| histidinuria | Excretion of considerable amounts of histidine in the urine; frequently observed in later months of pregnancy, and in histidinaemia. (05 Mar 2000) |
|---|---|
| histidyl | The acyl radical of histidine. (05 Mar 2000) |
| histio- | Tissue, especially connective tissue. Origin: G. Histion, web (tissue) (05 Mar 2000) |
| histioblast | A tissue-forming cell. Synonym: histoblast. Origin: histio-+ G. Blastos, germ (05 Mar 2000) |
| histiocyte | <pathology> Long lived resident macrophage found within tissues. (11 Jan 1998) |
| histiocytic | Relating to or involving histiocytes (macrophages). (09 Oct 1997) |
| histiocytic disorders, malignant | Distinctive neoplastic disorders of histiocytes. Included are acute monocytic leukaemias, malignant histiocytosis (histiocytosis, malignant), and true histiocytic lymphomas. (12 Dec 1998) |
| histiocytic lymphoma | <tumour> A malignant tumour of reticular tissue composed predominantly of neoplastic histiocytes. See: large cell lymphoma. (05 Mar 2000) |
| histiocytoma | <tumour> A tumour composed of histiocytes. Origin: histio-+ G. Kytos, cell, + -oma, tumour (05 Mar 2000) |
| histiocytoma, fibrous | A tumour composed, wholly or in part, of cells with the morphologic characteristics of histiocytes and with various fibroblastic components. There are many variants and many names. Superficially located histiocytic lesions behave benignly but deep, benign histiocytomas may invade locally into surrounding tissue. Fibrous histiocytomas can occur anywhere in the body. Superficial lesions are always cured by simple excision; a wider margin of tissue should be obtained for deep, benign types. Local recurrence is uncommon. (12 Dec 1998) |
| histiocytosis | A condition marked by the abnormal appearance of histiocytes (macrophages) in the blood. Lipid h., Niemann-Pick disease. Sinus h., a disorder of the lymph nodes in which the distended sinuses are completely or nearly completely, filled by histiocytes, as a result of active multiplication of the littoral cells. H. X, a generic term embracing eosinophilic granuloma, Letterer-Siwe disease and Hand-Schuller-Christian disease and indicating a shared common origin for the three entities. (16 Dec 1997) |
| histiocytosis x | An immunologic disorder of unknown cause where there is proliferation of histiocytes (a type of cell in the immune system) in the bloodstream. The disorder is characterised by inflammation of the bronchioles and small pulmonary vessels that leads to fibrosis and destruction of alveolar cell walls. Cigarette smoking is considered a risk factor. Individuals with this disorder are also at increased risk for spontaneous pneumothorax. Symptoms include cough, chest pains, shortness of breath, fever, weight loss and malaise. Bronchoscopy with biopsy confirms the diagnosis. Childhood forms exist and cause more systemic symptoms and findings such as failure to thrive, weight loss, fevers, irritability, rash and bone pains. Treatment is with corticosteroids. (27 Sep 1997) |
| histiocytosis Y | A papilloma of the oral mucosa and skin in which squamous epithelium covers connective tissue papillae filled with large foamy histiocytes. Synonym: histiocytosis Y. (05 Mar 2000) |
| histiocytosis, langerhans-cell | Group of disorders of histiocyte proliferation which includes letterer-siwe disease, hand-schueller-christian syndrome, and eosinophilic granuloma. Langerhans cells are components of the lesions. (12 Dec 1998) |
| histiocytosis, malignant | A rare, usually rapidly progressive disorder, characterised by abrupt onset, fever, weight loss, hepato-splenomegaly, pancytopenia, and lymphadenopathy. (12 Dec 1998) |