{"paper_id":"66af3b16-93c4-4bd2-9bac-2efa2e21fbce","body_text":"REVIEW\nAbdominal Radiology\nhttps://doi.org/10.1007/s00261-026-05650-7\n \r Belma Gözde Özdemir\ngzdgrgn35@gmail.com\nHalis Özdemir\ndrhalisozdemir@gmail.com\n1 Selçuk University, Konya, Turkey\n2 KTO Karatay University, Konya, Turkey\nAbstract\nEndometriosis is a chronic inflammatory disease affecting approximately 10% of women of reproductive age. Urinary \ntract involvement is rare, occurring in approximately 1–2% of cases, with the bladder being the most frequently affected \norgan. Bladder endometriosis is often associated with deep infiltrative endometriosis and can lead to delays in diagnosis \ndue to non-specific symptoms. In recent years, advances in magnetic resonance imaging (MRI) techniques have increased \ndiagnostic accuracy, and minimally invasive surgical methods have come to the forefront in treatment. This review pres -\nents the pathogenesis, clinical features, diagnostic approaches, and current treatment options of bladder endometriosis, \nalong with a review of the literature.\nKeywords Bladder endometriosis · Deep infiltrating endometriosis · MRI · Cyclic hematuria\nReceived: 30 March 2026 / Accepted: 16 June 2026\n© The Author(s) 2026\nBladder endometriosis: a current overview of pathogenesis, diagnosis, \nand treatment approaches\nBelma Gözde Özdemir1  · Halis Özdemir2\nPathogenesis and etiology\nThe pathogenesis of endometriosis is multifactorial, with \nthe most widely accepted theory being retrograde menstrua-\ntion [5]. According to this theory, endometrial cells migrate \nto the peritoneal cavity and implant there. However, theo -\nries of coelomic metaplasia and lymphatic/hematogenous \nspread are also important in explaining the development \nof the disease [ 6]. In bladder endometriosis, the most \nlikely mechanism is considered to be direct invasion from \nthe anterior wall of the uterus into the bladder. Iatrogenic \nimplantation may also play a role in patients with a history \nof uterine surgery [7].\nClinical findings\nBladder endometriosis is generally characterized by cyclic \nurinary symptoms. The most common findings are dysuria, \npollakiuria, and suprapubic pain. Menstruation-related \nhematuria is a highly specific finding for the disease and \nprovides an important clue in diagnosis. However, its \nabsence in all patients can make diagnosis difficult.\nIntroduction\nEndometriosis is a chronic, estrogen-dependent inflamma -\ntory disease characterized by the extrauterine localization of \nthe endometrial gland and stroma [1]. It is estimated to affect \napproximately 10% of women of reproductive age. While \nthe disease most commonly involves the ovaries and pelvic \nperitoneum, extrapelvic locations have also been described \n[2]. Urinary system endometriosis is a rare clinical entity, \naccounting for approximately 1–2% of all cases [3]. Bladder \ninvolvement is present in 70–85% of these cases [ 4]. Blad-\nder endometriosis is frequently included within the deep \ninfiltrative endometriosis spectrum and can lead to serious \nlower urinary tract symptoms. Diagnostic delay is a signifi-\ncant clinical problem, reported to be between 4 and 7 years \non average. In recent years, advances in MRI techniques \nhave increased diagnostic accuracy, and minimally invasive \nsurgical approaches have come to the forefront of treatment.\n\n1 3\nAbdominal Radiology\nDiagnosis\nThe diagnosis of bladder endometriosis is made by a com -\nbination of clinical suspicion, imaging methods, and histo -\npathological confirmation. The most important step in the \ndiagnostic process is carefully questioning the presence \nof cyclic symptoms. The presence of dysuria, pollakiuria, \nor hematuria, especially related to menstruation, provides \na strong clinical clue for diagnosis. However, diagnosis is \noften delayed because the symptoms are non-specific and \ncan overlap with many diseases. Physical examination find-\nings are often limited, but tenderness in the anterior com -\npartment or the presence of nodular structures on bimanual \nexamination may suggest deep infiltrative endometriosis. \nHowever, advanced imaging methods are needed to reach a \ndefinitive diagnosis.