S.B., a healthy 47-year-old woman, comes to your office for a routine check-up. S.B. has fair skin and a history of frequent sun exposure and sunburns when she was in college more than 25 years ago. She has no personal or family history of skin cancer.
Case Study Questions
Which one of the following approaches is most consistent with the U.S. Preventive Services Task Force (USPSTF) recommendation on screening for skin cancer?
A. Advise S.B. to perform regular skin self-examination for signs of melanoma.
B. Screen S.B. for skin cancer because of her history of sun exposure and sunburns.
C. Do not screen S.B. for skin cancer because of the potential harms of screening, such as false-positive results leading to biopsies and possibly unnecessary treatment.
D. When conducting S.B.'s physical examination, be alert for skin lesions with malignant features.
E. Screen S.B. for skin cancer because earlier treatment as a result of screening has been demonstrated to improve health outcomes.
While measuring S.B.'s blood pressure, your medical assistant notices a small mole on S.B.'s arm that S.B. had not noticed before. You examine the lesion. Which of the following findings would indicate an increased risk of developing skin cancer?
A. A round lesion with irregular border and uniform color that is 8 mm in diameter.
B. A symmetric lesion with uniform border and color that is 4 mm in diameter.
C. A symmetric lesion with uniform border and color that is 2 mm in diameter.
D. An asymmetric lesion with irregular border and variable color that is 7 mm in diameter.
Which one of the following patients is at substantially increased risk of developing skin cancer?
A. A 36-year-old fair-skinned woman who spends most of her time indoors and has no atypical moles.
B. A 74-year-old dark-skinned woman with average sun exposure.
C. A 45-year-old woman with a history of sun exposure and sunburns.
D. A 38-year-old fair-skinned woman with 20 moles.
E. A 67-year-old fair-skinned woman with an atypical mole and a history of considerable sun exposure and sunburns.
1. The correct answer is D. The USPSTF found insufficient evidence to assess the balance of benefits and harms of screening for skin cancer by primary care physicians or by patient skin self-examination. Potential harms include misdiagnosis, overdiagnosis, and harms from biopsies and overtreatment. The USPSTF suggests that physicians stay alert for skin lesions with malignant features during physical examinations performed for other purposes.
2. The correct answers are A and D. Asymmetry, border irregularity, color variability, diameter greater than 6 mm (the ABCD criteria), and rapid change are features of lesions associated with malignancy. Biopsy of suspicious lesions is warranted.
3. The correct answer is E. Persons older than 65 years with fair skin, persons with atypical moles (as described in the previous answer), and those with more than 50 moles are at substantially increased risk of developing skin cancer. Other risk factors include a considerable history of sun exposure and sunburn, and a family history of skin cancer. The USPSTF recommendation on screening for skin cancer does not apply to patients at extremely high risk of skin cancer, such as those with familial syndromes (e.g., familial atypical mole and melanoma syndrome) or those with a history of premalignant or malignant lesions.