Transrectal sonographic features of prostatic intraepithelial neoplasia: correlation with pathologic findings.

Purpose: This study was conducted to evaluate the transrectal sonographic (TRUS) features of prostatic intraepithelial neoplasia (PIN) by comparing the histopathologic results with TRUS findings in patients who had undergone TRUS-guided prostate biopsy.

Methods: From an initial set of 307 patients who underwent TRUS-guided prostate biopsy, TRUS findings for 44 patients whose pathologic results were consistent with PIN were reviewed retrospectively. Among these 44 patients, 12 had only PIN, 20 PIN associated with prostatitis, and 12 PIN associated with prostate cancer foci. After exclusion of the foci that included PIN associated with prostatitis and PIN associated with prostate cancer at the same site, the pathologic results for the core specimens from the 100 PIN foci were correlated with TRUS findings according to their location. The sonographic features sought were hypoechoic areas and regions of heterogeneous echogenicity.

Results: Positive TRUS findings were detected in 43% of PIN and 36% of high-grade PIN (HGPIN) focise. For the HGPIN foci with positive TRUS findings, the detected sonographic features were clusters of millimetric hypoechoic foci (CMHF) (53%), hypoechoic areas with well-defined borders (27%), and heterogeneous echogenicity (20%) (not significant). The sensitivity of the presence of CMHF for the diagnosis of HGPIN was only 19%.

Conclusions: TRUS-detected CMHF may indicate HGPIN. Because of the limited sensitivity of this finding, TRUS detection of CMHF does not warrant biopsy, although these lesions warrant close monitoring.