Ultrasound diagnosis of bladder endometriosis
[Dec 2022]

The 30-year-old patient presented with complaints of cyclical dysmenorrhea, dysuria, and chronic pelvic pain and dyspareunia. No previous Cesarian sections were documented. The patient had undergone urine tests, which revealed only microhematuria, particularly during menstruation; and culture examination which was normal. Previous ultrasound scans and cystoscopy, performed several months ago, were apparently unremarkable. Despite negative urine microscopy, the patient was managed as chronic cystitis.

Transabdominal (fig.1 and 2) and transvaginal (fig. 3) sonography, performed with a filled bladder, revealed a hypoechoic nodule with irregular contours in the posterior wall of the urinay bladder (bladder dome). The lesion was only slightly projecting into its lumen. Muscularis mucosa and submucosa were involved. The endometriotic lesions was poorly vascularized (fig. 4). Loss of posterior bladder wall mobility was documented, therefore uterovesical region was considered obliterated. Posterior bladder wall was tightly adhered to anterior myometrium (fig. 5 and 6). Transvaginal sonography (fig. 7) also showed circumscribed (hypoechoic/heterogeneous) areas with ill-defined margins and light mass effect, located in asymmetrically thickened anterior myometrium, suggesting focal adenomyosis. Other sites of pelvic endometriosis were not detected. A diagnosis of bladder endometriosis, focal adenomyosis and utero-vesical adhesions was suggested.

The diagnosis of bladder endometriosis was based on ultrasound findings and clinical presentation.

BACKGROUND:
Endometriosis is a chronic condition that affects up to 10% of people assigned female at birth, leading to pain, infertility and reduced quality of life. The two phenotypes are superficial endometriosis (SE) and deep endometriosis (DE). Endometriosis of the urinary system accounts for less than 1% of all endometriosis. However, the real prevalence remains unclear, since around 50% of affected women may be asymptomatic. Diagnosing both types remains challenging, resulting in diagnostic delays for patients. Bladder endometriosis is defined as endometriosis infiltrating the detrusor muscle, more frequently the bladder base and bladder dome, less the trigonal zone and extra-abdominal bladder and it is the most common, representing 85% of urinary tract endometriosis. Typically, women with bladder endometriosis present with cyclical and non-cyclical pelvic pain, dysuria, but may also have urinary frequency, recurrent urinary tract infections and hematuria, and, more atypically, urinary incontinence.

CLINICAL PERSPECTIVE:
The initial evaluation of suspected bladder endometriosis includes the medical history, a physical examination, and complementary tests (laboratory testing, cystourethroscopy and imaging techniques). Ultrasound is an accurate tool to diagnose urinary tract involvement in women with suspected pelvic endometriosis. A moderately filled bladder allows better assessment of bladder wall and endometriotic nodules detection. Common ultrasound features are hypoechoic linear or nodular nodules, with or without regular contours involving the muscularis (most common) or submucosa of the bladder. Usually, endometriotic lesions are poorly or no vascularized. Bladder endometriosis is diagnosed only if the muscularis of the bladder wall is affected; lesions involving only the serosa represent superficial disease. Pelvic organ mobility and obliteration of the uterovesical region can be evaluated using the “sliding sign”. However, adhesions in the anterior pelvic compartment are present in nearly one third of women with a previous Cesarean section and are not necessarily a sign of pelvic endometriosis. The cystourethroscopy may be helpful to confirm the diagnosis. Cystoscopically, bladder endometriosis can have a spectrum of possible appearances from normal-appearing mucosa that is noticeably raised due to a nodule beneath the mucosa to infiltration through the mucosa. In the latter scenario, lesions can appear to be multiloculated with a combination of colors (from the same color as the bladder mucosa to a blue/violet color).

THERAPY PLANNING:
Treatment can be expectant, medical or surgical. Hormonal therapy is an effective option for those who are not planning to conceive or to undergo surgery. For patients with pain symptoms due to bladder endometriosis, continuous progesterone-based regimens (pills, intrauterine device, implant, injection), combined estrogen-progesterone therapy (continuous or sequential regimens) and gonadotropin-releasing hormone agonist (with or without add-back therapy) have all been associated with an improvement of symptoms of bladder endometriosis. Specifically, Dienogest may be suitable for patients refusing surgery, considering the effectiveness and tolerance for long-term use. Segmental bladder resection/partial cystectomy is the bladder-preserving surgery and offers the complete removal of bladder endometriotic nodules.

OUTCOME & PROGNOSIS:
Women who respond to medical management can continue the treatment until menopause or until the desire to conceive from pregnancy or to achieve an optimal quality of life and reduce the risk of progression. The mentioned patient accepted conservative management with a sonographic follow-up. Dienogest administration was effective and tolerable in alleviating urinary symptoms. The size of the endometriotic nodule lesion remain stable during Dienogest administration, and the effect was maintained until 36 months thereafter.

Transvaginal sonography is the first-line diagnostic tool in the work-up of women with potential underlying deep endometriosis and sufficiently accurate to detect and characterize the extent of lesions. Beyond the basic steps to identify endometriosis, thorough ultrasound assessment of anterior and posterior pelvic compartment is mandatory, particularly in settings of symptoms and signs of endometriosis.

Ultrasound is more than just a diagnostic test as it can help patients and clinicians to understand the extent and location of endometriosis by interpreting real-time tenderness and mobility, as well as facilitate objective monitoring of disease over time and in many cases is helpful in planning a multidisciplinary surgical approach

I declare that consent from the patient was obtained to publish this case.

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