Extra-skeletal osteosarcoma is a malignant mesenchymal neoplasm that originates from soft tissue. This tumor occurs spontaneously in dogs, but there are few cases described in the literature. The objective of this study was to describe the epidemiological and pathologic features of extra-skeletal osteosarcoma in 36 dogs. Cases diagnosed as osteosarcoma affecting dogs (n=216), during 2006 to 2016 were reviewed. Of these, 36 cases were diagnosed as extra-skeletal osteosarcoma. The mean age of affected dogs was 10.4 years, and the mean weight was 19.5kg. No breed predisposition was observed. The most frequently affected sites were the mammary glands (80.6%; 29/36), subcutaneous tissue (5.6%; 2/36), liver (5.6%; 2/36), spleen (2.8%; 1/36), omentum (2.8%; 1/36), and kidney (2.8%; 1/36). Histological examination revealed that 61.1% (22/36) of the tumors were osteoblastic, 33.3% (12/36) chondroblastic, 2.8% (1/36) fibroblastic, and 2.8% (1/36) were giant cell-rich osteosarcomas. Histological grade II and III were the most frequent. Lymph node metastases were observed in 21.4% (3/14) of the cases of mammary gland osteosarcoma. Distant metastases were observed in 23.1% (3/13) of cases by diagnostic imaging and in 71.4% (5/7) during autopsy. Metastases were observed in the lungs (57.1%; 4/7), liver (14.3%; 1/7), spleen (14.3%; 1/7), and in multiple sites (14.3%; 1/7). Pulmonary metastases were more frequently observed in cases of mammary gland osteosarcoma.
Canine visceral leishmaniasis is a systemic, zoonotic disease widely spread in several countries. The disease is caused by Leishmania spp., and the dog is the main reservoir of this parasite. Clinical signs in the muscle skeletal system consist of muscle atrophy, weakness, lameness, abnormal locomotion, osteitis, polyarthritis, heat and swelling of the joints, enlarged local lymph nodes and pain. In this note, a case of canine myositis of the lumbar region associated with Leishmania spp. infection is reported. Clinical signs included weakness, fever, mild dehydration, enlarged mandibular, pre-scapular and popliteal lymph nodes and a large palpable soft mass in the lumbar region, semi-adhered and not painful. Serologic diagnosis resulted reagent by indirect immunofluorescence reaction method. Findings of ultrasonography of the lower back are described, revealing the misalignment of muscle fibers, interspersed with anechoic areas compatible with edema. Local fine needle aspiration cytology was crucial for a definitive diagnosis, revealing amastigote forms. In endemic areas of leishmaniasis, clinicians should consider this disease as a differential diagnosis in the presence of musculoskeletal injuries with no apparent cause.
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