Persisting active and proliferative intrinsic ureteral endometriosis under GNRH agonists therapy: a case with immunohistological study.

We report the case of a 30-year-old patient who underwent a segmental ureteral resection with ureteroureterostomy because of the presence of a left ureterohydronephrosis caused by an intrinsic ureteral endometriotic lesion. Preoperatively, the patient received a 3 months course of GNRH agonists. The serum estradiol level was at 12 pg/ml at the moment of surgery. Histology and immunohistochemistry performed on the resected specimen showed the presence of numerous large haemorrhagic endometriotic foci containing very high levels of alpha-estrogen and progesterone nuclear receptors, a high Ki-67 labeling index and a strong positivity for EGF-receptor. This is the first report of immunohistochemical study performed on ureteral endometriosis preoperatively treated with GNRH agonists. Because hormonal treatments are often prescribed in the treatment of ureteral endometriosis, clinicians should be aware of the possibility of persisting very active and proliferative ureteral endometriotic lesions even under treatment with GNRH agonists and very low levels of circulating estradiol.