Premalignant lesions of the prostate

Abstract

It is now universally accepted that high-grade prostatic intraepithelial neoplasia (HGPIN) is the key preneoplastic lesion associated with prostate cancer, and it has a well recognized characteristic morphology, with variants and immunochemical expression pattern. Low-grade PIN has not yet been accepted as a preneoplastic lesion. Because of the high incidence of prostate cancer, HGPIN is also extremely common. When first identified on needle biopsies, it had a high predictive value for the later development of prostate cancer: however, this association is being lost in the era of extended biopsies as most tumors are sampled at first biopsy procedure. However, multiple foci of HGPIN appear more predictive of later malignancy than single foci, and this has implications for patient surveillance. Atypical acinar proliferations are not true preneoplastic lesions but merely statements of pathological uncertainty about the presence of carcinoma. However, their identification is important because of a strong association with the presence of malignancy on later biopsy. Intraductal carcinoma is an unusual and rare entity, which may represent spread of a preexisting carcinoma down prostatic ducts thus mimicking a preneoplastic lesion. It is nearly always found associated with invasive malignancy. It has been suggested that proliferative inflammatory atrophy is a premalignant lesion and occurs at a stage before PIN, though this is unproven.