Cutaneous neoplasms Flashcards
Seborrheic keratoses:
- One of the most common cutaneous neoplasms in individuals >50 years of age.
- Coin-like, macular to raised verrucoid lesion with “stuck on” appearance.
Leser-Trelat sign:
- Associated with seborrheic keratoses.
- Rapid increase in number of keratoses.
- Phenotypic marker for stomach adenocarcinoma.
Actinic keratosis:
- AKA solar keratosis.
- Develop as a result of chronic sun damage.
- Red or tan-brown macules with “gritty” sandpaper-like scale.
- Precursor of squamous cell carcinoma; 0.1-10% become malignant.
Squamous cell carcinoma:
- 20% of all skin cancers.
- UV radiation is the most common cause.
- Other predisposing factors: chronic ulcers, old burn scars, HPV, radiation, arsenic exposure, immunosuppression (higher risk of metastasis).
- In situ (confined to epidermis) presents as red scaly plaque.
- Invasive tend to be nodular and may ulcerate.
- The likelihood of metastasis is related to the location and degree of invasion (lips/ears more likely to metastasize).
- SCCs favor lower lip, BCCs favor upper lip.
Keratoacanthoma:
- Variant of SCC (well-differentiated).
- Rapidly growing, crateriform tumor with a central keratin plug.
- Develops in sun-exposed areas.
- Can cause extensive local destruction; excision recommended.
Basal cell carcinoma:
- Most common malignant skin tumor; caused by chronic exposure to UV light.
- RARELY metastasizes - if it does, the patient is often immunocompromised.
- Multifocal in origin; makes it difficult to get free margins after surgery.
- *Associated wit dysregulation of the sonic hedgehog or PTCH pathway.
- Raised papule with a central crater, sides of the crater are surfaced by telangiectatic vessels.
3 types of histological melanocytic nevi:
- Junctional (epidermis only - usually acquired)
- Compound (epidermis and dermis)
- Intradermal (in dermis only)
Distinguish dysplastic nevi from acquired nevi:
Dysplastic nevi are larger (>0.5 cm), irregular in shape and uneven color.
Important because patients with multiple dysplastic nevi have increased risk for melanoma.
Dysplastic nevus syndrome mutation:
- Autosomal dominant.
- CDKN2A gene mutation.
Difference between sporadic and familial dysplastic nevus syndrome:
Sporadic: lower number of nevi, lifetime risk of melanoma is 10%.
Familial: hundreds of nevi, lifetime risk of melanoma approaches 100%.
Melanoma risk factors:
- UV exposure at early age (most important).
- Fair complexion and older age.
- Dysplastic nevus syndrome.
- History of melanoma in the family.
- Tanning bed use.
- Xeroderma pigmentosum.
Clinical features of melanoma:
A: asymmetry B: borders (notched, uneven, blurred) C: color (uneven) D: diameter (>6 mm) E: evolution of color and size
Radial vs vertical growth phase:
Radial: melanocytes will proliferate within the epidermis (NO metastatic potential).
Vertical: dermal invasion and potential for metastasis.
Most important prognostic indicator in melanoma:
Breslow thickness (depth of invasion)
Other indicators of metastatic potential in melanoma:
- Ulceration
- Mitotic rate
- Angioinvasion
