This document discusses various histological structures and lesions that can mimic prostate carcinoma on biopsy. It describes entities such as atrophy, basal cell hyperplasia, adenosis, non-specific granulomatous prostatitis, and clear cell cribriform hyperplasia that resemble low or high-grade prostate cancer. Distinguishing these mimickers from cancer relies on architectural features, cytology, immunohistochemistry, and the presence of basal cells. While some mimickers can be difficult to differentiate from cancer on limited biopsy sampling, correlation with clinical findings and use of immunohistochemical markers are important to arrive at an accurate diagnosis.