Multicystic Dysplastic Kidney

Vol. 118, August Printed in U.S.A.

THE JOURNAL OF UROLOGY

Copyright © 1977 by The Williams & Wilkins Co.

Pediatric Articles MULTICYSTIC DYSPLASTIC KIDNEY DANIEL P. DEKLERK, FRAY F. MARSHALL

AND

ROBERT D. JEFFS

From the James Buchanan Brady Urological Institute, Department of Urology and Division of Pediatric Urology, The Johns Hopkins Hospital, Baltimore, Maryland

ABSTRACT

We reviewed 29 cases of congenital multicystic dysplastic kidneys. Isolated renal pelvic atresia has an excellent prognosis but lower ureteral atresias are associated with a high incidence of contralateral renal disease and have a worse prognosis. The importance of a congenital multicystic dysplastic kidney in the differential diagnosis of abdominal masses of the neonate is well recognized. •-:i Although this pathological entity has been recognized since Hildebrandt's description in 18944 Spence' was the first to differentiate clearly this condition from unilateral infantile poly cystic disease of the kidney. Osathanondh and Potter confirmed this observation and clarified the pathogenesis ofpolycystic disease by elegant microdissection techniques. ,i A congenital multicystic dysplastic kidney is a non-familial, maldevelopment of the kidney with no associated cystic disease of the pancreas, liver or lung. The kidney is composed grossly oflarge irregularly sized cysts. The renal pedicle and pelvis are often atretic or hypoplastic. Microscopically, few or no functional elements may be recognized in loose connective tissue stroma. Spence describes a congenital multicystic dysplastic kidney as a benign unilateral condition of good prognosis but subsequent studies have emphasized the high incidence of contralateral renal abnormalities. 7• 8 Herein we present the clinical and pathological features in an effort to clarify the prognosis of this condition. MATERIALS

A retrospective study was done on the clinical and pathological features associated with 29 cases of congenital multicystic dysplastic kidneys seen at this hospital from 1950 to 1973. Sex, age at presentation, race, birth weight, parity, mother's age, clinical presentation, and radiological, sonographic and pathologic features were noted. In all cases the implicated kidney was available for pathological study postoperatively or at autopsy and complied with the gross and microscopic criteria for a congenital multicystic dysplastic kidney. RESULTS

Patients were subdivided into 2 groups according to the level of ureteral atresia (fig. 1). Renal pelvic atresia was associated with no significant contralateral renal abnormality but a lower level of ureteral atresia was associated with a worse prognosis. Diagnosis was made before the patients were 1 year old and equal racial distribution was noted. Table 1 shows the incidence of side and sex. The mothers' ages ranged from 13 to 30 years and 60 per cent were primigravidas. Thirty-six per cent of the patients weighed less than 2,500 gm. at birth. No Accepted for publication October 27, 1976. Read at annual meeting of American Urological Association, Chicago, Illinois, April 24-28, 1977.

306

fam.ilial history of congenital genitourinary abnormality was noted in any case. On physical examination 20 of 29 infants presented with an upper quadrant abdominal mass but occasionally the mass extended to the lower quadrant across the midline. The mass was classically slightly irregular, ballotable, non-tender and translucent. Other patients also presented with abdominal distension (2), anuria (1), respiratory distress (1), sepsis (1) or incidentally at operation or autopsy (4). Laboratory data revealed a normal urinalysis in all cases except for 2 patients with pyuria and 3 with mild proteinuria. df these 5 cases 3 had bilateral disease and in only 1 case of renal pelvic atresia was pyuria (4 to 10 white cells per high power field) present. The hematocrit and blood urea nitrogen (BUN) were normal except in bilateral disease (6 patients) in which uremia and anemia of varying degrees invariably developed and in 1 child with associated diabetes mellitus who presented with a hematocrit of 34 and a BUN of 30 mg. per cent. The affected kidney was invariably non-functioning on excretory urography (IVP). High dose urography may delineate the congenital multicystic dysplastic kidney during total body opacification" but this phenomenon was not seen in our series, probably owing to lower doses of contrast material. In all cases with renal pelvic atresia satisfactory function could be demonstrated on the contralateral side. On sonography a large cystic mass was found, displacing the whole kidney with internal echoes consistent with multiple septa. 10 Voiding cystourethrography was done in 7 children and revealed bilateral reflux in 2, both of whom had lower ureteral lesions. Renal scan showed no perfusion on the affected side in 2 patients. Six children underwent cystoscopy and in only 1 was unilateral absence of the ureteral orifice and a poorly developed hemitrigone noted. Retrograde catheterization and pyelography demonstrated a blind-ending ureter on 2 occasions. Renal arteriography in 1 child revealed no renal artery but otherwise was of little diagnostic value. The associated congenital anomalies are seen in tables 2 and 3. With the exception of a simple cyst in 1 patient the contralateral kidney was normal in patients with renal pelvic atresia. A high incidence of contralateral disease, either multicystic or hydronephrotic, was noted in congenital multicystic dysplastic kidney patients with lower ureteral lesions. In 2 patients a triad of congenital multicystic dysplastic kidney, hypospadias and congenital hip dislocation was found. A congenital multicystic dysplastic kidney occurred in only 1 of monozygous twins.

