Megacalycosis.

Megacalycosis is a primary disease of the renal calyx which is diagnosed usually because of its complications, such as calculi or infections in the urinary tract. In the absence of complications, the disease is discovered accidentally in the course of urologic examination undertaken for a different reason. The present article reports 4 cases of megacalycosis: one with histologic confirmation in addition to radiologic diagnostic criteria and 3 with diagnosis based on radiologic findings alone. Alertness to the possible existence of megacalycosis in patients suffering from infections and calculi in the urinary tract contributes to and facilitates choice of appropriate treatment.