Images for Histiocytic Sarcoma
Images are from representative mice (contributed by Rick van Etten/Scott Kogan)
Induction of murine recipients with BCR-ABL retrovirus causes 3 principal hematologic malignancies:
- MPD-like Myeloid Leukemia
- Precursor B Cell Lymphoblastic Lymphoma/Leukemia and
- Histiocytic Sarcoma
Originally described as appearing in recipients of BCR-ABL transduced marrow as an isolated malignancy (Daley et al., 1990; Elefanty et al., 1990). Malignant cells are fairly differentiated monocytic/macrophage-like cells, positive for CD11b, F4/80, FcRgammaII/III, non-specific esterase. Tumors in diseased animals typically are long-latency (8-20 weeks post-transplant), oligo- to monoclonal by provirus integration, and involve periportal areas of liver, often with involvement of mesentery and peritoneum with malignant ascites, spleen, and occasionally lung, heart, and kidneys. The tumors appear similar to spontaneous histiocytic sarcomas commonly observed in aging C57Bl/6 mice (Ward et al., 2000) but are less common in Balb/c. The BCR-ABL-induced histiocytic tumors can grow in culture (with some difficulty) and the disease is transplantable into syngeneic mice but often only after a long latent period. The tumors also produce myeloid cytokines in vivo, including G- and GM-CSF (Elefanty et al., 1990), and can cause paracrine expansion of neutrophils in these mice (Daley et al., 1990; Elefanty et al., 1990). This phenomenon has lead to considerable confusion in the literature because several investigators assumed that increase circulating neutrophils in these mice were indicative of primary myeloproliferative disease (Han et al., 1991; Kelliher et al., 1990). However, the neutrophils in pure histiocytic sarcoma lack the retroviral provirus and BCR-ABL expression (Scott et al., 1991) and cannot be considered part of a malignant process.