Transthoracic fine needle aspiration biopsy. Sensitivity in relation to guidance technique and lesion size and location.

To obtain site- and size-specific data on transthoracic fine needle aspiration (TFNA) and determine the sensitivity in relation to guidance technique and lesion size and location.Data on 112 patients undergoing TFNA between 1992 and 1993 were analyzed for accuracy rates, stratified according to lesion size and location within the lung. The series included 13 benign lesions, 53 metastatic neoplasms and 46 primary carcinomas.Overall sensitivity was 90%, with 92% specificity. There was a clear relationship between nodule size and sensitivity of TFNA, with a sensitivity of 60% for lesions < 1 cm but 93% sensitivity for nodules > or = 2 cm in diameter. Similarly, lesion location affected sensitivity. Sensitivity was 100% for peripherally located nodules but was as low as 82% for nodules in the centrobasal portion of the lung. Sensitivity was higher for fluoroscopy (97%) than computed tomography (80%).The guidance technique as well as lesion location and size affect diagnostic accuracy.