Langerhans cell histiocytosis revisited: Case report with review.

Langerhans cell histiocytosis (LCH) is a group of idiopathic disorders characterized by proliferation of bone marrow derived Langerhans cells and mature eosinophils. Their clinical features simulate common oral findings such as gingival enlargement, oral ulcers, and mobility of teeth, along with nonspecific radiographic features; hence, diagnosing such lesions becomes difficult for the oral physicians. These lesions are commonly seen in childhood; however, we are reporting a case of LCH in 29-year-old adult male. A provisional diagnosis of giant cell granuloma was considered based on history and examination, although the lesion was histologically proven to be LCH and was confirmed with immunohistochemical staining of S100 protein and CD1a antigen. The purpose of this paper is to enhance the understanding of diverse, nonpathognomical oral presentation of LCH that is easily misdiagnosed and overlooked by dentist.