Pulmonary blastoma.

A case of pulmonary blastoma in a 8-year-old girl is reported. The histopathologic analysis evidenced carcinomatous tubes with several cell layers developing into a mesenchymal cell mass with undifferentiated elements forming a dendroreticulated network with minimal endothelial, fibroblastic and collagenous differentiations. The initial tumoral formation within the lower left lobe was rapidly followed after resection by a local recidive and nine months later by a voluminous metastatic formation within the upper left lobe, radiologically treated. Discussion of the histopathologic characteristics of this case supports the hypothesis of a peculiar neoplastic entity of the lung, in which only the epithelial component of the lung was involved, while the mesenchymal mass presented an unaffected fetal structure.