| lymphoma, large-cell | A form of malignant lymphoma in which the malignant cells resemble histiocytes morphologically but are presently considered to be derived from lymphoid elements. These cells are irregular in shape with relatively abundant, frequently acidophilic cytoplasm. Large-cell lymphoma can occur in both nodular (follicular) and diffuse forms, with the latter being more frequently seen. (12 Dec 1998) |
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| lymphoma, large-cell, diffuse | Malignant lymphoma composed of large cells which may be both cleaved and noncleaved. The pattern is predominantly diffuse. most of these lymphomas represent the malignant counterpart of B-lymphocytes at midstage in the process of differentiation. (12 Dec 1998) |
| lymphoma, large-cell, follicular | Malignant lymphoma in which the majority of neoplastic cells within the follicles are large cleaved or noncleaved cells. The degree to which the follicular centre cells retain their ability to form follicles varies with the state of B-cell transformation. (12 Dec 1998) |
| lymphoma, large-cell, immunoblastic | Malignant lymphoma characterised by the presence of immunoblasts with uniformly round-to-oval nuclei, one or more prominent nucleoli, and abundant cytoplasm. This class may be subdivided into plasmacytoid and clear-cell types based on cytoplasmic characteristics. A third category, pleomorphous, may be analogous to some of the peripheral T-cell lymphomas (lymphoma, T-cell, peripheral) recorded in both the united states and japan. (12 Dec 1998) |
| lymphoma, large-cell, ki-1 | A large-cell, non-hodgkin's, malignant lymphoma with pleomorphic appearance and reactivity with the monoclonal antibody ki-1. The lymphoma is most often found in the skin and lymph nodes and expresses the ki-1 (CD30) antigen (antigens, CD30) on its surface. It is often mistaken for metastatic carcinoma and malignant histiocytosis. (12 Dec 1998) |
| lymphoma, low-grade | One of the three major prognostic groupings for non-hodgkin lymphomas as proposed in the working formulation of the non-hodgkin's lymphoma pathologic classification project sponsored by the national cancer institute (1981). Lymphomas falling within this group have a relatively favourable survival potential. (12 Dec 1998) |
| lymphoma, lymphoblastic | A high-grade malignant lymphoma composed of a diffuse, relatively uniform proliferation of cells with round or convoluted nuclei and scanty cytoplasm. The cells are cytologically similar to the lymphoblasts seen in acute lymphocytic leukaemia, and in some cases, the disease may evolve into a leukaemic phase morphologically indistinguishable from acute t-lymphocytic leukaemia (leukaemia, T-cell, acute). Lymphoblastic lymphoma represents approximately one-third of the cases of non-hodgkin's lymphomas in children and 5% of the cases in adults. It is more prevalent in males. (12 Dec 1998) |
| lymphoma, mixed-cell | Malignant lymphoma characterised by the presence of a mixed population of cells, with the smaller cells resembling lymphocytes and the larger ones histiocytes. It usually presents in a nodular (follicular) pattern, but may evolve into a diffuse pattern. (12 Dec 1998) |
| 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, mixed-cell, follicular | A low-grade malignant lymphoma of follicular pattern in which there is no clear preponderance of one cell type (small or large) over another. The large cells, cleaved or noncleaved, are often 2-3 times larger in diameter than normal lymphocytes. (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) |