[Bronchiolo-alveolar carcinoma]. Histologic analysis of 3 cases, one of which with ultrastructural study].

A histological analysis was performed on 3 cases of bronchiolo-alveolar carcinoma (BAC) in one of which an electronmicroscopic research was made. It was about a case of BAC with pneumonocytes of type I the lasting in life of which from the ascertainment of the tumor was 1.2 years (autopsy); and of a case of BAC with pneumocytes of type II (operatory case) and of a case of BAC with conventional cells (autoptic case) who survived an average of 4.3 years. All the cases had metastasis in the ilar lymph nodes. The three BAC were localized in the superficial area of the lung and it is also evident that they occupy the alveolar cavities, taking the thin alveolar wall as the only interstice. Besides in the following development there was evident tendency to hypertrophy of the interstizial collagen tissue, in the BAC with pneumocytes of type II and respectively with cells of conventional type; and the subtotal PAS negativity in the BAC with pneumocytes of type I. The included nuclears present in the only BAC with pneumocytes of the second type take the origin from the cytoplasm in the shape of small round masses penetrating into the nucleus, as from electronic microscopy. In the considered BAC, it was about surfactant apoproteins wich, in the nucleus, precipitate in morphologically different shapes.