[Hypothalamic histiocytosis X--report of a case].

Histiocytosis X is a non-neoplastic disorder of unknown etiology characterized by a mass of proliferating histocytes, plasma cells and inflammatory cells forming a granuloma within the reticuloendothelial elements of any organ system in the body. The three clinical syndromes of this condition, eosinophilic granuloma, Hand-Schüller-Christian disease and Letterer-Siwe disease were unified into a single nosological entity by Lichtenstein in 1953. The complication of the central nervous system is shown in the cerebrum, cerebellum, sella turcica, hypothalamus and so on. Hypothalamic histiocytosis X is often found in cases of disseminated histiocytosis X, but an isolated histiocytosis X of the hypothalamus is very rare. Including our case, 16 cases of hypothalamic histiocytosis X were reviewed in this paper. Age at onset was older than disseminated histiocytosis X. The sex ratio was almost equal. Diabetes insipidus was equally found as in other suprasellar masses and it was important as an initial symptom. The CT finding was shown as a homogeneously enhanced mass but no specific finding of CT was seen as suprasellar histiocytosis X. Therefore, differential diagnosis was very difficult. Treatments for this disease were variable. Chemotherapy, irradiation or combination of both were reported. The combination therapy was thought to be the most effective treatment. The relation between this disease and disseminated histiocytosis X is not known. But possibility of transformation of this disease into disseminated histiocytosis X was reported in some papers. Therefore, early diagnosis by biopsy of the hypothalamic lesion was stressed.