| foraminal lymph node | <anatomy> One of the hepatic nodes located adjacent to the epiploic foramen. Synonym: nodus foraminalis, foraminal node. (05 Mar 2000) |
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| lateral lacunar lymph node | A lymph node of the external iliac group located lateral to the external iliac artery at the vascular lacuna. Synonym: nodus lacunaris lateralis, lateral lacunar node. (05 Mar 2000) |
| lymph node | <anatomy> Small bean-shaped organ made up of a loose meshwork of reticular tissue in which are enmeshed large numbers of lymphocytes, macrophages and accessory cells located along the lymphatic system. Recirculating lymphocytes leave the blood through the specialised high endothelial venules of the lymph node and pass through the node before being returned to the blood through the lymphatic system. Because the lymph nodes act as drainage points for tissue fluids, they are also regions in which foreign antigens present in the tissue fluid are most likely to begin to elicit an immune response. Nodes filter out bacteria or cancer cells that may travel through the lymphatic system. Synonym: lymph glands. (14 Oct 1997) |
| lymph node excision | Surgical excision of one or more lymph nodes. Its most common use is in cancer surgery. (12 Dec 1998) |
| lymph node of azygos arch | A lymph node of the posterior mediastinal group located adjacent to the arch of the azygos vein. Synonym: nodus lymphaticus arcus venae azygos. (05 Mar 2000) |
| lymph node of ligamentum arteriosum | A lymph node of the anterior mediastinal group located adjacent to the ligamentum arteriosum. Synonym: nodus ligamenti arteriosi, lymph node of ligamentum arteriosum. (05 Mar 2000) |
| lymph node permeability factor | A substance, released by lymphocytes when stimulated or damaged, that increases capillary permeability and the accumulation of mononuclear cells. (05 Mar 2000) |
| lymph sinus | The channels in a lymph node crossed by a reticulum of cells and fibres and bounded by littoral cells; there are subcapsular, trabecular, and medullary sinus's. Synonym: lymph sinus. Maier's sinus, an infundibuliform depression on the internal surface of the lacrimal sac which receives the lacrimal canaliculi. Marginal sinuses of placenta, discontinuous venous lakes at the margin of the placenta. (05 Mar 2000) |
| malignant histiocytosis | A rapidly fatal form of lymphoma, characterised by fever, jaundice, pancytopenia, and enlargement of the liver, spleen, and lymph nodes; the affected organs show focal necrosis and haemorrhage, with proliferation of histiocytes and phagocytosis of red blood cells. (05 Mar 2000) |
| regressing atypical histiocytosis | A rare disease characterised clinically by multiple ulcerating cutaneous papules and nodules which show spontaneous regression; the skin is infiltrated by malignant-appearing histiocytes. (05 Mar 2000) |
| 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, 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) |
| histiocytosis, non-langerhans-cell | Group of disorders which feature accumulations of active histiocytes and lymphocytes, but where the histiocytes are not langerhans cells. The group includes haemophagocytic lymphohistiocytosis, infection-associated haemophagocytic syndrome, sinus histiocytosis, xanthogranuloma, reticulohistiocytoma, juvenile xanthoma, xanthoma disseminatum, as well as the lipid storage diseases (sea-blue histiocyte syndrome and niemann-pick disease). (12 Dec 1998) |
| 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) |