[Clinicopathological study of small adenocarcinoma of the lung]

Until December, 1987, a total of 55 cases of small primary adenocarcinoma of the lung (2 cm or less in diameter) were surgically treated in our department. Resected specimens were classified into three groups; 18 advanced cases (Stage III, IV), 22 early cases (Stage I) without recurrence, and 10 early cases (Stage I) with recurrence after surgery. Histopathologically, in advanced cases, lymphatic invasion, mitosis and cellular atypia were more frequently noted than in early cases. Fibrotic scar, which meant long-term existence of cancer, and vessel invasion were more frequently found in early cases with recurrence than in early cases without recurrence. The postoperative survival was largely dependent on distant metastasis via vessel invasion in advanced cases as well as early cases with recurrence. Mediatinal recurrence often occurred even in early cases with marked lymphatic invasion.