Endometriosis is a common condition where tissue similar to the lining of the uterus grows outside the uterus. While this tissue most frequently implants on pelvic organs, it can occasionally affect the urinary tract. Endometriosis can affect the bladder, though this is a less common manifestation of the disease. When bladder involvement occurs, it can cause significant urological symptoms and complications.
Defining Bladder Endometriosis
Bladder endometriosis is defined by the presence of endometrial-like tissue implants on or within the wall of the urinary bladder. This condition is part of urinary tract endometriosis, which is a rare occurrence. The bladder is the most frequently affected organ within the urinary tract.
The lesions are classified based on how deeply they penetrate the bladder wall. Superficial endometriosis involves implants located only on the outer surface of the bladder. Deep Infiltrating Endometriosis (DIE) is a more complex and symptomatic form where the tissue penetrates the detrusor muscle, the muscular layer of the bladder wall. This deep infiltration often leads to more severe symptoms. Bladder involvement is notably higher, up to 50%, in individuals already diagnosed with DIE elsewhere in the pelvis.
Recognizing Specific Symptoms
The presence of endometrial-like tissue on the bladder causes urological symptoms that often mimic other common conditions. Symptoms include painful urination (dysuria), increased urinary frequency, and urgency (a sudden, strong need to urinate).
These bladder symptoms frequently follow a cyclical pattern, which is a significant clue for diagnosis. They tend to worsen noticeably during the menstrual period when the implants are hormonally stimulated. Blood in the urine (hematuria) is also a specific symptom.
The symptoms can easily be mistaken for a chronic urinary tract infection (UTI) or interstitial cystitis, a chronic bladder pain syndrome. Many patients report that antibiotics fail to resolve their symptoms, delaying the correct diagnosis. The discomfort is caused by painful inflammation and swelling of the bladder wall, particularly when the detrusor muscle is infiltrated.
Methods for Accurate Diagnosis
Diagnosis of bladder endometriosis begins with a review of the patient’s symptoms, especially looking for the cyclical nature of the urinary complaints. Specific imaging is performed once this condition is suspected. Transvaginal ultrasound and pelvic Magnetic Resonance Imaging (MRI) are the primary tools used to visualize the lesions.
MRI is particularly valuable because it accurately determines the depth of the lesion, showing whether it has penetrated the muscular wall of the bladder. This information is important for planning treatment. However, the definitive diagnostic procedure is often a cystoscopy.
Cystoscopy involves inserting a thin, camera-equipped tube into the bladder through the urethra to directly visualize the bladder lining. This procedure may not always reveal the lesion if the endometrial tissue has not broken through the inner lining. When visible, the implants may appear as characteristic reddish or bluish nodules on the bladder wall, and a biopsy can be taken for confirmation.
Treatment Approaches
Management of bladder endometriosis involves two main strategies: medical suppression and surgical excision. Medical management typically uses hormonal therapies aimed at suppressing the growth and activity of the endometrial-like implants. Medications such as continuous oral contraceptives or GnRH agonists can reduce the hormonal stimulus, thereby easing pain.
Hormonal therapy is often considered palliative because it manages symptoms but rarely eliminates the deep-infiltrating nodule. Symptoms frequently return when treatment stops. For Deep Infiltrating Endometriosis in the bladder wall, surgical excision is often necessary for long-term relief. The goal of surgery is the complete removal of the endometrial nodule.
This typically requires a specialized laparoscopic or robotic procedure that involves a partial cystectomy, the removal of the portion of the bladder wall containing the lesion. This precise excision preserves as much healthy bladder tissue as possible while ensuring the entire nodule is removed to minimize the risk of recurrence. Due to the proximity to the ureters, which drain urine from the kidneys, a multidisciplinary team often performs these complex excisions.