Veterinary Tumor Diagnosis Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which tumor type has the highest incidence based on the provided data?

STS

Adenoma

Lipoma

Histiocytoma (correct)

What is one of the primary criteria for diagnosing tumors?

High Mitotic Index

Prominent, multiple or variable sized nucleoli (correct)

Multinucleation

Basophilic Cytoplasm

Which aspect defines a mesenchymal tumor?

Lymphoproliferative disorders

Sarcoma originating from connective tissues (correct)

Discrete cell tumors of round cell types

Carcinoma originating from glandular tissues

What characteristic of a tumor cell indicates a benign nature in the cytology algorithm?

Clusters of cells Signup and view all the answers

Which of the following tumors is categorized as a round cell tumor?

Lymphoma Signup and view all the answers

What is the primary purpose of performing a biopsy?

To obtain a definitive diagnosis and/or histologic grade Signup and view all the answers

In which situations is an excisional biopsy considered appropriate?

If the treatment will not be affected by histopathology results Signup and view all the answers

What potential issue can arise from poor excisional biopsy technique?

Compromise of definitive surgical resection Signup and view all the answers

Which type of biopsy is specifically described as removing a small section of a mass?

Incisional biopsy Signup and view all the answers

What is the typical prognosis for papillomas in young dogs?

Excellent, typically resolve spontaneously Signup and view all the answers

Where are mast cell tumors typically more aggressive and have a higher metastatic potential?

Muzzle area Signup and view all the answers

What is a common characteristic associated with histiocytomas in dogs?

Associated with paraneoplastic signs Signup and view all the answers

What type of biopsy technique is typically performed first when diagnosing a lesion?

Fine Needle Aspiration (FNA) Signup and view all the answers

Which of the following are top feline cutaneous tumours?

Sebaceous Adenoma/Hyperplasia Signup and view all the answers

What is the primary purpose of a pre-operative biopsy?

To establish a diagnosis Signup and view all the answers

Which fine needle aspiration technique works best with tumours that exfoliate easily?

Pincushion/capillary technique Signup and view all the answers

Which parameter is NOT listed as a key parameter in evaluating nodular dermatoses?

Presence of hair Signup and view all the answers

What is a common issue when a fine needle aspirate is non-diagnostic?

Insufficient cell sample Signup and view all the answers

Which staining method is adequate for most cytological diagnoses?

Diff-Quik stain Signup and view all the answers

What aspect of tumours does RECIST criteria primarily evaluate?

Longest single dimension Signup and view all the answers

In the pincushion/capillary technique of fine needle aspiration, which is NOT true?

Negative pressure is used Signup and view all the answers

What is a common characteristic of canine soft tissue sarcomas?

They can occur subcutaneously and are mobile. Signup and view all the answers

Which factor is NOT considered a prognostic factor for canine mast cell tumors?

Canine age at diagnosis Signup and view all the answers

Which type of tumor is considered the most common skin tumor in cats?

Basal cell tumor Signup and view all the answers

What distinguishes high grade tumors from low grade tumors in canine sarcomas?

Degree of cellular differentiation and invasion Signup and view all the answers

Mast cell tumors that occur in which locations have been identified for specific prognostic factors?

Inguinal and perineal regions Signup and view all the answers

What is a common treatment approach for benign hair-follicle tumors in dogs?

Conservative surgery Signup and view all the answers

Which of the following is NOT a common site for squamous cell carcinoma (SCC) in dogs?

Hind leg Signup and view all the answers

What is the typical outcome for dogs with trichoepithelioma?

Typically benign and cured by conservative surgery Signup and view all the answers

Study Notes

Approach to Nodular Dermatoses/Neoplasia

Nick Bacon is an expert in veterinary dermatology and oncology
He is a founding fellow of ACVS (American College of Veterinary Surgeons) and a specialist in surgical oncology
He is a clinical director at AURA Veterinary and a professor at the University of Surrey

Patient Case Example

A dog, Buddy, has a skin tumor
Owner was told there's a chance of melanoma based on the tumor's color
Buddy will undergo surgery to remove the tumor
The removed tumor will be sent to a lab for testing

Common Canine Cutaneous Neoplasms

Data on the incidence of various tumor types in dogs are presented.
Lipoma is the most common tumor type, followed by adenoma.
Other frequently observed types include mast cell tumors, papillomas, histiocytomas, and various sarcomas (e.g., hemangiosarcoma, fibrosarcoma, and lymphangiosarcoma).
Melanoma and other tumors are also listed

Feline Cutaneous Tumors

Basal cell tumors, mast cell tumors, and fibrosarcoma are common in cats
Squamous cell carcinoma, and sebaceous adenoma/hyperplasia are also frequently observed

History Taking for Skin Tumors

Duration/chronicity of the condition
Growth rate and changes in the tumor's characteristics
Previous masses or growths at the same location
Travel history
Breed and age may be helpful in some cases (e.g., boxers, bulldogs, and Boston terriers)
Young dogs are more prone to histiocytomas and papillomas

Key Parameters for Evaluating Skin Lesions

Skin vs. subcutaneous location
Appearance (alopecia, color changes, ulceration, bleeding, etc.)
Size using RECIST criteria (longest dimension) and body mapping
Importance of evaluating 3D dimensions (length, width, height)

Pre-operative Biopsy

Fine needle aspiration to establish diagnosis
Pincushion/capillary technique involves avoiding negative pressure; this method reduces cell distortion and works well for easily exfoliating tumors, like round cell and epithelial neoplasms
Aspiration with negative pressure is better suited for dense tumors

