Hemangiosarcoma of the external naris in a cow.

A tumor was removed from the nose of a 4-year-old Holstein. Hemangiosarcoma was diagnosed on histologic examination. Redevelopment of the tumor necessitated a second surgery. Routine CBC and serum biochemical analysis were normal. Clinical signs of metastasis were not reported by the owner during the next 13 months before the cow was sold for slaughter.     

Cutaneous Hemangiosarcoma in a Dog

A male golden retriever of unknown age presented with multiple cutaneous and subcutaneous masses from the left elbow to the digits. Histopathologically, multiple tumor foci had formed from the dermis to the subcutaneous tissue. Tumor foci consisted of a vascular structure, alveolar structure and solid proliferative area. The borders among these areas were not clear. Some neoplastic cells resembled a mature endothelium, while others were large pleomorphic cells. Immunohistochemically, the tumor cells were usually strongly positive for CD31 and often positive for PROX-1, the lymphatic endothelial cell marker. Based on these findings, the tumor was diagnosed as a hemangiosarcoma with lymphatic differentiation.     

Hemangiosarcoma in a geriatric Labrador retriever

A geriatric Labrador retriever dog was presented for acute collapse. The dog was conscious but lethargic, tachypneic, tachycardic with weak femoral pulses, occasional pulse deficits, and pale mucous membranes. Radiography, ultrasonography, quick assessment tests, and a complete blood (cell) count (CBC)/biochemistry panel indicated internal hemorrhage and potential problems with hemostasis. The dog was euthanized. A necropsy, histopathology, and immunohistochemistry for CD31 and Factor VIII-related antigen cell markers supported a diagnosis of splenic hemangiosarcoma.     

Splenic Hemangiosarcoma in a Young Sprague-Dawley Rat

The present report describes a rare case of spontaneous hemangiosarcoma in a nine-week-old male Sprague-Dawley rat. At necropsy, multiple white nodules of various sizes were observed on and within the enlarged spleen and liver and were histopathologically determined to be composed of spindle- to oval-shaped cells that showed invasive growth without encapsulation and were arranged solidly but partially in whorls or faint alveolar patterns with vascular-like spaces containing small clefts or erythrocytes in the tumor mass. Immunohistochemical analysis revealed that most of the tumor cells were strongly positive for vimentin, von Willebrand factor (vWF) and CD34 but negative for podoplanin. In addition, electron microscopic examination revealed the presence of Weibel-Palade bodies in the cytoplasm of the tumor cells. Based on these findings, this case was diagnosed as a hemangiosarcoma. The splenic masses were larger than the hepatic ones, with tumor cells mainly observed at periportal regions with tumor embolism in the liver, suggesting that primary hemangiosarcoma initially developed in the spleen before metastasizing.     

Hemangiosarcoma of the third eyelid in a dog

Abstract A case of hemangiosarcoma of the third eyelid in a 7-year-old Caucasian Sheepdog is reported. A voluminous red mass protruding from the free edge of the third eyelid in the right eye was present. The mass and the free edge of the third eyelid were surgically excised. On histopathologic examination the tumor was seen to infiltrate the propria of the third eyelid and was composed of neoplastic mesenchymal cells forming irregular channels containing blood. These plump cells showed moderate anisocytosis and anisokaryosis with a low mitotic index. The surgical wound healed successfully and after 9 months there had been no recurrence. To the authors' knowledge, this is the first hemangiosarcoma of the third eyelid reported in the dog.     

Hemangiosarcoma of the third eyelid in a cat

A case of hemangiosarcoma of the third eyelid in a 15-year-old Domestic Short-haired cat is reported. A small red mass protruding from the anterior surface of the third eyelid in the left eye was present. Only mild bilateral conjunctivitis and nuclear sclerosis were revealed on initial ophthalmic examination. After anti-inflammatory treatment, surgery and cryotherapy were performed. On histopathologic examination the mass was located just beneath the conjunctival epithelium, suggesting that the conjunctiva was the tissue of origin. The tumor showed high cellularity and was composed of pleomorphic spindle and polygonal cells arranged in interlacing bundles and solid sheets. The presence of slit-like spaces between tumor cells containing erythrocytes demonstrated the vascular differentiation. Mitotic activity was moderate, but atypical mitoses were detected. The surgical area healed uneventfully and after 7 months there was no recurrence. To the authors' knowledge, this is the first report of conjunctival hemangiosarcoma of the third eyelid in a cat.     

Hemangiosarcoma in 11 young horses

Hemangiosarcoma is a rare neoplasm of horses and hemangiosarcoma in young horses might behave differently than in mature horses. The purpose of this study was to identify the characteristics of hemangiosarcoma occurring in horses < or = 3 years of age. Medical records from 1982 to 2004 were searched for horses < or = 3 years of age with a histopathologic diagnosis of hemangiosarcoma. Eleven records were identified. Thoroughbred and Thoroughbred crosses predominated. Age ranged from 9 days to 3 years. All horses presented with cutaneous or leg swellings or joint effusion. Physical examination findings included tachycardia, fever, and depression. Laboratory abnormalities included anemia (5/11), hyperfibrinogenemia (4/11), hypofibrinogenemia (3/11), thrombocytopenia (2/11), and neutrophilic leukocytosis (1/11). Ultrasonographic and radiographic evaluation was not diagnostic in any case. Antemortem histopathologic diagnosis was obtained in 10 cases. Six of 11 horses were euthanized. Surgical resection was performed in 5 horses, 2 of which were later euthanized. Diagnosis was confirmed histologically at postmortem examination in all euthanized horses. Two cases resolved spontaneously. Early histopathologic diagnosis may allow cure if the mass is localized and amenable to surgical resection. In cases where the horse is medically stable, and masses are not interfering with quality of life, a period of observation may be warranted.     

