Cystic renal neoplasms of infancy and childhood: a light microscopical, lectin histochemical and immunohistochemical study.

Cystic renal neoplasms of infancy and childhood, represented largely by cystic variants of nephroblastoma, form a spectrum of clinicopathological entities with differing behaviours. Cystic nephroma and cystic partially differentiated nephroblastoma occupy the benign end of the tumour spectrum, while polycystic Wilms' tumour forms the malignant end. A wide variety of names, reflecting different theories on aetiology, has been applied to the lesions comprising this spectrum, and this has undoubtedly caused confusion in their recognition and classification. We examined five cases of cystic renal tumours in young children which illustrate the entire spectrum, and lectin histochemical and immunohistochemical analysis of these cases showed a close similarity in the pattern of staining of the three variants of cystic tumours. This finding, which has not previously been reported to our knowledge, supports the concept of a close pathogenetic relationship between these tumours.