MORPHOLOGICAL STUDY OF 406 CASES OF BRONCHOGENIC CARCINOMA IN JAPAN

Abstract

406 cases of bronchogenic carcinoma in Japan have been collected from medical schools and hospitals of almost all parts of the country. Although its initial symptoms and histogenesis were discussed, the principal purpose of the authors' work was to carry out a morphological study of bronchogenic carcinoma. Therefore, macroscopical classification of the tumor in eleven types is presented. Histologically, bronchogenic carcinoma was divided into three major groups of epidermoid carcinoma, adenocarcinoma and undifferentiated carcinoma, and these groups were further divided in 4 or 5 subgroups respectively according to their differentiation and histological features. Special emphasis was extended to a group tentatively named "under-differentiated adenocarcinoma", as it has a histological pattern easily confused with undifferentiated or epidermoid carcinoma.
According to the present classification, 369 cases of bronchogenic carcinoma with well preserved specimen were divided in 117 cases of epidermoid carcinoma, 136 cases of adenocarcinoma and 116 cases of undifferentiated carcinoma. As seen here, adenocarcinoma occupied the largest number of the groups in contrast to many reports dealing with histological classification by various authors, who classified epidermoid or undifferentiated carcinoma as the largest group of bronchogenic carcinoma. The difference will probably consist in the grouping of "under-differentiated adenocarcinoma" discussed here. Two cases of bronchogenic adenomas were briefly presented, and the malignancy of the cylindromatous type is added.
Coexistent tuberculosis was found in 53 cases of 406, and its relation to carcinoma was discussed with the presentation of histology.
Concerning metastasis, only two cases were free from it, and distributions of metastases in various organs and lymph nodes of different sites were described in correlation with histological pattern.