[Medullary sponge kidney. Description of a pediatric case].

The case of a 11 year old boy with medullary sponge Kidney and nephrolithiasis discovered because of abdominal pain is described. Functional tubular impairment (concentrating defect, distal tubular acidosis) was present. No hypercalciuria nor hyperparathyroidism was detected. The diagnosis of medullary sponge Kidney was confirmed histopathologically. The pediatric cases described in the literature are characterized by a higher incidence of concentrating defect and acidosis, while the adults subjects often show hypercalciuria and or hyperparathyroidism. The careful study of tubular functions in the pediatric cases appears to be very useful to understand which are primary tubular disturbances and which are only secondary.