Implications of small, peripheral hypoechoic lesions in endorectal US of the prostate

Endorectal ultrasound (US) can demonstrate small, nonpalpable, or subtly palpable lesions of the prostate. However, differentiation of benign from malignant processes has not always been possible. Because early diagnosis may have immense clinical implications, the possibility that endorectal US can be used to diagnose early prostate cancer has been suggested. The authors prospectively evaluated with endorectal US 80 small (less than 1.5 cm) peripherally oriented hypoechoic lesions in 79 patients with a normal or questionably abnormal digital rectal examination. In all patients at least two biopsies per lesion were performed. The transperineal sonographically guided biopsies were performed with both cytologic and core biopsy techniques. Seventeen of the 80 lesions (21.3%) were malignant. These findings suggest a low, but perhaps clinically significant, rate of diagnosis of small prostate cancers. While these data are interesting, they are insufficient to recommend use of endorectal US as a screening tool for prostate cancer.