The purpose of this study was to improve the diagnostic accuracy of CT-guided biopsy of small lung nodules with the aid of frozen-section histopathologic diagnosis.

Since 1993, we have evaluated 52 lung nodules smaller than 3 cm with CT-guided transthoracic biopsy. Thirty-five lesions were malignant and 17 were benign. Biopsy always started with a 20-gauge spring-operated core biopsy needle. Tissue samples were sent to the pathology laboratory immediately after biopsy for histopathologic diagnosis of the frozen sections.

In 47 (90%) of 52 lesions, sufficient material for histologic diagnosis was obtained, including 34 (97%) of 35 malignant lesions and 13 (76%) of 17 benign lesions. In the 13 benign lesions for which histologic sampling was successful, a specific diagnosis of benign was made for 10 lesions (77%). In three cases, the sample was too small to make a histologic specimen, but cytologic study using the same sample led to the correct final diagnosis: one as malignant and two as benign. In the remaining two cases, biopsy was unsuccessful. The lesions were both 1 cm in size and were found to be benign on follow-up studies.

CT-guided biopsy with the aid of frozen-section specimens using small-bore spring-operated core needles is a feasible technique with good results in the histologic diagnosis of small lung lesions.