1995 Volume 35 Issue 2 Pages 141-148
Solid carcinoma with mucus formation, a subtype of pulmonary adenocarcinoma by the WHO classification, was classified as a large cell carcinoma according to the Japanese Lung Cancer Society Classification. In order to study which classification best represents the clinicopathologic characteristics of the tumor, we analyzed and compared these characteristics with those of other subtypes of adenocarcinomas and large cell carcinomas.The examined materials were 459 cases of surgically resected lung cancers (solid carcinomas with mucus formation: 20 cases; well differentiated adenocarcinomas: 179 cases;moderately differentiated adenocarcinomas: 142 cases; poorly differentiated adenocarcinomas: 61 cases;large cell carcinomas: 57 cases) from 1980 to 1992 in the Cancer Institute Hospital.
The male to female ratio for solid carcinomas with mucus formation was about 4 to 1, which was lower than for large cell carcinomas (13:1) but similar to that of poorly differentiated adenocarcinomas (3:1). The prognosis of solid carcinomas, showing a similar figure to that of moderately differentiated adenocarcinomas in 5-year survival curves, was not as poor as with large cell carcinomas.Although many of carcinoma cases showed bulky progression, 50% of them showed no lymph node metastasis. These findings were also similar to those of moderately and poorly differentiated adenocarcinomas. Therefore, the clinicopathologic findings suggest that a solid carcinoma with mucus formation might better be classified as an adenocarcinoma rather than a large cell carcinoma.
