Derm 1 Flashcards
T/F- melanocytes are absent in albinism?
False, melanocytes are present but do not make melanin properly
What is the mutation responsible for albinism?
Tyrosinase mutations
In vitiligo, are melanocytes present or absent?
absent
what is the average age of onset in vitiligo?
20 yrs
Lentigo presents with brown macules but no seasonal variation. Are melanocyte numbers changed or is melanin production changed?
melanocyte numbers are increased
In a compound nevus, nests are present in the dermal epidermal junction and in the ______.
dermis
in a dermal nevus, the cells are confined to what layer?
dermis
With a giant congenital nevus, what is a concern in infants?
risk of CNS involvement when located on the head and neck, and an approximately 5% risk of melanoma
A blue nevus, what is the color from?
dermal pigment
What will you see in the dermis of a blue nevus histologically?
spindled melanocytes and melanophages
A dysplastic nevus is also called what?
atypical or clarks nevus
T/F- multiple dysplastic nevi are a marker for increased risk of melanoma
true
Name 3 characteristic features of a dysplastic nevus
- melanocytes show “atypia” and bridge across rate bridges
- dermal fibroplasia is seen in the papillary dermis
- epidermal component extends beyond the dermal component “shouldering”
Do white males or females get more melanoma?
males
Name environmental risk factors for melanoma (5)
- intense intermittent sun exposure
- chronic sun exposure
- tanning bed use
- immunosuppression
- live near equator
What is the median age of diagnosis of melanoma?
57
Name the most common type of malignant melanoma which starts with intraepidermal disease and then invades
superficial spreading type
T/F- the nodular type of melanoma is invasive from onset so prognosis is poorer because patients present with deeper tumors.
true
Name they type of melanoma that is especially common in elderly patients and has a prolonged inset phase and is usually >3 cm
lentigo maligna melanoma
If you have melanoma on your foot what is it called? Which ethnic group gets it the most? How’s the prognosis?
- acral lentiginous melanoma
- risk not stratified by ethnic pigmentation
- presents with thick lesions so poor prognosis
What two genetic mutations are most common in non-chronically sun damaged skin (CSD)?
BRAF>KIT
What genetic mutation predominates in CSD, acral, and mucosal melanomas?
KIT
Are BRAF mutations common in normal nevi as well?
yes
What is pagetoid spread?
upward spreading of melanocytes in melanoma
Review clark levels for melanomas
I: In situ II: Invades papillary dermis III: Expands, but confined to papillary dermis IV: Invades reticular dermis V: Invades fat
What is breslow depth as it relates to melanomas?
- Microscopic measurement from the granular layer of the epidermis to the point of deepest tumor invasion
- Most important prognostic factor
What is the basal cell carcinoma to squamous cell carcinoma ratio in immunocompetent normal people?
20:1 BCC/SCC
Which type of skin cancer is more common in immunosuppressed people?
SCC > BCC
Over 90% of basal cell carcinomas occur where?
head and neck
T/F- basal cell carcinoma is not related to chronic sun exposure?
False, it is
Do BCC’s metastasize often?
no
T/F- actinic keratosis presents with scaly papules on SUN EXPOSED skin and a small percentage will develop into invasive SCC
true
What is the primary risk factor for SCC?
ultraviolet light exposure
What percentage of SCCs metastasize?
5%
What areas of body have increased risk of SCC?
ear, lip, genitalia
BCC occurs on _____ lip and SCC occurs on ______ lip
BCC: upper lip
SCC: lower lip
