Prostate, benign biopsy

The prostate gland is an organ of the male lower urogenital tract which encircles the urethra at the level of the bladder neck. The prostate is divided into four zones: peripheral zone, central zone, transitional zone, and the anterior fibromuscular stroma. As seen in this example, the normal prostate is histologically composed of glands with two cell layers: 1) columnar secretory cells with clear to eosinophilic cytoplasm, and 2) basal cells which are cuboidal with high nuclear:cytoplasmic ratio. Corpora amylacea may also be seen within the glands.

The distinction between benign prostate and prostatic acinar adenocarcinoma may be made histologically. Features supporting malignancy typically include an infiltrative appearance, glands with lack of basal cells, and prominent nucleoli. Other helpful features include an amphophilic cytoplasm, intraluminal crystalloids, intraluminal mucin, perineural invasion, and/or extraprostatic extension. In equivocal cases, staining with basal cell markers (p63, high molecular weight cytokeratin) and AMACR which is upregulated in prostatic adenocarcinoma may aid in making the diagnosis.