Hemostatic Abnormalities in Dogs With Hemangiosarcoma

The hemostasis profiles of 24 dogs with histologically confirmed hemangiosarcoma were prospectively evaluated. Microangiopathic hemolysis was defined as the presence of schistocytes; disseminated intravascular coagulation was defined as 1) thrombocytopenia, 2) fibrin(ogen) degradation products greater than 10 micrograms/mL, 3) prolongation of one or more coagulation times (activated partial thromboplastin time or one-stage prothrombin time) by greater than 25% of the control, 4) fragmented red blood cells (greater than or equal to 1+ based on a semiquantitative grading scale), and 5) fibrinogen less than or equal to 80 mg/dL. Three of the five criteria listed above had to be met for disseminated intravascular coagulation to be diagnosed. Fifty percent of the dogs were considered to have disseminated intravascular coagulation at presentation. Thrombocytopenia was present in 75% of the dogs and was the most common abnormality. The mean platelet count was 137,800/microL. Twenty-five percent of the dogs died as a result of the hemostatic abnormalities. Only 12% of the dogs had microangiopathic hemolysis without other evidence of disseminated intravascular coagulation. Hemostatic abnormalities are present in many dogs with hemangiosarcoma at the initial clinical presentation and represent an important clinical finding.     

Laparoscopic Splenectomy for Treatment of Splenic Hemangiosarcoma in a Dog

Objective: To report laparoscopic splenectomy in a dog. Study Design: Clinical report. Animals: Mixed breed dog (n=1). Methods: Hemangiosarcoma was diagnosed by ultrasound‐guided fine‐needle aspiration of a splenic mass in an 11‐year‐old, 30 kg, mixed breed dog. No metastatic disease was identified during complete staging (chest radiographs, echocardiogram, and abdominal ultrasonography); however, cystic calculi were identified. Laparoscopic splenectomy using Ligasure V was performed through 3 portals and the calculi were removed by laparoscopic‐assisted cystoscopy. Results: Total surgical time was 2 hours and for laparoscopic splenectomy, 65 minutes. The celiotomy incision for splenic removal was 7 cm. The dog recovered uneventfully and was ambulatory 2 hours postoperatively. Conclusion: Laparoscopy with Ligasure V facilitated successful removal of a spleen with a 3 cm mass. Clinical Relevance: Laparoscopic splenectomy in dogs is feasible for removal of a normal‐sized spleen with a moderate‐sized mass.     

Hemangiosarcoma in dogs and cats.

Hemangiosarcoma (HSA, including angiosarcoma and malignant hemangioendothelioma) is a highly malignant tumor derived from the endothelial cell line and is characterized by early and aggressive metastasis. HAS is a common tumor type in dogs, but is rare in other species. Treatment options include surgery, chemotherapy, and possibly radiation, but survival times are invariably short (usually < 1 year), except for patients with superficial dermal HSAs. Further options to treat this tumor type are currently being investigated.     

Intracranial Lesions in Dogs With Hemangiosarcoma

A retrospective analysis of 85 dogs with hemangiosarcoma (HSA) that underwent complete necropsy, including gross examination of the brain, was conducted. Grossly identifiable intracranial lesions were present in 17 dogs. Twelve of 85 dogs (14.2%) had brain metastases. Four of 85 dogs (4.7%) had hemorrhagic lesions and/or ischemic necrosis without identifiable tumor. One dog had a primary central nervous system tumor. Signs of intracranial disease were present in six of 85 dogs (7.1%) with HSA; four had brain metastases and two had nonneoplastic lesions. Metastases had a propensity for cerebrum and gray matter. Dogs with brain metastases had more widely disseminated disease than dogs without brain metastases (P less than 0.001). Dogs with pulmonary metastases were at greater risk for developing brain metastases than dogs without pulmonary metastases (odds ratio = 8.31). Although thoracic radiography accurately identified ten of 12 dogs (83%) with pulmonary metastases, too few cases were available to assess the applicability/accuracy of thoracic radiography in predicting the presence or absence of brain metastases in dogs with malignancy and signs of intracranial disease.     

Hemangiosarcoma in a South American sea lion (Otaria byronia).

A 10-yr-old male South American sea lion (Otaria byronia) died after several weeks of depression, anorexia, weight loss, and progressive respiratory distress. At necropsy, three confluent, lobulated, dark-red masses were noted in the mesentery. Similar masses were also observed in the lung and both kidneys. Hemangiosarcoma was diagnosed based on gross findings, histopathology, and immunohistochemistry. This is the first case of hemangiosarcoma reported in pinnipeds.