Langerhans cell histiocytosis


histiocytosis

 [his″te-o-si-to´sis] a condition marked by the abnormal appearance of histiocytes in the blood.Langerhans cell histiocytosis a generic term that encompasses a group of disorders characterized by proliferation of Langerhans cells, which are specialized cells found in the epidermis that function as part of the immune system. These disorders are believed to arise from disturbances in regulation of the immune system. Children are more often affected than adults, and the bone marrow, endocrine system, and lungs may be involved (the lungs are affected more commonly in adults than in children). Langerhans cell histiocytosis is divided into unifocal and multifocal variants; there is also an acute, disseminated form (letterer-siwe disease). This group of disorders was formerly called histiocytosis X and was classified in three forms: Letterer-Siwe disease, Hand-Schüller-Christian disease, and eosinophilic granuloma. Called also eosinophilic granuloma, eosinophilic granulomatosis, and Langerhans cell granulomatosis. Langerhans cell histiocytosis, acute disseminated Letterer-Siwe disease.Langerhans cell histiocytosis, multifocal Langerhans cell histiocytosis occurring as erosive accumulations of proliferating Langerhans cells. It occurs most commonly in the marrow cavities of bones, but may also affect the skin, gingiva, lungs, and stomach. When the triad of involvement of the bones of the skull, exophthalmos, and diabetes insipidus is present, it is referred to as Hand-Schüller-Christian disease.Langerhans cell histiocytosis, unifocal Langerhans cell histiocytosis occurring as a single osteolytic lesion, usually in a long or flat bone; it may be asymptomatic or may produce bone pain, tenderness, and swelling and, sometimes, pathologic fracture.histiocytosis X former name for Langerhans cell histiocytosis.

Lang·er·hans cell histiocytosis

(lahng'ĕr-hahnz), [MIM*604856] a set of closely related disorders unified by a common proliferating element, the Langerhans cell. Three overlapping clinical syndromes are recognized: a single site disease (eosinophilic granuloma), a multifocal unisystem process (Hand-Schuller-Christian syndrome), and a multifocal, multisystem histiocytosis (Letter-Siwe syndrome.) Formerly this process was known as histiocytosis X. Synonym(s): histiocytosis X

Langerhans cell histiocytosis

n. Any of several disorders of varying severity in which immature dendritic cells having the appearance of Langerhans cells proliferate, causing lesions or tissue damage in one or more organ systems. Symptoms include bone lesions, swollen gums, rashes, anemia, dysfunction of the liver, spleen, or lungs, and diabetes insipidus.

Lang·er·hans cell his·ti·o·cy·to·sis

(lahng'er-hahnz sel his'tē-ō-sī-tō'sis) A set of closely related disorders unified by a common proliferating element, the Langerhans cell. Three overlapping clinical syndromes are recognized: a single site disease (eosinophilic granuloma), a multifocal unisystem process (Hand-Schüller-Christian syndrome), and a multifocal, multisystem histiocytosis (Letterer-Siwe syndrome.) Formerly this process was known as histiocytosis X.

Lang·er·hans cell his·ti·o·cy·to·sis

(lahng'er-hahnz sel his'tē-ō-sī-tō'sis) [MIM*604856] Set of closely related disorders unified by a common proliferating element, the Langerhans cell. Three overlapping clinical syndromes are recognized: single site disease, multifocal unisystem process, and a multifocal, multisystem histiocytosis.