A case report of langerhans cell histiocytosis

ABSTRACT

Langerhans cell histiocytosis (LCH) is a group of idiopathic disorders characterized by the proliferation of specialized bone marrow derived Langerhans cells and mature eosinophils. LCH is a disease that primarily affects bone but can be associated with a clinical spectrum that ranges from a solitary bone lesion with afavorable natural history to a multisystem, life-threatening disease process. Bone involvement with or without other associated sites is the most common manifestation of LCH and has been observed in 80-100% of cases. Despite the preference for bone, the disease may demonstrate extraosseous manifestations as well. While uncommon, this may complicate the clinical picture, occurring most commonly in infants and children with multisystem disease. Although the described triad of diabetes insipidus, exophthalmos, and eosinophilic granuloma does occur occasionally in children, multisystem disease may present in a variety of ways and may be life threatening. The microscopic examination is critical for the diagnosis. Immunohistochemistry using CD1a is now used routinely as a diagnostic tool. Although a positive CD1a immunohistochemical stain in the setting of appropriate histology is usually considered adequate for diagnosis, demonstrating Birbeck granules in the abnormally proliferating Langerhans cells using electron microscopy (EM) is the most specific diagnostic test. The etiology and pathogenesis of LCH has remained an enigma despite of continuous research. We report a case of eosinophilic granuloma of the mandible in 12 year-old female with literature review.