Address correspondence to Zoltán Papp, MD, PhD, I. Department of Obstetrics and Gynecology, Semmelweis University Medical School, Budapest, Hungary, Ph: 36-1-114-0461, Fax: 36-1-114-0231

Synonyms: None.

Definition: Distention of the vagina (and also the uterine cavity in hydrometrocolpos) caused by accumulation of watery-mucoid fluid due to the obstruction of the genital orifice.

Etymology: From the Greek udro = water, mhtra, womb and kolpoV, vagina.

Prevalence: 2-2.5: 10,000 births.

Etiology: Multifactorial.

Pathogenesis: The incomplete absence of the fusion and canalization of the müllerian ducts, often associated with the defects of the urogenital system.

Associated anomalies: Anomalies of the urinary system (müllerian duct aplasia or hypoplasia, renal agenesis or ectopy) can be observed in one-third of cases. Several deformities of the spine and the extremities are also common.

Differential diagnosis: Obstruction of the posterior urethral valve, ovarian cyst, omental cyst, and mesenteric cyst.

Prognosis: Good, especially in early diagnosed and treated cases.

Recurrence risk: None.

Management: Surgical treatment of the newborn is necessary in all cases.

MESH Vagina-abnormalities, -diseases; uterus; genitalia,-female-abnormalities BDE 0483 CDC 752.435 ICD9 752.4 MIM 277000

Introduction

The majority of malformations grouped as gynatresia (such as vaginal atresia or aplasia) are recognized in adolescence or after1,5,9. This paper discusses a case of hydrocolpos detected by prenatal ultrasound and the difficulties of diagnosis differentiation.

Case report

A 27-year-old pregnant woman was presented for ultrasound examination. She previously delivered by cesarean section a 4,480g live-born girl that died on her first day of postnatal life of "multiple congenital malformations" of unclassified origin. The current pregnancy was unremarkable. The results of all laboratory tests were within normal range. An ultrasound examination of the fetus indicated a cephalic presentation. The quantity of amniotic fluid was slightly decreased. The following measurements were obtained: biparietal diameter: 91 mm; occipito-frontal diameter: 106 mm; femur length: 71 mm; abdominal perimeter: 316 mm. The intracranial structure and the spine were normal. The diaphragm was visible. The abdomen contained a 74*65*68 mm mass that was too big to be a bladder (fig. 1).

Figure 1: The tumor in the lower abdomen of the fetus.

Both kidneys were enlarged; the left one was 65*31 mm in size (fig. 2), while the right kidney measured 72*31 mm (fig. 3) with the width of the cortex at 10-12 mm and the size of pyelons at 37*11 mm.

Figure 2: Pyelectasia of the left kidney.

Figure 3: Pyelectasia of the right kidney.

The ultrasound image suggested a sequence of obstructions in the urethra, causing urine stagnation in the bladder and in the renal pelvis. After a few days of observation, elective cesarean section was performed in the 37th week of gestation. The baby girl weighed 3350g, was 51 cm long and had a head circumference of 35 cm. The chest of the newborn was proportionate without abnormalities in the heart or the lungs. A tense, flexible swelling could be palpated above the umbilicus in the protruding abdomen. The liver was palpable but not the spleen. The 5th toe was duplicated on the right foot. Planter flexion was observed on both feet. The vagina could not be probed. The newborn passed urine and meconium spontaneously after birth.

Postnatal ultrasound

The liver, spleen and gallbladder were normal in structure and size. Both kidneys corresponded in size to the age of the newborn. Their collecting system and the proximal ureters were slightly enlarged.

A round, thin-walled (2 mm) cyst filled with thick, swirling liquid was observed extending over the umbilicus to the small pelvis. The presence of vaginal atresia and hydrocolpos caused compression of the urethra. We decided to surgically relieve the obstruction. 200 ml of turbid matter were discharged from the vagina through the perineum. A balloon catheter was introduced into the vagina.

Discussion

Definition

Hydrocolpos is the distention of the uterus and vagina by fluid other than blood or pus, resulting in a cystic structure in the lower abdomen.

