Endometriosis is the presence of functional endometrial tissue in ectopic foci outside the uterine cavity. Urinary tract endometriosis(UTE) is observed in 1-2% of women with endometriosis. Women with UTE, about 80% have urinary bladder involvement.Endometrial lesions may assume the appearance of a polypoid mass similar to that of urinary bladder carcinoma when they grow towards the mucosa alongside the muscle layers. There is no clear protocol anywhere in the literature about how bladder endometriosis is managed as it is a very rare entity.Here we present a interesting and rare case of Endometriosis of urinary bladder masquerading as urothelial carcinoma.

A 39 year old lady presented with symptoms of Supra pubic pain,Irritable voiding symptoms ( frequency, urgency, dysuria),Dysmenorrhea,Hematuria with normal blood investigation and clinical examination. Radiological findings showed ; A well-defined iso-echoic lesion with irregular margins measuring around 3.7 x 1.4 cm noted arising from base of right lateral wall and protruding through the right VUJ into the lumen showing vascularity on color doppler with right HUN. Patient was referred from OBG-YN in view of bladder findings after complete evaluation.With the suspicion of CA bladder patient was taken for TURBT.

Histopathology showed fragments of bladder mucosa showing abundant urothelial Von Brunn nests with cystic changes exhibiting vague lobular distribution of invaginations. Gland-like lumens with columnar cell lining (Cystitis glandularis) and cystically dilated lumens filled with eosinophilic fluid (cystitis cystica) are noted. Multiple fragments of muscle bundles showing foci of round to tubular endometrial glands with endometrial stroma.

Urinary tract endometriosis (UTE) is a very rare but serious form of infiltrating endometriosis because of the risk of urinary tract obstruction and loss of renal function. We report a case of a endometriosis of the bladder whose diagnosis was only established by pathological examination.Every case of bladder endometriosis is unique and the management mostly relies on patient age and preference.In our experience we managed the patient surgically followed by medically on OC pills for next 6 months. Negative urinary cultures in symptomatic individuals may suggest urinary bladder endometriosis. So one should be cautious as bladder endometriosis can mimic CA bladder.