title: Ultrastructure and lectin histochemistry of equine cutaneous histiolymphocytic lymphosarcomas.
abstract: Tissues from subcutaneous lymphosarcomas and regional lymph nodes were examined by light and electron microscopy and by lectin histochemistry. Tumors were composed of two major cell types: small lymphocytes with few organelles and pleomorphic histiocytic cells with undulant surfaces, large numbers of cytoplasmic vacuoles, and many mitochondria with large crystalline inclusions. A large gram-positive coryneform bacterium was isolated from tumor nodules but was not identified morphologically in tumor tissues. Evaluation of sections of tumors with lectins as histochemical probes revealed three staining patterns: 1) lectin labeling histiocytic cells only (wheat germ, succinylated-wheat germ, Phaseolus vulgaris and soybean agglutinins); 2) lectins labeling histiocytic, interstitial and some lymphoid cells (concanavalin A, and Pisum sativum, Lens culinaris, and Ricinus communis I agglutinins); and 3) lectins failing to label any cell (peanut, Sophora japonica, and Ulex europaeus I agglutinins). In the lymph node, macrophages were labeled by lectins of groups 1 and 2; interdigitating reticular cells were labeled by group 2 lectins. Lectin staining of histiocytic cells in tumor tissues suggested that these were reactive cells and that lymphoid cells were the primary neoplastic component.
authors.affiliation: US Department of Agriculture, National Animal Disease Center, Ames, IA.
authors.forename: P G
authors.initials: PG
authors.lastname: Detilleux
authors.forename: N F
authors.initials: NF
authors.lastname: Cheville
authors.forename: B J
authors.initials: BJ
authors.lastname: Sheahan
mesh_terms: D000818:Animals; D005260:Female; D006644:Histiocytes / Q000473:pathology / Q000648:ultrastructure; D006651:Histocytochemistry; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D037102:Lectins; D008198:Lymph Nodes / Q000473:pathology / Q000648:ultrastructure; D008221:Lymphoid Tissue / Q000473:pathology / Q000648:ultrastructure; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology / Q000648:ultrastructure / Q000662:veterinary*; D008854:Microscopy, Electron; D012878:Skin Neoplasms / Q000473:pathology / Q000648:ultrastructure / Q000662:veterinary*
chemical_list: D037102:Lectins