PARAURETHRAL J. G. BLAIVAS, CYSTS IN FEMALE zyx M.D. V. M. PAIS, M.D. A. B. RETIK, NEONATE zyxw M.D. From the Department of Pediatric Urology, Boston Floating Hospital for Infants and Children, and Department of Urology, St. Elizabeth’s Hospital, Boston, Massachusetts ABSTRACT - Paraurethral cy sts in the female neonate are uncommon lesions. All reported cases have either ruptured spontaneously or responded to simple marsupialization. However, complete urologic evaluation is mandatory because they simulate ectopic ureteroceles in appearance. Herein is reported our experience with 5 patients. The etiology, embryogenesis, natural history, differential diagnosis, and treatment are discussed. Paraurethral cysts are occasionally observed in the neonatal period, but their true incidence is unknown. The natural history and treatment have received little attention, but the etiology has been the subject of much debate. Herein we present our experience with five such lesions and review the pertinent literature. Case Reports Case 2 This newborn white female was noted to have a 1 by l-cm. paraurethral cystic mass at birth. A ventriculoseptal cardiac defect was also discovered, and for this reason she was followed up for four months. Findings on routine laboratory tests were normal as were excretory urogram, voiding cystourethrogram, and cystourethroscopy. The zy Case 1 A newborn white female, the product of a normal gestation and delivery, was noted to have a 1 by l-cm. cystic paraurethral mass displacing the urethral orifice to the left (Fig. 1). Findings on urinalysis, urine culture, blood urea nitrogen, serum creatinine, excretory urography, voiding cystourethrography, and cystourethroscopy were normal. Needle aspiration of the contents of the cyst revealed sterile, cloudy white fluid which contained many squamous epithelial cells. Contrast study of the cyst revealed a smooth, contoured 7 by 12-mm. cavity with no connection to the genitourinary tract (Fig. 2). Treatment consisted of partial excision of the cyst with marsupialization of its wall. Histologic examination revealed the cyst wall to be lined with squamous epithelium (Fig. 3). 504 zyxwvutsrqp FIGURE 1. M ass 1 by 1 cm. displacing urethral meatus to left. UROLOGY / MAY 1976 ! VOLUME VII, NUMBER 5 Case 5 This one-day-old Puerto Rican female was the product of a normal gestation and delivery. At birth she was noted to have a 1 by l-cm. cystic paraurethral mass just to the right of the meatus. Urinalysis and urine culture were normal. Excretory urogram revealed a right pelvic kidney. On the third hospital day the cyst ruptured spontaneously and did not recur. Incidence and Natural History Infantile paraurethral cysts are considered to be uncommon. Standard textbooks either do not mention them or present only a brief discussion 1*2On the other hand, we compiled 5 cases in less’ than three years and Cohen, Klein, and Lavel3 recorded 5 cases in a shorter interval. It appears then that they are more common than previously recognized. The paucity of published reports is probably due to the benign nature of the lesion. Five of the 12 reported cases (including our series) underwent spontaneous rupture without sequelae. None were associated with other significant genitourinary abnormalities. In only 1 case did the mass obstruct the urethra requiring urgent treatment. Although long-term follow-up is incomplete, it appears that all the patients remained well. zyxwvuts FIGURE 2. Percutaneous injection of cyst cavity reveals no connection with genitourinary tract. mass remained unchanged, and the patient underwent partial excision and marsupialization of the cyst wall. Histologic examination revealed a simple cyst lined with squamous epithelium. One year later the patient was asymptomatic and had normal-appearing genitalia. Case 3 This six-month-old white female was the product of a normal gestation and delivery. A cystic paraurethral mass noted at birth was unchanged in size. Findings on excretory urography and cystoscopy were normal, but voiding cystourethrography revealed bilateral vesicoureteral reflux (grade II-B). Results of laboratory tests were normal. The patient underwent partial excision and marsupialization of the cyst wall. Histologic examination revealed a simple cyst lined with squamous epithelium. Three years later she was symptom-free with normal genitalia. The vesicoureteral reflux subsided. Normal Embryology The mesonephric duct arises in the first few weeks of fetal life as the excretory duct of the pronephros. With pronephric degeneration it persists as the duct of the mesonephros which, in Case 4 A six-month-old white female was noted to have a 3 by 3-cm. blue cystic mass lying just inferior to the urethral meatus in the anterior vaginal wall. Results of routine laboratory tests were normal as were excretory urogram, voiding cystourethrogram, and cystourethroscopy. Partial resection and marsupialization of the cyst wall eventuated in normal genitalia one year later. Histologically, the cyst was lined with squamous epithelium. UROLOGY / MAY1976 / VOLUMEVII, NUMBER5 FIGURE 3. Histologic examination lined with squamous epithelium. reveals cyst wall 505 During development ____ of female genital _ zyxwvutsrqponmlkjihgfedcbaZYX sy stem mesonephric remnants (solid black) may be present any w here between broad ligament and vag- the male, gives rise to the genital duct system paradidymis, epididymis, vas deferens, seminal vesicle, and ejaculatory duct. In the female, however, the mesonephric system degenerates and remains only as a vestigial structure. A cranial group of tubules may persist near the ostium of the fallopian tube as the epoophoron. The duct of the epoophoron continues caudally in the broad ligament to another group of mesonephric tubular remnants, the paroophoron. Gartner’s duct, the caudal end of the mesonephric duct, may be present anywhere between the broad ligament and the anterolateral vaginal wall (Fig. 4).