lymphadenoma

n.

[NL. See Lymph, Aden-, and -oma.]
(Med.) See Lymphoma.

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(lĭm-făd'n-ō'mə)
n.

A tumorlike enlargement of a lymph node. No longer in technical use.

Any neoplastic disorder of lymphoid tissue. Often used to denote malignant lymphoma, classifications of which are based on predominant cell type and degree of differentiation; various categories may be subdivided into nodular and diffuse types, depending on the predominant pattern of cell arrangement. There is also a great deal of difference in the types of disease in the different animal species. There is a system of classification based on the histological characteristics of the lymphocytes.

• African l. — see burkitt's lymphoma.
• angiotropic large-cell l. — an uncommon form of the disease seen rarely in dogs; lesions most commonly in the lungs producing a syndrome similar in many ways to congestive heart failure.
• bovine malignant l. — the tumor form of bovine viral leukosis.
• Burkitt's l. — see burkitt's lymphoma.
• canine malignant l. — the commonest hemopoietic neoplasm of dogs. It is characterized by lymphoid tumors in multiple lymph nodes, spleen, liver or other organs. Lymphocytic leukemia with involvement of bone marrow is much less common.
• cutaneous l. — round, raised cutaneous nodules or plaques caused by the infiltration of neoplastic lymphocytes with a tropism for epithelial cells. Occurs in cattle, dogs and humans. See also mycosis fungoides.
• follicular l. — a malignant lymphoma in which the lymphomatous cells are in clusters in the lymph node resembling follicles. Called also giant follicular lymphoma, nodular lymphoma.
• giant follicular l. — see follicular lymphoma (above).
• Hodgkin's type l. — rare, but reported most frequently in the dog. A diagnosis depends on the identification of the Reed–Sternberg cell in a mixed population of lymphocytes accompanied by sclerosis.
• immunoblastic l. — may be nonsecretory or may secrete immunoglobulins. See also myeloma.
• large cell l. — classified as diffuse, large cells, large cell immunoblastic or mixed tumors with large cells.
• lymphoblastic l. — tumors of medium-sized lymphocytes or small noncleaved lymphocytes.
• malignant l. (histiocytic) — a form in which the predominant cell is the prolymphocyte (reticulum cell).
• malignant l. (mixed cell) — a form containing proliferations of both prolymphocytes and lymphocytes.
• malignant l. (poorly differentiated lymphocytic) — a form in which the predominant cell is morphologically similar to the lymphoblast, containing a fine nuclear chromatin structure and one or more nucleoli.
• malignant l. (small cell lymphocytic, small cleaved cell, well-differentiated lymphocytic) — the form in which the predominant cell is the mature lymphocyte.
• malignant l. (undifferentiated) — a form in which relatively large stem cells with large nuclei, pale, scanty cytoplasm and indistinct borders predominate.
• nodular l. — see follicular lymphoma (above).
• T cell l. — a form in which the predominant cell is the mature lymphocyte.
• thymic l. — occurs most commonly in yearling cattle and cats. In cattle, it causes obstruction of the esophagus leading to ruminal tympany, engorgement of jugular veins and edema of brisket and submandibular space. In cats it is caused by feline leukemia virus infection and is usually associated with pleural effusion and accompanying dyspnea and regurgitation.

IN BRIEF: n. - An abnormally enlarged oval or round body, located along particular vessels.