In addition, there is no associated soft tissue swelling so this lesion is not attributable to any recent trauma. Myeloma would also be excluded in this age group. Histiocytosis X is a proliferative disorder of macrophages of unknown etiology causing cholesterol laden macrophages to collect in bone and soft tissues. The lesions may occur in any portion of the body including bones, skin, brain, lungs, lymph nodes, liver, and spleen. Although cholesterol deposition is prominent in macrophages and there are scattered eosinophils there is no defined abnormality related to cholesterol metabolism or peripheral eosinophilia.
Histiocytosis represents three related diseases which range from benign to aggressive.
Eosinophilic granuloma which is a relatively benign self limiting unifocal disease involving lytic lesions of bones in children and young adults. The calvarium is most often affected, thereafter followed in decreasing order of frequency the mandible, spine, ribs, large long bones. The second is Hand Schuller Christian disease which also affects children and young adults but is a multifocal disease involving bones and soft tissues and is accompanied by symptoms related to affected organ. Lytic lesions in the jaw bone may yield a radiologic impression of floating teeth. Deafness may be due to involvement of the external auditory canal and mastoid air cells.