Percutaneous fine needle aspiration of pulmonary mass lesions--a critical examination of the accuracy of cell typing of malignant tumours.

All the biopsies of pulmonary mass lesions obtained by percutaneous needle aspiration over a seven year period were reviewed. Emphasis is laid upon the differences in cell typing of malignant tumours when two types of preparation of the same tissue, cytological smears and tissue sections are examined. Some problems in cell typing are discussed and suggestions for improved proficiency are made.