Chapter 120 Merkel Cell Carcinoma Flashcards
there is a five to tenfold increase in incidence after age
70
Multiple forms of immune suppression are associated with an increasein MCC risk. These include ___, ___, ___
HIV/AIDS, chronic lymphocytic leukemia, and the immune suppressive regimens associated with solid organ transplant
_____ was reported to be present in 80% of MCC tumors compared to only 7% of skin controls
MCPyV
characterized clinical features
If a lesion exhibits ____ of these features, suspicion of MCC should increase and biopsy be considered
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
_______ is a very common feature and often can be found when it is specifically searched for even in a “negative” margin
Lymphovascular invasion
Hematoxylin and eosin staining:
The most common type is the _____
intermediate type
- uniform small cells with minimal cytoplasm, pale nuclei, and a dispersed chromatin appearance
Hematoxylin and eosin staining:
The second most common pattern is the ____
small cell type
- irregular, hyperchromatic cells with scant cytoplasm and malignant cells that are arranged in linear patterns infiltrating stromal structures
Hematoxylin and eosin staining:
The least common but perhaps most histologically distinctive type is the ____
trabecular type
- lattice-like, or network appearance
- differential diagnosis includes metastatic carcinoid tumor
This intermediate lament protein is expressed in MCC as well as in adenocarcinomas of the colon, stomach, and pancreas
cytokeratin 20 (“perinuclear dot” pattern of cytokeratin is essentially pathognomonic for MCC)
_____ detects multiple human cytokeratin epitopes, typically reacts with both MCC and small cell lung carcinoma
CAM5.2 (cocktail of antibodies)
MCC recurs rapidly with ∼80% of recurrences occurring within
2 years of diagnosis
______ has become quite common in staging malignant melanoma presenting with a depth of greater than 1 millimeter
sentinel lymph node biopsy (SLNB)
- performed at the time of the wide resection
______ for patients presenting with more advanced disease, such as positive nodal involvement or clinical evidence of metastatic disease.
CT or PET-CT scans
define lymphovascular invasion (LVI)
tumor emboli within vascular spaces
*MCC tumors with detectable LVI had a worse overall survival
Tumor growth pattern was described as _____ (well-circumscribed interface between tumor and surrounding tissue) or ____ (rows, trabeculae, or single cells that penetrate the dermis)
nodular
infiltrative
*infiltrative tumor growth pattern was associated with poor outcomes as compared to MCC tumors with a nodular growth pattern
___________ followed by __________ is a reasonable approach to management in many cases
Excision with narrow but clear margins (carried out at the time of SLNB)
adjuvant radiation therapy
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 ______
Completion lymphadenectomy and radiation therapy
chronic lymphedema
Adjuvant radiation clearly is critical if __________ or if microscopic margins are __________
surgical margins are positive relatively narrow (<0.5 cm)
The typical doses of radiation for MCC are ________ for a primary site with negative excision margins.
50–56 Gy
Radiation doses are typically given in _______________
2-Gy fractions, five times/week over 4–6 weeks
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 _____
alopecia
epidermal atrophy
skin or mucosal dryness
secondary skin cancers (with a life expectancy of greater than 20 years after the radiation treatment)
lymphedema
The most commonly used chemotherapeutic regimen for MCC is the combination of _____ and either _____ or _______
etoposide PLUS
cisplatin (perhaps more clinically effective)
carboplatin (less nephrotoxic)
optimal treatment for MCC should involve obtaining pathologically clear margins by surgery, typically with ______ as possible, depending on the site
1- to 2-cm margins
Although still controversial, we currently do not recommend adjuvant radiation therapy for MCC patients with all of the following five good prognostic
(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.
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%).
draining nodal basin or adjacent skin
skin (28%), lymph nodes (27%), liver (13%)
