Oncology - Mast Cell + Others Flashcards Preview

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Flashcards in Oncology - Mast Cell + Others Deck (60)
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1
Q

What is a mast cell?

A

A bone marrow derived cell that lives in the periphery involved in allergic reactions

2
Q

True or False: MCTs are the most common skin tumor and malignant skin tumor.

A

True

3
Q

Where are MCTs most commonly located?

A

50% trunk and perineum
40% extremities
10% head and neck

4
Q

When is the mean age of diagnosis for MCTs?

A

8-9 years

5
Q

What are the clinical signs associated with MCTs due to?

A

the release of histamine and heparin

6
Q

What is Darier’s sign?

A

erythema and wheal formation at a MCT

7
Q

What clinical signs are associated with MCTs?

A
Bleeding when mass aspirated/excised
GI ulceration
Fever
Peripheral edema
Hypotensive events/collapse
Coagulation abnormalities
8
Q

What are the prognostic factors for MCTs?

A

Histologic grade, clinical stage, anatomic location, cell proliferation rate, growth rate, recurrence, systemic signs, breed, tumor size, and C-KIT mutation

9
Q

If MCTs are going to metastasize, where do they metastasize most commonly?

A

Regional lymph nodes
Systemic - distant lymph nodes, spleen, liver
Pulmonary (very rare)

10
Q
  • Dogs with gross/visible MCTs are at increased risk of this systemic side effect due to the histamine present in their mast cells:
    a. Gastric ulceration
    b. epistaxis
    c. pulmonary metastasis
    d. uveitis
A

a. gastric ulceration

11
Q

What is the most common way to diagnose MCTs?

A

Fine-needle aspirate cytology +/-incisional biopsy

12
Q

How do you do a fine-needle aspirate cytology?

A

Use a 22G hypodermic needle and insert it into the mass for a minimum amount of 10 insertions. Then stain with Diff-Quik

13
Q

What cytological findings are consistent with a MCT?

A

Small to medium sized round cells

Abundant, small, uniform cytoplasmic granules that stain purplish-red

14
Q

What method should you NOT use to diagnose MCT?

A

excisional biopsy because it is very important to get margins on your first surgery

15
Q

What does the Patnaik system grade based on?

A

Cytoplasmic boundaries, nuclear shape/size, mitotic index, and granules

16
Q

Define grade I of the Patnaik system.

A

Well differentiated (10-20%)

17
Q

Define grade II of the Patnaik system.

A

Intermediate differentiated (60-80%)

18
Q

Define grade III of the Patnaik system.

A

Poorly differentiate/anaplastic with infiltrative growth (10%)

19
Q

What did the 2-tier grading scheme determine the survival time for a high grade MCT was?

A

less than 4 months

20
Q

What did the 2-tier grading scheme determine the survival time for a low grade MCT was?

A

greater than 2 years

21
Q

When should you consult a pathologist in MCT cases?

A

The histology does not = biologic behavior - rapidly growing, large tumor, and LN metastasis

22
Q

Why is palpation alone of the LN not recommended for MCT staging?

A

Because of the low sensitivity and specificity - normal LN size does not mean there is no metastasis

23
Q

How are 70-80% of MCTs managed?

A

With surgery alone

24
Q

How do you downstage large MCTs prior to surgery?

A

Chemotherapy, radiation therapy, and prednisone

25
Q

What surgical margins are recommended for cutaneous MCTs?

A

Lateral margins - 2 cm or maximal diameter of MCT, whichever is GREATER
Deep margins - fascial

26
Q

What surgical margins are recommended for subcutaneous MCTs?

A

Lateral margins - 2cm or maximal diameter of MCT, whichever is LESS
Deep margins - fascial layer

27
Q

What LN is most commonly excised in MCT patients?

A

the regional lymph node because they are often involved - recommendation is to excise it when possible

28
Q

True or False: Incomplete surgical excision followed by observation alone is correlated with a significant decrease in survival times in dogs and recurrence.

