[Mesoblastic nephroma: morphologic and clinical characteristics].

MN is a rare benign mesenchymal tumour of the kidney which occurs most commonly in the newborn period or early infancy. Tumour is successfully treated by surgery only and local recurrence and metastases are extremely rare. There are presented morphological and clinical features of 6 cases diagnosed among 123 tumours of the kidney. Histologically, mesoblastic nephroma is classified in leiomyomatous and cellular type, but distinction between the two types has no implication for survival. It is important to distinguish cellular type of mesoblastic nephroma from clear cell type of Wilms' tumour as their prognosis and treatment are so different.