[Medullary sponge kidney: a pathology still full of unknowns].

Medullary sponge kidney is a disease characterized by precaliceal dilatation of the renal tubules. Clinical manifestations include recurrent kidney stones, urinary tract infections, hematuria and back pain. Biological abnormalities such as hypocitraturia, hypercalciuria or hyperoxaluria are most often associated with active and recurrent lithiasis. Diagnosis is challenging, based on imaging, formerly intravenous urography and now Multidetector computed tomography urogram, or ureteroscopy. The pathophysiology is not well understood, hypotheses involve disturbances in renal organogenesis. Genetic origin and congenital nature of the disease are suspected. Treatment is mainly symptomatic and includes prophylactic dietary rules common to all nephrolithiasis patients. The natural course of the disease is unknown. Further data are needed to better characterize these patients.