[Pneumoblastomas. Apropos of 2 cases].

Pulmonary blastomas, also referred to as embryonal carcinosarcomas or, in the past, embryomas, are rare tumors of which thirty cases have been described in English, German, and Italian publications. We present two typical pulmonary blastomas one in a 43-year-old man and the other in an infant of six months, the youngest case yet reported. Several arguments exist in favor of the embryonic origin of these neoplams: their histogenesis, their resemblance to nephroblastomas, their bifocal or multifocal presence in certain cases, and in about one third of all cases their discovery in patients under 20 years of age. Histologically the tumoral tissue contains two components: an epithelial component in which tubes resembiling fetal bronchi are found, and a loose mesenchymal component of an embryonic type containing various areas of differentiation. Although some tumors evolve slowly or have been known for years, most of the time the appearance of symptoms is soon followed by hematogenous dissemination and rapid demise. Our two patients died quickly: the infant from mediastinal compression with cardiorespiratory insufficiency, and the adult form metastatic dissemination.