Canine intrathoracic sarcoma with ultrastructural characteristics of human synovial sarcoma - case report.

BACKGROUND: Canine joint sarcomas, designated synovial sarcomas, are uncommon malignant mesenchymal neoplasms that occur in the large joints of the extremities of middle-aged, large-breed dogs. We report the diagnosis of an intrathoracic sarcoma with ultrastructural characteristics reminiscent of human synovial sarcoma in a dog. CASE PRESENTATION: A 7-year-old female spayed Tibetan terrier crossbred dog was presented for acute severe labored breathing and diagnosed with an intrathoracic neoplastic mass. The neoplasm resulted in the accumulation of substantial amounts of viscous pleural fluid that led to dyspnea. The neoplastic mass consisted of interweaving bundles of large pleomorphic mesenchymal cells, supported by an alcian blue positive myxomatous matrix. The neoplastic cells were immunohistochemically negative for cytokeratin and CD18. Transmission electron microscopy indicated that the neoplastic cells had desmosome junctions, short microvilli-like structures and ample amounts of rough endoplasmic reticulum resembling type B-like synoviocytes and synovial sarcoma as reported in people. Despite complete surgical excision of the neoplastic mass, clinical signs recurred after a month and led to the euthanasia of the dog. CONCLUSION: Currently, there are no immunohistochemical markers specific for synovial sarcoma. Canine neoplasms with transmission electron microscopy characteristics resembling type B-like synoviocytes should be considered similar to the human sarcomas that carry the specific translocations between chromosomes X and 18.

Synovial Sarcoma Associated With Indwelling Intramedullary Pin in a Peach-Faced Lovebird (Agapornis roseicollis).

Sarcoma developing in association with a metallic orthopedic procedure is an uncommon but well-recognized complication in mammals. We report on a synovial sarcoma that developed at the site of an intramedullary pin after surgery to treat a bone fracture. A 17-year-old female peach-faced lovebird (Agapornis roseicollis) developed a spherical mass on the distal right dorsal wing at a site that was previously fractured and surgically repaired with an indwelling intramedullary pin. The right wing was amputated at the scapulohumeral joint. One year later, the bird died. Postmortem examination revealed metastases in the right lung, left thoracic wall, and proventricular serosa. Histologically, the tumor had a characteristic biphasic pattern. The tumor was immunohistologically and ultrastructurally identified as a synovial sarcoma. This is the first report of a suspected fracture-associated sarcoma in a bird.

Synovial myxosarcoma in the scapulohumeral joint of a dog: a case report.

A 12-year-old, 3 kg spayed female mixed-breed dog was evaluated to assess a 1-year history of intermittent right forelimb lameness that did not have adequate response to nonsteroidal anti-inflammatory drugs. The radiographic study performed under sedation showed multifocal radiolucent areas affecting both the right humerus and scapula with focal soft tissue swelling; a CT scan confirmed the existence of an aggressive and invasive soft tissue mass affecting the scapulohumeral joint. Fine needle aspiration results suggested a low-grade synovial sarcoma and therefore a scapulectomy was performed. The biopsy showed spindle to stellated cells immersed in a basophilic and mucinous (myxoid) matrix with mild to moderate anisocytosis, moderate anisokaryosis, some binucleated cells and sporadic multinucleated cells. These findings are consistent with low-grade synovial myxosarcoma, a not well described synovial neoplasm that can mimic other commonly seen joint tumors or even septic arthritis on radiographs. The purpose of this case report is to describe the first reported synovial myxosarcoma affecting the scapulohumeral joint of a small dog.

Palliative radiation therapy in the treatment of canine appendicular synovial sarcoma.

Synovial sarcoma is a rare tumor in dogs, occurring in approximately 27% of neoplasms involving joints, with the elbow representing a common site of occurrence. The recommended treatment of canine synovial sarcoma is amputation. The authors describe the use of palliative radiation therapy for the treatment of synovial sarcoma involving the elbow of a dog and conclude that this treatment modality may have use in some patients affected with synovial sarcoma.

Synovial sarcoma of the tendon and tendon sheath in a dog.

