Clinicopathologic spectrum of glomerulocystic kidneys: report of two cases and a brief review of literature.

Two cases of glomerulocystic kidneys (GK) are described and 35 cases are reviewed from the literature. Glomerular cysts formed by dilatation of Bowman's space are the basic and predominant lesion of GK. GK can occur in two different settings: (1) cases in which GK are the only major anomaly or are associated with variable types of anomalies that do not constitute a well-defined syndrome and (2) as part of a well-defined syndrome such as Zellweger's, trisomy 13, short-rib-polydactyly or oral-facial-digital syndrome. The genetic heterogeneity of GK is reflected in the different modes of inheritance of these syndromes. With one exception, no familial incidence is reported for GK unassociated with a syndrome. The morphologic heterogeneity is reflected in those cases in which the cysts show epithelial hyperplasia and/or presence of primitive/dysplastic glomeruli. It is not certain that these histologic variations represent different subtypes of GK. GK is characterized by bilaterality, renal enlargement, absence of urinary tract obstruction, presence of 2-3 mm cortical cysts lined by flattened to cuboidal epithelium and containing a glomerular tuft. GK cannot be distinguished morphologically from adult polycystic kidney disease (APKD) manifesting in the neonatal period. Familial incidence and autosomal dominant pattern of inheritance are the only clues to the correct diagnosis of APKD in such instances.