Mapping of bowel occult microscopic endometriosis implants surrounding deep endometriosis nodules infiltrating the bowel.

Objective: To provide a mapping of bowel occult microscopic endometriosis implants from colorectal specimens removed from patients who had undergone colorectal resection for deep endometriosis infiltrating the rectum.

Design: A series of consecutive patients with deep endometriosis infiltrating the rectum or/and sigmoid colon, between January 2013 and December 2013.

Setting: University tertiary referral center.

Patient(s): Twenty-six patients with deep endometriosis infiltrating the rectum or/and sigmoid colon.

Intervention(s): Surgical management by colorectal resection.

Main Outcome Measure(s): Twenty-six patients with prospective recording of data (age, clinical history, symptoms, preoperative assessment, and intraoperative findings) underwent colorectal resection for bowel endometriosis. Mapping of occult microscopic endometriosis implants from specimens was established by histologic examination of 1,051 microsection slides taken from transversal macrosections of 3-mm thickness (40 microsections per patient on average).

Result(s): The mean (SD) length of colorectal specimens was 110 (42) mm. Microimplants were found at varying distances up to 54 mm from macronodule limits. Multiple macroscopic nodules were identified in five patients (19.2%). In 18 specimens (69%) diffusion of endometriosis microimplants was longitudinal, whereas in 8 specimens (31%) diffusion was concentrated around the macroscopic nodule. Respectively, 31%, 19%, 8%, and 4% of patients presented with endometriosis microimplants at 2, 3, 4, and 5 cm from macroscopic nodules.

Conclusion(s): The present data suggest that in patients presenting with deep colorectal endometriosis, microscopically complete excision of rectal endometriosis may be unachievable because of bowel occult microscopic endometriosis implants located far from macroscopic nodules.