20 - 113: MERKEL CELL CARCINOMA Flashcards
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 A p.1920
Which of the following clinical features of MCC is not incorrect?
I. Asymmetry
J. Expanding
K. Immune suppression
L. Older than 50
Answer A p.1921
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 A p1921
True or false. Sun exposure is NOT required in the development of MCC
O. True
P. False
Answer A p1923
In immunohistochemical staining, MCC is positive for _____ .
Q. CK7
R. CK20
S. TTF-1
T. S-100
Answer B p.1926
MCPyV is present in ____ of MCC tumors
U. 70%
V. 80%
W. 90%
X. 100%
Answer B p1923
True or false. MCPyV positivity has worse outcomes.
Y. True
Z. False
Answer B p1929
Which among these neoplasias is an unusually radiosensitive tumor?
A. SCC B. BCC C. MCC D. EMPD
Answer C p 1929
In general, optimal treatment of MCC should involve obtaining pathologically clear margins by surgery, typically with _____ margins if possible, depend- ing on the site.
1-2 cm
What is the most commonly used chemotherapeutic regimen for MCC?
Etoposide + cisplatin or carboplatin
The risk of death from Merkel cell carcinoma (MCC) is how many times higher than melanoma?
2 to 3x
Risk factors for MCC
- Advanced age (Age greater than 65 years)
- Sun exposure
- Immune suppression
what virus is associated with MCC?
■ Merkel cell polyomavirus (MCPyV)
enumerate the AEIOU features of MCC
If a lesion exhibits at least 3 of these features, suspicion of MCC should increase, and biopsy of the lesion is indicated.`
what are the most common initial clinical impression of clinicians for MCC?
Cyst or acneiform lesion
MCPyV was reported to be present in _______ of MCC tumors compared to only 7% of skin controls.
80%
the only virus proven to integrate into and be causal for human cancer
Merkel cell polyomavirus (MCPyV)
pathognomonic pattern of staining of CK20
“perinuclear dot pattern”
Three histologic patterns of MCC
- intermediate type
- small cell type
- trabecular type
most common histologic type of MCC
intermediate type
This histologic type features uniform small cells with minimal cytoplasm, pale nuclei, and a dispersed chromatin appearance.
intermediate type
This histologic type shows irregular, hyperchromatic cells with scant cytoplasm and malignant cells that are arranged in linear patterns infiltrating stromal structures.
small cell type
This histologic type is the least common, but perhaps most histologically distinctive type
trabecular type
This histologic type has a lattice-like, or network appearance, and the differential diagnosis includes metastatic carcinoid tumor.
Trabecular type
the most useful immunohistochemical stain for MCC
Cytokeratin-20
This stain typically reacts with both MCC and small-cell lung carcinoma
CAM5.2
These stains are negative in MCC and positive in small-cell lung cancer
THYROID TRANSCRIPTION FACTOR1
Cytokeratin-7
MCC tumor tissue may be tested for the MCPyV oncoprotein using what antibody
CM2B4 antibody
- specific for MCC, rather than other tumors
excellent tool for determining if an MCC is virally induced or not
CM2B4 antibody
- specific for MCC, rather than other tumors
tumor emboli within vascular spaces is called
LYMPHOVASCULAR INVASION
- worse overall survival
T/F.
MCPyV positivity tends to be associated with worse outcomes
FALSE
MCPyV positivity tends to be associated with better outcomes
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
downregulated
- survival was improved in MCC patients whose tumors had higher vascular E-selectin expression
T/F: The higher vascular E-selectin expression, the better the survival outcomes.
TRUE
T/F: Transformation-related/tumor protein 63 negativity is associated with less aggressive clinical course.
TRUE
In 2 studies, cases that were positive for p63 demonstrated a more aggressive clinical course than those that were negative
T/F.
MCC is an unusually radioresistant tumor.
FALSE
MCC is an unusually radiosensitive tumor.
the most significant potential side effect of radiotherapy
lymphedema
an anti–programmed death 1 antibody
Pembrolizumab
T/F. Adjuvant chemotherapy is recommended for patients whose MCC has been treated with surgery, radiation therapy, or both.
FALSE
There are 6 reasons why we do not recommend adjuvant chemotherapy:
- Mortality: There is a 4% to 7% acute death rate from adjuvant chemotherapy in MCC partly because these patients are often elderly.12,35
- Morbidity: Neutropenia is reported to occur in 60% of patients with fever, and sepsis in 40%.36
- Decreased quality of life: This can be quite severe in this older population, including fatigue, hair loss, nausea, and vomiting.
- Resistance to chemotherapy: MCC that recurs after chemotherapy is less responsive to later palliative chemotherapy.
- Immunity: Chemotherapy suppresses immune function, and this is known in general to be very important in preventing and controlling
- 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.
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.
- clinical examination every 3 to 6 months for the first 2 years after diagnosis
- every 6 to 12 months thereafter
adjuvant radiation therapy for MCC patients is not recommended if all of these good prognostic features are present
(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.
