Prevalence of prostatic calcification subtypes and association with prostate cancer.

OBJECTIVE: To evaluate the prevalence and to classify prostatic calcification on transrectal ultrasonography (TRUS) and correlate the findings with histology. METHODS: A prospective, blinded study of men undergoing TRUS and prostatic biopsy was designed. A standardized reproducible technique was used with a BK 7.5- to 12.5-MHz multiplanar probe. Representative images of the calcification in the sagittal and transverse planes were captured. Blind analysis by an experienced observer was performed. TRUS findings were categorized using a novel classification and correlated with histologic data. RESULTS: A total of 274 patients (58.8%) had prostate cancer, 88 patients (18.9%) inflammation, and 104 patients (22.3%) had benign pathology. Interface calcification was present in 42.3% of patients. Peripheral or transitional zone calcification was unusual (6.8% and 9.0%, respectively). Of the peripheral zone calcification group patients, 78.1% had cancer on histology examination (P = .020). CONCLUSION: Prevalence and characteristics of prostatic calcification have been described using this novel and practical classification. Although interface calcification is common and not associated with any particular pathology, peripheral zone calcification appears to be strongly associated with prostate cancer.