Diagnosis of infiltrating bladder endometriosis after fourth cesarean section

A 32‐year‐old woman, gravida 7‐para 4‐aborta 3, with chronic pelvic pain noted increased in severity in March 2020 with dysuria and dyspareunia. She had no documented fever or hematuria. The patient had no significant past medical history, including urinary tract infections or urinary tract‐related complaints. Her surgical history included four cesarean sections with no complications. No prior diagnosis of endometriosis during these procedures were noted. Physical examination revealed no abnormal findings. Initial pelvic ultrasound revealed significant signs of pelvic congestion and mild posterior adenomyosis. The initial impression was pelvic congestion syndrome with associated dysmenorrhea. Urine analysis was normal. The patient was advised to take Primolut‐NOR‐5 mg (progesterone), Daflon, and Profinal‐XP (NSAID). Pap smear was unremarkable. In October 2020, the patient presented with the same symptoms. Further investigations included a pelvic ultrasound, which showed similar signs of congestion and adenomyosis, with an additional finding of a small lesion (1–1.5 cm) at the vesicouterine junction, suspicious of an endometriotic nodule. No abnormalities were seen in the ovaries. Urine analysis showed only traces of proteins. She was prescribed Decapeptyl (GnRH agonist) and scheduled for a follow‐up after 3 months. The patient showed improvement and required no further interventions during 2021–2022. In February 2023, the patient presented again with pelvic pain. Physical examination revealed a palpable nodule in the anterior pelvis. A pelvic MRI was performed, showing thickening of the right uterosacral ligament (10 mm) suggestive of posterior pelvic endometriosis, and an anterior bladder nodule measuring 33 × 24 × 18 mm, hypointense on T2, with diffuse spots of T1 hyperintensity, consistent with pelvic endometriosis (Fig.  1a,b ). Given the persistence of symptoms, a decision for surgical intervention was made. Excision of endometriotic nodule was performed (Fig.  2b ). Pre‐operative pelvic ultrasound confirmed a bladder endometriotic nodule (Fig.  3 ), measuring approximately 5 × 3.5 × 2 cm (Fig.  2a–c ). Interrupted single‐layer bladder closure was executed, and a Foley catheter was inserted post‐operatively. It took 2 weeks for the urine to become completely clear. The patient improved clinically with no further complaints. No other endometriotic deposits were found at other sites. MRI findings showing bladder endometriosis: (a) longitudinal section and (b) transverse section. (a) Intra‐op visualization of the bladder mass. (b) Intra‐op bladder mass excision. (c) Excised bladder mass. Pelvic ultrasound showing bladder endometriotic nodule (August 2023).

Bassem Skaff: Conceptualization; data curation; supervision; validation. Rayane Diab: Conceptualization; validation; supervision; visualization. Mohamad Moussa: Investigation; validation; visualization; supervision. Christopher Massaad: Conceptualization; investigation; visualization; writing – review and editing; supervision; formal analysis. Kariman Ghazal: Conceptualization; investigation; writing – original draft; writing – review and editing; visualization; validation; supervision; data curation.

Ethical approval to report this case was obtained from the New Mazloum Hospital by Dr. Bassem Skaff. However, due to the ongoing crisis in Beirut, Lebanon, the ethical approval number is unavailable. Despite the challenges posed by the current situation, all relevant rules and guidelines for conducting and reporting medical case studies were strictly adhered to. Patient confidentiality was maintained, and informed consent was obtained from the 40 patient for the publication of this case report and any accompanying images. The hospital's ethics committee reviewed the case to ensure that it met ethical standards for clinical reporting.

Written informed consent was obtained from the patient(s) for their anonymized information to be published in this article.

Not applicable.

