Lecture 8: Pigmented, Precancerous lesions Flashcards
What is Actinic Keratosis?
Solar keratosis Neoplastic condition in which precancerous epithelial lesions are found on sun-exposed areas of the body.
What skin type is actinic keratosis MC in?
Lighter skin
Where is Actinic Keratosis MC?
Any sun exposed skin
What does actinic keratosis look like?
- 2-6 mm plaques
- Yellowish
- Hypertrophic
- Rough
- Ill-defined border with some scale
- Underlying red base
Who is MC for actinic keratosis?
Immunosuppressed
What cancer can actinic keratosis evolve into?
squamous cell carcinoma
What can help and/or resolve actinic keratosis?
Protection from UV light
How do you find actinic keratoses?
Palpation
“gritty”
How is actinic keratosis dx?
Clinically, but refer to derm if unsure.
What is the lower lip involvement version of actinic keratosis called?
Actinic cheilitis
If you choose to do dermoscopy, what will show up for actinic keratosis?
- White to yellow surface scale
- Erythema with pseudo-network around hair follicles
- linear-wavy vessels
- follicle openings with yellowish keratotic plugs
Classic gritty feel
What causes actinic keratosis to be pigmented?
Collision of solar lentigo and actinic keratosis
Solar lentigo is like a dark spot/aka liver spot
When would a biopsy be indicated for actinic keratosis?
- Recurrent, hyperkeratotic
- Large > 6mm
- Indurated
- Painful
R/u invasive carcinoma
What is the MC type of tx for actinic keratosis that is lesion-targeted?
Cryosurgery
Since cryo is superficial but precise
What meds can treat actinic keratosis?
- 5-FU
- Imiquimod cream
- Ingenol mebutate
- Diclofenac gel
What is the MOA of 5-FU?
Blocks DNA synthesis and leading to selective cell death.
How often is 5-FU dosed?
BID to affected area for x 2-4w
QD for micronized to face/scalp
What is the main pt education for using 5-FU for actinic keratosis?
Success is parallel to pt compliance.
What you put in is what you get out of it
MOA of imiquimod
Immunomodulator that stimulates local cytokine induction.
Imi(mod) = immune modulator
When is imiquimod used?
ImmunoCOMPETENT people with non-hypertrophic AK on their face or scalp
You don’t wanna use immune drugs on some with a weak immune.
How is imiquimod given?
Cream nightly, wash after 8 hrs. 2x/wk for 16 wks.
Start at 5%
Main SE of both 5-FU and imiquimod?
Local skin rxn
Main pt education for imiquimod
- SE = getting better
- Wash hands before and after
- Wash area before
What is the MOA of ingenol mebutate (Picato)?
- Disruption of the cell membrane and DNA => necrosis
- Neutrophil-mediated cytotoxicity that eliminates remaining tumor cells
PLANT DERIVATIVE
When is ingenol mebutate (Picato) used?
Actinic Keratosis
How is ingenol mebutate (Picato) administered?
- 0.015% gel for the face/scalp.
- 0.05% gel for trunk/extremities
Cover affected area for 3d for face, 2d for trunk.
What is the risk of ingenol mebutate (Picato)?
Invasive SCC
What is the MOA of diclofenac 3% gel?
COX-2 inhibitor
PGE production makes non-melanoma skin CA
How long do you apply diclofenac 3% gel?
BID for 60-90 days
Much longer than other tx modalities
Why might diclofenac 3% gel be preferred over other agents for Actinic Keratosis?
Mild skin reaction compared to others.
However, tx is much longer. 60-90d
What are the 5 procedural field therapies for actinic keratosis?
- Cryopeeling
- Dermabrasion
- Chemical Peels
- Laser Resurfacing
- Photodynamic therapy
A patient is being seen for their first derm visit regarding a few suspicious actinic keratosis. What is the first-line tx?
Lesion targeted therapy
- Cryosurgery
- Curettage
- Shave excision
- Patient education on sunscreen
- 3 mo f/u
What would be the first two drugs you would choose for a 2nd visit of multiple AKs?
- 5-FU
- Imiquimod
A patient compliant with topical field therapy and having multiple AKs does not like 5-FU or imiquimod. What can you give them?
Diclofenac gel
What is Squamous Cell Carcinoma?
Malignant cutaneous epithelial cells, MC on sun-exposed areas.
AK often is a precursor.
What area, if found, is SCC highest risk for metastasis?
Oral mucosa and lip
How does differentiated SCC present?
- Hard/firm papule/plaque/nodule
- Thick, adherent keratotic scale
- Erythematous, yellow, or skin colored.
- Found on sun-exposed areas
- Can cause regional LAN with metastasis
Undifferentiated SCC, what does it look like?
- Soft, fleshy, erosive papule/nodule
- Papillomatous, like a cauliflower.
- Bleeds easily
- Not found on sun-exposed areas prior to differentiation
Top RFs for SCC
- Chronic sun exposure
- Fair skin, blue eyes
- FHx
- Old
- Scarring
- HPV
- Tattoos if traumatic
What is the MC skin cancer in AA?
SCC
Even though it is 80x less likely to occur in dark skin.
Why do dark skin ppl rarely get dxd with SCC?
- Doesn’t occur often in darker skinned
- Occurs in scars and non-sun-exposed areas for darker skin, so its not caught.
What is SCC in situ?
Confined to epidermis
Includes Bowen dz and erythroplasia or Queyrat (on testes)
Who is SCC in situ more frequent and aggressive in?
Immunosuppressed
What will you often see on the skin of patients with SCC? (besides SCC)
- Solar elastosis
- AKs
- Solar lentigines
Most important predisposing factors/locations for SCC
- Old burn scar
- Chronic cutaneous ulcers
- Inflammation
- Irradiation
- Chronic lymphedema
- Venous stasis
What is the classic presentation of SCC on dermoscopy?
Red vessels as dots, scale/crust, and shiny white structures (Crystalline Structures
What does pigmented SCC look like?
Red vessels + Shiny white structures + brown/gray dots in a linear arrangment.
Besides looking at the actual lesion in SCC, what else is essential to examine?
Regional lymph nodes