Canine Haemangiosarcoma

Lauren Ritchey

Megan 13yo Female Border Collie

Presentation: worsening lethargy. With a history of intermittent anemia over the last few weeks.

Clinical Findings:

QAR

Slightly pale MM, Normal CRT

Fluid thrill noted on abdominal palpation

HR 120 bpm, Temperature and RR wnl.

Investigations

Abdominal Ultrasound: revealed large volume of free fluid. Small cavitated mass adjacent to the spleen, and a larger mass arising in cd abdomen.

Abdomenocentesis: Blood (PCV 32%)

Orthogonal thoracic radiographs: unremarkable

Cardiac scan: No obvious masses

Hematology: Moderate Anemia (HCT 28%) (ref 37-55%) Neutrophilia (15x10^9/L) (ref 6-12x10^9/L) Thrombocytopenia (60x10^9/L) (ref 200-500x10^9/L)

Mildly prolonged APTT (37 seconds) (ref 17-24sec)

Diagnosis

Haemoabdomen, likely secondary to abdominal neoplasia.

Non Traumatic/Spontaneous Causes of Haemoabdomen

• Neoplasia***• Splenic hematoma • Splenic torsion• Coagulopathies • Vena caval syndrome secondary to Dirofilariasis

Plan

Referred to Soft Tissue service for an emergency exploratory laparotomy.

Findings of Exlap: Small mass on falciform fat Larger caudal abdominal mass 800ml of free blood Grossly abnormal liver

Both masses, and a liver biopsy were sent for histopathology.

Histopathology

The histological appearance of the two masses was consistent with an haemangiosarcoma.

No normal tissue is present in the examined sections to suggest a site of origin.

Haemangiosarcoma (HSA) Highly malignant tumor of endothelial cells.

Occurs more frequently in dogs than in any other species and is characterized by a high fatality rate (1)

The overall prevalence is reported to be 0.3% to 2.0% of all tumors in dogs; German shepherds, golden retrievers, and Labrador retrievers are overrepresented (2).

The etiology of HSA is still unknown, although the strong breed association suggests an inherited or familial predisposition.

Haemangiosarcoma (HSA) cont.

The 3 most common primary sites of HSA are the spleen (28% to 50%), right atrium/auricle (up to 50%), and skin or subcutaneous tissue (13%) (1,3).

Most common sites of metastasis of HSA: Lungs (65%) Spleen (36-60%) Kidneys (55%) Liver (41-55%)

which can occur via haematogenous spread or by local seeding after tumor rupture (1).

Common Laboratory Findings

Hematology: Anemia morphological changes to red blood cells:

nucleated erythrocytes Polychromasia poikilocytes, anisocytes, shistocytes, and

reticulocytes Neutrophilia

due to either stress or tumor rupture and necrosis thrombocytopenia

Common Diagnostic Imaging Findings

Thoracic Radiographs

Metastatic patterns in dogs with HSA: widely disseminated nodular pattern (common) diffuse interstitial pattern (uncommon)

Abdominal US

primary HSA: mixed pattern of anechoic and hyperechoic regions

metastatic HSA: diffusely anechoic or hypoechoic appearance

Echocardiography

Helps detect structural abnormalities, presence of tumours, clots or fluid.

Electrocardiography

ventricular arrhythmias are commonly associated with HSA due to hypoxia, anemia, or hypovolemia

Treatment of HSA

Usually a combination of:

Chemotherapy: Doxorubicin

+/- Cyclophosphamide (AC) +/-Vincristine (VAC)

Metronomic Chemotherapy Continuous low dose oral cyclophosphamide.

Surgical: Try to remove the primary tumour. Ex: SPLENECTOMY:

Historically the treatment of SPLENIC HSA.

HSA Staging

Clinical Stage

Tumour Node Metastasis

I T0-1 N0 M0

II T1-2 N0-1 M0

III T2-3 N0-2 M1T (Primary Tumour)

T0 No evidence of neoplasia

T1 <5cm diameter, confined to primary site

T2 >5cm diameter, ruptured, or invading subcutaneous tissue

T3 Invading adjacent structures including muscle

Node

N0 No evidence

N1 Regional LN involvement

N2 Distant LN involvement

Metastasis

M0 No evidence of metastasis

M1 Evidence of distance metastasis

Prognosis

Relatively Poor

MST (Mean survival times)

Surgery alone: 2-3 months

Surgery followed by Chemotherapy: 4-6 months

Back to Megan…

Post Operatively:

Due to her loss of blood and thrombocytopenia she required fresh frozen plasma and Packed red cell transfusion

(post operative PCV 6%, Hg 2 g/dl) with good response over the following 24h.  

She was sent home on strict cage rest, pain medications, antibiotics, and antiemetics. With a recheck in 10 days to remove the sutures and talk about chemotherapy treatment options.

Megan’s Treatment Plan

Pre Chemotherapy: Heart Scan

Showed adequate contractility Abdominal scan

Revealed a nodule on the left kidney that should be monitored

Start Doxorubicin therapy. One dose every 3 weeks, for 4-6 doses. She received her first dose this week. If protocol not tolerated, discussed switching to metronomic

chemotherapy.

Questions?

References

Canine hemangiosarcoma: retrospective analysis of 104 cases.Brown NO, Patnaik AK, MacEwen EG J Am Vet Med Assoc. 1985 Jan 1; 186(1):56-8.

Kahn, S. Anthony, et al. "Doxorubicin and deracoxib adjuvant therapy for canine splenic hemangiosarcoma: A pilot study." The Canadian Veterinary Journal 54.3 (2013): 237.

Sorenmo, K. U., Baez, J. L., Clifford, C. A., Mauldin, E., Overley, B., Skorupski, K., Bachman, R., Samluk, M. and Shofer, F. (2004), Efficacy and Toxicity of a Dose-Intensified Doxorubicin Protocol in Canine Hemangiosarcoma. Journal of Veterinary Internal Medicine, 18: 209–213. doi: 10.1111/j.1939-1676.2004.tb00162.x

Thamm DH. Hemangiosarcoma. In: Withrow SW, Vail DM, editors. Small Animal Clinical Oncology. 4th ed. St Louis, Missouri: Saunders/Elsevier; 2007. pp. 785–795.