EXPRESSION OF ANDROGEN RECEPTORS IN NASOPHARYNGEAL ANGIOFIBROMA - AN IMMUNOHISTOCHEMICAL STUDY OF 24 CASES

Angiofibromas are uncommon benign tumors that typically occur in the l ateral portion of the nasopharynx of adolescent boys. Numerous reports showed indirect evidence for the presence of sex-hormone receptors, i .e., androgen (AR), estrogen (ER), and progesterone (PR) receptors, in these tumors. The goal of the current study was to show direct eviden ce of sex hormone receptor expression in angiofibromas with use of sen sitive immunocytochemical techniques and to document which cell popula tions express the receptor. Twenty-four nasopharyngeal angiofibromas w ere obtained from archived tissue, and immunocytochemical studies were performed with antibodies to AR, PR, and ER. Positive stromal and end othelial nuclear immunostaining, implying the presence of ARs, was see n in 18 (75%) of 24 cases, whereas 2 (8.3%) of 24 cases were positive with antibodies to PR. None of the 24 cases examined was positive with antibodies to ER, These results provide the first direct evidence for the presence of ARs in angiofibromas, which might help to explain the unique clinicopathologic features of these tumors.