Pulmonary blastoma. Immunohistochemical and ultrastructural studies of a case

The immunohistochemical and ultrastructural features of a case of pulmonary blastoma in a 39-year-old woman are documented. Three types of cells were observed: epithelial, mesenchymal and 'blastomatous'. The latter stained with intermediate filament antibodies similar to those of mesenchymal and epithelial elements, thus supporting the hypothesis that this tumour is derived from a pluripotent undifferentiated element.