Cytopathologic findings in pulmonary blastoma.

The exfoliative cytologic description of a pulmonary blastoma is reported. The debated histogenesis of these tumors is briefly reviewed. A review of all case reports recording cytopathology findings indicates that these rare tumors yield diagnostic cells in only a minority of cases. In the present case, as in previous reports, only the epithelial component (carcinoma) was recognized prior to the histopathologic diagnosis. The stromal cells were less numerous and not as conspicuous as the epithelial cells. The diagnosis of pulmonary blastoma should be considered whenever nonsquamous carcinomatous cells plus a separate population of smaller malignant cells are seen in a pulmonary cytology specimen.