Dermatopathology Case Studies


CASE 6: Squamous cell carcinoma


Clinical History:

This 41-year-old former lifeguard spent a lot of time on the beach. She developed multiple scaling, erythematous lesions on the face that were 0.5 to 1 cm in size. One of the larger lesions that was ulcerated and had an indurated border was excised.
  1. What is the diagnosis?

    2. This is a squamous cell carcinoma. The surrounding skin probably shows actinic keratoses.

  2. Why did this lesion develop?

    3. Sun exposure predisposes to development of skin malignancies. Ultraviolet light striking the skin forms pyrimidine dimers in the DNA of epidermal cells. There are DNA repair mechanisms, but these can be overwhelmed with increased sun exposure over time. Ultraviolet light consists of UVA and UVB radiant energy. The UVA accelerates the tanning process (melanin production) while the UVB is more harmful from risk for skin damage. Most sun lamps in tanning parlors emit mainly UVA radiation with "tanning rays" that are less likely to cause a sunburn than UVB radiation from sunlight. But that does not make them completely safe because UVA has been linked to malignant melanoma.

    Skin TypeTanning Characteristics
    I
    		Always burns and never tans
    II
    		Burns easily and tans minimally
    III
    		Burns moderately and tans gradually to light brown (average Caucasian person)
    IV
    		Burns minimally and always tans well to moderately brown (olive skinned person)
    V
    		Rarely burns and tans profusely and darkly (brown-skinned person)
    VI
    		Never burns, deeply pigmented, and not sensitive (dark-skinned person)

    Persons in categories I and II are at greatly increased risk for skin damage and skin tumors from sun exposure.

    Prevention steps recommended to minimize sun damage to the skin and eyes include:

    • Plan outdoor activities to avoid times when UV light is maximal. As a general rule, avoid being out in the sun between 10 a.m. and 4 p.m.

    • Wear protective covering such as broad-brimmed hats, long pants, and long-sleeved shirts to reduce exposure.

    • Wear sunglasses that provide 100% UV protection.

    • When outdoors, apply a broad-spectrum sunscreen with at least sun protection factor (SPF) 15 to help block both UVA and UVB, and reapply it according to manufacturer's directions.