Ureteroscopic Excision of Distal Ureteral Endometriosis

Background: Endometriosis is the presence of endometrial tissue outside the uterus. Involvement of the urinary tract is uncommon; however, ureteral endometriosis (UE) is even more unusual. Most patients are clinically asymptomatic, which may lead to silent renal loss secondary to obstructive urinary tract endometriosis. Only a few cases of intrinsic UE treated by endoscopic excision have been reported. Case Presentation: We report a case of a 40-year-old woman with chronic right flank pain, with a right distal ureteral obstructive lesion. Ureteroscopy identified a lesion and ureteroscopic resection was performed. Histologic analysis revealed intrinsic UE.

Ureteroscopic excision of intrinsic UE is a feasible option for treatment as we have shown in this case.

endometriosis, endourology, ureteral endometriosis, ureteroscopy

Endometriosis is the presence of endometrial tissue outside the uterus. Although it is a common entity, it is not commonly seen in urologic practice. Ureteral endometriosis (UE) is rare, occurring in 1% to 5.5% of women with endometriosis1 and representing approximately 9% to 15% of cases of urinary tract endometriosis (UTE). A few cases of intrinsic and obstructive ureteral endometriotic lesions treated by ureteroscopic excision have been described.1 We report a case of endourologic treatment of symptomatic UE. Case Presentation A 40-year-old woman was admitted to our urology unit with a history of recurrent right renal colic for the past 2 years. She described having cyclic pain with radiation to her right abdomen and nausea. Two years previously, she had undergone an uncomplicated right flexible ureteroscopy for nephrolithiasis, achieving a stone-free state. She had a history of two C-sections and later went on to have a hysterectomy for symptomatic leiomyomatosis. She denied receiving hormonal therapy. Physical examination was unremarkable. Blood test reported a hemoglobin of 13.8 g/dL and serum creatinine of 0.7 mg/dL. Triphasic abdominal/pelvic CT revealed severe right hydronephrosis and hydroureter with delayed excretion of the right kidney. An obstructing round mass in the right distal ureter was observed (Fig. 1). The patient underwent right ureteroscopy. Retrograde pyelography was performed that showed a round filling defect in distal right ureter (Fig. 2). During ureteroscopy, a well-defined rounded pedunculated lesion was found in the distal right ureter (Fig. 3). Endoscopic Ho:YAG laser resection was performed, removing the lesion from the ureter. Laser parameters used for excision were 0.8 J and 8 Hz. Once the lesion was freed from its base, extraction was accomplished using a stone retrieval basket. A 6F × 23 cm Double-J ureteral stent was placed in the right ureter afterward. Pathology analysis reported a 0.5 × 0.2 × 0.2 cm lesion, characterized by endometrial glands with subnuclear vacuolization and luminal secretion. (Fig. 4). The Double-J stent was removed 1 month after the procedure. She was seen by her gynecologist without hormonal therapy being prescribed. She continued well upon discharge, with appointments scheduled every 3 months during the 1st year of follow-up, and every 6 months for the 2nd and 3rd year, with repeated ultrasonography and urine analysis. Months after endoscopic treatment, the patient is asymptomatic with no evidence of hydronephrosis by ultrasonography.

