Endogenous lipid pneumonia- and alveolar proteinosis-type changes in the vicinity of non-small cell lung cancer: histiopathologic, immunohistochemical, and ultrastructural evaluation.

Endogenous lipid pneumonia (ELP) and pulmonary alveolar proteinosis (AP) are the most common pathological conditions of lung tissue in which there is an increased accumulation of surfactant elements in pulmonary alveoli. This paper evaluates the morphology, morphogenesis, and pathogenesis of ELP- and AP-type changes in the immediate vicinity of non-small cell lung cancer (NSCLC). The analyses used lung tissue obtained from the vicinity of 56 NSCLC. ELP- or/and AP-type changes in histopathological studies were found in lung tissue surrounding 35 NSCLC. Ultrastructural analyses by transmission electronmicroscopy identified 15 cases with advanced ELP and confirmed the possibility of coexistence of ELP- and AP-type changes in the vicinity of NSCLC and the evolution of ELP into AP. Most cases analyzed showed morphological features characteristic of both AP and ELP, the intensity and degree of these changes being considerably differentiated. Type II pneumocytes, macrophages, and neutrophilic granulocytes play a significant part in the morphogenesis of ELP and AP.