FROM THE ARCHIVES OF THE AFIP - MULTILOCULAR CYSTIC RENAL TUMOR IN CHILDREN - RADIOLOGIC-PATHOLOGICAL CORRELATION

Multilocular cystic renal tumor is a term that encompasses two histolo gically distinct but grossly indistinguishable lesions: cystic nephrom a and cystic partially differentiated nephroblastoma (CPDN). Cystic ne phroma is a segmental, purely cystic mass characterized by multiple se ptations composed entirely of differentiated tissues, without blastema l elements. CPDN is also a multiloculated lesion without nodular solid components, but its septa contain embryonal cells, Multilocular cysti c tumors primarily affect boys during early childhood, with a substant ial number of the lesions containing blastema (CPDN), and adult women, with lesions that more commonly lack septal blastema (cystic nephroma ), As a rule, nephrectomy is curative and the clinical course benign, but CPDN may recur locally, Although cystic nephroma and CPDN cannot b e distinguished radiologically, failure to do so has no practical impa ct on management, since all of these tumors are surgically removed, Ho wever, the differential diagnosis includes other pediatric cystic rena l masses that may require different treatment stratagems: Wilms tumor with cyst formation due to hemorrhage and necrosis, cystic clear cell sarcoma, cystic mesoblastic nephroma, cystic renal cell carcinoma, mul ticystic dysplastic kidney, and segmental multicystic dysplasia in a d uplicated renal collecting system.