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Cloacal malformations are a spectrum of congenital pelvic malformations that result from abnormal cloacal division during early embryogenesis. Depending on the timing of the developmental arrest, a spectrum of abnormalities can result, ranging from urogenital sinus malformations to cloacal dysgenesis. This case highlights the unique imaging features of cloacal dysgenesis, which is an extremely rare variant of this malformation spectrum. This variant is also the most severe manifestation of the cloacal malformation spectrum.

Cloacal dysgenesis sequence (CDS) is a rare and lethal malformation. We report such a case of long-term survival, currently to 12 years of age. In the fetal period, she received a timely placement of vesico-amniotic shunt for a megabladder due to a severe urethral obstruction. Postnatally, cystostomy and colostomy were created because of no perineal opening of urethra, vagina, and anus. Anorectoplasty, construction of efferent conduit, and colostomy closure were performed at 4 years of age. Ileovaginoplasty and ileovesicostomy which was a Mitrofanoff-type of conduit, and labioplasty were performed at the age of 11 years. To the best of our knowledge, only five survivors with CDS over 1 year of age have been reported.

Aims of Study: Retinoid-mediated signal transduction plays a crucial role in the embryogenesis of various organs. We previously reported the successful induction of anorectal malformations in mice using retinoic acid (RA). Retinoic acid controls the expression of essential target genes for cell differentiation, morphogenesis, and apoptosis through a complicated interaction in which RA receptors form heterodimers with retinoid X receptors. In the present study, we investigated whether the retinoid antagonist, LE135, could prevent the induction of anorectal malformations (ARMs) in mice., Methods: Retinoic acid was intraperitoneally administered as 100 mg/kg of all-trans RA on E9; and then the retinoid antagonist, LE135, was intraperitoneally administered to pregnant ICR strain mice on the eighth gestational day (E8), 1 day before administration of RA (group B) or on E9, simultaneously (group C) with RA administration. All of the embryos were obtained from the uteri on E18. Frozen sections were evaluated for concentric layers around the endodermal epithelium by hematoxylin and eosin staining., Results: In group A, all of the embryos demonstrated ARM with rectoprostatic urethral fistula, or rectocloacal fistula, and all of the embryos showed the absence of a tail. In group B, 36% of the embryos could be rescued from ARM. However, all of the rescued embryos had a short tail that was shorter than their hind limb. The ARM rescue rates in group B were significantly improved compared to those in group A (P < .01). In group C, 45% of the embryos were rescued from ARM, but all of the rescued embryos had short tail. The ARM rescue rate in group C was significantly improved compared to that in group A (P < .01). However, there was no significant difference in the ARM rescue rate between group B and Group C., Conclusion: The present study provides evidence that in the hindgut region, RAR selective retinoid antagonist, LE135, could rescue embryos from ARM. However, the disturbance of all-trans RA acid was limited to the caudal region. Further study to establish an appropriate rescue program for ARM in a mouse model might suggest a step toward protection against human ARM in the future., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A newborn boy was brought to us, 2 hours after birth, with a mucosal-lined left hemiperineal lesion associated with classical bladder exstrophy and an anterolaterally displaced anus. Perineal anatomy was restored by excising the mucosa lined lesion. The bladder closure for classical bladder exstrophy was done at the same time. Histologically, gastric, respiratory, and small intestinal epithelia were present in the mucosa. A rectal duplication cyst that had ruptured in utero through the hemiperineum could explain the anomaly. The association of classical bladder exstrophy with ruptured rectal duplication cyst has never previously been described in the literature., (Copyright 2010 Elsevier Inc. All rights reserved.)

A specimen of accessory phallic urethra duplication (triplication) in a 32.5-week gestation female was studied histologically. The specimen demonstrated an anterior "phallic urethra" ending inside a penoclitoral organ in a megalourethra-like dilatation with a narrow epispadiac meatus and "anterior urethrocutaneous fistula" and a posterior canal opening with the anal canal. With histology suggestive of a split persistent urogenital sinus, correlation to normal development strongly suggests an error in the formation of the cloacal membrane and developing superficial cloaca at 26 to 29 days' ovulation age (2 to 4 mm), causing an isolated interruption of the membrane by mesenchyme, which by participating in the growth of the early cloaca may extend as far as the vaginal orifice later. Differences in number, position, and size of such mesenchymal interruptions can explain other duplications and triplications and offer a single alternative for the many current theories of pathogenesis, none of which are compatible with new insights in normal development.

Cloacal dysgenesis sequence is a rare congenital malformation seen in 1:50000 to 250000 neonates. It shows a phallus-like structure, smooth perineum, and absence of urethral, vaginal, and anal openings as primary malformations. We report a case of a 4-day-old preterm female neonate. The prenatal ultrasound showed singleton fetus in breech presentation with echogenic bowel, dilated colon, perineal mass, dilated bladder, and fetal hydrops. The complete autopsy revealed smooth perineum without patent urethral, vaginal, and anal openings, and enlarged wrinkled clitoral-like structure. Other anomalies included renal hydronephrosis, hydroureter, megacolon, and urethral agenesis. The chromosomal analysis showed normal female karyotype. These findings are consistent with cloacal dysgenesis sequence, and it results from the defect in cloaca formation during the first 50 days of gestation. It is usually fatal and should be differentiated from other conditions having better prognosis such as fetal obstructive uropathies and persistent cloaca.

