Adenocarcinoma of the lung: electron microscopy of fine-needle aspiration biopsy specimens--a review of 73 cases.

During a 10-yr period, 128 consecutive cases of pulmonary adenocarcinoma of varying differentiation were diagnosed with percutaneous fine-needle aspiration biopsy. Sediments from the needle and syringe washings with 3% glutaraldehyde were obtained and processed for electron microscopic evaluation in 73 cases. Our results showed three types of adenocarcinoma: 62 cases of nonciliated bronchiolar cell origin, 6 cases of bronchioloalveolar cell origin, and 3 cases of mucous cell origin. In addition, there was an example of combined adenosquamous carcinoma and an instance of amphicrine carcinoma. Our study provided a more precise definition of the cytologic diagnosis and insight into the heterogeneity of lung adenocarcinoma. However, prognostic differences between cell types of lung adenocarcinoma were not observed.