Familial association of pleuropulmonary blastoma with cystic nephroma and other renal tumors: a report from the International Pleuropulmonary Blastoma Registry

OBJECTIVE: To characterize the association of pleuropulmonary blastoma (PPB) with cystic nephroma (CN) and other renal tumors. STUDY DESIGN: Complete clinicopathologic review of cases from the International PPB Registry and literature. RESULTS: We identified 18 patients with PPB associated with 20 renal tumors (15 CN), either in themselves or family members. All patients with PPB were <5 years of age. All but one of the renal diagnoses were made before 4 years of age. Eleven children had both PPB and renal tumor, one of whom also had a sibling with CN. Six children with PPB alone had one or more family members with CN. The mother of one child with PPB had Wilms' tumor. Pulmonary disease was bilateral in four patients. Renal disease was bilateral in three patients. Two children with PPB and bilateral renal cystic tumors also had intussusceptions because of small bowel juvenile polyps. In six families, dysplasia/neoplasia affected organs other than lung and kidney. CONCLUSIONS: CN or related tumors were found in 9.2% of 152 Registry-reviewed PPB cases. The occurrence of rare pulmonary and renal tumors together in patients and/or family members, the early age of onset, and the multiplicity of tumors is compatible with a constitutional genetic predisposition.