Immunohistochemical evaluation of androgen receptor, HER-2/neu, and p53 in benign pleomorphic adenomas.
BACKGROUND
Immunohistochemical stains for androgen receptor (AR), HER-2/neu, and p53 are used as diagnostic markers associated with malignancy in several histologic types of salivary gland tumors. These markers may be useful in differentiating pleomorphic adenoma with cytologic atypia from intracapsular carcinoma ex pleomorphic adenoma (CXPA), as these tumors are often difficult to distinguish on the basis of morphology alone.


OBJECTIVE
To determine whether AR, HER-2/neu, and p53 expression can be seen in entirely benign pleomorphic adenomas.


METHODS
Androgen receptor, HER-2/neu, and p53 immunoreactivity was assessed in 41 histologically and clinically benign pleomorphic adenomas.


RESULTS
A total of 3 of 41 pleomorphic adenomas exhibited multifocal areas with moderate staining for HER-2/ neu and AR. The positive staining was mainly confined to the epithelial component, where the ductal epithelium showed no cytologic atypia. Immunoreactivity for p53 was observed in the epithelial component of 5 of 41 cases, none of which stained for HER-2/neu and AR. Mean mitotic rate and Ki-67 index were 1 per 10 high-powered fields and 2.7% in HER-2/neu- and AR-positive cases and 1 per 10 high-powered fields and 2.2% in p53-positive cases.


CONCLUSIONS
HER-2/neu, AR, and p53 are expressed in a subset of histologically and clinically benign pleomorphic adenomas. These markers cannot be used to reliably predict early carcinomatous transformation in pleomorphic adenoma.
DeRoche
Tom C
TC
Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH 44195, USA.
Hoschar
Aaron P
AP
Hunt
Jennifer L
JL
D008949:Adenoma, Pleomorphic / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011944:Receptors, Androgen / Q000378:metabolism*; D012189:Retrospective Studies; D012468:Salivary Gland Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D055815:Young Adult
D018719:Erb-b2 Receptor Tyrosine Kinases; D011944:Receptors, Androgen; D016159:Tumor Suppressor Protein p53; C508053:ERBB2 protein, human