Fig. 2

Lymphoma classification in pigs. Representative images of different lymphoma subtypes. a-c Diffuse large B-cell lymphoma – centroblastic (DLBCL-CB), spleen, adult sow, case 20. a Splenic nodule composed of dense sheets of lymphoid cells arranged in a diffuse pattern, with intermediate to large nuclear size and scant cytoplasm, cells often exhibit multiple nucleoli (centroblastic) (arrowheads), rarely immunoblastic cells (one single central nucleoli) (black arrow) are observed. HE, 630x. b Most infiltrating cells have a mild to moderate cytoplasmic CD20 immunolabelling. IHC for CD20, hematoxylin counterstain, 400x. c Infiltrating cells are negative to CD3 immunolabeling, very few small mature, non-neoplastic lymphocytes show positive CD3 immunolabeling. IHC for CD3, hematoxylin counterstain, 400x. d-f Unspecified, peripheral T-cell lymphoma (PTCL), lymph node, adult sow, case 21. d Effacing the normal lymph node architecture there are dense sheets and rows of lymphoid cells arranged in a diffuse pattern, with intermediate to large nuclear size and scant. HE, 630x. e Infiltrating cells are negative to CD20 immunolabeling. IHC for CD20, hematoxylin counterstain, 400x. f Most infiltrating cells have moderate to strong cytoplasmic CD3 immunolabelling. IHC for CD3, hematoxylin counterstain, 400x. g-i B-lymphoblastic leukemia/lymphoma (B-LBL), vertebra, bone marrow, fattening pig, case 47. g Dense sheets and rows of lymphoid cells arranged in a diffuse pattern, with intermediate to large nuclear size and scant cytoplasm infiltrating the bone marrow. HE, 400x. h Most infiltrating cells have moderate to strong cytoplasmic CD20 immunolabeling. IHC for CD20, hematoxylin counterstain, 400x. i Infiltrating cells are negative to CD3 immunolabeling, very few small mature, non-neoplastic lymphocytes show positive CD3 immunolabeling. IHC for CD3, hematoxylin counterstain, 400x