0022-534 7/85/1344-0714$02.00/0 Vol. 134, October
THE JOURNAL OF UROLOGY
Printed in U.S.A.
Copyright © 1985 by The Williams & Wilkins Co.
CONGENITAL MEGACALICES IN A BLACK WOMAN L. C. HAMRICK AND J. R. BURNS From the Department of Surgery, Division of Urology, University of Alabama at Birmingham, Birmingham, Alabama
ABSTRACT
Congenital megacalices is an uncommon anatomical malformation of the kidney. It has been reported previously only in white patients with a strong male predominance. We report congenital megacalices in a black woman. Congenital megacalices is an uncommon abnormality that has characteristic clinical and diagnostic findings that make it distinguishable from hydronephrosis. Careful analysis of available information may avoid unnecessary surgery for the appearance of obstruction when it is not present. Previously, this entity has only been reported in white patients with a strong male predisposition. We report congenital megacalices in a black woman. CASE REPORT
A 40-year-old black woman presented to our institution with left flank pain. She had been evaluated elsewhere 15 months previously for similar symptoms. An excretory urogram (IVP) at that time was interpreted as left ureteropelvic junction obstruction (fig. 1). Several small calculi were present in a lower pole calix of the left kidney. A dismembered pyeloplasty was performed. A stricture developed at the anastomotic site and the pyeloplasty was revised 3 months later. The anastomotic site restrictured and an indwelling ureteral stent was placed. The patient was lost to followup. The initial IVP at our institution showed no visualization of the left kidney. An IVP 2 weeks after exchange of the indwelling ureteral stent showed improved excretion of contrast material by the left kidney. A renal scan demonstrated a total effective renal plasma flow of 350 ml. per minute with the right kidney contributing 87 per cent of total function. Peak times were 6 minutes on the left side and 9 minutes on the right side. Several attempts were made to remove the ureteral stent but on each occasion acute left flank pain developed following stent removal. Because of poor renal function and dense scarring around the left ureter left nephrectomy was performed. Pathological examination of the specimen revealed marked dilatation of the calices (fig. 2). The medullo-papillary junction appeared to be foreshortened. The glomeruli and tubules were well preserved. Some areas of mild interstitial fibrosis were present. Postoperatively, the patient remained asymptomatic. A followup diuretic renal scan 2 years after nephrectomy showed an effective renal plasma flow of 341 ml. per minute, with a peak time of 7 minutes (fig. 3).
The differential diagnosis of congenital megacalices includes obstructive hydronephrosis and papillary necrosis. Obstructive hydronephrosis usually can be excluded by a renal scan that demonstrates delayed uptake and excretion. Papillary necrosis often is suspected by a history of analgesic abuse, diabetes mellitus or sickle cell disease. Renal size often is decreased and the calices are clubbed or eroded. According to Gittes, male subjects predominate (ratio greater than 6:1) in the incidence of congenital megacalices. 5 The racial distribution is striking in that megacalices have been reported only in white patients.5
FIG. 1. IVP interpreted as left ureteropelvic junction obstruction with features of congenital megacalices.
DISCUSSION
Congenital megacalices is an unusual anatomical malformation of the kidney. It was first described in 1963 by Puigvert1 and has been extensively studied by Gittes and Talner since 1972. 2- 5 Congenital megacalices has a characteristic appearance on the IVP. 2 Large ectatic calices are present in 1 or both kidneys. The infundibula and renal pelvis usually are of normal caliber. The outline of the kidney is smooth with good cortical thickness. The diagnosis of megacalices can be supported further by an isotope renal scan that will show normal uptake of isotope followed by prompt washout with furosemide administration.4·6 Accepted for publication June 14, 1985. Supported by the Veterans Administration.
FIG. 2. Underdeveloped medulla appears as falciform crescent. Normal caliber tubules with minimal chronic inflammatory infiltrate. 714
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It is interesting to speculate as to the original lesion of the left kidney. The original IVP was consistent with megacalices of both kidneys. Since a renal scan was not done, it is impossible to assess the degree of obstruction present. The histological findings of megacalices include normal cortical width, absence of cortical scars and normal caliber collecting ducts. Pathological examination of the left kidney showed many similar findings. The calices were markedly dilated. The diameter of the collecting ducts was normal. A mild degree of cortical scarring and interstitial fibrosis was present. This scarring, although usually not present with megacalices, may have occurred secondary to the infection and obstruction associated with the indwelling ureteral stent. REFERENCES
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Minutes FIG. 3. Diuretic renal scan (131 iodine-orthoiodohippurate) with furosemide washout.
Our patient seems to fit the criteria for megacalices. She had no history of urinary tract infection or other illnesses to suggest papillary necrosis. The renal scan is not suggestive of obstruction. The outline of the right kidney is smooth with normal cortical thickness.
1. Puigvert, A.: Megacaliosis: diagn6stico deferencial con la hidrocaliectasis. Med. Clin., 41: 294, 1963.
2. Gittes, R. F. and Talner, L. B.: Congenital megacalices versus obstructive hydronephrosis. J. Urol., 108: 833, 1972. 3. Talner, L. B. and Gittes, R. F.: Megacalyces. Clin. Rad., 23: 55, 1972. 4. Talner, L.B. and Gittes, R. F.: Megacalyces: further observations and differentiation from obstructive renal disease. Amer. J. Roentgen., 121: 473, 1974. 5. Gittes, R. F.: Congenital megacalices. Monogr. Urol., 5: 1, 1984. 6. O'Reilly, P. H., Lawson, R. S., Shields, R. A. and Testa, H. J.: Idiopathic hydronephrosis-the diuresis renogram: a new noninvasive method of assessing equivocal pelvioureteral junction obstruction. J. Urol., 121: 153, 1979.