A case of bladder endometriosis that became symptomatic during the third trimester

The urinary tract endometriosis is observed in 1–2% of the patients and in 90% of these cases, there are endometriotic nodules in the bladder. With respect to knowledge, it is generally believed that pregnancy cures endometriosis. However in this case, symptoms developed during the third trimester of pregnancy. We report a case of 31year old, 30week pregnant woman with a vegetative mass with 33×33×21 mm dimensions and irregular borders on the posterior wall of the bladder. After the cesarean section, the vegetative and superiorly localized mass on the internal wall of the bladder was excised with partial bladder excision. The patient had no other apparent findings of pelvic endometriosis at operation but the pathology result indicated endometriosis. Although this case shows that endometriosis may become symptomatic during pregnancy, it has to be underlined that it cannot be discerned whether it is consequent to progress of the disease or to pregnancy-mediated modifications of a pre-existing lesion. •Endometriosis may become symptomatic during pregnancy.•When a mass detected in the bladder, the most appropriate tool for diagnosis is cystoscopic biopsy.•Cystoscopy during pregnancy may fail to detect bladder nodules.•With decidual changes endometriotic nodules in the bladder can mimic malignancy during pregnancy.