Gómez Tellado M, Pais E, Méndez R, Montero M, Vela D, Caramés J, Candal J
Servicio de Cirugía Pediátrica, Complejo Hospitalario Juan Canalejo, La Corunña, España.
Arch Esp Urol. 1997 Sep;50(7):762-6.
Megacalycosis or Puigvert's disease is a congenital anomaly of renal development characterized by caliceal dilatation, an increased number of calyces, associated with hypoplasia of the pyramids of Malpighi, and a normal renal pelvis. Renal function is always normal and there is no evidence of obstruction to urinary flow. The foregoing are important in distinguishing megacalycosis from congenital hydronephrosis. We have studied two pediatric patients with this renal anomaly by means of non invasive techniques, in order to demonstrate they had no urinary flow obstruction despite the caliceal dilatation.
Two cases of megacalycosis that had been diagnosed at our hospital from 1991 to 1995 are described and the literature is reviewed. Diagnosis was basically by intravenous urography. A diuretic renogram with technetium 99m diethylenetriaminepentaacetic acid (Tc 99m DTPA) showed no urinary flow obstruction in the anomalous kidney. This test was repeated several times, together with renal function studies like the technetium 99m dimercaptosuccinic acid scan (DMSA Scan).
Both patients are asymptomatic and have a normally functioning kidney with no scars demonstrable on the DMSA scan. Renal urinary flow studies have remained within the normal ranges (elimination of more than 40% of the radionuclide 20 min after the administration of furosemide). US control evaluations have shown adequate renal growth and persistent caliceal dilatation in both cases.
This congenital malformation must be considered when investigating renal dilatation, since megacalycosis does not require surgical treatment. Intravenous urography is useful in the diagnosis of this condition and Tc 99m DPTA is the best test for subsequent control evaluations.
