Twenty-three canine malignant lymphomas were studied to correlate morphologic and immunologic properties of the neoplastic cells. Morphologic characterization included histologic classification of cell type and growth pattern, anatomic distribution of lesions, and transmission electron microscopic examination. Parameters examined to indieate B- or T-cell nature of lymphoma cells included demonstration of mitogen responsiveness, cell-surfaee Ig, spontaneous rosette formation with human red blood cells, and scanning electron microscope (SEM) examination of cell-surfaee features. Results Indicated that the cells from histiocytic lymphomas were Iymphocytes rather than histiocytes or macrophages. Most cells from lymphomas examined possessed cell-surfaee Ig, indicating B-cell nature. The cell types represented by the different Ig-positive lymphomas were compatible with maturation arrest at different stages in normal Iymphocyte differentiation. For the two most common histiologic cell types, mitogen responsiveness and the presenee of cell-surface Ig indicated that diffuse, poorly differentiated lymphocytie cases were biologically heterogenous, whereas nodular histiocytic lymphomas were biologically homogenous. Most canine lymphomas had a multicentric anatomic distribution; however, one thymic and two allmentary forms were observed. Lymphomas with a nodular pattern In Iymph nodes had multifocal splenic involvement centered on small arteries, whereas lymphomas with a diffuse pattern in Iymph nodes had diffuse involvement of splenic white pulp. The cells of Ig-positive and Ig-negative neoplasms examined by SEM were predominantly of the smooth-cell type.
ASJC Scopus subject areas
- Cancer Research