A 19.5-year-old male mongrel dog developed a progressive lameness and swelling around the right carpus. A tumor (6 x 3 x 3 cm) was found in the caudal of distal antebrachium of the right forelimb, including tendons of the superficial digital flexor muscle and deep digital flexor muscle. No joint destruction was observed. The tumor consisted of round and spindle cells arranged in a compact sheet. There were occasional slit-like spaces or lumina, and areas rich in collagen fibers giving an appearance of tendon tissues. Neoplastic cells gave a positive immunoreaction to vimentin, but negative reactions to antibodies against S-100 protein, cytokeratin and myoglobin. Based on these findings, this tumor was diagnosed as a synovial sarcoma generating from the tendon and tendon sheath, which is very uncommon in dogs.

Serum granulocyte colony-stimulating factor (G-CSF) and interleukin-1 (IL-1) concentrations after chemotherapy-induced neutropenia in normal and tumor-bearing dogs.

Hematopoiesis is regulated by complex interactions of hematopoietic growth factors known as colony-stimulating factors and interleukins. We used sensitive bioassays to quantitate serum granulocyte colony-stimulating factor (G-CSF) and interleukin-1 (IL-1) concentrations in normal and tumor-bearing dogs following administration of myelosuppressive chemotherapy (vincristine, doxorubicin, cyclophosphamide). Serum G-CSF and IL-1 increased during the neutrophil nadir in 13 of the 16 dogs. Serum G-CSF concentrations were significantly increased in normal and in tumor-bearing dogs on neutropenic compared to non-neutropenic days. Serum IL-1 concentrations increased significantly on neutropenic days in normal dogs but not in tumor-bearing dogs. A marked neutrophilia was observed in normal dogs, but not in tumor-bearing dogs, following the increases in serum G-CSF and IL-1 concentrations (days 7, 8, and 9, p < 0.05). Normal dogs produced significantly more G-CSF on neutropenic days compared to dogs with lymphoma. On non-neutropenic days, serum IL-1 concentrations were significantly increased in dogs with lymphoma and in dogs with nonlymphoid malignancies compared to normal dogs. These results suggest an important role for G-CSF and IL-1 in hematopoietic recovery after chemotherapy-induced myelosuppression and document an altered hematopoietic regulation in animals with malignancy compared to normal subjects.

Development of an ELISA for the detection of 2-nitroimidazole hypoxia markers bound to tumor tissue.

Canine and rodent tumors covalently bind the fluorinated 2-nitroimidazole, CCI-103F, in a way that immunohistochemical analysis shows is consistent with the location of tumor hypoxia. We have now developed a rapid, quantitative, and non-radioactive enzyme linked immunosorbent assay for the binding of CCI-103F in biopsy samples of spontaneous canine tumors. Issues of antigen stability during tissue processing, calibration of the ELISA, and the use of biopsy samples for measuring tumor hypoxia by the ELISA approach are addressed.

Synovial sarcoma of the jaw in a dog.

A case of synovial sarcoma of the jaw with pulmonary metastasis is described in a dog. It appears to be a rare or underdiagnosed neoplasm in animals and not previously reported in the jaw. Its diagnostic microscopic features are the biphasic cellular pattern and cleft formations. It may otherwise resemble haemangiopericytoma, malignant fibrous histiocytoma, reticulum cell sarcoma, fibrosarcoma, or giant-cell tumour of soft tissue.

Nonweightbearing lameness secondary to synovial sarcoma in a young dog.

Synovial sarcoma was diagnosed in the right carpus of a 2 1/2-year-old mixed-breed dog. The dog had developed a right forelimb lameness before one year of age. The lameness was progressive for nearly 2 years, resulting in severe disuse atrophy of the right forelimb musculature and pronounced osteopenia. A definitive diagnosis was not made until the dog was referred after 2 years of conservative treatment was ineffectual. Right forelimb amputation was done and the dog survived an additional 15 months. The protracted clinical course before definitive diagnosis underscores the need for aggressive pursuit of a diagnosis when conservative treatment of a lameness is not efficacious.

Chemotherapy of synovial cell sarcoma in a dog.

A synovial cell sarcoma of the tarsus in a 6-year-old dog was treated with doxorubicin HCl and cyclophosphamide. The tumor regressed after treatment. There was no recurrence 3 years after initiation of treatment. Previously, synovial cell sarcoma has not been reported to be responsive to chemotherapeutic agents, and the treatment of choice has been amputation.

Evaluation of prognostic factors for dogs with synovial sarcoma: 36 cases (1986-1991).

