A Case of Colonic Endometriosis Mimicking Colon Cancer

Purpose: Background: Colonic endometriosis is a diagnostic challenge and is difficult to differentiate from colon cancer. This case demonstrates the difficulty of establishing an accurate diagnosis and the propensity of intestinal endometriosis to mimic malignancy in the setting of previous history of colon cancer. Case: A 44 year old female with past history of stage 3 adenocarcinoma of the colon, s/p surgical resection presented with left lower quadrant abdominal pain, vomiting and rectal bleeding. Physical exam was positive for left lower quadrant tenderness and positive stool guaiac. Laboratory tests are significant for hemoglobin and hematocrit of 6.8 and 19.3, respectively. CT scan of the abdomen showed a large mass in sigmoid colon. Colonoscopy revealed an exophytic mass at sigmoid colon resembling colon neoplasm. Patient underwent laparoscopic resection of the mass. Biopsy specimen were consistent with endometriosis involving the full thickness of the bowel wall. Patient's symptoms have resolved after the resection and there was no recurrence after one year follow up. Conclusion: Intestinal endometriosis is often a diagnostic challenge mimicking a broad spectrum of diseases. The clinical, radiological and endoscopic picture may be confused with neoplasms,inflammatory bowel disease, and infection. Biopsies obtained endoscopically usually yield insufficient tissue for a definite pathologic diagnosis. In conclusion, intestinal endometriosis should be considered in any young woman with symptoms from the lower gastrointestinal tract. Treatment options include surgery or hormonal manipulations.Figure: CT scan demonstrating mass in the colon.Figure: Endoscope demonstrating a polypoid mass in the colon