Low Grade Prostatic Intraepithelial Neoplasia

**Semantic type:** Neoplastic Process

**Definition:** Prostatic intraepithelial neoplasia characterized by the proliferation of secretory cells with irregular spacing in the ducts and acini. Although some proliferating epithelial cells may contain prominent nucleoli, the cytologic atypia and architectural growth patterns that are seen in the high grade prostatic intraepithelial neoplasia are absent. The presence of low grade prostatic intraepithelial neoplasia in needle biopsy is not a risk factor for the subsequent detection of carcinoma on repeat biopsy.

**Synonyms:** - Grade 1 PIN - Grade 1 Prostatic Intraepithelial Neoplasia - Grade I PIN - Grade I Prostatic Intraepithelial Neoplasia - Low-Grade Intraepithelial Neoplasia of Prostate - Low-Grade Intraepithelial Neoplasia of the Prostate - Low-Grade PIN - Low-Grade Prostatic Intraepithelial Neoplasia - PIN-1