Medical records of 36 dogs with synovial sarcoma confirmed by microscopic examination of H&E-stained sections of tissue were selected for retrospective analysis from dogs admitted between 1986 and 1991 to participating institutions of the Veterinary Cooperative Oncology Group. Metastasis was evident at the time of diagnosis in 8 (22%) dogs, and 15 (41%) dogs ultimately developed metastatic tumors. Median survival time for all dogs, as determined by life-table analysis, was 17 months. For dogs that were subsequently treated and became tumor free, the median disease-free interval was 30 months. Nine dogs had previously had localized excision attempted, but all had recurrence of the tumor locally (median, 4.5 months). Of 29 dogs that underwent amputation, including the 9 with localized recurrence, 2 had tumor recurrence on the amputation stump. Most dogs had survival time and disease-free interval of > 36 months after amputation. Four dogs that had received chemotherapy for tumors of advanced clinical stages did not respond to treatment. One dog that had received locally applied radiotherapy after localized excision did not have evidence of tumor recurrence 2 years after radiotherapy. Clinical stage, histologic grade, and a positive result for tests that used cytokeratin immunohistochemical staining significantly (P < 0.05) influenced survival time and disease-free interval. Analysis of data for the study reported here suggested that histologic criteria can be an excellent predictor of dogs that are likely to have tumor recurrence after amputation and that would most likely benefit from aggressive treatment with adjuvants.

Synovial sarcoma in a dog.

A 6.5-year-old, female Saint Bernard had a slowly growing tumor of the right tibiotarsal joint. Radiographically, bone surrounding the tumor was not involved. Subtotal surgical resection was undertaken. The tumor was classified histologically as a synovioma. Within 6 months, the tumor recurred locally and invaded the soft tissue proximal to the tibiotarsal joint. Eighteen months after initial examination, there was widespread right tibial invasion and pulmonary metastasis. The dog was euthanatized. The final histopathologic diagnosis was synovial sarcoma.

Synovial sarcoma in a cat.

A 9-year-old male castrated cat was examined because of right forelimb lameness of 2 months' duration. The right cubital area was large, and the range of motion of the cubital joint was limited. Radiography revealed a mild periosteal reaction of the humerus, radius, and ulna. There was cortical remodeling of the distal portion of the humerus and punctate osteolysis within the proximal portion of the ulna. Arthrocentesis was performed and neoplastic cells were found, which led to a tentative diagnosis of osteogenic sarcoma or synovial cell sarcoma. Histologic diagnosis of synovial cell sarcoma was made after amputation of the limb.

Canine biphasic synovial sarcoma: case report and immunohistochemical characterization.

The clinical, radiological and pathologic features of a biphasic synovial sarcoma in the left elbow joint of a two-year-old male Rottweiler are presented. The tumor showed positive immunoreactivity for vimentin, Epithelial Membrane Antigen (EMA), p53 and PCNA, while it was negative for the cytokeratin used, S-100, Rb and p21. Immunohistochemistry for EMA allowed the identification of epithelioid components of synovial sarcoma, and may, therefore, contribute in establishing a diagnosis of biphasic synovial sarcoma. Intratumoral variation in PCNA immunoreactivity was minimal, indicating that the various tumor components proliferate at more or less similar rates. Overall, the characterized immunohistochemical profile for canine synovial sarcoma, not defined previously, may provide clues to the histogenesis of the phenotypically mesenchymal and epithelial elements of the tumor, and may be of value in the differential diagnosis of challenging cases, decreasing the risk of under- and mis-diagnosis. Although more cases need to be studied to determine whether there is a consistent pattern of immunostaining in canine synovial sarcoma, its potential significance is discussed in relation to the histogenesis, molecular pathology and differential diagnosis of canine synovial sarcoma.

A non-joint tissue biphasic synovial sarcoma in a dog.

A subcutaneous tumour was identified in the malar region of a 14-year-old neutered female mixed breed dog. The dog was humanely destroyed and necropsy examination was performed. The tumour did not invade neighbouring tissues and no metastasis was found. Microscopically, the tumour showed a range of features including the presence of multinucleated giant cells, chondrocyte differentiation and cystic or slit-like structures. All of these features are consistent with previously reported descriptions of synovial sarcomas in dogs. Mesenchymal cells accounted for the majority of the tumour, but cytokeratin-positive epithelioid components were also confirmed by immunohistochemistry. The tumour was diagnosed as a biphasic type of synovial sarcoma. Synovial sarcoma in man may develop in tissues unrelated to joints and this is the first report of a non-joint synovial sarcoma in a dog.