Table I.

Hierarchical Taxonomic Classification of Tumors of the Prostate.

Category	Family (Class)	Type
Epithelial tumors of the prostate	Glandular neoplasms of the prostate	Prostatic cystadenoma
		High-grade prostatic intraepithelial neoplasia
		Intraductal carcinoma of the prostate
		Prostatic acinar adenocarcinoma*
		Prostatic ductal adenocarcinoma
		Treatment-related neuroendocrine prostatic carcinoma
	(Baso)squamous neoplasms of the prostate	Adenosquamous carcinoma of the prostate
		Squamous cell carcinoma of the prostate
		Adenoid cystic (basal cell) carcinoma of the prostate
Mesenchymal tumors unique to the prostate	Stromal tumors of the prostate	Prostatic stromal tumor of uncertain malignant potential
		Prostatic stromal sarcoma

*Acinar PCa is the only tumor type in this chapter with subtypes, which are signet-ring cell–like (≥ 25% signet-ring cell component), sarcomatoid carcinoma, pleomorphic giant cell adenocarcinoma, and PIN-like carcinoma. Atrophic (including p63-positive), pseudohyperplastic, microcystic, foamy gland, and mucinous (≥ 25% composed of glands with extracellular mucin) are considered histologic patterns. PCa, prostatic adenocarcinoma; PIN, prostatic intraepithelial neoplasia.