CM: Derm Malignancy

Question 1

What are risk factors for non-melanoma skin cancers (BCC and SCC)?

Answer 1

UV radiation
fair skin, light hair, blue eyes
immunosuppression - transplant pts, leukemia/lymphoma
HPV inf
exposure to chemical carcinogens, ionizing radiation
hx of prior skin cancer
chronic irritation, inflammation, scar
genetics - albinism (absent melanin), xeroderma pigmentosum (defective repair of UV DNA damage)

Question 2

What are risk factors for melanoma?

Answer 2

fair skin, blue eyes, blond or red hair
UV radiation
precursor lesion - dysplastic nevus, congenital or other type of nevus - 1/3 develop from these
family hx - P16 mutation, melanocytic nevi >50, dysplastic nevus syndrome
prior skin cancer
immunosuppression
response to UV light: inability to tan, nonfacial freckling (solar lentigines)

Question 3

What are the different types of BCC?

Answer 3

nodular type
superficial type
sclerotic or morpheaform type
pigmented type

Question 4

What are the features of the nodular type of BCC?

Answer 4

dome shaped, pearly or flesh colored papule or nodule w telangiectasia, center may be ulcerated, rolled border
aggregates of basaloid cells contiguous w epidermis
large nuclei and scant cytoplasm
palisading cells in periphery

Question 5

What are the features of the superficial type of BCC?

Answer 5

erythematous scaly patch w irregular borders - can be mistaken for eczema
trunk and extremities, rarely ulcerates
basaloid neoplastic cells extending from under surface of epidermis
grows in horizontal or radial fashion in lower epidermis and upper dermis

Question 6

What are the features of the sclerotic or morpheaform type of BCC?

Answer 6

white plaque or macular scar like lesion
no connection to epidermis - cords, strands, small nests of basaloid cells in fibrotic stroma
much more aggressive type - require Mohs surgery to decrease recurrence

Question 7

What are the features of the pigmented type of BCC?

Answer 7

dark colored, often mis-diagnosed as melanoma
grow slowly but can expand to involve skin and underlying collagen and bone
usually asymptomatic, can ulcerate and bleed after minor trauma
similar histology to nodular type w abundant melanin

Question 8

What are the basic clinical features of BCC in general?

Answer 8

85% on head and neck
25% on nose = most common site
metastasis is rare

Question 9

What are the precursor lesions of SCC?

Answer 9

actinic keratoses = hyperkeratotic papules or plaques usually on sun-exposed skin
asymptomatic, but can be peeled and tend to recur
focal atypical keratinocyte proliferation confined to epidermis w overlying parakeratosis, spare adnexal structures
can arise from chronic scars or ulcers, or areas previously exposed to radiation

Question 10

What are the different forms of SCC in situ?

Answer 10

bowens dz: scaly plaque w scalloped border, arsen ingestion
erythroplasia of queyrat: bright erythematous plaque, usually on glans penis, esp if uncircumcised
erythroplakia and leukoplakia: bright erythematous or white hyperkeratotic plaques in oral cavity

Question 11

What are the features of invasive SCC?

Answer 11

hyperkeratotic indurated papule or plaque
may ulcerate
often have surrounding erythema
can grow quickly and metastasize

Question 12

What is the histology of invasive SCC?

Answer 12

basal zones of full thickness atypical keratinocyte proliferation w invasion into dermis and varying hyperkeratosis, parakeratosis, and acantholysis
inflammatory dermal infiltrates

Question 13

What are keratoacanthomas?

Answer 13

nodules/plaques with well-defined hyperkeratotic core
histologically similar to SCC but benign
if aggressive - treat w surgery like SCC

Question 14

What is the histology of keratoacnathomas?

Answer 14

exo-endophytic keratinocyte proliferation w central crater or fibrotic base w abscess formation

Question 15

What features should you look out for in melanoma?

Answer 15

ABCDE
Asymmetry
Border irregularity
Color
Diameter (greater than 6 mm is suspicious)
Evolving

Question 16

What growth pattern does most melanoma exhibit?

Answer 16

biphasic - first horizontally w/i epidermis, then later vertically into dermis
if removed during horizontal phase - risk of metastasis reduced
if vertical - greater chance of spreading to vasculature

Question 17

What is the most important prognostic factor in melanomas?

Answer 17

depth of melanoma
in situ - restricted to epidermis
invasive - extends at least into dermis
measured by Breslow depth

Question 18

What are the clinical subtypes of melanoma?

Answer 18

superficial spreading melanoma: horizontal growth for a while before vertical
lentigo maligna: subtype of in situ arising on sun-damaged, freckled skin, broad macular lesion
acral lentiginous melanoma: subungual or periungual
nodular melanoma
nodular melanoma: very aggressive, only vertical phase, often extends above surface of skin

Question 19

What is the histology of melanoma in situ?

Answer 19

melanocytes scattered throughout all levels of epidermis rather than just in basal layer

Question 20

What is solar lentigo?

Answer 20

sun freckles, liver spots, age spots

Question 21

What is a melanocytic nevus?

Answer 21

mole, benign neoplasm of melanocytes

Question 22

What are the different types of nevuses?

Answer 22

junctional - flat, tan-medium brown, uniform pigment and regular border, melanocytes at dermoepidermal jxn
compound nevus - brown dome-shaped papule w uniform pigment and regular border, melanocytes at dermoepidermal jxn and in dermis
congenital - larger than acquired, raised and pigmented, maybe some hair, giant have increased rate of nevi

Question 23

What is a dysplastic nevus?

Answer 23

multiple nevi w one or more ABCDs
fried egg appearance w darker center (or lighter)
increased risk for melanoma if also family hx