1. INTRODUCTION TO VETERINARY ONCOLOGY
AJADI R. ADETOLA
VETERINARY MEDICINE AND SURGERY

2. DEFINITION
The study of the behaviour of tumors, its diagnosis and management

3. OUR SCOPE Causes of tumors Effect of tumors Diagnosis of tumors
Staging of tumors
Management of tumors

4. CAUSES OF TUMORS Most tumors occur spontaneously
Genetic inheritance : renal cystadenocarcinoma in German Shepherd Dog
Irradiation : Squamous cell carcinoma in white skinned horses
Oncogenic viruses: Feline leukemia virus
Diet: Mammary tumors
Hormones: Mammary adenocarcioma
Chemical carcinogens: Transitional cell carcinoma of the bladder
Transmissible agents: Canine transmissible venereal tumor

6. EFFECTS OF TUMORS Space occupying effects
Excessive production of the secretion of the gland
Loss of function
Invasion of adjacent organs
Paraneoplastic syndrome
Hypercalcemia

7. PARANEOPLASTIC SYNDROME
Altered coagulability
Hypoglycemia
Anaemia
Polycythemia
Hypertrophic osteopathy
Fever
Eosinophilia
Immune complex disease
Neutrophilic leukocytosis
Cachexia

8. TUMOR DIAGNOSIS Cytology Histopathology Immunohistochemistry
Flow cytometry
Molecular cytogenetics
Diagnostic imaging

9. CYTOLOGICAL CRITERIA OF MALIGNANCY
Pleomorphism with many large cells
Ectopic cell population
High nuclear/ cytoplasmic ratio
Variation in nuclear size, shape and number
Prominent nucleoli
Variation in nucleoli size, shape and number
Abnormal mitotic figure
Irregular and /or coarse chromatin

10. SAMPLE COLLECTION Fine needle aspirate
Tracheal washing and trans-tracheal aspiration
Incisional biopsy
Excisional biopsy
Broncho-alveolar lavage

11. DIAGNOSTIC IMAGING Radiography Ultrasonography Computed Tomography
Magnetic resonance imaging
Radionuclide imaging

12. RADIOGRAPHY Involved the use of radiant energy.
Depend on the interaction of x-ray with matters.
X-ray cannot penetrate bone, limiting its use in the brain and spinal cord.
Good for the thorax and abdomen.
Visualization depends on subject density and contrast.
Contrast agent can be administered to improve visualization.

15. ULTRASONOGRAPHY
Use of high frequency sound waves to obtain real time images of body parts
Depends on the interaction of sound with matter.
It is non invasive.
Not limited by poor contrast.
Not impaired by fluid.
Can assess internal architecture.
Can allow for the evaluation of internal cardiac anatomy, motion and function.
Can diagnose pregnancy; determine fetal sex, estimate fetal size and expected date of delivery.

17. MAGNETIC RESONANCE IMAGING
Depends on physical principles of nuclear magnetic resonance
Does not depend on tissue density but on proton density, proton bulk motion, diffusion magnetic susceptibility and chemical shift.
It provides details image of soft tissue.
Images can be enhanced by intravenous injection of paramagnetic contrast medium, gadolinium.
Diagnosis is based on lesion size, location and edema.
Very expensive and not available

19. COMPUTED TOMOGRAPHY
Involve the use radiant energy to create attenuation map of patient.
It allows one to obtain a cross-sectional image slice of a subject, so that internal structural can be visualized directly.
X-ray attenuation is dependent on the energy of the x-ray, election and physical density of the material thickness of patient and effective atomic number substance within the patient.
Good for the brain, spinal cord, thorax and abdomen.
Useful when suspecting tumors of the brain, spinal cords, lung or pancreases.
Very expensive and not generally available

21. RADIONUCLIDE IMAGING
Depends on the distribution of radio-pharmaceuticals in the body.
Technetium – 99m is the most commonly used radio pharmaceuticals.
Planar imaging allows for region of interest analysis (ROI).
Dynamic flow studies assist in evaluating patient for possible porto-systemic vessel anomalies, GFR determination, distal limb perfusion and cardiac studies.
Single photon emission computed tomography (SPECT) allows for dimensional image reconstruction thus improving anatomical location of lesion.
Position emission tomography (PET) provides a functional assessment of tumor metabolism.
Required hospitalization unit because of risk of radioisotopes.
Very expensive and not available.

23. TUMOR STAGING To assess the prognosis of a tumor
To aid in planning of treatment
To assist in evaluation of results
To assist in investigating of tumor

24. TUMOR STAGING: CRITERIA
Size of mammary tumor
Lymph node involvement
Distant metastasis

28. MANAGEMENT OF TUMOR Surgery Chemotherapy Radiotherapy Immunotherapy
Hyperthermia
Multimodal therapy

29. RADIOTHERAPY External beam radiotherapy Orthovoltage Supervoltage
Interstitial Brachytherapy
Systemic radiotherapy

30. CHEMOTHERAPY Alkylating agents: cyclophosphamide
Antimetabolites: methotrexate
Plant alkaloids: vincristine
Antibiotics: doxorubicin
Hormones: prednisolone
Miscellaneous compounds: cisplatinum