Multilocular cystic nephroma: a radiographic-pathologic correlation of 58 patients.

Clinical radiographic, and pathologic findings of multilocular cystic nephroma (MLCN) in 58 patients are presented. The lesion that affects predominantly boys in childhood and women in adulthood is usually solitary but rarely can be multiple, and it commonly occurs as an asymptomatic mass, occasionally with hematuria. Tumors may grow slowly over years or rapidly within months. A mass that is usually identified on plain radiographs occasionally has curvilinear calcification. Excretory urography and retrograde pyelography are helpful when pelvic herniation of the tumor is recognized, or when septae are noted with total body opacification. Angiography showed an avascular mass (six lesions), a hypovascular mass (14 lesions), or a hypervascular mass three lesions). Ultrasonography is helpful when multiple circumscribed sonolucent areas are identified. Similarly, a multilocular mass with septae is usually identified by computed tomography (six of seven cases). Our findings and a review of the literature indicate that this lesion is a neoplasm that can be strongly suspected preoperatively if pelvic herniation or a multilocular pattern is noted on imaging studies.