CHARACTERIZATION OF VERRUCIFORM XANTHOMA BY IN-SITU HYBRIDIZATION ANDIMMUNOHISTOCHEMISTRY

Verruciform xanthoma (VX) is a rare, benign lesion, mainly found in th e oral mucosa. Histologically and ultrastructurally, the lesion is cha racteristic and well defined. However, the etiology of the lesion rema ins unclear. The purpose of the present study was to elaborate upon th e pathogenesis of VX by evaluation of an additional series of oral exa mples for human papillomaviruses (HPV), using immunohistochemistry and in situ hybridization, and to further characterize the cellular compo nents of VX immunohistochemically. Twelve specimens diagnosed as VX we re retrospectively collected. One of the twelve specimens was positive for HPV types 6/11 by in situ hybridization. None of the twelve speci mens demonstrated the presence of HPV antigen by immunohistochemistry. By immunohistochemical studies, the predominant cells in the inflamma tory infiltrate were T cells, The foam cells were of monocyte/macropha ge lineage. S-100-positive (Langerhans) cells were occasionally found in the suprabasal layer of the epithelium. HLA-DR-positive keratinocyt es were noted at the intense inflammatory sites. Taken together, these findings suggest that an immune response may play a role, at least in part, in VX pathogenesis.