| Abstract: | Some factors influencing the diagnostic accuracy for primary lung cancer in bronchial washings were studied in 276 consecutive cases seen between 1959 and 1974. Diagnostic accuracy increased during the years under study; the reasons included increasing expertise of the laboratory staff, better documentation of cytologic criteria and improved collection techniques. The overall accuracy was 74%. Detection of malignant cells was highest for squamous-cell and adenosquamous carcinomas (81%), small-cell carcinoma, adenocarcinoma and large-cell carcinoma (70%) and lowest for bronchioloalveolar-cell carcinoma (47%). Accuracy was 84% for central tumors as compared to 30% for peripheral lesions. Tumors of less than 2 cm in diameter yielded very poor results (15%) while those greater than 2 cm yielded 82% accuracy. The specificity of diagnosis of cell type in those specimens with malignant cells was over 93% for squamous-cell carcinoma, small-cell carcinoma and adenocarcinoma, 77% for large-cell carcinoma and below 50% for adenosquamous carcinoma, bronchioloalveolar carcinoma and the uncommon tumors. Two bronchial washings per case gave an appreciably better result (92%) than one per case (68%). The percentage of unsatisfactory specimens from those with cancer was 13.5 and from a control group was 29.9. Reasons for unsatisfactory specimens included limited cellular material, excessive blood and/or leukocytes and drying artifacts. |