Sonic hedgehog (Shh) has been shown to be involved in the morphogenesis of many organ systems including the notochord, floor plate and limbs, as well as in the development of the left-right axis in vertebrates. Recent evidence suggests the Shh cascade plays a crucial role in the development of the foregut and hindgut. We have previously shown that prenatal exposure of fetal rats to ethylenethiourea (ETU) induces hindgut malformations and other abnormalities of the VACTERL association. The aim of this study was to determine the pattern of expression of Shh and its downstream genes during hindgut development in ETU-exposed embryos with anorectal malformations (ARMs). Pregnant Sprague-Dawley rats were mated together overnight and a positive vaginal plug was marked as gD0. On gD10, 1% ETU (125 mg/kg) was given to the experimental group and controls received the same volume of saline. Embryos were collected from both groups at gD12-16. The developing hindgut of each embryo was dissected under magnification and snap frozen. Highly purified RNA was isolated from each hindgut and first strand cDNA was prepared with appropriate negative controls. Reverse transcriptase (RT) polymerase chain reaction (PCR) was done to determine the transcripts of Shh in each sample and quantitative real-time PCR was carried out to show relative quantitative expression of Shh at each time point. Shh was detected in all samples confirming that Shh is active during the process of hindgut development in fetal rats. Relative quantitation demonstrated that Shh expression shows time-dependent changes in the developing hindgut of ETU-exposed rat embryos, and when results were compared with control samples, there was significant decrease in expression on gD14 and 15, when the cloaca normally separates into the rectum and urethra occurs in the rat fetus. The misregulated expression of Shh in the hindgut of ETU-exposed rat embryos suggests that ETU may interfere with Shh signalling. Downregulation at the time of cloacal separation into rectum and urethra indicates that Shh plays a crucial role in the development of hindgut.

Cloacal anomalies exhibit a wide variety of morphologic types and accompanying clinical severity. The association of malformations of the cloaca with partial, complete, or conjoined twinning has been appreciated for some time, but, with the advent of prenatal ultrasound technology, appears to occur with a greater frequency than once thought. This observation has important implications for pathogenesis. We present 2 representative cases, a 19-week-old female fetus with duplication of several caudal structures and a 21-week-old male fetus with cloacal exstrophy variant and demised co-twin with lower abdominal wall defect, extruded intestinal tract, absent external genitalia, and imperforate anus. These findings and previously published theories suggest that certain models of monozygotic twinning may apply to the pathogenesis of cloacal anomalies. Specifically, the partial or complete duplication of the organizing center within a single embryonic disc may increase the risk of mesodermal insufficiency and thus account for the failure of complete development of the cloacal membrane and consequent exstrophy or other aberration.

A 20-day-old female presented in acute renal failure with an absent bladder and vaginal atresia. The right ureter opened into the uterus, resulting in a urometrocolpos, and the left ureter opened through a stenotic opening into the introitus. The literature is reviewed for reported cases and the embryo-pathology of bladder agenesis is discussed.

First-trimester sonographic findings associated with omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex and review of the literature regarding this rare congenital anomaly are presented.

As presently understood, cloacal exstrophy results from a migration failure of the lateral mesodermal folds of the infraumbilical anterior abdominal wall, and rupture of the resulting enlarged, persistent cloacal membrane before the eighth week of gestation. The authors present ultrasonographic evidence that disputes this embryological theory. Routine ultrasonography of a twin gestation at 18 weeks showed that one twin had a dilated cloacal abnormality, bilateral hydronephrosis, and oligohydramnios. Repeat ultrasonography at 24 weeks demonstrated rupture of the cloacal anomaly, with resolution of both the hydronephrosis and oligohydramnios. This twin was born with classic cloacal exstrophy. This striking ultrasound evidence of an intact cloacal membrane at 18 weeks, which ruptured before 24 weeks, relieving the urinary tract outlet obstruction, forces us to rethink how this surgically correctable anomaly develops.

Extrophic lesions of the ventral abdominal wall are represented by a range of anomalies of which the most severe is cloacal extrophy. By 1986, only 190 cases were reported in the world literature and it is estimated that only 15 cases are seen in the United States of America per year. In Nigeria today, with improvement in antenatal and perinatal services, children who one or two decades ago would have been stillborns or products of miscarriages are now born alive. This paper reports a case of cloacal extrophy in a Nigerian neonate and reviews the current management of the condition.

This article proposes the hypothesis that allantois is the anatomical homologue of bursa of Fabricius in mammalia. This hypothesis is based on immunohistochemical study of sections from hematopoietic organs of three fetuses with cloacal exstrophy. In the complex maldevelopment of cloacal exstrophy the common features are absence of distal midgut and exstrophy of cloaca with an exstropic intervening intestinal band. It has been suggested that gut is of dual origin and in addition to the yolk sac, allantois, absent in this maldevelopment, is involved in the embryogenesis of intestines by developing into distal midgut. There was absence of B-lymphocyte in two of three fetuses with rudimentary midgut and aplastic allantois. Meanwhile, B-cells were identified in the hematopoietic tissues and the prominent Peyer's patches of the more developed exstrophic allantois in the third case presented here. Therefore, it is concluded that allantois as the origin of distal midgut and lymphatic-rich ileocecal portion of digestive system is directly involved in the B-cell formation and represents the bursa of Fabricius in man.

The radiographs of 28 patients with bladder exstrophy and five with cloacal exstrophy were reviewed at an average age of 8 years 3 months to assess congenital vertebral malformations. Fourteen malformations in 11 patients were noted, including abnormal lumbosacral segmentation in five, congenital scoliosis and kyphosis in four, partial sacral agenesis in three, and interpedicular lumbar widenings in two. These findings are explained by an abnormal embryologic development of the spine and cloaca between 4 and 6 weeks of intrauterine life. We recommend entire spinal radiographs in these patients.