| lymphoma, mixed-cell, diffuse | A heterogeneous group of intermediate-grade lymphomas of mixed cellular composition. Although they have not been extensively studied, it appears that they are predominantly B-cell diseases. (12 Dec 1998) |
|---|---|
| lymphoma, mucosa-associated lymphoid tissue | Extranodal lymphoma of lymphoid tissue associated with mucosa that is in contact with exogenous antigens. Many of the sites of these lymphomas, such as the stomach, salivary gland, and thyroid, are normally devoid of lymphoid tissue. They acquire malt tissue as a result of an immunologically mediated disorder. (12 Dec 1998) |
| lymphoma, non-hodgkin | Any of a group of malignant tumours of lymphoid tissue that differ from hodgkin disease, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumours is the absence of giant reed-sternberg cells, a characteristic of hodgkin's disease. (12 Dec 1998) |
| lymphoma, T-cell | A group of heterogeneous lymphoid tumours representing malignant transformations of T-lymphocytes. (12 Dec 1998) |
| lymphoma, T-cell, cutaneous | A group of lymphomas exhibiting clonal expansion of malignant T-lymphocytes arrested at varying stages of differentiation as well as malignant infiltration of the skin. Mycosis fungoides and sezary syndrome are the best characterised of these disorders. (12 Dec 1998) |
| lymphoma, T-cell, peripheral | A group of malignant lymphomas thought to derive from peripheral T-lymphocytes in lymph nodes and other nonlymphoid sites. They include a broad spectrum of lymphocyte morphology, but in all instances express T-cell markers admixed with epithelioid histiocytes, plasma cells, and eosinophils. Although markedly similar to large-cell immunoblastic lymphoma (lymphoma, large-cell, immunoblastic), this group's unique features warrant separate treatment. (12 Dec 1998) |
| lymphoma, undifferentiated | A form of lymphoma in which relatively large stem cells with large nuclei, pale, scanty cytoplasm, and indistinct borders are predominant. The cells are undifferentiated, i.e., show no morphologic evidence of maturation toward lymphocytes or histiocytes. (12 Dec 1998) |
| bilaterally small, smooth kidneys | <radiology> Generalised atherosclerosis, nephrosclerosis - benign and malignant, atheroembolic renal disease, chronic glomerulonephritis, papillary necrosis, hereditary diseases, hereditary chronic nephritis (Alport's syndrome), medullary cystic disease, amyloidosis (late), arterial hypotension Cf: other urographic patterns (12 Dec 1998) |
| carcinoma, non-small-cell lung | A heterogeneous aggregate of at least three distinct histological types of lung cancer, including squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. They are dealt with collectively because of the shared properties of poor response to conventional chemotherapy and the potential for cure with surgical resection in a fraction of patients. (12 Dec 1998) |
| carcinoma, small cell | An anaplastic, highly malignant, and usually bronchogenic carcinoma composed of small ovoid cells with scanty neoplasm. It is characterised by a dominant, deeply basophilic nucleus, and absent or indistinct nucleoli. There are admixtures of small cell lung carcinoma with other types of lung cancer. Small cell carcinomas are distinguished by their distinctive biological features, response to chemotherapy and radiotherapy, and by their nearly universal tendency to develop overt or subclinical metastases, which frequently eliminates surgery in most patients. (12 Dec 1998) |
| generalised small bowel disease | <radiology> Hypoproteinaemia, sprue, Whipple (12 Dec 1998) |
| mesenteric portion of small intestine | The freely movable portion of the small intestine supplied with a mesentery, comprising the jejunum and ileum. Synonym: mesenteric portion of small intestine. (05 Mar 2000) |
| ribonucleoproteins, small nuclear | Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm. The u3 snrnp is localised in the nucleolus, where it aligns into base pairs with the 28s rrna precursor in a still unidentified region and functions in pre-rrna processing. The u7 snrnp aligns into base pairs with a conserved sequence in the 3'-end of histone pre-mRNA and is an essential cofactor for the cleavage that creates the mature nonadenylated 3'-end. (12 Dec 1998) |
| ribonucleoproteins, small, u1 | A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the u1 snrnp along with other small ribonucleoproteins (u2, u4-u6, and u5) assemble into spliceosomes that remove introns from pre-mRNA by splicing. The u1 snrnp base pairs with conserved sequence motifs at the 5'-splice site and recognises both the 5'- and 3'-splice sites and may have a fundamental role in aligning the two sites for the splicing reaction. (12 Dec 1998) |
| ribonucleoproteins, small, u2 | A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the u2 snrnp along with other small ribonucleoproteins (u1, u4-u6, and u5) assemble into spliceosomes that remove introns from pre-mRNA by splicing. The u2 snrnp base pairs with conserved sequence motifs at the branch point, which associates with a heat- and rnaase-sensitive factor in an early step of splicing. (12 Dec 1998) |