Clinical History.—A large left flank mass was detected in a premature female infant (2,715 gm). The remainder of the physical examination was unremarkable. At 24 hours of age a high-dose intravenous urogram was performed (Fig 1 and 2). Subsequently, the infant was referred to the Geisinger Medical Center for further observation and treatment.
Screening blood and urine biochemical values were normal. On the third day of life, a renal scan using 2 mCi of 99m Tc-DMSA (dimercaptosuccinic acid) was done (Fig 3). Surgical exploration was performed on the seventh day of life.
Denouement and Discussion
Congenital Multicystic Kidney
At surgery, a 190-gm multicystic mass was removed along with the ureter. Gross and microscopic examination of the specimen showed a typical multicystic kidney (Fig 4 and 5) with obliteration of the ureter and pelvis (pelvoinfundibular atresia). Small remnants of renal tissue were present in various portions of the mass,