Desquamating apoptotic variant of high-grade prostatic intraepithelial neoplasia: a possible precursor of intraductal prostatic carcinoma

SummaryVarious patterns of high-grade prostatic intraepithelial neoplasia have been have been described, many of which show morphologic similarity to patterns of prostatic intraductal carcinoma, which is thought to develop either directly from high-grade prostatic intraepithelial neoplasia or by invasion of existing ducts by Gleason pattern 4 or 5 carcinoma. We document a rare and previously unreported “desquamating apoptotic variant” of high-grade prostatic intraepithelial neoplasia where desquamating cells containing apoptotic nuclear material coalesce in the gland lumens to form basophilic intraluminal masses in up to one third of involved acini. This lesion shares features of both high-grade prostatic intraepithelial neoplasia and prostatic intraductal carcinoma and supports the hypothesis that some forms of prostatic intraductal carcinoma evolve directly from high-grade prostatic intraepithelial neoplasia.