Radiologic features of "adult type" polycystic kidney disease in the neonate.

Two cases are reported of adult type polycystic renal disease (autosomal dominant) presenting in the newborn as a unilateral abdominal mass. The radiographic findings in the involved kidney simulated the ectatic tubules of infantile polycystic disease, yet histologic examination was consistent with the adult variety and both infants had other family members with adult type polycystic kidneys. These cases emphasize some of the ambiguities that exist in the definition and classification of polycystic renal disease.