Langerhans' cell histiocytosis of the frontal bone.

Two cases of Langerhans' cell histiocytosis of the frontal bone are presented. This condition was previously known as eosinophilic granuloma and rarely involves the orbit but may be associated with widespread and life-threatening disease. Clinical, radiological and histopathological features are presented. A discussion of the light and electron microscopic appearances, investigation and management follows.