1.7 Introduction to Veterinary Oncology

Question 1

What are the diagnostic options for a mass lesion?

Answer 1

(1) cytology (FNA)

• quick, cheap, and easy
• can reveal cell type and morphology
• inflammation vs neoplasia, benign vs malignant

(2) histopathology (biopsy)

• gold standard for diagnosis and tumor grading
• can see what FNA can, with the addition of tissue architecture and invasion of surrounding tissues
• blood vessels, lymphatics, tumor grade

Question 2

What are the three neoplastic cell types?

Answer 2

1. epithelial
2. mesenchymal
3. round cell

Question 3

What are two neoplasia grading systems?

Answer 3

grading depends on mang features, such as

Kiupel system:

• low grade
• high grade

Patnaik system:

• grade I, II, and III (low, intermediate, high)

Mitotic index

• less than or equal to 5 (good prognosis)
• greater than 5 (poor prognosis)

Ideally we want all three grading systems on a report as they each have pros and cons! For instance, many pathologists give a patnaik grade of II, which is indicisive.

Question 4

How do you appropriately stage the cancer patient?

Answer 4

staging the patient is NOT the same as grading a tumor

• after making the diagnosis as cancer, staging is used to assess the extent of the disease
• staging assesses: primary tumor, drainage lymph nodes, and distant metastasis

TNM system: good for solid tumors but not for lymphoma

• T(umor): 1-3
• N(ode): 0-1
• M(etastasis): 0-1

WHO system: for lymphoma

• stage 1-4, depending on involvement

Question 5

How do you assess concurrent illness in the cancer patient?

Answer 5

illness may be unrelated or paraneoplastic

minimum database for the cancer patient:

• hematology / CBC
• biochemistry
• urinalysis
• coagulation profiles

presentation due to paraneoplastic effects, rather than a mass:

• hypercalcemia: PU/PD, lethargy, anorexia, depression, V+, weakness, bradycardia
• hypoglycemia: weakness, collapse, seizures
• hyperviscosity: with hyperglobinemia, polycytemia - neurological signs, retinal detachment, seizures

Question 6

What are the most common cancer treatment options?

Answer 6

(1) surgery

• best for primary carcinomas, sarcomas, and MCT
• often used in combination with radiation therapy or chemotherapy

(2) radiation therapy

• may be primary treatment (nasal tumors)
• may be adjunctive therapy (post-surgery)

(3) chemotherapy

• best for disseminated cancers or tumors with high metastatic potential
• hematopoietic tumors (lymphomas, leukemias)
• systemic/high grade MCT
• others

(4) novel: rare

• photodynamic (SCC)
• immunotherapy
• electrochemotherapy

Question 7

What is supportive care for cancer patients?

Answer 7

Question 8

How do you safely handle cytotoxic drugs?

Answer 8