Diagnosis: PINATYP

Comment: The term PINATYP (atypical high-grade prostatic intraepithelial neoplasia) was coinned by Epstein to refer to a few atypical glands immediately adjacent to high-grade PIN. The differential diagnosis is whether these small glands represent tangential sectioning or outpouching off of the high-grade PIN glands or a small focus of carcinoma adjacent to the high-grade PIN. Considering that PIN has discontinuous basal cells, a negative immunohistochemistry does not mean adenocarcinoma, unless there are a sufficiently large number of glands that are not immunoreactive. PINATYP should undergo repeat biopsy (Kronz JD, Shaikh AA, Epstein JI. High-grade prostatic intraepithelial neoplasia with adjacent small atypical glands on prostate biopsy. Hum Pathol 2001;32:389-95).