Cytology

Diff-Quik staining is adequate for most diagnoses
However, mast cell tumors (MCTs) may stain poorly with Diff-Quik (5-10% of cases)

Diff-Quik Staining Techniques

Fixative
Solution I (pink)
Solution II (blue)

Non-diagnostic Aspirates

If no cells are seen in the aspirate, the sample is deemed non-diagnostic
Potential causes for a non-diagnostic result include the tumor's absence or a lack of viable cells
In any case, failure to identify cells in the aspirate is important information for further evaluation

Canine Neoplasia Incidence Rates

Incidence rates for different tumor types in the UK, considering insured dogs, are presented (e.g., histiocytoma, lipoma, adenoma)

Primary and Secondary Criteria for Cytological Diagnosis

High nuclear-to-cytoplasmic ratio, prominent nucleoli, anisokaryosis, and nuclear pleomorphism are primary criteria
Criteria such as multinucleation, basophilic cytoplasm, and high mitotic index are secondary criteria

Algorithm for Cytological Evaluation

Based on the sample type, proceed through an algorithm to distinguish between benign and malignant tumors or between other possible entities
Epithelial, mesenchymal, and round cell types can be differentiated based on shape, cellularity, cell association, and the location of the nucleus.

Categorizing Tumors

Tumors are categorized into epithelial (carcinoma, glandular/lining tissues), mesenchymal (sarcoma, connective tissue), and discrete cell/round cell (mast cell tumor, lymphoma, histiocytoma, plasmacytoma, melanoma) categories

Locations of Different Tumor Types

The origin or suspected spread of different categories of tumors (epithelial, mesenchymal, and discrete cell/round cell) is described.
Specific sites of interest include lymph nodes, lungs, liver, spleen

Reasons for Biopsy

Obtain definitive diagnosis and histological grade
Lesions in difficult areas for reconstruction (e.g., head, neck, tail, periocular, perineal)
Knowledge of the specific tumor type impacts client treatment decisions.

Biopsy Techniques

Needle core biopsy (for soft tissues)
Tru-cut biopsy
Incisional biopsy
Excisional biopsy (treating the patient while acquiring information / diagnosis)

Excisional Biopsy Considerations

Treatment is not altered by histopathology
FNA diagnoses can be helpful in making the diagnosis
Excisional biopsy ensures that the lesion or tumor is completely removed without compromise of the patient's treatment choices.

Excisional Biopsy Limitations

Poor excisional biopsy can compromise definitive surgical resection
Difficult to remove the malignant cells completely leaving them behind in the body
Metastasis may need to be evaluated prior to surgery

Excisional Biopsy Alternatives

Biopsys may not be optimal in all cases
Dirty margins may require additional difficult surgeries

Differentials

Papilloma (young dogs associated with viruses, typically resolves spontaneously), histocytoma (young dogs, solitary, resolve within weeks, conservative surgery often sufficient), mast cell tumor (up to 21% skin masses, no sex preference, increased risk with age, retrievers, boxers, Shar-pei, pugs, obese dogs more prone)

Stages and Grades

Tumor stage and grade are important data to collect in cases of malignant tumors.

Prognostic Factors for Canine Skin Tumors

Appearance
Growth rate and duration (>7 months)
Paraneoplastic signs
Clinical stage
Histological grade
- Size (<5cm vs >5cm)
- Depth of tumor (superficial vs. deep)
- Mobility (mobile vs. fixed)
- Grade (low vs. high)

Specific Tumor Types and Locations

Mast cell tumors (MCTs) prevalence, preputial or inguinal are less severe, while tumors of the muzzle are more aggressive with higher metastatic potential)
Soft tissue sarcoma and where the tumor can arise
Soft, fluctuant, mobile, and subcutaneous skin/SQ masses (15% of canine cases)
Categories are determined (epithelial, mesenchymal, and discrete cell/round cell) to guide prognostic evaluation and treatment choices

Squamous Cell Carcinoma (SCC)

Less common in dogs compared to cats
Can develop in nail beds, planum, and anus.

Basal Cell Tumors

Usually benign
Common in cats
Often fluid-filled cysts
Typically found on head, neck, or shoulders

Sebaceous Tumors

Hyperplasia or warts
Cured with conservative surgery
Adenomas and carcinomas are less common

Hair Follicle Tumors (Trichoepithelioma and Pilomatricoma)

Usually benign
Cured with conservative surgery
Malignancy/metastasis very rare

Melanoma

Typically less than 2cm in diameter.
85% of cases are benign
3 mitoses per 10 high-power fields
Muco-cutaneous and oral forms can also occur

Lipomas

Surgery is usually indicated for lipomas in situations like rapid growth, texture changes, restricting function, bothering the dog, or bothering the owner

Ear Canal Tumors

Older cats and dogs are susceptible to ear canal problems
Tumors often are polyps, cysts, papillomas, or adenomas.
Ceruminous adenocarcinoma/SCC are locally aggressive with metastasis in less than 15% of cases.
Median survival times are presented for both dogs and cats.

Summary of Important Considerations for Skin Tumors

Biopsy is crucial for proper diagnosis and classification
Treatment is often more easily chosen with the complete characterization of the tumor

Thank you Note

There is a gratitude message to the audience
There are logos of the Veterinary Societies and institutions.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the various types of tumors, diagnosis criteria, and biopsy techniques relevant to veterinary medicine. This quiz covers essential concepts related to tumor behavior and prognosis in both dogs and cats.