Morphologic lesions in non-neoplastic bronchial mucosa associated with bronchial carcinomas

The histomorphologic alterations of bronchial mucosa were analyzed in 332 cases with primary bronchial carcinomas and 48 cases with intrapulmonary metastases. The surgical specimens (lobes and lungs) were cut into serial sections after expansion and fixation, and the bronchial mucosa was analyzed in relation to its distance from the tumor boundary. Samples of the bronchial mucosa were taken at distances 10 mm, 20 mm, 30 mm and 40 mm. The following results were obtained: In primary bronchial carcinomas 18% of cases revealed a normal mucosa at 10 mm distance and 45% at 40 mm distance. The histomorphological alterations included hyperplasia of basal cells and goblet cells and less frequent squamous metaplasia. They were seen twice as frequent in primary bronchial carcinomas as in intrapulmonary metastases and were found to be distance-related only in small-sized primary bronchial carcinomas (maximum diameter less than 30 mm). Epidermoid carcinomas and small cell carcinomas displayed hyperplasia of basal cells in 40-60% of cases, adenocarcinomas only in 20-40%. Squamous metaplasia was seen in 10-15% of epidermoid carcinomas and small cell carcinomas, and only rarely in adenocarcinomas and metastases. The histomorphologic changes of bronchial mucosa associated with primary bronchial carcinomas can clearly be separated from those seen in intrapulmonary metastases in respect to their frequency and distance-relation. The findings indicate that the analyzed morphological alterations are probably associated with the histogenesis of the bronchial carcinomas.