Urachal anomalies are usually found in early chi- ldhood or just after birth. These usually involve patent ductus urachus, urachal cyst, umbilical- urachal sinus or ...
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Allantoic remnants presenting as a giant retroperitoneal cyst ........ .................................
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Antic S, Petrovic J, Barisic G, Dimitrijevic I, Micev M, Krivokapic Z First Surgical Clinic, Clinical Center of Serbia, Belgrade
Urachal anomalies are usually found in early childhood or just after birth. These usually involve patent ductus urachus, urachal cyst, umbilicalurachal sinus or vesicourachal diverticulum. Very rarely are urachal anomalies found in adults, usually as an infected urachal cyst. We are presenting a case of surgically removed giant urachal retroperitoneal cyst that was found by chance during the abdominal ultrasound examination of a 22 year old man who was initially treated for idiopathic hypertension. Key words: allantoic remnants, retroperitoneal cyst, urachus, urachal cyst
INTRODUCTION
U
rachus is a normal embryonic remnant of the primitive bladder dome1,2. It is derived from the allantois and the ventral cloaca, but exact contribution of each is contentious3,4. It occupies the potential midline space between the peritoneum and the transversus fascia and has obliterated umbilical arteries on each side2,5. In fetus it extends with its growth to form an epithelialized tube at four months. This tube has transitional (70%) or columnar epithelium (30%) surrounded by connective tissue and the outermost muscular layer is in continuity with the detrusor muscle6,7. Its lumen obliterates in utero in 98%8. It rarely remains patent in part or as whole, resulting in urachal anomalies, further classified as congenital or acquired. Congenital urachal anomalies present as patent urachus, umbilical-urachal sinus, vesico-urachal diverticulum and urachal cyst10. By this case report we wanted to show another rarity of the presentation of urachal remnants in an adult.
FIGURE 1 and 1A GIGANTIC SEPTATED CYSTIC FORMATION DISLOCATING THE RIGHT KIDNEY LATEROSUPERIORLY AND PANCREAS TO THE LEFT
CASE REPORT A young male, 22 years old, had one year history of hypertension. Additional ultrasonographic examination showed a large cystic formation in the right side of the abdomen, extending from the pelvis to the liver. On the admittance to the hospital all blood, biochemical and urine analysis were within normal ranges (RBC 5.72, WBC 5.8, Hgb 169, Hct 48.2, PLT 237, Glucose, 5.2, Urea 6.2, Creatinin 80, K 4.4, Na 141). Physical examination revealed a large, non tender mass in the right half of the abdomen, extending up to about 5 cm to the left of the umbilicus, giving dull sound on percussion. Repeated ultrasound of the abdomen revealed dislocation of the right kidney towards the lateral abdominal wall and the diaphragm by a large cystic formation, as well as few other, smaller cysts in the region of the left kidney and the right side of the prostate, appearing to be communicating with the main one. CT scan of the abdomen confirmed the position of the right kidney and showed the gigantic septated (Fig. 1) cystic formation extending from the right kidney to the periprostatic area, compressing pancreas to the left and givi-
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FIGURE 2, 2A and 2C POSITION OF THE CYST IN THE PELVIS GIVING THE IMPRESSION IN THE BLADDER WALL FROM THE DIRECTION OF THE PROSTATE
ng the impression in the bladder wall by the cyst from the direction of the prostate. (Fig. 2). Radiologist was under the impression that there were few satellite cysts in the left kidney area. Intravenous urography (IVU) showed slight distension of the right pyelocalyceal system, with the widening of the right ureter and the compression by a low density formation in the right half of the abdomen. There were no extralumination of the contrast in the bladder, which was slightly impressed from the direction of the prostate. (Fig. 3) Intraoperatively a large irregularly shaped (tortuous) retroperitoneal cyst was revealed, extending from the diaphragm to the ileocoecal region. There were neither satellite cysts nor other abnormalities in the abdomen. It was carefully separated from the surrounding structures and a lower, tubular extension of this formation was found, extending into the pelvis. At this point the cyst was pierced and about 4000 ml of the clear, serous liquid was evacuated. This tubular part of the cyst, which had several projections, extended under the prostate and anteriorly towards the inferior wall of the bladder, was ligated and carefully extirpated. (Fig. 4) There were no postoperative complications and the patient was released from the hospital seven days later. Pathohistological examination revealed transitional type of epithelium, what brought us to the conclusion that this formation was the cyst of the urachus. Thick muscular layer with the desquamated mucosa was showed on some slides, but in the wall of the wider part of the cyst even thicker muscular layer with the normal or slightly decreased stratified epithelium with recognizable Dogiel’s umbrella cells on the surface was revealed. (Fig. 5) DISCUSSION During gestation allantois appears on abut day 16 as a small fingerlike projection from the caudal wall of the yolk sac. The bladder develops from the ventral portion of the expanded terminal part of the hindgut, the cloaca, which is continuous with the allantois ventrally, so the
FIGURE 3 IVU OF THE CYST SHOWING DISTENSION OF THE RIGHT PYELOCALYCEAL SYSTEM, WITH THE WIDENING OF THE RIGHT URETER AND THE COMPRESSION BY A LOW DENSITY FORMATION IN THE RIGHT HALF OF THE ABDOMEN. THERE IS NO EXTRALUMINATION OF THE CONTRAST IN THE BLADDER, SLIGHTLY IMPRESSED FROM THE DIRECTION OF THE PROSTATE
Br. 2
Allantoic remnants presenting as a giant retroperitoneal cyst
FIGURE 4 INTRAOPERATIVE VIEW OF THE CYST
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varies from 3-10 cm in length and from 8-10 mm in diameter9. Congenital urachal remnant diseases are due to urachal remnants that stay patent and are often subject to infections. An umbilical-urachal sinus (representing about 15% of cases), vesicourachal diverticulum,(3-5%) or urachal cyst may all close normally afer birth, but than reopen in association with pathologic conditions. This categorizes them as acquired diseases7,10,13,14,15. Signs and symptoms in this case can often be confused with a wide spectrum of midline intaraabdominal or pelvic inflammatory disorders at examination, or with malignant tumors at imaging10, 11,12 . CT and ultrasound are diagnostic means that are suited for demonstrating urachal remnant diseases. Patent urachus presents at longitudinal ultrasound and occasionally at CT as a tubular communication of the umbilicus and bladder. A vesicourachal diverticulum is usually discovered incidentally at axial CT or at US of the bladder as extraluminally protruding fluid filled sack that does not communicate with the umbilicus16. In this case, the vesicourachal diverticulum extended anteriorly, inferiorly into the pelvis and superiorly filling up the retroperitoneal space all the way to the lower edge of the liver. The communication with the bladder had previously spontaneously closed, leaving the irregularly shaped cystic formation. Such a large cyst is an extremely rare anomaly. All the diagnostic procedures could only show the presence of the cyst, without its origin. Since there was no communication with the bladder, only pathohistology could offer the final diagnosis.
