Öz
Abstract: Langerhans cell histiocytosis (LCH) is an unusual disorder characterized by high proliferation of Langerhans
cells. A 27-year-old male patient was referred to the Oral Medicine Clinic, Faculty of Dentistry, Altınbaş University
with a complaint of wound that does not heal for eight months. The clinical examination showed palatal mucosal
ulceration extending to the bone at the upper right first molar region and ulceration at the lingual mucosa of the
lower right first molar. The patient had been previously evaluated by a different dentist and was told that it was an
aphthous lesion. A punch biopsy from the palatal mucosa and alveolar mucosa near the lesion revealed Langerhans
cells and positive reaction to CD1 so the patient was diagnosed with LCH. The insignificant treatment trials may lead
to diagnostic delay. Oral lesions may be the earliest symptom of LCH and in most cases; the oral cavity may be the
only area involved. Awareness of lesions in the oral mucosa is important in achieving the accurate and early diagnosis
and effective treatment plan.