Pleomorphous macrocellular pulmonary carcinomas. An anatomoclinical study on 193 cases.

A pathomorphologic study was carried out by the conventional histologic methods in 193 cases of pleomorphous macrocellular pulmonary carcinoma, of a total of 1,637 cases of lung cancer diagnosed histologically between January 1, 1961 and December 31, 1974. In comparison to other histologic types, the incidence of macrocellular carcinomas was of 11.8%, 62.6% belonged to the 40-60 years age-group, with male predominance. The results showed this carcinoma to be an autonomous type of neoplastic proliferation. The pathomorphologic particularities observed in the 193 cases and their evolution are conclusive arguments for considering pleomorphous macrocellular carcinomas as a separate histologic type in the classification of lung cancers. The term of pleomorphous macrocellular carcinoma appears to be the most comprehensive and in keeping with the histologic structure of these tumours. Cellular pleomorphism is an important diagnostic feature. Zones of specific differentiation observed in some cases may be included in the pleomorphism of these carcinomas. Notions of histogenesis are likewise discussed. It is increasingly assumed that these carcinomas are morphologically the expression of a cellular proliferation, differentiation and maturization response to the action of complex factors. The reduced stroma of these carcinomas indicate a more rapid increase of the tumoural parenchyma.