\nImaging methods\nUltrasonography is generally the first-line method, but it has \nlimited sensitivity [8]. Transvaginal ultrasonography, espe-\ncially in experienced hands, can be useful in detecting ante-\nrior compartment lesions; however, it may be insufficient \nfor evaluating small lesions showing deep invasion of the \nbladder wall. Furthermore, operator dependence is one of \nthe significant limitations of ultrasonography.\nMagnetic resonance imaging (MRI) is considered the \ngold standard imaging modality for the evaluation of blad -\nder endometriosis, particularly in patients with deep infiltrat-\ning endometriosis. A dedicated pelvic MRI protocol should \ninclude high-resolution T2-weighted sequences in sagit -\ntal, axial, and coronal planes, fat-suppressed T1-weighted \nimaging, and diffusion-weighted imaging (DWI) [ 9, 10]. \nMRI accurately demonstrates lesion localization, size, depth \nof bladder wall invasion, and relationships with adjacent \npelvic structures. Typical findings include T2-hypointense \nnodules reflecting fibrosis and smooth muscle hyperplasia, \ntogether with T1-hyperintense foci corresponding to hem -\norrhagic implants. These imaging characteristics are highly \nsuggestive of endometriosis and help differentiate the dis -\nease from urothelial carcinoma. Furthermore, MRI plays a \ncrucial role in preoperative planning by assessing detrusor \nmuscle involvement, proximity to the ureteral orifices, and \nthe extent of associated pelvic endometriosis, thereby guid-\ning surgical management and reducing intraoperative com -\nplications (Fig. 1).\nMedical treatment\nMedical treatment options include GnRH agonists, oral con-\ntraceptives, and progestins [11]. These agents aim to reduce \nthe activity of endometriotic foci and control symptoms by \nsuppressing estrogen production. Oral contraceptives and \nprogestins are generally preferred as first-line treatment and \ncan be effective, especially in patients with mild symptoms. \nGnRH agonists can provide stronger hormonal suppres -\nsion but their long-term use is limited by hypoestrogenic \nside effects. However, medical treatment generally does not \neradicate the disease, and symptoms may recur after treat -\nment discontinuation. Therefore, medical therapy is mainly \nreserved for patients with mild disease, those who are \npoor surgical candidates, or as adjunctive treatment before \nsurgery.\nSurgical treatment\nThe management of bladder endometriosis should be indi -\nvidualized based on symptom severity, lesion size and depth, \nextent of disease, and patient-specific factors such as age, \nfertility desire, and comorbidities. While surgical excision \nremains an important and often definitive treatment option, \nparticularly in cases of deep infiltrating disease involving \nthe detrusor muscle or in patients with refractory symptoms, \nit should not be considered universally as the “gold stan -\ndard” for all patients. Instead, a tailored approach that inte -\ngrates both medical and surgical strategies is recommended. \nMedical treatment aims to suppress ovarian function and \nreduce the activity of endometriotic lesions, thereby alle -\nviating symptoms and potentially delaying disease pro -\ngression. Commonly used agents include combined oral \ncontraceptives and progestins; among these, dienogest has \ndemonstrated significant efficacy in pain control and lesion \nstabilization. The levonorgestrel-releasing intrauterine \nsystem (LNG-IUS) also represents an effective long-term \noption, particularly in patients seeking fertility preserva -\ntion or wishing to avoid systemic side effects. In addition, \nnewer oral GnRH antagonists, such as elagolix and relu -\ngolix, have emerged as valuable alternatives by providing \nrapid and reversible suppression of gonadotropin secretion \nwith a more favorable side-effect profile compared to GnRH \nagonists. These agents allow dose-dependent modulation of \nestrogen levels and are increasingly incorporated into mod-\nern endometriosis management algorithms. Surgical inter -\nvention, including partial cystectomy, is generally reserved \nfor patients with severe symptoms, bladder wall invasion, \nureteral involvement, or failure of medical therapy. There -\nfore, optimal management requires a multidisciplinary and \n\n1 3\nAbdominal Radiology\npatient-centered approach, balancing symptom control, dis-\nease progression, and reproductive goals.