Veterinary Oncology: Canine Hemangiosarcoma

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Questions and Answers

Which imaging technique is noted for identifying concurrent cardiac masses in splenic HSA cases?

AUS

Echocardiography (correct)

CXR

What is the recommended surgical treatment for a splenic mass?

Pericardectomy

Splenectomy (correct)

Partial splenectomy

Liver lobectomy

Which chemotherapy agent is considered the best choice for treating HSA?

Cyclophosphamide

Doxorubicin (correct)

Methotrexate

Vincristine

What is the purpose of performing a pericardectomy in cases of cardiac HSA?

To prevent cardiac tamponade Signup and view all the answers

What is a key consideration in the effectiveness of radiation therapy for cardiac HSA?

Movement of the heart complicates treatment Signup and view all the answers

What is the primary cell of origin for hemangiosarcoma?

Endothelial cells Signup and view all the answers

Which anatomical site is most commonly affected by hemangiosarcoma in dogs?

Spleen Signup and view all the answers

What factor is strongly linked to dermal hemangiosarcoma?

UV exposure Signup and view all the answers

Which breed of dog is NOT commonly associated with hemangiosarcoma?

Beagles Signup and view all the answers

What is a key characteristic of the biological behavior of hemangiosarcoma?

Highly locally invasive Signup and view all the answers

What symptom might indicate a dog is suffering from a hemoabdomen due to hemangiosarcoma?

Muffled heart sounds Signup and view all the answers

Canine hemangiosarcoma is particularly aggressive in its metastatic behavior. Which organ is most commonly targeted for metastasis?

Lungs Signup and view all the answers

In an emergent setting, what is crucial to do for a dog diagnosed with a ruptured splenic mass?

Stabilize the patient Signup and view all the answers

What is a common finding in bloodwork for a patient suspected of having hemangiosarcoma?

Thrombocytopenia Signup and view all the answers

Which imaging technique is used specifically to assess for peritoneal effusion?

Abdominal ultrasound Signup and view all the answers

What is the primary method to determine the nature of a splenic mass?

Histopathology Signup and view all the answers

When staging cutaneous hemangiosarcoma, what T classification indicates a better prognosis?

T1 - isolated to the dermis Signup and view all the answers

What percentage of incidentally noted splenic nodules is typically benign?

70% Signup and view all the answers

In cases of ruptured splenic masses, what rule can be used to estimate the likelihood of malignancy?

Double 2/3 rule Signup and view all the answers

What is one of the primary reasons fluid cytology may not be helpful in diagnosing hemorrhagic effusions?

Hemodilution of the sample Signup and view all the answers

During imaging for staging hemangiosarcoma, which method is less likely to be helpful in diagnosis?

Chest X-ray Signup and view all the answers

What is the primary function of aminocaproic acid and tranexamic acid?

Prevent fibrinolysis Signup and view all the answers

What is a notable aspect of the polysaccharopeptide from Coriolus versicolor?

It delays progression of metastases. Signup and view all the answers

What is the prognosis for Stage 1 cutaneous tumors that are completely excised?

Good prognosis with a survival rate greater than 2 years. Signup and view all the answers

What is a common characteristic of splenic HSA at Stage 2?

Surgery alone typically results in a survival of 1-3 months. Signup and view all the answers

Which of the following is true regarding patients with stage I UV-induced lesions?

They require regular physical exams due to high recurrence risk. Signup and view all the answers

What is the expected survival period for a cardiac tumor treated with surgery and chemotherapy?

Approximately 6 months. Signup and view all the answers

What is a characteristic of feline HSA compared to canine HSA?

It behaves similarly to other soft tissue sarcomas. Signup and view all the answers

What aspect of complementary and alternative therapies for HSA is highlighted?

They often lack substantial toxicity. Signup and view all the answers

Study Notes

Hemangiosarcoma Overview

Hemangiosarcoma (HSA) is a cancer originating from endothelial cells.
The exact cause of HSA isn't fully understood, but exposure to UV light is strongly linked to dermal HSA in dogs.
Approximately 50% of canine HSA cases have mutations in the PTEN tumor suppressor gene.
High levels of VEGF, a pro-angiogenic peptide, are frequently observed in HSA.

Objectives for the Lecture

Students will learn the anatomical locations of canine hemangiosarcoma.
Students will understand the biological behavior of canine hemangiosarcoma.
Students will be able to differentiate between potential diagnoses for a ruptured splenic mass in a dog.
Students will be able to create a diagnostic and staging plan for a patient with hemangiosarcoma.
Students will be able to determine the prognosis of cutaneous, splenic, and cardiac hemangiosarcoma cases.

Anatomic Sites

Spleen is a common location for HSA.
Skin is a less common location for HSA.
Right atrium/auricle is a less common location for HSA.
Liver is a less common location for HSA.
Bone is a rare location for HSA.
Retroperitoneal is a rare location for HSA.

Biological Behavior

HSA is highly invasive locally.
HSA is highly metastatic, often spreading to lungs, liver, regional lymph nodes, and omentum/mesentery.
Stage 1 cutaneous HSA is an exception and tends to be less metastatic.
HSA is a rapid-growing tumor, common in dogs, and a common cause of brain tumors in dogs.

Signalment

Older dogs are more prone to HSA.
Breeds such as German Shepherds, Goldens, and Labradors are overrepresented in HSA cases.
Cutaneous HSA cases are often seen in lightly haired, lightly pigmented dogs who frequently sunbathe.

