Chapter 120 Merkel Cell Carcinoma

Question 1

there is a five to tenfold increase in incidence after age

Answer 1

70

Question 2

Multiple forms of immune suppression are associated with an increasein MCC risk. These include ___, ___, ___

Answer 2

HIV/AIDS, chronic lymphocytic leukemia, and the immune suppressive regimens associated with solid organ transplant

Question 3

_____ was reported to be present in 80% of MCC tumors compared to only 7% of skin controls

Answer 3

MCPyV

Question 4

characterized clinical features

If a lesion exhibits ____ of these features, suspicion of MCC should increase and biopsy be considered

Answer 4

Asymptomatic (non-tender, firm, red, purple, or skin-colored papule or nodule; ulceration is rare)

Expanding rapidly (significant growth noted within 1–3 months of diagnosis, but most lesions are <2 cm at time of diagnosis)

Immune suppression (HIV/AIDS, chronic lymphocytic leukemia, solid organ transplant)

Older than 50 years
Ultraviolet-exposed site on a person with fair skin (most likely presentation, but can also occur in sun-protected areas)

at least three

Question 5

_______ is a very common feature and often can be found when it is specifically searched for even in a “negative” margin

Answer 5

Lymphovascular invasion

Question 6

Hematoxylin and eosin staining:

The most common type is the _____

Answer 6

intermediate type

- uniform small cells with minimal cytoplasm, pale nuclei, and a dispersed chromatin appearance

Question 7

Hematoxylin and eosin staining:

The second most common pattern is the ____

Answer 7

small cell type
- irregular, hyperchromatic cells with scant cytoplasm and malignant cells that are arranged in linear patterns infiltrating stromal structures

Question 8

Hematoxylin and eosin staining:

The least common but perhaps most histologically distinctive type is the ____

Answer 8

trabecular type

• lattice-like, or network appearance
• differential diagnosis includes metastatic carcinoid tumor

Question 9

This intermediate lament protein is expressed in MCC as well as in adenocarcinomas of the colon, stomach, and pancreas

Answer 9

cytokeratin 20
(“perinuclear dot” pattern of cytokeratin is essentially pathognomonic for MCC)

Question 10

_____ detects multiple human cytokeratin epitopes, typically reacts with both MCC and small cell lung carcinoma

Answer 10

CAM5.2 (cocktail of antibodies)

Question 11

MCC recurs rapidly with ∼80% of recurrences occurring within

Answer 11

2 years of diagnosis

Question 12

______ has become quite common in staging malignant melanoma presenting with a depth of greater than 1 millimeter

Answer 12

sentinel lymph node biopsy (SLNB)

- performed at the time of the wide resection

Question 13

______ for patients presenting with more advanced disease, such as positive nodal involvement or clinical evidence of metastatic disease.

Answer 13

CT or PET-CT scans

Question 14

define lymphovascular invasion (LVI)

Answer 14

tumor emboli within vascular spaces

*MCC tumors with detectable LVI had a worse overall survival

Question 15

Tumor growth pattern was described as _____ (well-circumscribed interface between tumor and surrounding tissue) or ____ (rows, trabeculae, or single cells that penetrate the dermis)

Answer 15

nodular
infiltrative

*infiltrative tumor growth pattern was associated with poor outcomes as compared to MCC tumors with a nodular growth pattern

Question 16

___________ followed by __________ is a reasonable approach to management in many cases

Answer 16

Excision with narrow but clear margins (carried out at the time of SLNB)
adjuvant radiation therapy

Question 17

regional control rates were 100% for each modality (___ and ____) and the combination of radiation and surgery to the lymph node bed greatly increases risk of ______

Answer 17

Completion lymphadenectomy and radiation therapy

chronic lymphedema

Question 18

Adjuvant radiation clearly is critical if __________ or if microscopic margins are __________

Answer 18

surgical margins are positive
relatively narrow (<0.5 cm)

Question 19

The typical doses of radiation for MCC are ________ for a primary site with negative excision margins.

Answer 19

50–56 Gy

Question 20

Radiation doses are typically given in _______________

Answer 20

2-Gy fractions, five times/week over 4–6 weeks

Question 21

Chronic radiation skin changes include temporary or permanent ____ within the irradiated field, ______, loss of adnexal structures leading to _______, and risk of subsequent _________ in the irradiated region in patients

Perhaps the most significant potential side effect is _____

Answer 21

alopecia
epidermal atrophy
skin or mucosal dryness
secondary skin cancers (with a life expectancy of greater than 20 years after the radiation treatment)

lymphedema

Question 22

The most commonly used chemotherapeutic regimen for MCC is the combination of _____ and either _____ or _______

Answer 22

etoposide PLUS
cisplatin (perhaps more clinically effective)
carboplatin (less nephrotoxic)

Question 23

optimal treatment for MCC should involve obtaining pathologically clear margins by surgery, typically with ______ as possible, depending on the site

Answer 23

1- to 2-cm margins

Question 24

Although still controversial, we currently do not recommend adjuvant radiation therapy for MCC patients with all of the following five good prognostic

Answer 24

(1) primary tumor diameter ≤1 cm;
(2) microscopic margins that are confidently negative following surgery;
(3) no lymphovascular invasion noted in the tumor;
(4) no profound immune suppression (HIV, chronic lymphocytic leukemia, etc.); and
(5) SLNB that was negative with proper immunohistochemistry studies.

Question 25

The most common site of recurrence is the ___ or ___.
For those who have recurrences, the locations and frequencies are ___, ____, ____, lung (10%), bone (10%), brain (6%), bone marrow (2%), pleura (2%), and other sites (4%).

Answer 25

draining nodal basin or adjacent skin

skin (28%), lymph nodes (27%), liver (13%)