ABSTRACT
The diagnosis of prostatic cancer present in a limited amount within needle biopsy tissue, is often challenging. The most common mimickers giving rise to false-positive cancer diagnosis are atypical adenomatous hyperplasia, prostatic intraepithelial neoplasia, atrophy and post-atrophic hyperplasia. Various diagnostic criteria including assessment of basal cells should be used for diagnosis of limited carcinoma. Immunohistochemical staining for both basal cells, such as 34betaE12 and p63, and AMACR, which label the cytoplasm of approximately 80% of prostatic adenocarcinoma, may be a useful adjunct in the diagnosis of limited prostatic cancer. However there are problems with both sensitivity and specificity. When the glands lacking sufficient criteria to establish a definitive carcinoma is present, we use the term 'atypical small acinar proliferation'.
