Malignant Histiocytosis in Cattle.

Abstract

ABSTRACT. 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. KEY WORDS: bovine, erythrophagocytosis, HAM56, histiocytic marker, malignant histiocytosis.

Malignant histiocytosis and other causes of death in Bernese mountain dogs in Denmark

“…The initial clinical signs are often subtle and non-specific, and the disease is often diagnosed in its terminal stages. Although malignant histiocytosis has been known in human beings since the late 1940s, the first report of malignant histiocytosis in dogs was in 1978 (Schalm 1978), and the disease has since been described in cats, cattle and horses (Lester and others 1993, Freeman and others 1995, Walton and others 1997, Anjiki and others 2000, Kraje and others 2001). …”

Intranuclear Coccidiosis in a Calf

“…Some of the former were considered to be CAE-positive large granular lymphocytes or WC1-positive  T cells, because CAE and WC1 have been demonstrated in bovine large granular lymphocyte lymphoma [13] and epitheliotropic  T cell lymphoma, respectively [10]. The latter were positive for HAM56, which is a marker for human and bovine macrophages [1]. Since the number of gametocytes was far smaller than that of meronts and merozoites, these inflammatory cells were thought to be reactive chiefly to extracellular merozoites, which were observed in the previous study [4] but not in the present study.…”

What is your diagnosis? Perifemoral mass in a cow

“…10 Other histiocytic markers, such as MAC387 and HAM 56, were not available for use in this case. 11 A peripheral nerve sheath tumor was ruled out on the basis of negative staining for S-100. Finally, synovial sarcoma was ruled out at gross necropsy examination by the lack of articular involvement.…”