Nasopharyngeal Angiofibroma: A Clinical, Histopathological and Immunohistochemical Study of 42 Cases with Emphasis on Stromal Features.

Nasopharyngeal angiofibroma is a benign but aggressive tumor of unknown etiology, typically occurring in adolescent males. It is described as a rare neoplasm; however, the prevalence seems to have geographic differences. All cases referred to our head and neck clinical and pathology service were reviewed. Most of the patients presented at an advanced stage. The clinical and radiographic features are presented and discussed. Histologically, the tumor shows a highly vascular fibrous proliferation with characteristic plump, angulated and stellate cells, categorized as fibroblasts. Immunohistochemistry was performed on 42 cases to further elucidate the nature of these cells. The stromal cells expressed vimentin and factor XIIIa, the latter expressed most commonly in the giant stellate cells. Inflammation was almost exclusively present in peripheral subepithelial areas. Mast cells were abundant, even in the absence of other inflammatory cells. Lymphatics were observed principally in peripheral regions. Proliferating cells (Ki-67 reactive) were restricted to endothelial cells.