A 29-year-old man comes to the physician for a routine preventive examination. He is currently feeling well but states that he has always had "some dark spots" on his back. The patient has no family history of heart disease or cancer. He does not spend much time outdoors and had no prior sunburn. He does not smoke. Physical examination shows many pigmented lesions on his back as shown below.
Which of the following is the best factor to assess risk of malignancy in a suspicious skin lesion in this patient?

Question

A 29-year-old man comes to the physician for a routine preventive examination.  He is currently feeling well but states that he has always had "some dark spots" on his back.  The patient has no family history of heart disease or cancer.  He does not spend much time outdoors and had no prior sunburn.  He does not smoke.  Physical examination shows many pigmented lesions on his back as shown below.  
Which of the following is the best factor to assess risk of malignancy in a suspicious skin lesion in this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_be7a_76ed_8f63_295ffe1915bc_MD0005_00 Several clinical rating systems have been proposed to identify the likelihood of malignant melanoma in a patient with a suspicious pigmented lesion. The best validated rule uses the mnemonic "ABCDE": asymmetry, border, color, diameter, and evolving. The use of a single criterion (any 1 of 5 positive) gives a sensitivity of 97% for melanoma with a specificity of 36%. However, using all 5 criteria lowers the sensitivity to 43% but has 100% specificity. Sensitivity of individual factors ranges from 57%-90%. Other factors suggesting melanoma include inflammatory changes, crusting/bleeding, and sensory abnormalities. (Choice A) Café-au-lait macules are a characteristic feature of neurofibromatosis. Café-au-lait macules (Choice B) A herald patch is a pruritic 2-10 cm pink/tan colored lesion which usually appears on the back and is an early sign of pityriasis rosea. Within several days, numerous similar but smaller lesions are usually seen. herald patch (Choice C) The "ugly duckling sign" is a proposed clinical rule in which the likelihood of malignancy of a pigmented lesion may be judged with respect to its similarity or difference from other lesions on the same patient. It has not been well validated, though it may be useful for assessing lesions when "ABCDE" criteria are indeterminate or the clinician has a persistent suspicion. (Choice D) Seborrheic keratoses are pigmented papules or plaques characterized by a verrucous "stuck-on" appearance. These are uncommon before age 30 but the number increases with age. Seborrheic keratoses Educational objective: The "ABCDE" criteria (asymmetric shape, border irregularities, color variegation, diameter >6 mm, and evolving size, shape or color) are useful to assess the likelihood of malignancy in a pigmented skin lesion. References: Semiological value of ABCDE criteria in the diagnosis of cutaneous pigmented tumors. (http://www.ncbi.nlm.nih.gov/pubmed/9693179)

A 29-Year-Old Man Comes to the Physician for a Routine