Immunohistochemical pitfalls in prostate pathology.
The diagnosis of prostatic adenocarcinoma relies on a constellation of architectural, cytological, and immunohistochemical features. Although the diagnosis of prostatic adenocarcinoma is straightforward in most cases, due to earlier detection of the disease in the modern era, pathologists have become increasingly challenged in diagnosing small foci of cancer when only a few atypical glands are present in needle biopsies. Immunohistochemistry has therefore become an essential tool in the evaluation of such foci to confirm the absence of basal cells. In this context, the 2 most commonly used basal cell markers are anti-keratin 34BE12 and p63. Furthermore, α-methylacyl-CoA racemase, a marker found to be overexpressed in the cytoplasm of prostatic adenocarcinoma glands, is also commonly used in routine practice. Another diagnostic role of immunohistochemistry is to confirm the prostatic origin of the tumor in the primary or metastatic setting of high-grade prostatic adenocarcinoma, which may be confused with nonprostatic carcinomas. We herein review the utility as well as the limitations of immunohistochemistry in the diagnosis of prostatic adenocarcinoma, and we describe the most important pitfalls in the interpretation of various immunostains that pathologists should be aware of to minimize misdiagnoses.
Department of Pathology, McGill University Health Center, Montreal, QC, Canada H3A 2B4.
Fadi
F
Brimo
Jonathan I
JI
Epstein
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D001284:Atrophy / Q000175:diagnosis / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control*; D050990:GATA3 Transcription Factor / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D007633:Keratins / Q000378:metabolism; D008297:Male; D011467:Prostate / Q000378:metabolism / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D019998:Racemases and Epimerases / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism
D014408:Biomarkers, Tumor; D050990:GATA3 Transcription Factor; C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D007633:Keratins; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase