Skin Cancers

Question 1

Basal Cell Carcinoma

Answer 1

• cancer of basal cells, germinative keratinocytes
• basophilic (BLUE!) hyperchromatic cells that form nodules, extends from basal layer into epidermis/outward
• within a nodule: peripheral cells form a palisade (wall), and are set in a mucinous stroma, which can retract and form a cleft

Question 2

Squamous Cell Carcinoma

Answer 2

• cancer of epidermal keratinocytes, resembles s. spinosum
• hyperchromatic, pleomorphic nuclei, disorganized growth, mitoses and invasion through the basal layer.
• cells are pink and keratinizing, make keratin pearls and scales externally
• progression:
  1) minimal atypia, aka actinic keratosis
  2) SCC in situ - based on full thickness atypia
  3) invasion - into dermis; metastases

Question 3

Risk Factors for BCC

For SCC

Answer 3

• BCC: UV, light skin, h/o sunburns (esp blistering), fam h/o BCC, imm.supp. (but not as influential here as in SCC)
• SCC: UV, HPV, chronic inflammation, burn scars, chemicals esp. arsenic, radiation, leukoplakia, imm.supp.

Question 4

Actinic keratosis

Answer 4

• “pre-cancerous” skin lesions
• usually very flat/thin and not indurated, because they consist of a few atypical keratinocytes in the epidermis (not the whole epidermis)
• often appear in sun-exposed areas of skin
• nuclei may be retained in the cornified layer, which corresponds to the scale on the surface of the skin

Question 5

SCC in situ

Answer 5

characterized by atypical cells spanning the full-thickness of the epidermis; can notice this clinically when the lesion is indurated

Question 6

Risk of SCC metastasis - rate, location, and RFs

Answer 6

• Overall risk of mets is 4mm deep (or SQ extension)

4) SIZE of tumor: greater risk if >2cm

Question 7

Keratoacanthoma

Answer 7

Painful neoplasm of keratinocytes (possibly a subtype of SCC) that grows rapidly over 2-6 weeks; may involute spontaneously.
In the picture looks like a bump with a gross scaly topping of keratin.

Question 8

Marjolin’s Ulcer

Answer 8

An ulcerated invasive SCC arising on a background of chronic inflammation, scarring, radiation, trauma—basically the SCC RFs
*a classic presentation is SCC in a burn scar

Question 9

Bowen’s disease

Answer 9

A type of SCC in situ, but with highly atypical cells

Question 10

Erythroplasia of Queyrat

Answer 10

A type of SCC in situ but specifically on penis/vulva