histiocytosis


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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.

his·ti·o·cy·to·sis

(his'tē-ō-sī-tō'sis),
A generalized proliferation of histiocytes.
Synonym(s): histocytosis

histiocytosis

(hĭs′tē-ō′sī-tō′sĭs)
n. pl. histiocyto·ses (-sēz)
Any of several diseases characterized by the abnormal proliferation of histiocytes in the tissues or organs.

his·ti·o·cy·to·sis

(his'tē-ō-sī-tō'sis)
A generalized multiplication of histiocytes.
Synonym(s): histocytosis.

histiocytosis

One of several disorders in which HISTIOCYTES occur in abnormal numbers, in localized areas, without any of the usual causes, such as infection. Histiocytosis LESIONS may be single or multiple. The condition is also known as histiocytosis X.
References in periodicals archive ?
Langerhans cell sarcoma (LCS), also known as malignant histiocytosis X, is a rare entity defined as a tumor characterized by its LC immunophenotype and appearance.
Currently available data suggest that manipulation of the BCL2 family (with the decrease of both MCL1 and BCL2A1) in DC, associated with a therapeutic vaccination with autologous tolerogenic DC, might represent a suitable treatment in rheumatoid arthritis and Langerhans cell histiocytosis, possibly leading to a cure.
Gastrointestinal RDD commonly affect ileocecal area and distal colon in middle-aged females with an over whelming majority of the cases being located beyond the pylorus.1 Involvement of liver was previously reported in literature but RDD with liver cirrhosis was reported recently in previous year.5 Histopathologically, diffuse histiocytosis, homogeneous chromatin and a single small nucleolus are characteristic features of both nodal and extra nodal RDD, along with emperipolesis, which consists of the passage of intact, often multiple lymphocytes through the cell within intracytoplasmic vesicles.
Management of Langerhans Cell Histiocytosis (LCH)-Induced Central Diabetes Insipidus and Its Associated Endocrinological/Neurological Sequelae.
Langerhans cell histiocytosis: Histiocyte society evaluation and treatment guidelines.
PET-CT in pediatric Langerhans cell histiocytosis. Pediatr Radiol.
Xanthoma disseminatum is a subset of non-Langerhans cell histiocytosis (NLCH).
Purely cutaneous Langerhans' cell histiocytosis in an adult woman.
Echocardiographic and clinical characteristics of pulmonary hypertension complicating pulmonary Langerhans cell histiocytosis. Mayo Clin Proc.
observation of rare tumours like Haemangiopericytoma, Adenocarcinoma and Langerhans cell histiocytosis were reported in this case series.
Langerhans cell histiocytosis (LCH) is a rare proliferative disorder with unknown etiologies.
Langerhans cell histiocytosis (LCH) results from an abnormal accumulation of immature Langerhans cells, causing tumor formation or organ damage.