Ureteral endometriosis: MR imaging appearance for predicting complex procedures

Abstract

Rationale and objectives: To describe MRI characteristics of ureteral endometriosis (UE) in identifying intrinsic involvement of the ureteric wall and predicting complex procedures.

Methods: Thirty-three UE lesions in 30 patients treated for UE over a 20-year period were reviewed. A systematic analysis of 13 MRI (ureteric wall thickening, circumference, T1 signal, T2 signal, ureterectasis, lateral parametrial endometriosis (LPE), rectal endometriosis, the foregoing three-characteristic diameter, ovarian endometriomas, adenomyosis, paraurethral endometriosis) and 5 clinical (age, BMI, CA125, creatinine and rAFS stage) characteristics was performed. MRI results were compared to histology and surgical procedure performed (simple versus complex ureteral procedures).

Results: Twenty-five extrinsic and 8 intrinsic UE were pathologically identified. Twenty lesions underwent a simple procedure, and 12 underwent a complex procedure, with 1 ureteroscopic biopsy. There were significant differences in the characteristics of ureteric wall thickening, the diameter of dilated ureter and LPE, rectal endometriosis and adenomyosis between extrinsic and intrinsic UE (p < 0.05). UE was associated with LPE (p = 0.033). The criteria of ureteral wall thickening more accurately predicted intrinsic UE than circumference, but the AUC was not significant difference (AUC, 0.806 and 0.639; 95 % CI, [0.594, 0.937] and [0.419, 0.823], respectively; p = 0.350). There were significant differences in creatinine, thickening and adenomyosis between the simple and complex procedures (p < 0.05). In 11 lesions with the absence of ureterectasis, 4 lesions with hydronephrosis and thickening were intrinsic and underwent complex procedures, while 7 lesions extrinsic and simple.

Conclusions: Ureteric wall thickening as a analytical criterion may accurately predict intrinsic UE and complex ureteric procedures.

Keywords: Endometriosis; Magnetic resonance imaging; Surgical procedure; Ureter.

Fig. 1

The criteria diagrams of both ureteric wall thickening and the contact circumference between the ureter and the endometriosis lesion. According to multiple parameters characteristics of UE on T2WI and enhanced T1WI, the characteristic of ureteric wall (classified into thickening and absence of thickening) and the circumference of enclosed ureter (classified into equal to 360°, 180°-360°and <180°).

Fig. 2

Evaluation of ureteric wall thickening with ureterectasis in a 50-year-old women with history of lumbar pain during menstrual period. Complex ureteric procedure (i.e. ureteroneocystostomy) performed, and intrinsic UE confirmed pathologically. Sagittal T2-weighted MR image shows a endometriosis nodular involved the left lower ureter and posterior uterus (white dashed arrow). The spike nodular shows hypointensity mixed spot high signal and defines as mixed intensity. The circumference of which enclosed lower ureter is equal to 360°. Left ureter shows dilated (white arrow) with the diameter of 11 mm (double-headed black arrow) defined as ureterectasis. Posterior uterus muscle layer thickening indicates adenomyosis. In addition, left ovarian endometriomas shows hyperintensity on T2WI and adhered to the uterine fundus (black arrow). Transverse T2-weighted MR images show the transverse diameter of parametrium endometriosis nodule is 2.4 cm (dashed line). Transabdominal sonography shows ureterectasis caused by a spike endometriosis nodular (white arrow). The morphology of the resected ureter performs irregular. The presence of endometrial glands and stroma cells is observed in the adventitia, the muscularis and the mucosal layers of the ureteric wall, which confirms intrinsic UE (haematoxylin and eosin [H&E] stain, × 2).

Fig. 3

Evaluation the absence of ureteric wall thickening with ureterectasis in a 37-year-old women with history of pelvic mass. Simple ureteral procedure (i.e.ureterolysis) performed, and extrinsic UE confirmed pathologically. Coronal T2-weighted MR image shows a endometriosis nodular involved the left lower ureter (white dashed arrow) and the circumference of which enclosed lower ureter is equal to 360°. Left ureter shows dilated (white arrow) with the diameter of 8 mm. Transverse T2-weighted MR image shows a spike parametrium endometriosis nodule (white dashed arrow) and a oval ovarian endometriomas, which is at the right lateral of parametrium nodule. Sagittal T2-weighted and contrast-enhanced T1-weighted MR images show absent of the ureteric wall thickening characteristic. TVS shows left ureterectasis caused by a spike endometriosis nodular (white dashed arrow). Laparoscopy shows the endometriosis lesion enclosed the lower ureter, and after ureterolysis the ureter recovers the normal morphology. The presence of endometrial glands and stroma cells is observed in the adventitia layers of the ureteric wall, which confirms extrinsic UE (haematoxylin and eosin [H&E] stain, × 2).

Fig. 4

Evaluation of ureteric wall thickening with the absence of ureterectasis in a 37-year-old women with history of lower abdominal pain during menstruation. Complex ureteral procedures (i.e. ureteral resection) performed, and intrinsic UE confirmed pathologically. Sagittal and coronal T2-weighted MR image shows a endometriosis nodular involved the right lower ureter (white dashed arrow) and the circumference of which enclosed lower ureter is 180°–360°. Right ureter shows the absence of ureterectasis (white arrow). Transverse T2-weighted and contrast-enhanced T1-weighted MR images show right ureteric wall thickening (white arrow) and right ovarian endometriomas (white dash arrow). TVS shows right parametrium endometriosis nodule (white dashed arrow) adhesions to right lower ureter with the absence of ureterectasis. Laparoscopy shows the endometriosis lesion enclosed the lower ureter, and ureteral resection is performed. The presence of endometrial glands and stroma cells is observed in the muscularis layers of the ureteric wall, which confirms intrinsic UE (haematoxylin and eosin [H&E] stain, × 2).

Fig. 5

Evaluation absent of ureteric wall thickening and ureterectasis in a 43-year-old women with history of secondary dysmenorrhea with progressive aggravation. Simple ureteral procedure (i.e.ureterolysis) performed, and extrinsic UE confirmed pathologically. Transverse, sagittal and coronal T2-weighted MR images show left parametrium endometriosis lesion (dashed circle). The left lower ureter was not observed because it is absent from ureteral dilation and hydronephrosis. Sagittal contrast-enhanced T1-weighted MR image shows absent of ureteric wall thickening. TVS shows an ovarian endometriomas and the normal morphology of both right ureter and kidney. Ureterolysis is performed and the presence of endometrial stroma cells in the adventitia layers of the ureteric wall confirms extrinsic UE (haematoxylin and eosin [H&E] stain, × 2).

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