MULTICYSTIC DYSPLASTIC KIDNEY

Dysplastic Kidney

Renal Pelvic Atresia

1

TABLE

~~-~·-----.------

subclassificotion by level of ureternl obstnicrion

Renal Pelvic Atresia

Ureteral Atresia

10

7 5 3

Side: Lt. Rt. Bilat. Totals Sex: Male Female Totals

number(%) -------

14 (48%)

4

0 14

15

9

10

Ji

5

14

15

2. Associated anomalies in renal pelvic atresia Contralat. Kid, Genitourinary Other ney

TABLE

Pts.

I Year Survival Conlrnlr.!l'eral Kidney Abnormalities

93% (7%)

-··-·-'--B~ Ure/era/ Atresia, with or without, Renal Pelvic Atresici 15 (52%)

VH

I Year Survival

(47%)

(40%)

Ovarian cysts

BBF

Hypospadias with chordee

HA Pt. totals

Contra lateral Kidney Abnormalities

Simple cyst

BGS BGG

1/14

2/14

1. Classification of congenital multicystic dysplastic kidney PATHOLOGY

was similar in all cases. The 2 to 4 cm. in diameter. The kidney consisted varying size (from microscopic to 3 cm. in diameter) uo<:rc,,·n•» by loose connective tissue with a loss ofreniforun contour. The cysts contained clear fluid. A central, small, to tan solid segment of tissue was commonly The microscopic sections were characterized multicysts lined a cuboidal epithelium (fig. 2, A). The stroma consisted of loose -v,,1,afZfJr1 r-.r," tissue with occasional foci of cartilage rarely primitive glomeruli and tubules 2, B). The level of ureteral atresia developed abruptly and ranged from a localized area to total ureteral atresia. Occasionally, the area of atresia was marked by a few small cysts. The condition of the renal vascular pedicle was noted at or u ~ u v , m , in 13 cases. In all 7 cases of renal pelvic atresia an atretic or vvi,nLwc,n.. renal pedicle was noted. In 3 ureteral atresia a normal renal of the 6 cases with vvas found. TREATMENT

has been the treatment of choice. A subcostal has the advantage of good exposure access to the contralateral kidney but if a confiof a congenital multicystic dysplastic kidney can be the peritoneal cavity seems undesirable. A conservative non-operative approach can be considered but final may rest with exploration. ~"'~"'"VU>C

DISCUSSION

dysplastic kidney is the most comvn,~·--· abdominal mass. H Diagnosis is relacareful clinical and radiographic eval-

Fm. 2. Microscopic sections show boida! epithelium and B, primitive

uation, which includes non-function on an on renal scan and a cystic mass with sonography. Nephrosonography has been a entiating among renal neoplasms,

Duodenal obstruct,on Micrognathia, cephalus, equinus va:rus and low lying ears Congenital hip dislocation Hemangioma of chest wall 4/14

308

DE KLERK, MARSHALL AND JEFFS TABLE

BBD BGL TA BBA

SP BBK

3. Associated anomalies in ureteral atresia

Contralat. Kidney

Pts.

Ureteropelvic junction obstruction and hydronephrosis Congenital multicystic dysplastic kidney Ureteropelvic junction obstruction and bydronephrosis Congenital multicystic dysplastic kidney

Hypoplasia of adrenals Hypospadias

Congenital multicystic dysplastic kidney

BGB

DY BBM

Congenital hip dislocation and talipes equinus varus Cleft palate Hypoplastic lungs, Potter facies and ventriculoseptal defect Imperforate anus, cleft palate, low set ears and duodenal atresia Ventriculoseptal defect and patent ductus arteriosus

Hydroureteronephrosis secondary to ureterovesical junction obstruction Ectopic testis