\nSurgical treatment remains the preferred definitive treat-\nment for patients with deep infiltrating bladder endometrio-\nsis, severe symptoms, or failure of medical therapy [ 12]. \nThe main goal of surgery is to eliminate symptoms and \nminimize the risk of recurrence by achieving complete exci-\nsion of the lesions. Partial cystectomy is the most effective \nmethod for removing lesions that invade the bladder wall. \nThis procedure can be performed laparoscopically or with \nrobotic surgery. Complete excision is critical in reducing the \nrisk of recurrence [13, 14]. In the case of incomplete resec-\ntion, both the continuation of symptoms and the progression \nof the disease may occur. While the laparoscopic approach \noffers the advantages of minimally invasive surgery, robotic \nsurgery provides better visibility, precise dissection, and \nergonomic ease [ 15]. During surgical planning, the depth \nof the lesion in the bladder wall, its proximity to the ure -\nters, and accompanying pelvic endometriosis foci should \nbe considered. A multidisciplinary approach (collaboration \nbetween urology and gynecology) plays an important role in \nincreasing surgical success in complex cases.\nDifferential diagnosis\nThe differential diagnosis of bladder endometriosis is clini-\ncally and radiologically important, given the overlap of \nsymptoms with other bladder pathologies. Urothelial car -\ncinoma represents the most critical condition to exclude, as \nit typically presents with painless hematuria and appears on \nimaging as an irregular, enhancing mass with predominant \nmucosal involvement, in contrast to the usually well-cir -\ncumscribed, submucosal or intramural lesions seen in endo-\nmetriosis. Interstitial cystitis/bladder pain syndrome should \nalso be considered, particularly in patients presenting with \nchronic pelvic pain and urinary frequency; however, imag -\ning findings are typically absent or nonspecific, and diag -\nnosis relies mainly on clinical criteria and cystoscopic \nevaluation. Urachal pathology, including urachal remnants \nor neoplasms, may mimic bladder dome lesions but are usu-\nally located in the midline along the urachal tract and may \nshow cystic or mixed solid-cystic characteristics on imag -\ning. In contrast, bladder endometriosis is often associated \nwith cyclical symptoms, characteristic MRI features such \nas T2-hypointense fibrotic nodules and T1-hyperintense \nFig. 1 MRI appearance of bladder endometriosis. A Axial T2-weighted \nimage demonstrating a hypointense nodule in the posterior bladder \nwall (arrow), consistent with fibrosis and smooth muscle hyperplasia. \nB Sagittal T2-weighted image showing infiltration of the detrusor mus-\ncle by the lesion (arrow). C Axial fat-suppressed T1-weighted image \nrevealing hyperintense hemorrhagic foci within the lesion (arrow). D \nDiffusion-weighted image demonstrating restricted diffusion within \nthe lesion (arrow), supporting deep infiltrative disease. These imaging \nfindings are characteristic of bladder endometriosis and are useful for \ndiagnosis, differential diagnosis, and preoperative assessment\n \n\n1 3\nAbdominal Radiology\nhemorrhagic foci, and coexistence with other deep infil -\ntrating endometriosis lesions. Therefore, integrating clini -\ncal history with advanced imaging findings is essential for \naccurate diagnosis and appropriate management.\nCystoscopy plays a complementary role in the diagnos -\ntic work-up by allowing direct visualization of the bladder \nmucosa. In cases of bladder endometriosis with mucosal \ninvolvement, cystoscopy may reveal characteristic bluish \nor reddish nodules, hyperemic areas, or polypoid lesions; \nhowever, it may also be normal when the disease is confined \nto the serosal or muscular layers. Therefore, negative cys -\ntoscopic findings do not exclude the diagnosis. Moreover, \ncystoscopy is particularly useful in differentiating endome -\ntriosis from urothelial carcinoma, as malignant lesions typi-\ncally present as irregular, friable masses with a tendency to \nbleed. When suspicious lesions are identified, biopsy during \ncystoscopy remains essential for histopathological confir -\nmation and definitive diagnosis. Consequently, the integra -\ntion of clinical presentation, MRI findings, and cystoscopic \nevaluation is crucial for accurate diagnosis and appropriate \nmanagement.