Patients with bladder endometriosis can present with lower urinary tract symptoms. These can include hematuria, dysuria, and bladder pain. 6 , 7 , 8  Such symptoms can be exacerbated during menstruation. Indeed, a pathognomonic sign for bladder endometriosis is cyclical menstrual hematuria which is experienced by approximately 20% of patients. 9 , 10  Nonetheless, it is worth noting that 50% of women with bladder endometriosis can be asymptomatic. When it comes to bladder endometrioses, both gynecologists and urologists can manage the condition depending on the degree of the clinical manifestation. 11 , 12 In most cases, deep infiltrating endometriosis is associated with severe pelvic pain and can lead to infertility. 3 The etiology behind bladder endometriosis is not clearly defined. 13 The latter can either arise spontaneously in generalized pelvic disease or stem from iatrogenic causes, including hysterectomy and cesarean section. 10 One important clue in our patient might be the past surgical history of the patient, as DIE might present following a cesarean section. 14 It is also worth noting that endometriotic lesions of the bladder do affect in particular the detrusor muscle in the bladder trigone and apex, which is the case of our patient. Accordingly, bladder endometriosis in this patient, despite no prior diagnosis during her cesarean sections, might be related to microscopic endometrial tissue implantation during surgery. Moreover, the current body of literature denotes that a Pfannenstiel incision does carry a higher risk of Caesarian section endometriosis (CSE) when compared to a vertical midline incision. Accordingly, it is important to perform thorough cleaning of the fascia layer and both corners of the adipose layer in order to prevent CSE. When clinically suspected, transvaginal ultrasound (TVS) must be the first‐line imaging to be performed in the DIE workup. 15 , 16 Additionally, pelvic MRI has been proven as an important tool in achieving accurate diagnosis. Bladder endometriotic implants are usually seen as hypointense on T2‐weighted images and with possible diffuse hyperintensities on T1‐weighted images, 17 , 18 as seen in our case. In the cases whereby the patient presents with proven hematuria or bladder nodule visible on TVS or MRI, cystourethroscopy can be used as an effective tool in order to confirm bladder endometriosis. Indeed, the latter can identify solid nodular lesions on the vesical dome and vesico‐uterine fossa. It can further assist in delimiting the lesion and keeping a margin of 5 mm of healthy tissue during surgery. For our patient, she initially exhibited symptoms of pain and dysuria. However, she did not present with hematuria, and the urine analysis showed no blood. Consequently, we did not utilize diagnostic techniques involving cystoscopy. This was proven to be an effective approach in bladder endometriosis. 19 Moreover, hysterectomy is a surgical option for women who do not wish to conceive, who have failed to respond to conservative treatment, and especially for those who have associated adenomyosis. 20 After the surgical intervention, the patient was instructed to follow up for post‐operative evaluation and management. However, the patient did not return for scheduled follow‐up visits but informed us that she was feeling well and had no further complaints.

This case report highlights a rare presentation of bladder endometriosis in a patient with non‐specific symptoms like severe pelvic pain, dysuria, dyspareunia, contrasting with similar cases that include hematuria and urinary infections. Diagnosis was achieved through clinical suspicion supported by vaginal ultrasound, 3D imaging and MRI. While medical therapy offers temporary relief, resection of endometriotic nodule, remains the most effective treatment. The likely mechanism in this patient, given her history of four cesarean sections and no prior endometriosis diagnosis, might involve microscopic endometrial cell implantation during surgery rather than Sampson's theory of retrograde menstruation.

Endometriosis is defined as the extrauterine presence of endometrial glands and stroma. 1 Several theories have been proposed regarding its pathogenesis, but is not yet fully understood. Sampson's retrograde menstruation theory remains the most recognized explanation of how endometrial tissue invades the pelvic cavity. 2 When endometriosis invades adjacent structures, it is termed “deeply infiltrating endometriosis” (DIE). 3 This rare types affects 1–5% of women with endometriosis. 4 DIE typically presents with dysmenorrhea, severe pain, mictalgia, and dyschezia. 3 Bladder endometriosis is particularly rare, accounting for a small percentage of DIE cases and can often be underdiagnosed or misdiagnosed. It often presents with non‐specific symptoms such as chronic pelvic pain, dysuria, hematuria, urinary frequency, and urinary tract infections. 5 , 6 The primary treatment for bladder endometriosis involves a combination of medical and surgical approaches whereby excision of the endometriotic nodule is considered the best approach for eradicating endometrial lesions.

The authors declare no conflict of interest.