Skin Cancer

Question 1

Most common skin cancer

Answer 1

basal cell carcinoma

Question 2

Basal Cell Carcinoma

Answer 2

Most common skin cancer.
often PTCH mutation.
Locally invasive, but rarely metastasize.
Pink, pearly nodules commonly with telangiectasias, rolled borders, central crusting, or ulceration. Also appear as non healing ulcers with infiltrating growth, scaling plaque. “peripheral palisading nuclei” on his to
vismodegib anti SMO (in SHH pathway to RAF/MEK/ERK pathway)

Question 3

Squamous cell carcinoma

Answer 3

Second most common skin cancer.
Associated with excessive exposure to sunlight, immunosuppression, arsenic exposure.
Assoc with p53 mutation
Chronic erosive lichen planus.
Common on LOWER LIP, ears, hands.
Locally invasive, but may spread to lymph nodes and will rarely metastasize.
Ulcerative red lesions with frequent scale. Associated with chronic draining sinuses. “keratin pearls” on histo

Question 4

Actinic keratosis

Answer 4

scaly plaque of squamous proliferation that is sometimes precursor to squamous cell carcinoma

• has parakeratosis
• can progress to full thickness atypia (SCC in situ)

Question 5

Keratoacanthoma

Answer 5

variant of squamous cell carcinoma that grows rapidly (4-6 weeks) and may regress spontaneously over months; cup shaped tumor with keratin debris

Question 6

Melanoma

Answer 6

Malignant neoplasm of melanocytes.
Most common death from skin cancer. Significant risk of metastasis.
Associated with excess sun exposure and fair skin.
Look for ABCDE.
At least 4 diff types: spreading, nodular, lentigo, acrolentiginous.
Often b/c of activating mutation in BRAF kinase. Vemurafenib is a BRAF kinase inhibitor.
Lymph involvement, depth are most impt for prognosis.

Question 7

Seborrheic Keratosis

Answer 7

Benign squamous proliferation. Raised, discolored plaques on extremities and face, like “mud stuck on a wall”.
FGFR mutation
Histo: keratin pseudocysts

Question 8

Leser-Trelat sign

Answer 8

When multiple SKs show up of all a sudden, usually means GI malignancy

Question 9

Acanthosis nigicans

Answer 9

Epidermal hyperplasia involving skin darkening (velvet like) in axilla and groin. Assoc. with insulin resistance or malignancy (usually GI)

Question 10

Nevus

Answer 10

Benign neoplasm of melanocytes. Arise from proliferation of melanocytes at epidermal-dermal junction. Can go down into dermis and become intradermal nevi (as you age).

Question 11

Bowen’s Disease

Answer 11

SCC in situ; confined to epidermis and does not invade past E-D junction

Question 12

Erythroplasia of Queyrat

Answer 12

SCC in situ on penis

Question 13

Marjolin’s Ulcer

Answer 13

ulcerative invasive SCC