Progressive Congenital Valvular Aortic Stenosis

CHEST, VOL. 60, NO. 2, AUGUST 1971 noma. Stackhouse7 and associates, reviewing eight cases of pulmonary blastoma, stated that these cases should be considered as a distinctive group or subclassification of carcinosarcoma which simulates immature or developing lung blastema. Although more detail of differences in histogenesis of these two varieties of rare pulmonary tumors are given by others,7 it is important to recall that carcinosarcoma arises from cells of two separate germ layers, whereas pulmonary blastoma develops from a pleuripotential cell of a single germ layer. The benign or malignant nature of this tumor still remains mysterious. However, after reviewing the literature, it seems reasonable to postulate that it is the metastatic nature of this neoplasm which causes the very poor prognosis. The size of these lesions bears no relation to the extent of metastases and subsequently to ultimate outcome of these patients. The treatment of choice, from the available data, seems to be surgical intervention unless the risk of operation is considered hazardous to the life of the patient.