[Eosinophilic granuloma. Risk of fracture and rare site].

The eosinophilic granuloma of bone, Letterer-Siwe's disease and Hand-Schüller-Christian's disease are integrated under the conception Histiocytosis X. The same patho-histological findings, especially on bone and the observation that the 3 diseases can change one into the other are the reason for this conception. In the past the very different prognosis of the 3 diseases was the reason for difficulties of the classification and the therapy. In Letterer-Siwe's disease with bad prognosis and HSC with uncertain prognosis conservative therapy is mostly indicated. The eosinophilic granuloma in monotopic and polytopic localisation normally requires surgical procedure usually the excision of a specimen for the diagnosis. In special localisations with the fracture or the possibility of a fracture operative procedure with resection, bone grafting and osteosynthesis in order to get bone stability are indicated. 2 cases with special localisation are described.