Skin Cancer

Question 0

Leser-trelat sign

Answer 0

• Explosive development of brown papules

- Paraneoplastic syndrome

Question 1

• Brown “stuck on” papule that well circumscribed

- immature bland basaliloid keratinocytes with hyperkeratotosis acanthosis, keratin filled horn cysts

Answer 1

• seborrheic keratosis

- activating mutation in FGF-3

Question 2

• Soft, flesh colored, bag-like polyp

- fibrovascular covered by normal tissue

Answer 2

• acrochondron (skin tag, fibroepithelial)

Question 3

Well demarcated papule with central punctum

- recapitulate hair follicle

Answer 3

• epidermoid cysts ( aka sebaceous cyst)

- cyst will recur if entire lining is not excised

Question 4

Cyst with a stratified squamous cell layer that includes granular layer

Answer 4

Epidermoid cyst

- many call them sebaceous cysts

Question 5

Cyst with a stratified squamous cell layer that doesn’t include granular layer

Answer 5

Pilar cyst

Question 6

• Lesion of disorganized keratinocytes in the lower layers of epidermis
• does not involve full thickness of epidermis

Answer 6

• actinic keratosis

- premalignant: can turn into squamous cell carcinoma

Question 7

• Full thickness dysplasia

- irregular hyper chromatic nuclei

Answer 7

Squamous Carcinoma in situ

• excision is curative
• sun exposure is number 1 risk factor

Question 8

• Cup shaped lesion with central crater

- dome shaped nodule with central crater and keratin plug

Answer 8

Keratoacanthoma

Question 9

Most common skin carcinoma
Ulcer with rolled boarder or pink pearly papule with talengectasia
Slow growing, circumscribed

Answer 9

Basal cell carcinoma

Question 10

Gorlin syndrome

Answer 10

• nevoid basal cell carcinoma syndrome
• PTCH mutation (9:22)
• two hit pathology

Question 11

Lentigo vs. freckle

Answer 11

• lentigo: darker, doesn’t darken in sun, larger, includes mucous membrane
• freckle: smaller, darkens in sun, lighter, not on mucous membranes

Question 12

Nevi

Answer 12

• p16/INK4a, CDNK2 mutation
• benign
• moles
• melanocytes Nevis: nests of melanocytes in basal epidermis
• compound Nevis: junctional and intra dermal nests of melanocytes

Question 13

Fused nests of atypical melanocytes between rete pegs

Linear lamellar fibrosis of papillary dermis

Answer 13

Dysplastic Nevus

Question 14

Risk factors for malignant melanoma (genetic and environmental)

Answer 14

• CDNK2a gene mutation
• RAS/BRAF and PI3K
• sun exposure, lightly pigmented, giant congenital nevi

Question 15

Atypical melanocytes within epidermis, esp migrating in stratum spinosum, confluent single melanocytes at basal layer

Answer 15

Melanoma-in-situ

Question 16

Dysplastic melanocytes involve epidermis and invade the dermis

Answer 16

Malignant Melanoma

Question 17

Vertical growth down into dermis

Answer 17

• primary prognostic factor
• increases the risk in localized melanoma
• Breslow thickness (measured from granular layer)

Question 18

Tan-brown-red firm papule commonly on extremities

Fibroblasts and foamy histeocytes trap individual collagen bundles at periphery

Answer 18

Benign fibrous histyocytoma

Question 19

Condition involving optic gliomas and pigmented Hartomas in iris, cafe-au-lait spots on skin

Answer 19

Neurofibroma (NF-1: loss of RAS)

AD

Question 20

Cafe-au-lait spots without but no lisch nodules in the iris

Answer 20

NF-2

Question 21

Plexiform rubbery mass

Answer 21

NF tumor

Question 22

Firm solid nodule/plaque on trunk, uniform spindle cells/storiform fascicles invading subcubitus

Answer 22

Dermatofibrosarcoma protuberans

- unlikely to metastasize -> Fibrosarcoma may metastasize

Question 23

Chronic non-healing lesions on trunk

• atypical T cell infiltration with cerebriform nuclei
• beads on a string lining up on DE junction

Answer 23

Mycoses fungoides

• prognosis depends on % body coverage
• moves into blood -> sezary syndrome

Question 24

Dome shaped papules on nodules and forehead | - jigsaw like puzzle islands of basaloid cells with small ductal lumen and surrounding hyaline sheath

Answer 24

Cyclindroma, turban tumors

Question 25

Slow-growing flesh colored papule on head and neck of older adults - well circumscribed dermal nodule of sebocytes and outer layer if basaloid germanitive cells

Answer 25

Sebaceous Adenoma | - may be associated with HNPCC

Question 26

Solitary asymptomatic skin colored papules on face | - associoated with PTEN mutation

Answer 26

- trichilemmomas

Question 27

Tumor suppressor genes associated with skin cancer (2)

Answer 27

- p53 | - PTCH

Question 28

Solar elastosis

Answer 28

- elastic fibers get damaged and become disorganized | - not full thickness

Question 29

Insitu Squamous vs actinic keratosis

Answer 29

- generally size | - squamous cell is also full thickness with basal layer is intact (in situ)

Question 30

Sunlight damage

Answer 30

- UV -> pyrimidine dimers -> p53 activation (most common mutation in people who develop SCC) -> arrest cell division and corrupt cell dies - chronic immunosuppression increases risk factors - long term chronic lesion also increases risks

Question 31

Large light pink keratinocytes in well circumscribed cup

Answer 31

- keratoacanthoma

Question 32

BCC transformation

Answer 32

- main issue is damage to local tissue | - BCC rarely metastasize (.5%)

Question 33

BCC pathenogenesis (3 options)

Answer 33

- most are sporadic p53 mutation - 30% are PTCH - gorlin syndrome: Nevoid BCC, one hit mutation in all cells

Question 34

Long thin rete pegs, non-nested single large myelocytes

Answer 34

- lentigo

Question 35

BRAF-RAS path mutation

Answer 35

- Nevus | - often accumulates p16 (melanoma have decreased)

Question 36

Nests of melanocytes

Answer 36

Nevus | - junctional-> compound -> intradermal

Question 37

Decreased p16/ increase in RAS -> increase in BRAF

Answer 37

- associated with malignant melanoma

Question 38

17q11 - NF1 - eyes

Answer 38

RAS mutation | - plexiform

Question 39

22q11 | - acoustic fibromas

Answer 39

- NF2 | - no lisch nodules

Question 40

Mycoses fungoides prognosis

Answer 40

- % body coverage | - stage (patch, plaque, nodule)

Question 41

Pautrier abcess

Answer 41

- mycoses fungoides | - lymphocytes infiltrating

Question 42

Association with lynch syndrome

Answer 42

- sebaceous Adenoma

Question 43

Oncogenes tumor suppressor genes

Answer 43

- oncogenes: Dominant expression, gain of function (kinases, GFs et al) - tumor suppressors: (p53, PTCH) resistive expression, loss of function

Question 44

Bowen's syndrome

Answer 44

- squamous cell carcinoma in situ | - unlike Actinic keratosis (which rarely transforms), Bowens transforms in 26 % of cases

Question 45

Trt of AK

Answer 45

5-FU: lights up areas affected

Question 46

Eminems CD is Not Killer

Answer 46

Malignant melanoma | - CDNK2a

Question 47

Gore PiTCHed his Nevil scheme in Philadelphia

Answer 47

Nevoid basal cell carcinoma: gorlin syndrome: PTCH: t9;22