42 year old woman with repeated episodes of small bowel obstruction. She had history of endometriosis. Contrast enhanced axial (A,B) and coronal (C) CT shows small bowel obstruction with thickening of the terminal ileum (yellow arrow). The appendix is mildly thickened with no associated fat stranding (blue arrow).

At surgery: endometriosis was present on serosal surface of terminal ileum and appendix. Endometriosis involves the GI tract in 5 to 37% of cases. Most common locations are rectosigmoid followed by cecum and terminal ileum and appendix

66 year old woman with enlarging pelvic mass and right hydronephrosis Contrast enhanced axial CT (A,B,C) shows marked right hydronephrosis and a spiculated enhancing pelvic mass involving the rectum and the right bladder wall and engulfing the right urteter. T2 (D) and contrast MR (E) confirm the findings.

Endometriosis involving the urinary tract is uncommon. The bladder and distal ureter are usually affected either by compression from large endometriomas or infiltration from deep pelvic endometriosis.

40 year old woman presenting to the ED with acute pelvic pain.

A: axial CT with contrast shows 2 cystic adnexal masses. Left mass has thick wall. Note extensive localize fat stranding in the anterior pelvis (yellow arrows)

B, C: Endovaginal US confirms 2 cystic masses with diffuse low level echoes. The smaller lesion has echogenic foci in the wall (blue arrow), another characteristic finding in endometrioma. The patient was exquisitely tender over the largest mass and the possibility of torsed endometrioma was raised. D,E: Axial T1 and T2 MR confirms the diagnosis of endometriomas. Note T2 shading. In view of the patients’ acute symptoms and the marked mesenteric fat stranding seen on CT and MR, the diagnosis of endometrioma rupture was suggested on MR. This was confirmed at surgery.

“Endometriosis is a common cause of pelvic pain and infertility, with as many as 30% of women with endometriosis demonstrating tubal involvement at laparoscopy. Ruptured deep pelvic endometriomas release blood products that cause adhesions and fibrosis, which may lead to findings that can mimic PID, such as the development of complex pelvic masses, nodularity of the uterosacral ligaments, and peritubal adhesions with tubal obstruction.”
Pelvic Inflammatory Disease: Multimodality Imaging Approach with Clinical-Pathologic Correlation 
Revzin MV et al.
RadioGraphics 2016; 36:1579–1596