Pleuropulmonary blastoma (PPB) was defined in 1988 by Manivel et al. in a series describing 11 intrathoracic pulmonary neoplasms in young children . The PPB is a unique peripheral pulmonary or pleural-based tumor of childhood that is characterized in its earliest form as a bland-appearing multiloculated cyst with small foci of tumor cells and in later forms as mixed and predominantly primitive, overtly malignant neoplasms [2,3]. Prior to the introduction of the PPB as a distinct entity, this tumor had been reported in the literature as pulmonary blastoma, sarcoma arising in mesenchymal cystic hamartoma, embryonal sarcoma, malignant mesenchymoma, primary pulmonary rhabdomyosarcoma and rhabdomyosarcoma arising in congenital adenomatoid malformation or bronchogenic cyst. Over the past 15 years, PPB has come to be recognized in centers around the world. With the establishment of the Pleuropulmonary Blastoma Registry by Jack Priest, MD, and colleagues, there has been improved understanding of this rare pediatric neoplasm. The registry Web site serves as an important resource for physicians and families (http://www.ppbregistry.org).