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CONGENITAL VALVE FORMATION AND CYST


CONGENITAL VALVE FORMATION AND CYST
Congenital posterior urethral valves are serious anomalies of the posterior urethra. Thin folds of mucosa originate from the verumontanum and extend to the sides of the urethra and form a “wind sail” in the urethra. Urine flow fills the sails and results in chronic obstruction to urine flow, which then leads to compensatory bladder hypertrophy and eventually to bilateral hydronephrosis. The condition should be suspected when the following are observed: difficult urination, enuresis, intractable pyuria, recurrent urinary tract infection, or evidence of renal insufficiency. The diagnosis can be difficult to make, because the “valves” are difficult to see (the sails are floppy) when viewed in a retrograde fashion through cystoscopy. The diagnosis is best made with a voiding cystourethrogram. With transurethral approaches, the valve folds can be removed or fulgurated with complete relief of the urinary obstruction. Renal insufficiency, however, is usually irreversible.

Congenital cysts of the external genitalia are relatively rare. These cysts, simple or multiple, are usually situated along the median raphe of the penis at any point from the frenulum to the scrotum. On palpation they are freely movable, tense, rounded masses lying just beneath the skin.
CONGENITAL VALVE FORMATION AND CYST

Cysts of the internal genitalia may occur in the Cowper gland within the membranous urethra and also at the verumontanum (müllerian duct cysts). Cysts occurring in the verumontanum are vestigial ends of the müllerian ducts (see Plate 1-12) and can be large and project posteriorly to the prostate and seminal vesicles or occupy the space between the anterior rectal wall and the posterior bladder and prostate. Although usually small (few centimeters), they can approximate the size of a large orange or present as a large abdominal mass. There is usually communication by a small neck or channel to the utricle at the verumontanum. Wolffian or ejaculatory duct cysts are usually found laterally along either ejaculatory duct, unlike midline müllerian duct cysts. Either type of cyst can cause ejaculatory duct obstruction and present as a low ejaculate volume and azoospermia. They are quite treatable with transurethral cyst unroofing.
On occasion, wolffian and müllerian duct cysts may present with other symptoms beside infertility. A history of intermittent bloody urethral discharge, dysuria, a sensation of fullness in the rectum, or disturbances in sexual function that include hematospermia (blood in the semen) or dyspareunia (painful climax) are not uncommon. The diagnosis is confirmed with transrectal ultrasound, which may show the cyst in association with dilated seminal vesicles (>1.5 cm width) or dilated ejaculatory ducts (>2.3 mm wide). Sophisticated adjunctive techniques such as vasodynamic pressure measurements, based on the same concept as urodynamic assessment of bladder function, can confirm physical obstruction of the seminal esicles in cases of partial ejaculatory duct obstruction.
Other congenital anomalies (not illustrated) are rare. Congenital urethral diverticulae are located on the ventral urethra from the triangular ligament to the glans penis. These diverticulae may, in rare instances, develop to a size that almost completely obstructs the urethra, similar to cases of acquired urethral diverticulae resulting from strictures and tumors. Congenital stricture of the meatus causes dysuria and small ulcerations at the urethral meatus. Undiscovered meatal stenosis or strictures may lead to voiding dysfunction, cystitis, and pyelonephritis. Treatment requires antibiotics and urethral dilation or formal meatotomy. Absence or atresia of the urethra is very rare but may be associated with other anomalies in which the bladder urine drains through the urachus into the umbilicus or into the rectum. Congenital urethrorectal fistula, in which a communication exists between the membranous urethra and the rectum, is also very rare and is usually associated with imperforate anus.