Perils of hidden depths

Circumferential perineural/periganglionic invasion is a diagnostic of prostatic adenocarcinoma.3 On immunostaining, these glands lack basal cells supporting the diagnosis of prostate cancer (figure 2F). [...]morphological ‘PIN’ is heterogenous and may actually represent PIN, perineural invasion by prostate cancer, PIN-like ductal carcinoma or intraductal carcinoma (figure 3). The morphological appearance of the high-grade prostatic intraepithelial neoplasia (PIN) can be seen in at least four distinct biological entities: high-grade PIN, PIN-like prostatic adenocarcinoma, intraductal carcinoma of the prostate and perineural invasion by invasive prostate cancer.