Pathology
Histopathologically, several characteristics are frequently visible in urethral diverticula. These include nephrogenic adenoma, chronic inflammation associated with fibrosis around the glands, small or absent epithelium, chronic cystitis, cystitis cystica, cystitis glandularis, squamous metaplasia, and adenomatous metaplasia.Approximately 1/3 of diverticula are compound or multiple, and some can extend to surround the urethra. Diagnosis
Urethral diverticulum is often an incidental finding. It can be diagnosed using magnetic resonance imaging and/or micturating cystourethrography. Other studies that can be used to diagnose urethral diverticulum include intravenous urography, urethroscopy, and/or ultrasound. Conditions that should be distinguished from urethral diverticulum in a differential diagnosis include overactive bladder, Gartners duct cyst, Gartners duct abscess, ectopic caeco-ureterocele, interstitial cystitis, pelvic inflammatory disease, endometriosis, and cancer. Treatment
The primary treatment for urethral diverticulum is surgical. In women the surgery is conducted transvaginally, usually when there is no acute inflammation to better aid dissection of the delicate tissues. Prognosis
Left untreated, urethral diverticulum can cause significant morbidity (sickness).During surgery, there is a risk for complications due to the highly vascular nature of the tissue. The urethral sphincters and its smooth muscle, as well as the neck of the bladder, can be injured regardless of the surgical approach. Other complications from surgery can include urinary incontinence, stress incontinence, a urethrovaginal fistula, or recurrent diverticula. Horseshoe-shaped diverticula and diverticula that completely surround the urethra are both associated with worse outcomes, as are those located close to the bladder, and large (over 3–4 cm) diverticula.
When the proximal tubule is injured, sodium, potassium, bicarbonate, uric acid, and phosphate reabsorption may be reduced or changed, resulting in low bicarbonate, known as metabolic acidosis, low potassium, low uric acid known as hypouricemia, and low phosphate known as hypophosphatemia. Damage to the distal tubule may cause loss of urine-concentrating ability and polyuria.In most cases of acute tubulointerstitial nephritis, the function of the kidneys will return after the harmful drug is discontinued, or when the underlying disease is cured by treatment. If the illness is caused by an allergic reaction, a corticosteroid may speed the recovery kidney function; however, this is often not the case. Chronic tubulointerstitial nephritis has no cure. Some patients may require dialysis. Eventually, a kidney transplant may be needed. Epidemiology
Interstitial nephritis is uncommon (<1% incidence) in patients without any symptoms but occurs in about 10-15% of hospitalized patients with acute kidney injury of unknown cause. While it can occur in patients of all ages, it is more common in elderly patients, perhaps due to increased exposure to drugs and other triggering causes. References
External links
Merck Manual