Pulmonary blastoma.

A case of pulmonary blastoma is described in a man dying at the age of 50 from hepatic and cerebral metastases. Eleven previously reported cases are reviewed and the histogenesis is discussed. It is concluded that these rare tumours are a distinct form of pulmonary carcinosarcoma in which the epithelial element is an adenocarcinoma. It is this that gives it its characteristic and probably coincidental histological resemblance to foetal lung and the evidence for a blastomatous origin is regarded as insufficient.