Pulmonary fine needle aspiration biopsy - Assessing the negative diagnosis

OBJECTIVE: To assess the significance of the "negative for malignancy" cate gory when applied to pulmonary transthoracic fine needle aspiration biopsy (FNAB). STUDY DESIGN: Transthoracic lung FNABs diagnosed as "negative for malignanc y" were identified from the files of Barnes-Jewish Hospital's South and Nor th Campus over a period of five and nine years, respectively. Histologic co rrelation and clinical follow-up were obtained. RESULTS: Of the 1,181 lung FNABs performed during the study period, 108 cas es (9%) had a negative cytologic diagnosis. Histologic correlation was avai lable in 46 cases (43%), of which 23 cases had benign histologic findings, and 19 cases were malignant. Thirty-five of the 62 cases without histologic correlation had clinical follow-up consistent with a benign process. CONCLUSION: Based on the histologic correlation and clinical data available , the negative predictive value was 77%. Inadequate sampling was responsibl e for all false negative cytologic diagnoses in this series.