Transrectal ultrasound-guided core biopsies of the prostate. A comparison between the standard 1.2-mm needle and three thinner needles.

Transrectal ultrasound (TRUS) examination is a well established method for the diagnosis of prostate cancer. The examination technique has, however, certain limitations, and biopsies are needed to differentiate between malignant and benign lesions. In order to determine the influence of the thickness of the needle on the histopathological evaluation of specimens, core biopsies were taken from 36 patients with hypoechoic lesions suggestive of cancer detected by TRUS, using a 1.2-mm cutting needle followed by a thinner needle (0.9-, 0.8- or 0.7-mm). A total of 164 biopsies from 41 hypoechoic lesions were obtained. The specimens were coded and examined by a pathologist. They were judged according to amount of tissue obtained, quality, length, malignancy and grade. The best results were obtained with the 1.2- and 0.9-mm needles. The results were comparable and reliable for both needle types which can be recommended for clinical practice. The 0.8- and 0.7-mm needles were found to give more or less unsatisfactory results.