Histoenzymology of the lung. V. Histoenzymatic analysis of sixty lung tumors.

A series of sixty lung tumors operated during 1977 were histoenzymatically investigated (12 macrocellular carcionomas, 4 microcellular, 18 epidermoid, 18 cylindrocubic, 2 bronchiolo-alveolar cell carcinomas, 4 lung fibroblastic sarcomas, and 2 benign lung tumors: a haemangioma and a carcinoid tumor). There were tested 25 enzymes, hydrolases and oxidoreductases of different metabolic pathways. The histoenzymatic analysis of the neoplastic lung tissue compared with the normal adult human lung tissue pointed to a shifting of the metabolic balance, with the decrease of enzyme activities belonging to the Krebs tricarboxylic acid cycle and with the increase or maintenance of the level of enzymic activities belonging to the Embden-Meyerhoff-Parnas pathway and to the pentose shunt. The enzymes intervening in the protidic activity in all the malignant tumors of the lung. Some hydrolases were also more active lung tissue pointed out the existence of close relations between the normal epithelia and the cylindrocubic and bronchiolo-alveolar types, and of distant ones with the epidermoid and microcellular carcinomas which suffered more accentuated ecogenetic influences (stopping of differentiation/maturation, metaplasia) during the complex oncogenetic process.