Canine Hemophagocytic Histiocytic Sarcoma: A Proliferative Disorder of CD11d+ Macrophages

Abstract

Abstract. Histiocytic disorders of dogs include histiocytoma, localized histiocytic sarcoma (HS), disseminated HS (malignant histocytosis), and the reactive histiocytoses: cutaneous and systemic. A common element to these diseases is proliferation of dendritic cells (DC) of either Langerhans cell (epithelial DC) or interstitial DC lineage. In this report, 17 dogs with hemophagocytic HS are described. Breeds affected included Bernese Mountain Dog (6), Golden Retriever (4), Rottweiler (3), Labrador Retriever (2), a mixed-breed dog, and a Schnauzer, which were from 2.5 to 13 years old. The dogs presented with Coombs negative responsive anemia in 16/17 dogs (94%), thrombocytopenia in 15/17 dogs (88%), hypoalbuminemia in 16/17 dogs (94%), and hypocholesterolemia in 11/16 dogs (69%). All dogs died or were euthanized. The clinical course ranged from 2 to 32 weeks (mean 7.1 weeks). Diffuse splenomegaly with ill-defined masses was consistently present. Microscopic lesions were prevalent in spleen, liver, lung, and bone marrow. Metastasis occurred by insidious intravascular invasion with minimal mass formation. Histiocytes were markedly erythrophagocytic and accompanied by foci of extramedullary hemopoiesis. Cytologically, the histiocytes varied from well differentiated to atypical, with atypia more prevalent in spleen than bone marrow. These tumors arose from splenic red pulp and bone marrow macrophages, which expressed major histocompatibility complex class II and the b2 integrin, CD11d. They had low and/or inconsistent expression of CD1 and CD11c, which are dominantly expressed by canine nonhemophagocytic HS of DC origin. Canine histiocytic proliferative diseases now encompass proliferation of all members of the myeloid histiocytic lineage: Langerhans cells, interstitial DC, and macrophages.

Feline Progressive Histiocytosis

“…Some canine histiocytic sarcomas arise from the splenic red pulp and the bone marrow; their immunophenotype and marked hemophagocytic activity indicates a macrophage origin. 26 Histiocytic proliferative diseases are uncommon in cats and their documentation is limited to a few case reports. Most cases were not associated with cutaneous lesions, but presented with internal disease and prominent weight loss.…”

“…Some canine histiocytic sarcomas are of macrophage origin and primarily arise in the splenic red pulp or the bone marrow. 26 Histiocytic proliferative diseases are uncommon in cats, and their documentation is limited to a few case reports. 10,[12][13][14]18 The goal of this study was to characterize a histiocytic proliferative disease observed in 30 cats.…”

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

“…Provisional pathological criteria for inclusion in the study as possible HHS cases were derived from Moore et al (8). Dogs were selected if the histiocytic tumor cells showed phagocytosis of erythrocytes, a diffuse pattern of tissue involvement, with preferably intra-sinusoidal (liver/lymph nodes) and intravascular spread and involvement of splenic red pulp, while encroaching on the white pulp with only sparse lymphocytic infiltration.…”

“…The differential diagnoses for HS are many and include not only almost the entire spectrum of poorly differentiated round cell tumors, but also other histiocytic diseases such as reactive cutaneous/systemic histiocytosis (CH/SH), hemophagocytic syndrome, immune-mediated hemolytic anemia, and granulomatous inflammation (1,(5)(6)(7)(8)(9).…”

Sarcoma Histiocítico Com Múltiplas Localizações Em Um Cão

“…Esse último possui uma abordagem clinicopatológica diferente, sendo que estudos mostram sua origem no baço, advindas de macrófagos da polpa vermelha que têm origem na medula óssea (MOORE et al, 2006;HENDRICK, 2017;). O sarcoma histiocítico localizado se difere do disseminado quanto à suas características clínicas.…”