20 - 113: MERKEL CELL CARCINOMA

Question 1

Which of the following is false regarding Merkel Cell Carcinoma?

A. It is more common in women

B It is more common among white individuals

C. Men have worse prognosis

D. UV radiation has a role in its pathogenesis

Answer 1

Answer A p.1920

Question 2

Which of the following clinical features of MCC is not incorrect?

I. Asymmetry

J. Expanding

K. Immune suppression

L. Older than 50

Answer 2

Answer A p.1921

Question 3

True or false. MCC patients presenting without an identifiable primary lesion—”unknown primary”—have better outcomes than similarly staged patients with known primary tumors

M. True

N. False

Answer 3

Answer A p1921

Question 4

True or false. Sun exposure is NOT required in the development of MCC

O. True

P. False

Answer 4

Answer A p1923

Question 5

In immunohistochemical staining, MCC is positive for _____ .

Q. CK7

R. CK20

S. TTF-1

T. S-100

Answer 5

Answer B p.1926

Question 6

MCPyV is present in ____ of MCC tumors

U. 70%

V. 80%

W. 90%

X. 100%

Answer 6

Answer B p1923

Question 7

True or false. MCPyV positivity has worse outcomes.

Y. True

Z. False

Answer 7

Answer B p1929

Question 8

Which among these neoplasias is an unusually radiosensitive tumor?

A. SCC B. BCC C. MCC D. EMPD

Answer 8

Answer C p 1929

Question 9

In general, optimal treatment of MCC should involve obtaining pathologically clear margins by surgery, typically with _____ margins if possible, depend- ing on the site.

Answer 9

1-2 cm

Question 10

What is the most commonly used chemotherapeutic regimen for MCC?

Answer 10

Etoposide + cisplatin or carboplatin

Question 11

The risk of death from Merkel cell carcinoma (MCC) is how many times higher than melanoma?

Answer 11

2 to 3x

Question 12

Risk factors for MCC

Answer 12

1. Advanced age (Age greater than 65 years)
2. Sun exposure
3. Immune suppression

Question 13

what virus is associated with MCC?

Answer 13

■ Merkel cell polyomavirus (MCPyV)

Question 14

enumerate the AEIOU features of MCC

Answer 14

If a lesion exhibits at least 3 of these features, suspicion of MCC should increase, and biopsy of the lesion is indicated.`

Question 15

what are the most common initial clinical impression of clinicians for MCC?

Answer 15

Cyst or acneiform lesion

Question 16

MCPyV was reported to be present in _______ of MCC tumors compared to only 7% of skin controls.

Answer 16

80%

Question 17

the only virus proven to integrate into and be causal for human cancer

Answer 17

Merkel cell polyomavirus (MCPyV)

Question 18

pathognomonic pattern of staining of CK20

Answer 18

“perinuclear dot pattern”

Question 19

Three histologic patterns of MCC

Answer 19

1. intermediate type
2. small cell type
3. trabecular type

Question 20

most common histologic type of MCC

Answer 20

intermediate type

Question 21

This histologic type features uniform small cells with minimal cytoplasm, pale nuclei, and a dispersed chromatin appearance.

Answer 21

intermediate type

Question 22

This histologic type shows irregular, hyperchromatic cells with scant cytoplasm and malignant cells that are arranged in linear patterns infiltrating stromal structures.

Answer 22

small cell type

Question 23

This histologic type is the least common, but perhaps most histologically distinctive type

Answer 23

trabecular type

Question 24

This histologic type has a lattice-like, or network appearance, and the differential diagnosis includes metastatic carcinoid tumor.

Answer 24

Trabecular type

Question 25

the most useful immunohistochemical stain for MCC

Answer 25

Cytokeratin-20

Question 26

This stain typically reacts with both MCC and small-cell lung carcinoma

Answer 26

CAM5.2

Question 27

These stains are negative in MCC and positive in small-cell lung cancer

Answer 27

THYROID TRANSCRIPTION FACTOR1
Cytokeratin-7

Question 28

MCC tumor tissue may be tested for the MCPyV oncoprotein using what antibody

Answer 28

CM2B4 antibody
- specific for MCC, rather than other tumors

Question 29

excellent tool for determining if an MCC is virally induced or not

Answer 29

CM2B4 antibody
- specific for MCC, rather than other tumors

Question 30

Question 31

tumor emboli within vascular spaces is called

Answer 31

LYMPHOVASCULAR INVASION
- worse overall survival

Question 32

T/F.
MCPyV positivity tends to be associated with worse outcomes

Answer 32

FALSE

MCPyV positivity tends to be associated with better outcomes

Question 33

Intratumoral vascular E-selectin, critical for T-cell entry into skin, was __________________ (upregulated/ downregulated?) in the majority (52%) of MCCs and its loss was associated with poor intratumoral CD8 lymphocyte infiltration

Answer 33

downregulated

• survival was improved in MCC patients whose tumors had higher vascular E-selectin expression

Question 34

T/F: The higher vascular E-selectin expression, the better the survival outcomes.

Answer 34

TRUE

Question 35

T/F: Transformation-related/tumor protein 63 negativity is associated with less aggressive clinical course.

Answer 35

TRUE

In 2 studies, cases that were positive for p63 demonstrated a more aggressive clinical course than those that were negative

Question 36

T/F.
MCC is an unusually radioresistant tumor.

Answer 36

FALSE

MCC is an unusually radiosensitive tumor.

Question 37

the most significant potential side effect of radiotherapy

Answer 37

lymphedema

Question 38

an anti–programmed death 1 antibody

Answer 38

Pembrolizumab

Question 39

T/F. Adjuvant chemotherapy is recommended for patients whose MCC has been treated with surgery, radiation therapy, or both.

Answer 39

FALSE

There are 6 reasons why we do not recommend adjuvant chemotherapy:

1. Mortality: There is a 4% to 7% acute death rate from adjuvant chemotherapy in MCC partly because these patients are often elderly.12,35
2. Morbidity: Neutropenia is reported to occur in 60% of patients with fever, and sepsis in 40%.36
3. Decreased quality of life: This can be quite severe in this older population, including fatigue, hair loss, nausea, and vomiting.
4. Resistance to chemotherapy: MCC that recurs after chemotherapy is less responsive to later palliative chemotherapy.
5. Immunity: Chemotherapy suppresses immune function, and this is known in general to be very important in preventing and controlling
6. Outcomes are not improved: A large analysis of 6908 patients from the National Cancer Database demonstrated no survival benefit among nodepositive patients who received chemotherapy as compared to those who did not. Even though this was a not randomized study, the results certainly do not suggest a clinically meaningful benefit for adjuvant chemotherapy.

Question 40

for the surverillance of MCC, current guidelines include relatively general recommendations for clinical examination every ____ months for the first _____ years after diagnosis, and every_______ months thereafter.

Answer 40

• clinical examination every 3 to 6 months for the first 2 years after diagnosis
• every 6 to 12 months thereafter

Question 41

adjuvant radiation therapy for MCC patients is not recommended if all of these good prognostic features are present

Answer 41

(a) primary tumor diameter ≤1 cm;
(b) microscopic margins that are confidently negative following surgery;
(c) no lymphovascular invasion noted in the tumor;
(d) no profound immune suppression (eg, HIV, chronic lymphocytic leukemia); and
(e) SLNB that was negative with proper immunohistochemistry studies.

Question 42