Endometriosis is defined as the presence of endometrial tissue outside the uterus. UTE can affect the kidneys, ureter, bladder, or urethra.1,2 Involvement of the urinary tract is uncommon, occurring in 1% to 5.5% of women with endometriosis,1 with a peak age of incidence between 40 and 44 years.3 UE is rare, representing ∼9% to 15% of the cases of UTE.1,2 The pathogenesis of UTE is still not well defined, although several theories have been proposed to account for the presence of endometrial tissue outside the uterus. Possible mechanisms include lymphatic or hematogenous spread, direct extension into or out of the uterine wall, and retrograde menstrual flow through the fallopian tube. An embryonic theory has been described in which a metaplastic reaction of a remnant Müller or Wolf duct is present, as well as iatrogenic theory in which extrauterine dissemination of endometrial cells takes place after pelvic surgery.1–3 UE can be classified as intrinsic (involvement of muscularis propria and mucosa) and extrinsic (involvement of the adventitia of the ureter),1–3 with the latter being more common.1,4 Involvement of the left ureter is more common, and the most frequently affected segment of the ureter is the distal.2–4 Ureteral involvement may lead to urinary tract obstruction, giving rise to hydronephrosis, and consequently results in a loss of kidney function.1,2,4 UE is characterized by nonspecific symptoms.1,2,4 Fifty percent of cases are asymptomatic,1,2 making diagnostic timeliness difficult.2 Common symptoms of UE are pelvic pain, dyspareunia, and dysmenorrhea.1,3 Hematuria can be found in <17% of patients.1 Imaging remains essential to the diagnosis; however, a preoperative diagnosis solely based on imaging is challenging. To ensure a correct diagnosis, histopathologic study of the specimen is required. Frequently, an initial abdominal ultrasonography reveals hydronephrosis;1 however, this is not found in all patients. Some other studies include intravenous pyelography, ureteroscopy with endoluminal ultrasonography, laparoscopy, CT, and MRI.1,3,4 The goal of treatment in UE is to relieve the obstruction, eliminate symptoms, and most importantly to preserve renal function.2,3 Treatment options include hormone therapy, surgical approaches, or the combination of both. Hormonal therapy agents include danazol, gonadotropin releasing hormone agonists, estrogen or progestin combination, progestin alone, and medroxyprogesterone.1 Hormonal therapy is contraindicated as the first line treatment in obstructive UE.1 Surgical interventions have been considered the best treatment for patients with obstruction.3 They include ureterolysis, distal ureterectomy, ureteral reimplantation, and endourologic management.1–4 Nephroureterectomy is an effective treatment alternative in refractory cases.3 Endoscopic management is indicated in patients with intraluminal endometriosis and may be effective only in a small percentage of patients because there is a high rate of recurrence.1 Endourologic options include ablation with laser, and balloon dilatation with stent placement. Few cases of intrinsic and obstructive ureteral endometriotic lesions treated by endoscopic excision have been described.1 Endoscopic management remains controversial due to different success rates. The risk of recurrence in patients with UE varies with the disease extension and type of treatment. The lowest recurrence rates are in ureteroneocystostomy procedures.1 In patients treated with endoscopic excision, the overall success rates have been reported between 60% and 80%.1 In the case presented, the only symptom was that of chronic flank pain. Imaging studies demonstrated distal ureteral obstruction and right unilateral hydronephrosis, whereas endoscopy confirmed the presence of a ureteral mass. These findings are nonspecific and raise the concern for a possible transitional cell carcinoma, but the diagnosis was confirmed with the pathology specimen. With this in mind, the diagnosis of UE is not an easy task. Ureteroscopic excision in cases like this patient is feasible. After 6 months of endoscopic treatment, the patient is asymptomatic with no evidence of hydronephrosis by ultrasonography.

We present a rare case of an effective ureteroscopic excision of symptomatic UE. This case supports the feasibility of endourologic treatment in UE. Acknowledgments This study did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. No personal or identifiable patient information was included. As such, consent from the patient was not needed. Abbreviations Used - CT computed tomography - MRI magnetic resonance imaging - UE ureteral endometriosis - UTE urinary tract endometriosis Disclosure Statement No competing financial interests exist. Cite this article as: González-Bonilla EA, Ruíz-García FJ, Estrada-Bujanos JM, León-Castorena E (2019) Ureteroscopic excision of distal ureteral endometriosis, Journal of Endourology Case Reports 5:4, 148–150, DOI: 10.1089/cren.2019.0029.

- 1. Bernal J, Tapia V, Astroza G. Urinary tract endometriosis: review of the literature. [In Spanish]. Revista Chilena de Urología 2014;79:54–58 [Google Scholar] - 2. Gupta SS, Singh O, Shukla S, et al. Rare case of ureteral endometriosis presenting as hydronephrotic kidney. Saudi J Kidney Dis Transpl 2011;22:130–133 [PubMed] [Google Scholar] - 3. Barra F, Scala C, Biscaldi E, et al. Ureteral endometriosis: A systematic review of epidemiology, pathogenesis, diagnosis, treatment, risk of malignant transformation and fertility. Hum Reprod Update 2018;24:710–730 [DOI] [PubMed] [Google Scholar] - 4. Hsieh MF, Wu IW, Tsai CJ, et al. Ureteral endometriosis with obstructive uropathy. Intern Med 2010;49:573–576 [DOI] [PubMed] [Google Scholar]