History

HSA symptoms range from mild lethargy and inappetence to collapse and hypovolemic shock.
Intermittent periods of lethargy or collapse can occur in days to weeks along with recovery periods.
Cutaneous HSA lesions are often red, ulcerated, and prone to frequent bleeding.

Physical Exam

Physical examination findings may be normal.
Cranial organomegaly with a palpable mass can occur.
Signs of acute to chronic blood loss—such as pale mucous membranes, weak or bounding pulses, tachycardia, and low body temperature—can be observed.
Muffled heart sounds indicating pericardial effusion might appear.
Cutaneous or subcutaneous masses should be noted.

Hemoabdomen/Splenic Mass Management

Prioritize stabilizing the patient.
Order bloodwork.
Perform abdominocentesis or pericardiocentesis.
Order imaging studies.

Diagnosis

Stabilize the patient.
Perform blood work (CBC, including cell counts, thrombocyte counts, chemistry profile).
Consider potential causes of anemia (regenerative vs. non-regenerative).
Monitor for schistocytes and liver function.
Assess clotting times.
Check for findings suggestive of disseminated intravascular coagulation (DIC).
Perform abdominocentesis or pericardiocentesis.
Perform imaging (ultrasound guided or blind abdominocentesis, radiographs, CXR, echocardiography, CT/MRI).
Fluid cytology from samples is typically not helpful due to hemodilution.

Diagnostic Imaging (Site Dependent)

Radiographs (AXR) may reveal peritoneal effusion, cranial abdominal mass effect, and/or globoid heart (less helpful for diagnosis).
They also help rule out distant metastasis.
Abdominal ultrasounds are important for evaluating masses and staging.
Echocardiography is essential for assessing cardiac involvement.
Cross-sectional scans such as CT/MRI can provide comprehensive information about the extent of disease.

Splenic Mass Differential Diagnosis

Potential diagnoses include benign tumors such as hematoma and hemangioma and malignant tumors like hemangiosarcoma (HSA).
The double 2/3 rule for differentiating between benign and malignant masses in the spleen can aid in initial estimates.
In that rule, two-thirds of the malignancies found in splenic masses are indeed HSA.
Also, about 70% of incidentally noted splenic nodules are benign.
The definitive diagnosis is histopathology.

Clinical Staging System for Canine Hemangiosarcoma

Table 33-2 outlines the stages of canine hemangiosarcoma based on primary tumor, regional lymph nodes, and distant metastasis.

Staging

CXR/CT (3-view chest radiographs or thoracic CT)
Abdominal ultrasound (AUS)
Echocardiography
Abdominal exploratory surgery with biopsy of any abnormalities for confirmation

Staging (Continued)

Abdominal ultrasound (AUS) or CT for complete staging
Key organs include spleen, liver, lymph nodes, omentum, mesentery, and other sites (kidney, retroperitoneum) to evaluate for metastasis.
Nodules in older dogs aren't always metastatic.

Treatment (Surgery)

Removal of the splenic mass (splenectomy).
Removal of cutaneous masses based on margins (2-3 cm, 1 fascial plane deep).
Rare resectability of right auricle masses (pericardectomy, to prevent tamponade).

Treatment (Radiation Therapy)

Palliative protocols for cardiac HSA.
Radiation impact is relatively unknown due to the heart's movement.
High radiation doses difficult to administer due to the difficulty targeting the tumor precisely with the heart moving.

Treatment (Chemotherapy)

Best outcome is surgery combined with chemotherapy.
Stage I cutaneous HSA is an exception where chemo alone might suffice.
Doxorubicin is the drug most used, IV administered every 2-3 weeks for 5 doses.
Chemotherapy alone is not beneficial for splenic HSA.
Doxorubicin improves survival for cardiac HSA.

Complementary and Alternative Therapies

Yunan Baiyao (herbal remedy): mechanisms are unclear, but it may enhance surface glycoprotein expression on platelets and potentially be mildly cytotoxic against HSA cells.
Aminocaproic acid and tranexamic acid both prevent fibrinolysis, helping with bleeding episodes.
Polysaccaropépetide (turkey tail mushroom): anti-tumor activity in vitro, but some toxicity concerns exist; additional research is needed for further conclusions.

Follow-up

Splenic HSA: AUS and CXR every 2-3 months.
Cutaneous HSA: q3m PE and restaging (AUS/CXR).
High risk factors include further lesion development (regular PE), metastasis, and local recurrence.
Patient care is site/treatment dependent.

Prognosis (Bleeding Splenic Mass)

Stage 2: surgery alone (1-3 months), surgery + chemo (4-6 months), Stage 3 (short duration—usually weeks).
Stage 2 Cutaneous (completely excised): stage 1, not invasive into subQ (good prognosis >2 years), stage 2, invasive into subQ (good with aggressive treatment like surgery + chemo up to 18 months).

Prognosis (Cardiac)

Surgery (rare) + chemotherapy (~6 months).
Chemotherapy alone (~3-6 months).
Radiation therapy (RT) is typically TBD.

Feline HSA

Most common locations: skin or SQ, abdominal.
Skin/SQ lesions are similar to other soft tissue sarcomas (STS).
Splenic HSA behavior is comparable to canine cases.

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Description

Test your knowledge on canine hemangiosarcoma including its surgical treatments, imaging techniques, chemotherapy options, and biological behavior. This quiz covers key factors, symptoms, and breeds associated with this aggressive cancer. Perfect for veterinary students and professionals alike!