Malignant giant-cell tumor of bone with lymph node involvement in a cat

: Th e present study describes giant-cell tumor of bone (GCToB) with lymph node involvement in a 5-year-old crossbred cat. Th e animal was referred to the surgery clinic with progressive subcutaneous swelling in the left proximal femoral region, severe lameness, constipation, and dysuria. A moderately fi rm, subcutaneous, palpable mass, 9 cm in diameter, was observed, and biopsy samples were taken. Histopathologically, the mass was constituted by ovoid-shaped mononuclear cells intermixed with many multinucleated giant cells (MGC). Immunohistochemically, the giant cells were positively stained with antivimentin, and the same cells were negative for antidesmin and anti-S100 staining. Tartrate-resistant acid phosphatase (TRAP) activity in tumor cells was evaluated and the tumor was diagnosed as malignant GCToB; the cat was euthanized. Macroscopically, while the regional lymph nodes were intact, giant cells were found in the left popliteal lymph node during microscopy. Although a few cases of GCToB have been reported in cats, the case herein displays, for the fi rst time, evidence of lymph node involvement during the process of metastasis.Peer Reviewe

Meningoencephalitis caused by pathogenic Sarcocystis species in a naturally infected sheep in Turkey

Meydanli, E. Elif Guzel/0000-0001-9072-3322; IPEK, VOLKAN/0000-0001-5874-7797WOS: 000394411200005PubMed: 28116411A 3-year-old sheep was examined after an acute onset of hind limb paralysis and ataxia. At necropsy, central nervous system, pulmonary and intestinal hyperaemia and ecchymoses in the aortic arch were observed. Main microscopic lesions were confined to the heart, cerebrum and cerebellum. There were a multifocal mild myocarditis and non-suppurative meningoencephalitis together with protozoal cysts in the heart and the brain. Protozoal cystic structures were observed within many of the myocardial fibers as well as in the cerebrum and cerebellum. Using light microscopy it could not be morphologically determined whether these organisms were Toxoplasma (T.) gondii or Neospora (N.) caninum. Additional diagnostic methods like immunohistochemistry and polymerase chain reaction provided differentiation of Sarcocystis from T. gondii and N. caninum. Transmission electron microscopy demonstrated characteristic features of Sarcocystis sp. as previously described. This is the first confirmed diagnosis of Sarcocystis sp. in the central nervous system of a sheep from Turkey.Uludag University Research Foundation, Bursa, Turkey [OUAP [V] 2013/28]This study was supported by a grant from the Uludag University Research Foundation, Bursa, Turkey (project number OUAP [V] 2013/28). The authors would like to thank Nicole Cohart for English editing support and Deniz Seyrek-Intas for German editing support

Mouse model recapitulates the phenotypic heterogeneity of human adult T-cell leukemia/lymphoma in bone

© 2019 The Authors Adult T-cell leukemia/lymphoma has a unique relationship to bone including latency in the marrow, and development of bone invasion, osteolytic tumors and humoral hypercalcemia of malignancy. To study these conditions, we established and characterized a novel mouse model of ATL bone metastasis. Patient-derived ATL cell lines including three that do not express HTLV-1 oncoprotein Tax (ATL-ED, RV-ATL, TL-Om1), an in vitro transformed human T-cell line with high Tax expression (HT-1RV), and an HTLV-1 negative T-cell lymphoma (Jurkat) were injected intratibially into NSG mice, and were capable of proliferating and modifying the bone microenvironment. Radiography, μCT, histopathology, immunohistochemistry, plasma calcium concentrations, and qRT-PCR for several tumor-bone signaling mRNAs were performed. Luciferase-positive ATL-ED bone tumors allowed for in vivo imaging and visualization of bone tumor growth and metastasis over time. ATL-ED and HT-1RV cells caused mixed osteolytic/osteoblastic bone tumors, TL-Om1 cells exhibited minimal bone involvement and aggressive local invasion into the adjacent soft tissues, Jurkat cells proliferated within bone marrow and induced minimal bone cell response, and RV-ATL cells caused marked osteolysis. This mouse model revealed important mechanisms of human ATL bone neoplasms and will be useful to investigate biological interactions, potential therapeutic targets, and new bone-targeted agents for the prevention of ATL metastases to bone