| Abstract: | Morphological study of bronchioloalveolar carcinoma (BAC) was performed by light or electron microscopy in 100 and 33 patients, respectively. BAC-1, 2 and 3 histologic subtypes were established basing on ultrastructural peculiarities which betrayed different cytogenetic origins. Electron microscopic signs of goblet cells were found in cells constituting BAC-1 tumors. BAC-2 tumor cells exhibited ultrastructural characteristics of Clara cells and/or type-II pneumocytes. BAC-3 tumors appeared less differentiated and contained mainly undifferentiated cells and cell clusters displaying various combinations of electron microscopic markers of goblet and Clara cells and type-II pneumocytes. |
