Searching for Melanomas
Extensive sun exposure and the risk of skin cancer go hand in hand and early diagnosis of malignant melanoma is key for the prognosis of the patient. In a study on a total of 1,800 patients, Aldridge et al. (p. 689–692) report that as many as 1/3 of melanomas were found as incidental lesions in patients who were referred for assessment of other potential skin cancers. The authors emphasise the importance of a total body skin examination and give two major reasons: (i) skin cancer incidence rate is so high that patients may present with more than one cancer at a single time point, and (ii) the assessment of an individual lesion is influenced by the morphology of other non-index lesions. Aldridge et al. ask an interesting and important question in their paper, namely how many melanomas would be missed if physicians only examined the index lesion, rather than conducting a full body skin examination? Results were based on two studies performed at two separate dermatology departments in Scotland and showed that a substantial proportion of the melanomas detected indeed were incidental owing to the fact that a total body skin examination was performed in addition to examination of the referred lesion. Single lesion assessment resulted in a melanoma pick up rate of 1.3% compared to 2.1% when the assessment was combined with a full body skin examination. The authors also made a serious observation that many of the incidental melanomas were located close to benign index lesions, which would suggest that the referring physicians do not possess the skills to choose the most relevant index lesion to submit for pathological assessment.
The importance of early diagnosis cannot be stressed enough. “Negative pigment network” (NPN) is a dermoscopic descriptor that has been reported in melanocytic and non-melanocytic lesions, and is proposed by Bassoli
et al. (p. 650–655) to be considered as a diagnostic indicator for a new melanoma subtype. Of 401 analysed malignant melanomas, a total of 107 malignant melanoma lesions were identified with NPN. The concept of main pattern is used to describe the main characteristics of a lesion to classify benign and malignant lesions. The data presented by Bassoli et al. showed that when NPN covers more than 50% of the area, the lesion acquires a symmetrical aspect, in contrast to traditional dermoscopic malignant melanoma criteria. It also had a higher prevalence in younger male patients and arose on a naevus in 41%. The description of malignant melanoma patterns is important for early diagnosis and for identifying new subgroups that may vary in their tendency to grow and metastasise.
Hanna Norsted, PhD, Scientific writer
Acta Dermato-Venereologica
