Abstract
Bronchoscopically, adenocarcinoma occasionally shows the type of longitudinal tumor infiltration that is frequently found in small cell carcinoma. We have evaluated the clinical characteristics of this type of adenocarcinoma in comparison with other adenocarcinomas of the lung. The incidence of longitudinal infiltration in adenocarcinoma was 0% in resected cases and 10.8% in nonresected cases, constituting 6.0% of all cases examined by fiberoptic bronchoscopy. This type of adenocarcinoma often showed an ill-defined infiltrative shadow or mass shadow accompanied by non-homogeneous reticular opacity on chest X-ray film, while most of the other adenocarcinomas showed a peripheral mass shadow. The positive rates of sputum cytology in the two types of adenocarcinoma were 82% and 45%, respectively. Bone and lung metastases were found in this type of adenocarcinoma more frequently than in the others. Some cases of this type of adenocarcinoma were pathologically considered to be tubular adenocarcinoma of the bronchial gland cell type. From these clinical features and characteristic findings of fiberoptic bronchoscopy, it is suggested that this type of adenocarcinoma may be an unique clinical entity. Further investigation should be carried out especially on the morphologic characteristics.
