[Ultrastructural study of the parenchyma of lung carcinoma]

Thirty three cases of human lung carcinoma were studied by both light microscopy and electron microscopy. The diagnoses of 24 cases initially made by light microscopy were changed, extended, or supplemented by electron microscopic observation. Nineteen cases showed heterogeneity. Bidirectional or tripartite differentiation was frequently found in the same case, even in the same cell. The diagnosis and heterogeneity of lung carcinoma were discussed.