Prostate cancer with a pseudocapsule at MR imaging: a marker of high grade and stage disease?

Clinicopathological correlates of prostate cancer associated with a pseudocapsule at T2-weighted magnetic resonance (MR) imaging are presented in a retrospective series of 15 patients. Of 15 tumors, 14 involved the peripheral zone. Extracapsular extension was seen in 14 cases. Tumor Gleason score was 8 or above in 12 of 15 cases, and ductal type adenocarcinoma was identified in 4 cases. Step section histopathological correlation (n=5) demonstrated that the pseudocapsule corresponded with dense compressive or reactive peritumoral fibrosis. A pseudocapsule around prostate cancer at T2-weighted MR imaging is a rare finding that appears to be associated with high grade and stage disease.