CEUSP. Valencia. Venezuela.

Case of a 34-year-old G2 P1 with was referred to our hospital at 18 weeks of gestation due to a cystic tumor located in front of the fetal abdomen. The referral diagnosis was omphalomesenteric cyst. We decided to perform an amniocentesis which resulted in a normal male karyotype. On the follow-up ultrasound exams the tumor disappeared and was replaced by a solid mass consistent with a bladder exstrophy. Intraabdominal cyst diagnosed later on revealed a concomitant intestinal atresia. Patient delivered at 39 weeks of gestation via cesarean section. A newborn male of 3100 grams and Apgar scores 8/10 in 5th/10th minute was transferred to the intermediate care unit. Physical examination confirmed the antenatal diagnosis of bladder exstrophy and anorectal atresia. Neonate underwent surgical closure of bladder exstrophy and colostomy. Epispadia will be corrected at six months of age.

Images 1,2: 16 weeks, image 1 shows a sagittal view, note a large cyst in front of the fetal abdomen. Image 2 shows a transverse view of the fetal abdomen and a large anechoic cystic structure.

Discussion

The true etiology of bladder exstrophy is not known. In classic bladder exstrophy, the lower urinary tract, genitalia, and musculoskeletal system are all affected. Prevalence of classic bladder exstrophy is 0.33 per 10,000 deliveries [2]. Some cases strongly suggest a genetic component [10]. Antenatal ultrasound findings suggestive of exstrophy-epispadias complex include the following:

• Repeated failure to visualize the bladder
• Lower abdominal wall mass
• Low-set umbilical cord
• Intestinal atresia
• Abnormal genitalia

• The bladder is open on the lower abdomen, with mucosa fully exposed through a triangular fascial defect
• The abdominal wall appears long because of a low-set umbilicus on the upper edge of the bladder plate
• The distance between the umbilicus and anus is shortened
• The rectus abdominis muscles diverge distally and attach to the widely separated pubic bones [4]
• Indirect inguinal hernias are frequent (>80% of males, >10% of females) due to wide inguinal rings and the lack of an oblique inguinal canal
• The phallus is broad, short with upward curvature, cryptorchidism or abnormalities of the scrotum may be present

Bladder exstrophy is a malformation complex involving the abdominal muscles, pelvis, urinary, genital and intestinal tracts. The mechanism of this malformation remains unknown so far. Umbilical cord cyst as a clue to prenatal diagnosis of bladder exstrophy was first described by Tong et al. [6]. Our case documents the history of this anomaly, it's difficult management and serious consequences. [1-13]

Taking into the account the evolution of this case, it is possible to formulate the hypothesis that the natural history of this congenital anomaly begins with a failure of the closure of the lower abdominal wall. We think that megacystis which was apparent at 16 weeks of gestation, emerged through the abdominal wall, ruptured and it's walls everted. This would explain why the follow-up ultrasound examination at 20 weeks showed different findings. A detailed ultrasound evaluation is necessary and requires an experienced sonographer. Multidisciplinary management and counseling are necessary. [1]

References

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2. Ebert AK, Reutter H, Ludwig M, Rösch WH. The exstrophy-epispadias complex. Orphanet J Rare Dis. 2009 Oct 30;4:23.

3. Tu W, Chueh J, Kennedy W. Dichorionic diamniotic twin pregnancy discordant for bladder exstrophy. Adv Urol. 2009:186483.

4. Mabille M, De Laveaucoupet J, Senat MV, Picone O, Levaillant JM, Mas AE, MussetD. Imaging of the fetal bony pelvis by computed tomography in a case of bladder exstrophy. Ultrasound Obstet Gynecol. 2009 Jun;33(6):716-9.

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10.  Froster UG, Heinritz W, Bennek J, Horn LC, Faber R. Another case of autosomal dominant exstrophy of the bladder. Prenat Diagn. 2004 May;24(5):375-7.

11. Mourtzinos A, Borer JG. Current management of bladder exstrophy. Curr Urol Rep. 2004 Apr;5(2):137-41.

12. Lee EH, Shim JY. New sonographic finding for the prenatal diagnosis of bladder exstrophy: a casereport. Ultrasound Obstet Gynecol. 2003 May;21(5):498-500.

13. Chandrasekharam VV, Bajpai M .Management of bladder exstrophy. Indian J Pediatr. 2000 Aug; 67(8):579-81.