DJ

BBP Pt. totals

Other

Genito urinary

Inguinal hernia 6/15

genital multicystic dysplastic kidneys. The contralateral kidney needs careful evaluation but retrograde pyelography and renal angiography will rarely be indicated. Anemia and azotemia make bilateral disease likely. In children with possible bilateral disease voiding cystourethrography is indicated. Despite multiple studies the prognosis of this condition remains unclear. Spence5 believed that the outlook was good and certainly the prognosis compared favorably with infantile polycystic disease but Greene and associates' have indicated the danger of associated contralateral renal disease. In our series the hematocrit, BUN, level ofureteral atresia and condition of the renal pedicle have been the most important prognostic indicators. In the infant with atresia at the renal pelvis (often associated with renal vascular pedicle atresia) the contralateral kidney has been uninvolved and the prognosis dependent on other non-urological anomalies (fig. 1). Twin studies are valuable in determining if genetic factors are important in any disease. 11 The disconcordant involvement of a monozygotic twin implies that environmental factors may be important in the etiology of this disease. A similar finding was reported on 1 previous occasion." The understanding of the pathogenesis of polycystic disease of the kidney was markedly improved by the work of Osathanondh and Potter." The basic site of injury in Potter types II and IV lies at the ureteral ampullae and probably differs only in the type, degree and timing of the initial insult. Although an inhibition of ampullary activity appears responsible for the development of congenital multicystic dysplastic kidney and other varieties of Potter type II polycystic kidney disease the etiology of this inhibition is unclear. Osathanondh and Potter have suggested urinary outflow obstruction as one possible cause for ampullary injury." Beck studied the effect of intrauterine urinary obstruction upon the development of the fetal kidney. 12 Although he could produce hydronephrosis, renal dysplasia (similar to Potter type IV) and unilateral polycystic disease he was unable to produce a typical multicystic dysplastic kidney. These studies were difficult because of the small size of the fetus but other factors in association with urinary obstruction appear to be necessary in the development of a congenital multicystic dysplastic kidney. Ampullary injury from vascular compromise and intrauterine infection are possibilities. A vascular lesion seems particularly attractive. Louw and Barnard have indicated the role of fetal vascular occlusion in the development of congenital intestinal atresia

2/15

6/15

and a similar mechanism may exist in the pathogenesis of congenital multicystic dysplastic kidneys. 13 The arteries of the metanephros arise from the primitive aorta and atrophy as the metanephros moves cranially. 14 A lack of transmission of arterial supply may lead to temporary ischemia with ampullary damage and subsequent ureteral stenosis. The suggested pathogenesis of congenital multicystic dysplastic kidney is vascular compromise of the ureter and developing ampullae. Subsequent ureteral stenosis will contribute in the further development of a congenital multicystic dysplastic kidney. REFERENCES

1. Griscom, N. T.: The roentgenology of neonatal abdominal masses. Amer. J. Roentgen., 93: 447, 1965.

2. Emanuel, B. and White, H.: Intravenous pyelography in the differential diagnosis of renal masses in the neonatal period. Clin. Pediat., 7: 529, 1968. 3. Kissane, J. M. and Smith, M. G.: Pathology of Infancy and Childhood. St. Louis: The C. V. Mosby Co., 1967. 4. Hildebrandt: Weiterer Beitrag zur pathologischen Anatomie der Nierengeschwulste. Arch. klin. Chir., 48: 343, 1894. 5. Spence, H. M.: Congenital unilateral multicystic kidney: an entity to be distinguished from polycystic kidney disease and other cystic disorders. J. Urol., 74: 693, 1955. 6. Osathanondh, V. and Potter, E. L.: Pathogenesis of polycystic kidneys. Type 1 due to hyperplasia of interstitial portions of collecting tubules. Arch. Path., 77: 466, 1964. 7. Greene, L. F., Feinzaig, W. and Dahlin, D. C.: Multicystic dysplasia of the kidney: with special reference to the contralateral kidney. J. Urol., 105: 482, 1971. 8. Pathak, I. G. and Williams, D. I.: Multicystic and cystic dysplastic kidneys. Brit. J. Urol., 36: 318, 1964. 9. Leonidas, J.C., Strauss, L. and Krasna, I. H.: Roentgen diagnosis of multicystic renal dysplasia in infancy by high dose urography. J. Urol., 108: 963, 1972. 10. Bearman, S., Sanders, R. C. and Oh, K. S.: B-scan ultrasound in the evaluation of pediatric abdominal masses. Radiology, 108: 111, 1973. 11. Burger, H. R. and Burger, S. E.: Genetic determinants of urologic disease. Urol. Clin. N. Amer., 1: 419, 1974. 12. Beck, A. D.: The effect of intra-uterine urinary obstruction upon the development of the fetal kidney. J. Urol., 105: 784, 1971. 13. Louw, J. H. and Barnard, C. N.: Congenital intestinal atresia; observations on its origin. Lancet, 2: 1065, 1955. 14. Patten, B. M.: Human Embryology. Philadelphia: The Blakiston Co., 1948.