Pulmonary fine needle aspiration biopsy -: Assessing the negative diagnosis

OBJECTIVE: To assess the significance of the "negative for malignancy" category when applied to pulmonary transthoracic fine needle aspiration biopsy (FNAB). STUDY DESIGN: Transthoracic lung FNABs diagnosed as "negative for malignancy" were identified from the files of Barnes-Jewish Hospital's South and North Campus over a period of five and nine years, respectively. Histologic correlation and clinical follow-up were obtained. RESULTS: Of the 1,181 lung FNABs performed during the study period, 108 cases (9%) had a negative cytologic diagnosis. Histologic correlation was available 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 responsible for all false negative cytologic diagnoses in this series.