Identifying pigmented moles that look different from a person's other moles - the "ugly duckling sign" - is a practical way to spot malignant melanoma skin cancer, doctors say.
The ugly duckling model is based on the observation that moles, or "nevi", in the same individual tend toresemble one another and that malignant melanoma often deviates from the individual's mole pattern, "even in those with multiple atypical nevi" Dr Ashfaq A. Marghoob, of Memorial Sloan-Kettering Cancer Centre in New York, and associates explain in the Archives of Dermatology this month.
Dr Marghoob's group studied the ability of 34 adults with varying levels of expertise to identify ugly duckling moles in patients with several atypical moles. The participants were eight mole experts, 13 general dermatologists, five dermatology nurses, and eight non-MD medical staff members.
The observers were presented with overview photographs from 12 patients who had five malignant melanomas, at least eight atypical moles and 140 benign pigmented moles. All five melanomas and three benign moles were perceived as different by at least two-thirds of the participants, Dr Marghoob reported.
Identification of the ugly duckling showed good diagnostic accuracy for the detection of malignant melanoma skin cancer, even among non-MDs, the investigators report.
The usefulness of the ugly duckling method in malignant melanoma skin cancer screening by general healthcare providers and lay persons "should be further assessed," the investigators concluded.
