Bronchiolo-alveolar carcinoma with nodal metastases. An ultrastructural study.

A case of bronchiolo-alveolar carcinoma of the lung was studied by light and electron microscopy. Type II granular pneumocytes were seen in the lymph node metastases of the tumor, a finding not reported previously. We feel that the presence of these cells in metastatic foci indicates their neoplastic nature, and provides evidence that bronchiolo-alveolar carcinoma arises from type II cells.