CONCLUSION Urachal remnants are very rare entities, but can be revealed with commonly available diagnostic procedures. In this case the initial diagnosis could only be given intraoperatively and stated with certainty after the pathohistological examination. By this report we wanted to draw the attention of doctors to the possibility of having allantoic remnants presenting as a retroperitoneal cyst. SUMMARY
FIGURE 5 SHOWS THE WALL OF URACHAL CYST COVERED BY TYPICAL TRANSITIONAL TYPE OF EPITHELIUM. (H&E, 64X RESP.)
bladder initially extends all the way to the umbilicus. By the 4th or 5th month of gestation the bladder descends into the pelvis and its apical portion progressivly narrows to a small epithelialised fibromuscular strand-urachus which
Anomalije urahusa se obi~no otkrivaju u ranom detinjstvu ili odmah po rodjenju. U njih obi~no spadaju perzistentni ductus urachus, umbiliko-urahalni sinus ili vezikourahalni divertikulum. Jako retko se anomalije urahusa nalaze kod odraslih ljudi i to obi~no kao inficirana urahalna cista. Ovom prilikom prikazujemo slu~aj 22 godine starog mu{karca, inicijalno le~enog od idiopatske hipertenzije, kod koga je slu~ajno otkrivena gigantska retroperitonealna cista urahusa ultrazvu~nim ispitivanjem trbuha. REFERENCES 1. A. Atala and A.B. Retik.: Patent urachus and urachal cysts. In: F.D. Burg, J.R. Ingelfinger and E.R. Wald Editors, Gellis & Kagan’s Current Pediatric Therapy WB Saunders, Philadelphia 1993; 386–387.
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2. J.P. Gearhart and R.D. Jeffs, Urachal abnormalities. In: P.C. Walsh, A.B. Retik, E.D. Vaughan et al.Campbell’s Urology (7th ed. ed.), WB Saunders, Philadelphia 1998; 1984–1987. 3. Bauer SB, Retik AB. Urachal anomalies and related umbilical disorders. Urol. Clin. North Am. 1978;5:195211. 4. Scheye T, Vanneuville G, Amara B, Francannet P, Dechelotte P, Campagne D. Anatomica basis of pathology of the urachus. Surg. Radiol. Anat. 1994.; 16:135-41. 5. R.C. Begg, The urachus: its anatomy, histology and development. J Anat 1930; 64:170–183. 6. Schubert GE, Pavkovic MB, Bethke-Bedurftig BA. Tubular urachal remnants in adult bladders. J. Urol. 1983.; 127:40-42. 7. Berman SM, Tolia BM, Laor E, Reid RE, Schweizerhof SP, Freed SZ. Urachal remnants in adults. Urology 1988; 31:17-21. 8. Stone NN, Garden RJ, Weber H. Laparoscopic excision of a urachal cyst. Urology 1995; 45:161-164. 9. Moore KL. The urogenital system. In Moore KL, ed. The developing human. 3rd ed. Philadelphia, Pa; Saunders, 1982; 255-297. 10. MacNeily AE, Koleilat N, Kiruluta HG, Homsy YL. Urachal abscesses: protean manifestations, their recognition and management. Urology 1992; 40:530-535. 11. Spataro RF, Davis RS, McLahlan MSF, et al. Urachal abnormalities in adults. Radiology 1983; 149: 59663. 12.Ward TT, Saltzman E, Chiang S. Infected urachal remnants in the adult: case report and review. Clin. Infect. Dis. 1993; 16:26-29. 13. Blichert-Toft M, Nielsen OV. A congenital patent urachus and acquired variants. Acta Chir Scand 1971; 137: 807-814. 14. Blichert-Toft M, Koch F, Nielsen OV. Anatomic variants of the urachus related to clinical appearance and surgical treatment of urachal lesions. Surg Gynecol. Obstet. 1973; 137:51-54. 15. DiSantis DJ, Siegel MJ, Katz ME. Simplified approach to umbilical remnant abnormalities. RadioGraphics 1991; 11:59-66. 16. Feong-Sik Yu, Ki Whang Kim, Hwa-Fin Lee, Young-Fun Lee, Chon-Sik Yoon, Myung-Foon Kim. Urachal remnant disease: spectrum of CT and US findings. RadioGraphics 2001; 21:451-461.
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