CONGENITAL, unilateral multicystic disease of the kidney is characterized by the replacement of one entire kidney by irregularly lobulated cystic masses of sizes varying from 1 to 30 mm which are held together by loose connective tissue (Figure). The cortical architecture, pyramids, and calyces are completely absent, and on the cut section no normal parenchyma except a very occasional scattering of solid tissue is seen. The ureter is characteristically absent or atretic, and the blood supply is variable, in some instances, being altogether absent. The cyst wall, on microscopic examination, is usually lined by a thin layer of flat cuboidal cells, and the occasional scattering of solid tissue often may contain a few immature glomeruli or tubules.
The recognition of this deformity as an entity separate from other renal cystic disorders has come about slowly since its first description by Schwartz1 in 1936. Bunge and Harness2 described one