Pleuropulmonary Blastoma and its association with other childhood neoplasms

Abstract

8542 Background: Pleuropulmonary Blastoma (PPB) is a rare childhood tumor of the chest wall and lung with three distinct pathology subtypes: type I—entirely cystic; type II—cystic and solid; type III—entirely solid. Poor outcomes have been observed in patients with types II and III PPB. Common sites of metastatic involvement are the brain and bones. In numerous cases, other dysplastic and/or neoplastic conditions occur in the PPB patient or in young, close relatives. Methods: The PPB Registry, established in 1988, collects diagnostic, treatment, and outcome data about this disease for patients worldwide. Results: Registry and literature cases reveal the following conditions associated with PPB in 30 families: Familial cases: -9 patients with relatives having childhood or young adult cancers -3 families with 2 PPB patients in each; an additional family with a child with PPB and another child with a brain sarcoma undistinguishable from PPB -6 patients with relatives having dysplasia in childhood or young adulthood Metachronous or synchronous conditions: -4 patients with additional cancers -5 patients with bilateral PPB -12 patients with additional dysplastic conditions Common associated dysplastic conditions are lung cysts and cystic nephroma. Other associated neoplastic conditions include germ-cell tumors, brain tumors, lymphoma and leukemia, sarcomas, histiocytosis, Wilms' tumor, thyroid tumors, neuroblastoma, and Sertoli-Leydig tumor. Conclusion: 19 of 82 registry patients (23%) with central PPB pathology review have a constitutional or familial association with other neoplasias/dysplasias. At least 3 PPB patients have relatives with germ cell tumors, an association that needs further exploration. Similarly, the preponderance of renal malformations/tumors implies a possible common genetic pathway. PPB is an extraordinary marker for familial childhood dysplasia and neoplasia which deserves intensive molecular study. No significant financial relationships to disclose.