. The BRCA1/BRCA2 genetic test showed negative results. The BRAF V600E genetic test also showed negative results; thus, we suspected Lynch syndrome due to mismatch repair (MMR). Unfortunately, her family members chose not to have an MMR genetic test for a definitive diagnosis. It is difficult to detect intestinal endometriosis, but its lesion can be discovered by endoscopy or MRI if it is suspected and carefully observed. If abdominal pain coincides with menstruation, it is important to consider further examination with endometriosis in mind.
