Fig 5 - available via license: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
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The lesion of the skin form lymphoma is characterized by CD3-positive cells in the dermis (bottom). Arrow indicates intraepidermal neoplastic cells showing CD3 positivity. ABC-IP. × 200.
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An acute myeloblastic leukemia was found in a 3.5-year-old Holstein cow. The neoplasm was characterized by massive tumor growths, and there were multiple tumor nodules in the dermis or subcutis and a large tumor mass in the mediastinum. This tumor showed negative reactivity for CD3, CD79a, major histocompatibility complex class II and myeloid/histi...
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Context 1
... all markers were absent in the neoplastic cells, although CD3-positive lymphocytes containing irregularly contoured nuclei were sparsely distributed in the epidermis and external root sheath as well as in the dermis and subcutis (Fig. 4). The lymphoma cells in the skin form were positive for CD3 (Fig. 5), but not for the other ...
Citations
... The present case was finally diagnosed as PRCA by both clinical and pathological findings. Although bone marrow disorders are very rare in large animal medicine, several diseases have been reported in cattle, including bone marrow aplasia (Fukunaka et al. 2010;Shimada et al. 2007) and myeloblastic leukemia (Takahashi et al. 2000). However, there have been no reports of PRCA in cattle. ...
A 3-month-old Holstein calf presented with lethargy. Hematological examination showed severe non-regenerative anemia without reduction in white blood cell and platelet counts. Serum biochemical analysis revealed both high erythropoietin activity and high serum iron concentration. Bone marrow examination revealed selectively decreased erythroid precursors and an increased myeloid:erythroid ratio of 7:1. Lesions that could have caused anemia were found only in bone marrow by necropsy. The calf was diagnosed with pure red cell aplasia (PRCA) based on these clinical and pathological findings. Although the cause of PRCA was not identified, this is the first confirmed clinical report of PRCA in a Holstein calf.
... Malignant histiocytosis is morphologically characterized by phagocytosis, especially of red blood cells, by tumor cells, but this phenomenon is not usually a conspicuous feature in human beings [3], and has been observed in other hematopoietic neoplasms, such as monocytic leukemia, myeloblastic leukemia [5] and plasmacytoma [7]. Erythrophagocytosis was seen also in bovine monocytic [12] and myeloblastic [18,19] leukemias, which had morphological features of immature monocytes and granulocytes, respectively, and which were quite unlike malignant histiocytosis. In our study, many hemosiderin-laden tumor cells were seen in case 3, and fair numbers of tumor cells showed erythrophagocytosis in hemorrhagic foci in case 1. ...
Malignant histiocytosis was diagnosed in 4 cows. In all cases the tumor tissues were composed of cytologically atypical histiocytes with evidence of erythrophagocytosis. The tumor in case 1 appeared highly anaplastic with marked nuclear pleomorphism, and had areas of spindle cell differentiation, but had no relation to malignant fibrous histiocytoma. The neoplastic tissue in case 2, characterized by cohesive growth of tumor cells, was distinguishable from anaplastic carcinoma cells by cytokeratin immunostaining. There were many hemosiderin-laden neoplastic cells suggestive of high phagocytic activity in a lymph node of case 3. The neoplastic cells in case 4, frequently multinucleated, were less atypical than in the other cases. All cases expressed histiocyte-associated markers (lysozyme and HAM56), and were negative for cytokeratin, S100, and T- and B-cell lineage-specific markers (CD3 and CD79a). The most frequent HAM56 immunoreactivity was detected in case 4, and the giant, multinucleated forms, reminiscent of epithelioid cell differentiation. seemed not to indicate cytological pleomorphism as a result of neoplastic transformation.
Immature T cell neoplasms in three young Holstein cattle with neoplastic involvement of the thymus are described. Case 1, with a precursor T lymphoblastic leukemia (calf form of leukosis), was an 86-day-old female calf. The leukemia was characterized by replacement of the bone marrow and spleen by leukemia cells, but preservation of epithelial frameworks throughout the thymus. The other two neoplasms were thymic γδ T cell lymphomas, which were observed in a 246-day-old steer (case 2) and a 16-month-old heifer (case 3). Histological examination revealed obliteration of the normal thymic architecture and stromal fibrosis, with the spleen and liver far less severely affected than in case 1. There were cytological differences bewteen the tumors in case 1 and cases 2 and 3. Additionally, WC1 and CD8 were expressed only in the latter. Thus, the leukemia and these lymphomas should be regarded as independent disease entities on the basis of histological and immunohistochemical characteristics.
Classification of myeloid neoplasms in veterinary medicine was modeled in the early 1990s after French-American-British and National Cancer Institute systems used in human medicine. Recently our physician counterparts, in collaboration with oncologists, constructed a new World Health Organization (WHO) standard. WHO revisions lower the blast threshold from 30% to 20% for diagnosing acute myeloid leukemia (AML) and expand and redefine AML categories. AML is now subdivided into 4 broad groups: 1) AML with recurrent genetic abnormalities, 2) AML with multilineage dysplasia, 3) AML with previous chemotherapy and/or radiation, and 4) AML, not otherwise categorized. AML alphanumeric designations (M1, M2, etc) have been discontinued as numbers of subtypes have increased. The lower blast percentage eliminates one category of myelodysplastic syndrome (MDS): refractory anemia with excess blasts in transformation. A new MDS category was created: refractory cytopenia with multilineage dysplasia (RCMD), with lineage dysplasia assessed using newly defined percentage limits. At least 10% of cells from each of 2 lineages must display atypia for a diagnosis of RCMD. That threshold is 50% for diagnosing AML with multilineage dysplasia. Chronic myelomonocytic leukemia has been removed from the MDS category and included in a new category of diseases that have features of both MDS and chronic leukemia. WHO revisions are a signal to veterinary clinical pathologists to assess the validity of our system, which was built on premises now questioned.