\nPrognosis and recurrence\nPost-surgical prognosis is generally good, and significant \nimprovement in symptoms is achieved in the vast majority \nof patients. However, recurrence rates are directly related to \nwhether surgical excision is complete or not [16]. In the case \nof incomplete excision, the presence of residual disease is a \nsignificant risk factor for recurrence. In addition, multifocal \ndisease and the presence of accompanying deep infiltrative \nendometriosis foci can also increase the risk of recurrence. \nTherefore, long-term follow-up of patients and planning of \nadditional treatment when necessary are important.\nCurrent discussions and future perspectives\nThe optimal approach between medical and surgical treat -\nment in the management of bladder endometriosis is still \ndebated. While medical treatment provides symptom con -\ntrol, surgical treatment offers more permanent results. How-\never, there is no standard approach for every patient, and \ntreatment should be individualized. The increasing use of \nrobotic surgery has the potential to improve surgical out -\ncomes. However, more studies are needed on the cost-\neffectiveness and long-term results of these techniques. In \nthe future, the development of biomarkers that enable early \ndiagnosis and further advancements in imaging techniques \nwill play a significant role in disease management. Fur -\nthermore, the widespread adoption of a multidisciplinary \napproach will improve treatment success, especially in com-\nplex cases.\nConclusion\nBladder endometriosis is a rare but clinically significant \ndisease. The presence of cyclic hematuria is an important \ndiagnostic clue and should be carefully evaluated. Magnetic \nresonance imaging plays a crucial role in diagnosis, while \nsurgical excision forms the basis of treatment. Early diagno-\nsis, appropriate treatment selection, and a multidisciplinary \napproach can significantly improve patients’ quality of life.\nAcknowledgements None.\nAuthor contributions BGÖ: Developing the concept and design of the \nstudy, conducting a literature review, analyzing data, and writing the \narticle draft.HÖ: Contributing to the design of the study, making criti-\ncal revisions, and approving the final version of the article.All authors \nhave read and approved the final version of the article.\nFunding Open access funding provided by the Scientific and Techno-\nlogical Research Council of Türkiye (TÜBİTAK). None.\nData availability No datasets were generated or analysed during the \ncurrent study.\nDeclarations\nConflict of interest The authors declare no competing interests.\nEthical approval This is a study that does not require ethical approval.\nOpen Access   This article is licensed under a Creative Commons \nAttribution 4.0 International License, which permits use, sharing, \nadaptation, distribution and reproduction in any medium or format, \nas long as you give appropriate credit to the original author(s) and the \nsource, provide a link to the Creative Commons licence, and indicate \nif changes were made. The images or other third party material in this \narticle are included in the article’s Creative Commons licence, unless \nindicated otherwise in a credit line to the material. If material is not \nincluded in the article’s Creative Commons licence and your intended \nuse is not permitted by statutory regulation or exceeds the permitted \nuse, you will need to obtain permission directly from the copyright \nholder. To view a copy of this licence, visit  h t    t p : / / c r e  a  t  i v e  c  o  m m o n s . o \nr g / l i c e n s e s / b y / 4 . 0 /     .  \nReferences\n1. Zondervan KT, Becker CM, Missmer SA. Endometriosis. Nat \nRev Dis Primers. 2020;6:9.\n2. Chapron C, Marcellin L, Borghese B, Santulli P (2019) Rethink-\ning mechanisms, diagnosis and management of endometriosis. \nNature reviews. Endocrinology 15(11):666–682\n3. Lorusso, F., Scioscia, M., Rubini, D., Stabile Ianora, A. A., Scar-\ndigno, D., Leuci, C., De Ceglie, M., Sardaro, A., Lucarelli, N., \n& Scardapane, A. (2021). Magnetic resonance imaging for deep \n\n1 3\nAbdominal Radiology\ninfiltrating endometriosis: current concepts, imaging technique \nand key findings. 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