Prostatic intraepithelial neoplasia (PIN)-like adenocarcinoma

Definition

• A variant of invasive prostatic carcinoma that is morphologically characterized by pseudostratified columnar epithelium, typically arranged in dilated glands with flat or tufted epithelium, and morphologic features that resemble high-grade prostatic intraepithelial neoplasia (HGPIN) but lack basal cells.

• Some refer to prostatic intraepithelial neoplasia (PIN)-like prostatic adenocarcinoma as “PIN-like ductal prostatic adenocarcinoma.” If classified strictly according to the definition, these tumors are variants of ductal adenocarcinoma as they have pseudostratified columnar cells and can co-mingle with usual papillary and cribriform ductal adenocarcinoma. However, some prefer “PIN-like carcinoma” since they have a better prognosis than tumors historically considered ductal adenocarcinoma. The concern is that even though a pathologist qualifies PIN-like ductal adenocarcinoma as having a similar prognosis to Gleason score 6 (Grade Group 1) acinar carcinoma, some clinicians may nevertheless equate any ‘ductal’ carcinoma of the prostate with aggressive behavior.

• A variant of Gleason pattern 3 prostatic adenocarcinoma.

Clinical features