Malignant histiocytosis in three Bernese mountain dogs

Abstract

Malignant histiocytosis is a rare disease which is characterised by the neoplastic proliferation of tissue macrophages (histiocytes) leading to excessive phagocytosis of erythrocytes. The clinical signs and pathological findings in three Bernese mountain dogs are described. Two of the dogs had the same sire. The disease has been established as a familial problem in Bernese mountain dogs in other countries, although it has not been previously recorded in the United Kingdom.

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers

“…The characteristic kidney-shaped nuclei have also been reported before in canine HS (33,39,46) and in human HS (47) and IDCS (14). Indentations of the nucleus have been reported in the canine literature (1,7,24,26,28) as well as in human HS (41) and IDCS (48), and a combination of indentations, grooves or folds in human HS (43,49), IDCS (14) and LCH (50). This indicates that a canine subtype comparable to human LCH/LCS may also exist.…”

“…This has been reported before in canine HS (1,6,7,28,(33)(34)(35)(36)(37)(38)(39) and is also often seen in human HS, sometimes simultaneously with spindle cells (40,41). In addition, extramedullary hematopoiesis was seen more often in BMD than in FCR.…”

“…Both in our study, as well as a earlier report (24), spindle cells were more often seen in this localized form compared to the disseminated HS. Spindle cells have been reported in canine HS before, but only in combination with round-oval cells (1,(24)(25)(26)(27)(28). This makes this study the first report of HS cases with spindle cells only.…”

Establishment and Biological Characterization of Canine Histiocytic Sarcoma Cell Lines

“…In addition, the reactions for ANBE were strongly inhibited by the addition of sodium fluoride. On immunohistochemical findings, all established cell lines were positive for vimentin (using a mouse anti-vimentin monoclonal antibody: clone V9, DAKO, Carpinteria, CA) and lysozyme (using a rabbit anti-lysozyme polyclonal antibody, DAKO), and negative for cytokeratin (using a mouse anti-cytokeratin antibody: clone AE1/AE3, DAKO), as observed in the original HS tumor cells [3,6,8].…”

“…The diagnosis of HS is based on the pathologic findings, including diffuse proliferation of large anaplastic histiocytes, multinucleated giant cells, and occasional phagocytosis of red blood cells and/or cell debris [2,4,13]. However, a definitive diagnosis is frequently difficult to make due to the presence of infiltrated macrophages and the immature features of tumor cells [5,8]. Cytochemical staining, such as with peroxidase and α-naphthyl butyrate esterase, and immunohistochemical staining, such as vimentin, lysozyme, and cytokeratin staining, are considered to be available techniques to diagnose HS [2,3,6,13].…”