Etiology and pathogenesis

Both female and male embryos have two pairs of genital ducts. The male (wolffian or mesonephric) ducts play an important role in the development of the male reproductive system, and the female (müllerian or paramesonephric) ducts play an important part in the development of the female reproductive system. The cranial, unfused portions of the paramesonephric ducts develop into the uterine tubes, and the caudal, fused portions into the uterovaginal primordium, which gives rise to the epithelium and glands of the uterus and the fibromuscular wall of the vagina (fig. 4-5). The endometrial stroma and the myometrium are derived from the adjacent mesenchyma. Part of the cranial end of the paramesonephric duct that does not contribute to the infundibulum of the uterine tube may persist as a small cyst, called hydatid of Morgagni. When both pairs of genital ducts are present, the genital duct system is in an undifferentiated stage. In the female, the mesonephric ducts almost completely disappear, and only a few remnants persist, such as appendix vesiculosa, epoöphoron, paroöphoron, Gartner"s duct and Gartner"s duct cyst. The paramesonephric ducts pass caudally, running parallel to the mesonephric ducts until they reach the caudal region. Here they cross ventrally to the mesonephric ducts, come together in the midline, and fuse into a Y-shaped uterovaginal primordium or canal. This tubular structure projects into the dorsal wall of the urogenital sinus and produces an elevation, called the sinus tubercle (fig. 4). The vaginal epithelium is derived from the endoderm of the pelvic part of the urogenital sinus. The vesical part of it forms to the urinary bladder and urethra, and the phallic part becomes the urethral and paraurethral glands and greater vestibular glands. The fibromuscular wall of the vagina develops from the uterovaginal primordium. Contact of the uterovaginal primordium with the urogenital sinus induces the formation of paired endodermal outgrowths, called sinovaginal bulbs. They extend from the urogenital sinus into the caudal end of the uterovaginal primordium. The sinovaginal bulbs soon fuse to form a solid cord, the vaginal plate. Later, the central cells of this plate break down, forming the lumen of the vagina. The peripheral cells remain as the vaginal epithelium. Until late fetal life, the lumen of the vagina is separated from the cavity of the urogenital sinus by a membrane called the hymen. The hymen usually ruptures during the perinatal period and remains as a thin fold of raucous membrane around the entrance to the vagina. Failure of canalization of the vaginal plate results in vaginal atresia (fig. 5). The most minor type results from failure of the hymen to rupture, a condition known as imperforate hymen. Membranous occlusion at higher levels also occurs and may be mistaken for imperforate hymen. In either case, if there is an excessive secretion of watery fluid, the condition is known as hydrometrocolpos11.

Figure 4: In the 7-week embryo (top), the genital ducts are undifferentiated. The mesonephric duct, which drains the mesonephric kidney, will evolve into the epididymis in the male, but regress in the female into the epoophoron, and the paraoophoron (bottom: 12 weeks fetus). A process of vaculolization transforms the urogenital primordium into the vagina and hymen. The paramesonephic ducts (m<129>llerian ducts) fuse to form the uterovaginal canal and then the uterus. The unfused portion persists as the tubes. The lumen of the vagina is separated from the vestibule by the hymen, which usually opens during the perinatal period.

Figure 5: Sagital sections (8-12 weeks). The sinovaginal bulb progressively differentiates into the vagina.

Diagnosis

Sherwood8 and his team have stated in a comprehensive pediatric statistical review that the incidence of abdominal tumors in newborns was approximately 0.2 percent. Longino et al4 seem to be of almost the same opinion. Their data suggest the following distribution of abdominal tumor type abnormalities:

Miller et al6 have made a noteworthy remark when stating that disorders of urogenital origin have been increasing.

Differential diagnosis

The most frequent differential diagnosis is the ovarian cyst. It exists in the lower abdomen, generally not in the midline, but laterally. It has a more circular than oval shape in form by ultrasound. Determination of the sex of the fetus can give an important aid to recognizing it. Other cystic formations, such as mesenteric cyst, and omental cyst, are very rare. Although they have no characteristic signs by ultrasound, it is necessary to keep them in mind.

Gynatresia may be of congenital origin or may be acquired. In the majority of cases, the first clinical symptoms of defects caused by vaginal atresia can be recognized during menarche. The stretch over the blockage enlarges significantly and causes tense lower abdominal cramp-like pain with occasional disorders of urination and/or defecation. Although our ultrasound results led us to suspect that the most likely cause was the narrowing of the urethral valve, this was excluded almost immediately after birth with participation of pediatric specialists. So our diagnosis was confirmed after the delivery only.

Associated anomalies

Intrauterine intervention (draining or shunting) can be necessary if the dilated uterus and vagina are causing a significant enlargement of the fetal kidneys. Otherwise, early postnatal therapy (surgical procedure) can be chosen.

Conclusion

We consider it to be worthy of attention that besides deformities of the urinary tract, a significant hydrocolpos may also be responsible for the fetal pyelectasia, as our case suggests. The case history of the newborn proves that pyelectasia has disappeared shortly after the retained matter was discharged.

References

1. Berman L, Stringer DA, St. Onge O, et al: Case report: Unilateral haematocolpos in uterine duplication associated with renal agenesis. Clin Radiol 38:545, 1987.

2. Greene RA, Bloch MJ, Huff DS: MURCS association with additional congenital anomalies. Hum Pathol 17:88, 1986.

3. Heidenreich W: Genitale und extragenitale Fehbildungen beim Mayer- Rokitansky-Kuster-Syndrome. Dtsch Med Wochenschr 113:1092, 1988.

4. Longino LA, Martin LW: Abdominal masses in the newborn infant. Pediatrics 21:596, 1988.

5. Massafra C, Bartolozzi M, Bartolozzi P et al: Case report: Rokitansky-Kuster-Hauser syndrome with ectodactyly. Acta Obstet Gynec Scand 67:557, 1988.

6. Miller EI, Thomas RH: Fetal hydrocele detected in utero by ultrasound. Br J Radiol 52:620, 1979.

7. Neinstein LS, Castle G: Congenital absence of the vagina. Am J Dis Child 127:669, 1983.

8. Scherwood DW, Smith RC, Lemmon RH et al: Abnormalities of the genito-urinary tract discovered by palpation Pediatrics 18, 752, 1956.

9. Seidel G, Graber G: Generalized endometriosis. Zbl Gynecol 110:465, 1986.

10. Spence HM: Congenital hydrocolpos J Am Med Assoc 180:1100, 1962 11. Moore KL: The developing human. Clinically oriented embryology 3rd Ed. WB Saunders Co. Philadelphia, Pennsylvania 1982.