*-‘j The paramesonephric or miillerian ducts arise lateral to the mesonephric ducts in the six-week embryo. Their fused solid tip reaches the urogenital sinus at the ninth week where it forms Miiller’s tubercle. The proximal end of the miillerian duct forms the fallopian tube while the fused distal end forms the uterus, cervix, and vagina (Fig. 4).4-6 Both the mesonephric and miillerian ducts are lined by cuboidal epithelium and surrounded by a muscular stroma. 6 The female urethra arises as a tubular elongation of the urogenital sinus during the sixth embryonic week. Shortly thereafter, twenty to forty glandular structures arise as the primordium of the prostate. These cuboidal lined glands regress in the female except for those that develop into Skene’s glands. In addition, there is another glandular outgrowth of squamous epithelium from the uterovaginal canal. These normally regress prior to birth, but their persistence might lead to the formation of paraurethral cysts.’ Embryogenesis of Paraurethral Cysts Although paraurethral cysts are usually thought to be remnants of the mesonephric system (Garner’s or wolffian duct cyst), there is actually little evidence to support this theory. The proponents argue that because these cysts are located in the course of the mesonephric duct, they are necessarily of mesonephric origin.3,8*g However, in our experience, these cysts have none of the characteristic mesonephric histology; that is, they are neither lined by cuboidal epithelium nor surrounded by a muscular stroma. We suggest that only those cysts which conform to these criteria be designated mesonephric cysts. Other theories claim that they are the dilated ends of obstructed paraurethral glands, abortive attempts at ectopic ureteral duplication,2 or obstructed urethral diverticula,” but once again the histology is inconsistent. The only naturally occurring squamous structure in the vicinity of the urethra is the vaginal mucosa, and it has been suggested that these cysts zyxwvutsr UROLOGY I MAY 1976 / VOLUME VII, NUMBER 5 represent vaginal inclusions.g Another equally plausible explanation is that they represent remnants of the squamous lined glands which arise from the uterovaginal canal. Differential Diagnosis and Treatment Paraurethral masses may be solid or cystic. Solid masses are usually evident on physical examination and include fibroma, leiomyoma, neurofibroma, lipoma, myoblastoma, hemangioblastoma, lymphangioma, and their malignant counterparts including sarcoma botryoides. g~11~i2 Urethral prolapse may simulate paraurethral cysts. It may occur spontaneously or follow an episode of violent coughing or vomiting, It involves the entire circumference of the urethra and the meatus appears in the center.2 Cystic structures include urethral diverticula, lo periurethral abscesses, and true embryonic cysts, but these are almost unheard of in the neonatal period. Most importantly, ectopic ureteroceles may be mistaken for paraurethral cysts. In fact, 7 per cent of a series of 59 ectopic ureteroceles actually presented as paraurethral cystic masses,13 and the diagnosis could only be made by complete urologic investigation. For this reason we believe that all paraurethral masses should be evaluated with excretory urography, voiding cystourethrography, and cystourethroscopy. Aspiration of the cyst contents and radiographic contrast study may further delineate the extent of the lesion. Once the diagnosis is certain, treatment consists of partial excision with marsupialization of the cyst wall. All the patients so treated were completely asymptomatic and had normal genitalia one to three years later. UROLOGY I Department of Urology New England Medical Center Hospital zyxwvutsr 171 Harrison Avenue Boston, Massachusetts 02111 (DR. BLAIVAS) zyxwvutsr M A Y 1976 / VOLUM E VII, NUM BER 5 References The Gynecology of A dolescence and 1. HUFFM AN,J. W .: Childhood, Philadelphia, W . B. Saunders, 1968, p. 210. Paediatric Urology, London, But2. W ILLIAM S, D. I.: terworths & Co., 1968, p. 238. 3. COHEN, B.: H. J., KLEIN, M . D., and LAVER, M . Cysts of the vagina in the newborn infant, Am. J. Dis. Child. 94: 322 (1957). Developmental B.: Anatomy, 4. AREY, L. Philadel- phia, W . B. Saunders, 1963, p. 323. 5. GRAY, S. W ., and SKANDALAKIS, J. E.: Embryology for Surgeons, Philadelphia, W . B. Saunders, 1972, p. 323. 6. GARDNER, G. H., GREENE, R. R., and PECKM AN,M . B.: Normal and cystic structures of the broad liga- ment, Am. J. Obstet. Gynecol. 55: 917 (1948). 7. JOHNSON,F. P. : The homologue of the prostate in the female, J. Urol. 8: 13 (1922). 8. JOHNSON,C. M .: Diverticula and cyst of the female urethra, ibid. 39: 506 (1938). 9. NOVAK, E. W .: R., JONES, S. G., and JONES, H. Novak’s Textbook of Gynecology, Baltimore, W il- liams and W ilkins, 1965, p. 197. 10. GLASSM AN,T. A., W EINERTH, J. L., and GLENN, J. F. : Neonatal female urethral diverticulum, Urology 5: 249 (1975). 11. KAUFM AN, R. H., mesodermal and GARDNER, H. L.: tumors, (1965). 12. RADM AN,H. M . : Clin. Obstet. Gynecol. Benign 8: 953 W olfian duct cyst of the vulva, Pacif. M ed. Surg. 74: 170 (1966). Problems in the management of ec13. W ILLIAM S, D. I.: topic ureteroceles, J. Urol. 92: 635 (1964). 507