| lymphoma, small-cell | A B-cell lymphoma presumably representing a tumour of interfollicular B-lymphocytes that may be functional. Those that are secrete identical immunoglobulin molecules. (12 Dec 1998) |
|---|---|
| lymphoma, small cleaved-cell, diffuse | An intermediate-grade malignant lymphoma in which the neoplastic cells (B-lymphocytes) exhibit variability in size, configuration, and degree of differentiation. The cells have distinctive nuclei, irregular in shape, with marked indentations and angularity. (12 Dec 1998) |
| lymphoma, small cleaved-cell, follicular | A low-grade malignant lymphoma of predominantly follicular pattern. Follicles are of relatively uniform size and shape and the cells are usually somewhat larger than normal lymphocytes. Nuclei are irregular with prominent indentations and cytoplasm can rarely be identified. Cells exhibiting these characteristics are often called centrocytes. (12 Dec 1998) |
| lymphoma, small lymphocytic | A low-grade malignant lymphoma that may, in some cases, be considered histologically identical to chronic lymphocytic leukaemia (cll; leukaemia, lymphocytic, chronic). It is diffuse in pattern, representing the neoplastic proliferation of well-differentiated B-lymphocytes. In patients with immunoglobulin gammopathies, the lymphocytes may exhibit plasmacytoid characteristics. (12 Dec 1998) |
| lymphoma, small noncleaved-cell | A high-grade malignant lymphoma that includes both burkitt tumour (burkitt lymphoma) and other lymphomas previously designated undifferentiated non-burkitt type. Nuclei in burkitt tumour are round to ovoid and uniform in size. The non-burkitt type exhibits greater nuclear variation and less evidence of cellular maturation with a correspondingly lesser degree of differentiation. (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) |
| androgenic zone | A transient adrenocortical zone present in some rodents at birth, most notably in mice, situated between the zona reticularis and the adrenal medulla; it degenerates in males with the secretion at puberty and in females during their first pregnancy; it slowly enlarges in unmated females after puberty and does not degenerate until middle age; the X zone appears to secrete no hormone. Synonym: androgenic zone. Misnomer for the foetal adrenal cortex of primates. Synonym: foetal reticularis. (05 Mar 2000) |
| arcuate zone | The inner third of the basilar membrane of the cochlear duct extending from the tympanic lip of the osseous spiral lamina to the outer pillar cell of the spiral organ (of Corti). Synonym: zona arcuata, zona tecta. (05 Mar 2000) |
| Barnes' zone | The lower fourth of the pregnant uterus, attachment of the placenta to any part of which may cause dangerous haemorrhage. Synonym: cervical zone. (05 Mar 2000) |
| buffer zone | <ecology> An area of land separating two distinct land uses that acts to soften or mitigate the effects of one land use on the other. (09 Oct 1997) |
| capillary zone electrophoresis | A method for separating molecules extremely rapidly based on their electrophoretic mobility. (05 Mar 2000) |
| vascular zone | An area in the external acoustic meatus where a number of minute blood vessels enter from the mastoid bone. Synonym: spongy spot, zona vasculosa. (05 Mar 2000) |