Solitary extragnathic langerhans cell histiocytosis - a rare case.

Langerhans cell histiocytosis (LCH), mainly affects the skull, vertebrae, ribs and mandible in children and the long bones of adults. Symptoms range from none to pain, swelling and tenderness over the site of the lesion. This disease presents oral manifestations which can sometimes be the first expression of the condition. It occurs in three forms namely eosinophilic granuloma in which isolated or multiple bones are involved, But has a good prognosis whereas other variants Hand-Shuller-Christian disease (chronic dessiminated variant) and Letterer-Siwe disease (acute dessiminated form) have poor prognosis. Occasionally only soft tissues are affected without bony involvement. Males are more commonly affected than females. This article describes a rare variant of eosinophilic granuloma of labial mucosa without bony involvement.