Loin Masses Due to Infant and Juvenile Unilateral Multicystic Kidney Disease

Abstract

Unilateral multicystic kidney is a congenital anomaly often diagnosable in infants and children. It is characterized by marked diminution in functioning renal parenchyma and by multiple cysts of varying size and shape with loss of normal renal contour.¹ These findings are unilateral; bilateral disease of this type is incompatible with life. This is in sharp contrast to true polycystic kidney disease. The recognition of infantile forms of the polycystic variety^2,3 includes the necessity to differentiate between true polycystic and multicystic disease.^4-6 Characteristically, true polycystic disease is an inherited⁷ anomaly^8,9 in which the renal contours are maintained. The cysts are relatively uniform in size and occur in great numbers. This gives the parenchyma a spongy texture. The renal parenchyma, rather than being primarily absent, is secondarily destroyed by pressure atrophy of the expanding cysts.^12,13 Since the earlier reports of Wakely,¹⁴ Schwartz,¹⁵ Howze and