Orofacial granulomatosis: insights from an immunohistochemical evaluation

Abstract

Objective: The aim of this paper was to report a case of orofacial granulomatosis, with immunohistochemical evaluation of some inflammatory cells that would be involved on its etiopathogenesis. Methods: The specimen was collected through biopsy for diagnostic proposal and was further submitted to immunohistochemistry for CD3, CD20, S-100, D2-40, and AE1/AE3. Immunohistochemical analysis was performed in inflammatory cells in granulomatous nodules and through the oral mucosa. Results: In the granulomas, CD3+ cells were the main component of inflammatory cells. S-100+ cells were seen diffusely distributed. CD20+ cells were observed in a lower amount than CD3+ and S-100+. D2-40 staining evidenced some large lymphatic vessels, which were surrounded by inflammatory cells. Besides the granulomas, an intense and diffuse inflammatory infiltrate was seen in connective tissue, immediately below the epithelium with a large number of CD3+ cells in intimate contact. A disorganization of the basal layer of epithelium was also present. AE1/AE3 was positive only in the keratinocytes. S-100+ cells were numerous in the connective tissue, and infiltrating the epithelium. CD20+ cells were observed in a lower number than CD3+ and S-100+, mainly located in a deeper region of the connective tissue. Conclusions: Dendritic cells and T lymphocytes were the major components of inflammatory infiltrate in oral mucosa and granulomatous nodules. The observed epithelial disorganization was quite similar to that of lichen planus. The findings corroborate to a cell-mediated immunological background of orofacial granulomatosis.