Intravascular and sclerosing bronchio-alveolar tumor.

A case of intravascular and sclerosing bronchio-alveolar tumor is presented with ultrastructural observations. The tumor cells appear to arise from the alveolar lining and are characterized by a fibrillary cytoplasm. These cells are enmeshed in interstitial tissue containing fibrils, elastin material, amorphous intercellular substance and degenerated cytoplasmic processes. The patient, a 49-year-old white woman, is alive without treatment, with no significant increase in size or number of lung nodules 7 years after the clinical discovery.