A

True

29
Q

In cases of incomplete surgical excision, what should you do?

A

Wide surgical excision or radiation therapy

Consider a MCT prognostic panel

30
Q

When is chemotherapy not indicated if there is incomplete surgical excision?

A

If it is a low grade MCT

31
Q

What are some prognostic panels for MCT?

A

Proliferation indicies, KIT staining patterns, and C-KIT mutation status

32
Q

When should you do KIT mutation testing?

A

In cases of a high/grade III/ high MI (metastatic index)

33
Q

What should you do if you get a positive KIT mutation result?

A

Chemotherapy + palladia

34
Q

What should you do if you get a negative KIT mutation result?

A

Chemotherapy alone vs. chemo and palladia

35
Q

When should you run a full MCT panel?

A

Incomplete resection
Biologic behavior does not fit histopathology
Hot anatomic sites (muzzles, mucocutaneous)
Low owner risk tolerance

36
Q

What are the indications for chemotherapy in MCT patients?

A

High-grade MCT, metastatic MCT, non-resectable MCT, and visceral MCT

37
Q
  • Chemotherapy is not indicated for which group of dogs with mast cell tumors?
    a. High-grade MCTs
    b. Metastatic MCTs
    c. Completely excised low-grade MCTs
    d. Non-resectable MCTs
    e. Visceral MCTs
A

c. Completely excised low-grade MCTs

38
Q

What is the MOA of palladia?

A

To shut of the KIT, VEGFR, and PDGFR receptors

39
Q

True or False: Palladia is FDA-approved for use in cats with MCT

A

False - dogs with MCT

40
Q

What does the Tigilanol tiglate intratumoral injection do?

A

PKC activator

41
Q

What are the supportive therapy considerations for MCT?

A

H1 blocker, H2 blocker, (or) Proton-pump inhibitor (PPI)
Antiemetic
Appetite stimulant

42
Q

What H1 blockers can you use for MCT patients?

A

Diphenhydramine and cetirizine

43
Q

What H2 blockers can you use for MCT patients?

A

Famotidine and ranitidine

44
Q

What PPIs can you use for MCT patients?

A

Omeprazole

45
Q

What antiemetics can you use for MCT patients?

A

Maropitant and ondansetron

46
Q

What appetite stimulants can you use for MCT patients?

A

Capromorelin

47
Q
  • Mutation of which gene/receptor is associated with a more guarded prognosis and worse clinical outcome for dogs with mast cell tumors?
    a. BRAF
    b. C-KIT
    c. VEGF
    d. PDGF
A

b. C-KIT

48
Q

What is the general recommendation for feline mast cell neoplasias?

A

surgical excision

49
Q

What is the median age for cutaneous SCC diagnosis?

A

10-11 years

50
Q

What anatomic locations have a predilection for cutaneous SCC?

A

Head/nasal planum and ventral abdomen

51
Q

What is the recommended treatment for cutaneous SCC?

A

Surgical when feasible
+/- radiation therapy
+/- chemotherapy

52
Q

What is the most common digital tumor?

A

digital SCC

53
Q

How is digital SCC treated?

A

Primarily surgical +/- chemotherapy

54
Q

What is the prognosis for digital SCC?

A

1-year survival (50-83%)

2-year survival (18-62%)

55
Q

Melanomas involving ________ often behave in a benign manner.

A

haired skin

56
Q

How is cutaneous/dermal melanoma treated?

A

Surgical excision is often curative - histopathological evaluation is important

57
Q

What is the second most common digital tumor?

A

digital malignant melanoma

58
Q

True or False: Metastasis is more common in digital SCC patients than in digital melanoma patients.

A

False - it is more common in digital melanoma patients

59
Q

What is the recommended treatment for digital malignant melanoma?

A

Primarily surgical +/- immunotherapy

60
Q

What is the prognosis for digital malignant melanoma?

A

1 year survival - 42-57%

2 year survival - 13-36%

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