History: A 57 year old man with elevated PSA. Biopsy of the prostate is performed and one core shows the following:
H&E: There is a small focus of atypical glands at one side of the core that are suspicious for low grade adenocarcinoma. Immunohistochemistry for PIN4 is requested.
IHC: The focus in question shows that the atypical glands are negative for high molecular weight cytokeratin and p63, consistent with the absence of basal cells. There is one gland with focal patchy staining for high molecular weight cytokeratin and p63.
Discussion: Although many atypical glands are negative for basal cell markers and are positive for racemase, there is focal patchy staining in a similarly atypical gland. Given that there is patchy stain for basal cells in one of the glands, the entire focus could represent high-grade PIN, and, therefore, a definitive diagnosis of carcinoma should not be made. Instead, the diagnosis of atypical glands suspicious for low grade adenocarcinoma is made with a recommendation for consideration of repeat follow-up biopsy if clinically indicated.
This case was provide by Dr. Andres Matoso, Associate Professor of Pathology, Urology and Oncology, and the Director of the Immunohistochemistry Laboratory at Johns Hopkins Hospital. The book Survival Guide to Prostate Pathology that he and Dr. Epstein wrote has been recently released. You can order your copy at: