少見的病理發現：造成腎盂積水的輸尿管輸卵管內膜異位症

鄭苑伶¹、曹智惟¹、蒙恩¹、孫光煥¹、于大雄¹、陳進利¹

三軍總醫院 外科部 泌尿外科¹

An unusual cause of hydronephrosis: Ureteral endosalpingiosis.

Yuan-Ling Cheng¹, Chih-Wei Tsao¹, En Meng¹, Guang-Huan Sun¹, Dah-Shyong Yu¹, Chin-Li Chen¹

Division of Urology, Department of Surgery, Tri‐Service General Hospital, National Defense Medical Center, Taipei, Taiwan¹

Abstract: Endosalpingiosis (ES) is the presence of normal tubal epithelium in ectopic locations. It is usually found incidentally during pathological examinations. Ureteral ES is exceptionally rare and has no known reported cases to our knowledge.

  We present a case of 58-year-old post-menopausal female with surgical history of bilateral salpingo-oophorectomy due to bilateral endometrioma, who had sudden onset of right flank pain. Urinalysis showed urinary tract infection and microscopic hematuria, and computed tomography revealed a soft tissue density located at the right lower third ureter, complicated with hydronephrosis. Ureteroscopy revealed a 1.5-cm mass over the lower third of the ureter. Thulium laser resection of the ureteral tumor was performed. Hematoxylin and eosin staining showed ciliated glandular epithelium, non-ciliated mucous-secreting cells, and peg cells without endometrial stroma. Immunohistochemistry staining showed positive PAX8 staining (Fig.C-c). The patient's symptoms relieved, and hydronephrosis improved without renal impairment.

  The primary Mullerian system develops from partially fused Mullerian ducts during embryonic development and includes the fallopian tubes, uterus, cervix, and proximal third of the vagina. Remnants of this system are known as the secondary Mullerian system and can give rise to conditions such as endometriosis, endocervicosis, and endosalpingiosis, which may occur together or separately. Müllerianosis is rare in the urinary tract, with less than 40 reported cases. Bladder ES is even rarer with only 7 case reports, and lower ureteral müllerianosis has only 3 reported cases. No cases of ureteral ES have been reported to our knowledge.

  ES is detected in 1.4% to 12.5% of women undergoing laparoscopy. It is difficult to diagnose due to its diverse appearance, and histopathologic examination is the gold standard for diagnosis. It is characterized by ectopic tubal epithelium with three cell types: ciliated glandular epithelium, non-ciliated mucous-secreting cells, and peg cells. PAX8 staining, a transcription factor involved in Müllerian tissue development, suggests ES. In our case, presence of ciliated glandular epithelium, non-ciliated mucous-secreting cells, and peg cells, suggests ES and absence of endometrial stroma rules out endometrioma. Positive PAX8 staining supports ES diagnosis, while negative GATA-3 staining suggests a urinary system origin is less likely. Although the morphology did not reveal any malignant findings, regular follow-up is necessary due to the increased risk of reproductive tract neoplasms in patients with ES, with ovarian serous neoplasm and cervical cancer being the most common.

Conclusion: In summary, our case of hydronephrosis was caused by a ureteral tumor, which was diagnosed as ES. ES is rare and often confused with other benign or even malignant tumors, highlighting the importance of accurate differential diagnosis for appropriate treatment. Moreover, there have been reports of a association between ES and gynecological malignancies, emphasizing the need for regular follow-up by the gynecology department.