Small-sized adenocarcinoma of the lung. Cytologic characteristics and clinical behavior.

Abstract

Although the cytologic characteristics of advanced adenocarcinomas of the lung have been described, the unique cytologic features of early adenocarcinomas have not been established. Cytologic specimens from 193 patients with small-sized lung adenocarcinoma, up to 2 cm in dimension, were reviewed. Cytologic investigations were performed on sputum, bronchial brushings or washings, or fine-needle aspirates obtained from the patients preoperatively. The cytologic characteristics of early adenocarcinoma were confirmed with Image Processor for Analytical Pathology from Sumitomo Chemical Co., Ltd. Nuclear size, variations in nuclear size, appearance of nucleolus, and nuclear atypia of the adenocarcinoma cells were found to differ between the various histologic subtypes of adenocarcinoma. The nuclei in small but advanced adenocarcinoma were generally larger and showed more variation in size than those in early adenocarcinoma (localized bronchioloalveolar carcinoma). Surgically curable, early adenocarcinomas of the lung were found to have a unique cytologic appearance, including small nuclear size and slight variation in nuclear size. Using these unique characteristics, they can be distinguished easily from advanced adenocarcinomas.