The “Ugly Duckling” Sign: Agreement Between Observers

Dermatology Service, Memorial Sloan-Kettering Cancer Center, 160 E 53rd St, New York, NY 10022, USA.
Archives of dermatology (Impact Factor: 4.79). 02/2008; 144(1):58-64. DOI: 10.1001/archdermatol.2007.15
Source: PubMed


To assess whether multiple observers can identify the same pigmented lesion(s) as being different from a patient's other moles ("ugly duckling" [UD] sign) and to explore whether the UD sign is sensitive for melanoma detection.
Baseline back images of 12 patients were obtained from a database of standardized patient images. All patients had at least 8 atypical moles on the back, and in 5 patients, one of the lesions was a histologically confirmed melanoma. The overview back images were supplemented with close-up clinical images of lesions. Participants were asked to evaluate whether the images showed any lesions on the back that differed from other nevi.
Dermatology clinic specializing in pigmented lesions.
Images were evaluated by 34 participants, including 8 pigmented lesion experts, 13 general dermatologists, 5 dermatology nurses, and 8 nonclinical medical staff.
A lesion was considered a generally apparent UD if it was perceived as different by at least two-thirds of the participants. Sensitivity was defined as the fraction of melanomas identified as different.
All 5 melanomas (100%) and only 3 of 140 benign lesions (2.1%) were generally apparent as different. The sensitivity of the UD sign for melanoma detection was 0.9 for the whole group, 1.0 for experts, 0.89 for general dermatologists, 0.88 for nurses, and 0.85 for nonclinicians. A limitation of the study is that assessment was done in virtual settings.
In the present study, melanomas were generally apparent as UDs. The potential of the UD sign for melanoma screening should be further assessed.

Download full-text


Available from: Giuseppe Argenziano,
  • Source
    • "The intra-individual comparative analysis (ICA) concept, formalized as the ''ugly duckling'' sign, was proposed (Grob and Bonerandi 1998) and subsequently evaluated (Scope et al., 2008; Argenziano et al., 2011) for use in diagnosing melanoma. ICA takes advantage of the fact that, although nevi are highly polymorphous in the general population, the many nevi in a given patient share similar features and can thus be classified into a few ''perceived similarity clusters'' (PSCs) that represent the dominant patterns of nevi in that particular patient. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Although nevi are highly polymorphous, it has been suggested that each individual is characterized by only a few dominant patterns of nevi. Therefore, a nevus which does not fit in with these patterns, the "ugly duckling" nevus, is suspicious. Our objective was to study the intra-individual diversity of nevi, using human ability to build "perceived similarity clusters" (PSCs). Nine dermatologists had to cluster all the nevi of 80 patients into PSCs, at the clinical scale (CS), and at the dermoscopic scale (DS) (subset of 30 patients). Nine novices did the same in a subset of 11 patients. The experts identified a mean of 2.8 PSCs/patient at CS. Concordance was higher between experts, than between novices at CS, and at DS. Despite a trend for more PSCs at DS than at CS, the number of nevus patterns per patient remained low, regardless of the number of nevi. Inter-expert concordance permits a consensus representation of nevus diversity in each individual. Nevus diversity is limited in each patient and constitutes an individual reference system, which we can intuitively perceive. This reference is probably crucial for nevus analysis and melanoma detection and opens perspectives for computer-aided diagnostic.Journal of Investigative Dermatology accepted article preview online, 17 April 2013; doi:10.1038/jid.2013.183.
    Journal of Investigative Dermatology 04/2013; 133(10). DOI:10.1038/jid.2013.183 · 7.22 Impact Factor
    • "In 1998, Grob and Bonerandi introduced the “ugly duckling” concept to demonstrate that nevi in the same individual tend to resemble one another and that atypical mole often deviates from the individual's nevus pattern. In other words, nevus that does not resemble other nevi is more likely to be suspicious of melanoma.[80] "
    [Show abstract] [Hide abstract]
    ABSTRACT: Clinical signs reflect the sheer and close observatory quality of an astute physician. Many new dermatological signs both in clinical and diagnostic aspects of various dermatoses are being reported and no single book on dermatology literature gives a comprehensive list of these "signs" and postgraduate students in dermatology finds it difficult to have access to the description, as most of these resident doctor do not have access to the said journal articles. "Signs" commonly found in dermatologic literature with a brief discussion and explanation is reviewed in this paper.
    09/2012; 3(3):159-65. DOI:10.4103/2229-5178.101810
  • Source
    • "In contrast, melanomas often deviate from the individual’s nevus pattern, so-called “ugly duckling sign” [9]. Recently, a high sensitivity for the early detection of melanoma with the help of the “ugly duckling sign” could be demonstrated [10]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Cutaneous melanoma is a highly aggressive malignant tumor of skin melanocytes with an increasing incidence in most countries of the world, especially in the fair-skinned populations. Despite all preventive and therapeutic efforts, malignant melanoma is still the most lethal skin cancer. A delayed diagnosis results in an advanced stage and worsened prognosis. Once distant metastases are present, the five-year survival rate is less than 10 percent. At the same time, patients may be cured by an early diagnosis of cutaneous melanoma followed by a wide excision. Therefore, the early detection of melanoma at curable stages is crucial for the patients' survival. Besides the investigation of pigmented lesions with the unaided eye, a wide range of examination techniques for improved diagnostic accuracy have been developed and validated in clinical trials. However, none of these techniques are able to provide a definite and final diagnosis or to replace an excisional biopsy of suspicious lesions followed by histological analysis. This review provides a concise overview of general principles as well as current and future strategies for an improved early diagnosis of cutaneous melanoma.
    07/2012; 2(3):203a06. DOI:10.5826/dpc.0203a06
Show more