Solitary Langerhans cell histiocytosis of the hard palate: a diagnostic pitfall.

Langerhans cell histiocytosis (LCH) is a relatively rare and unique disease characterized by an abnormal proliferation of immature dendritic cells. It is predominantly seen in children with adults showing less than ten times the incidence compared to childhood. The clinical presentation and organ involvement is highly variable. Oral manifestations generally consist of mucosal ulceration associated with lesions of the underlying bone. Lesions limited to the oral mucosa are rare. We present a case of a 45-year-old male who presented with an ulcer on the hard palate showing histopathologic features of LCH. The present case is a reminder of the possibility of occurrence of this unusual entity in the oral cavity. Appropriate use of immunohistochemistry is advocated to avoid diagnostic pitfalls.