Early Stages of Melanoma on the Limbs of High-risk Patients: Clinical, Dermoscopic, Reflectance Confocal Microscopy and Histopathological Characterization for Improved Recognition

Abstract

Early stages of 36 melanomas on limbs were morphologically characterised. Most occurred in high-risk patients (multiple and/or familial melanoma) attending a referral unit for melanoma and pigmented lesions. None of the tumours was clinically suspicious for melanoma (mean diameter of 4.3 mm). The tumours were classified into four dermoscopic groups: (i) prominent network (n = 16); (ii) delicate network (n = 5); (iii) hypo-pigmentation with dotted vessels (n = 10); and (iv) diffuse light pigmentation with perifollicular pigmentation (n = 5). Confocal microscopy performed in 12 cases allowed the identification of atypical, single cells within epidermal layers. Histopathology showed marked large atypical cells in a pagetoid spreading pattern in most cases. Significant associations were detected between the third dermoscopic group and naevoid histological appearance and delay in detection, and between the fourth group and lentigo-maligna-like features. Dermoscopy allowed an increase in the suspicious threshold in these difficult melanomas in high-risk patients and enabled the subclassification of early melanomas on the limbs, with a correct confocal and histopathological correlation. Although the biological behaviour of these incipient tumours remains uncertain, the most appropriate treatment seems to be recognition and proper excision.

Characterization of 1152 lesions excised over 10 years using total-body photography and digital dermatoscopy in the surveillance of patients at high risk for melanoma

“…23,31 Currently, there is enough evidence to consider the use of sequential digital dermatoscopy imaging, in selected high-risk populations when available, to detect early melanomas even in the absence of specific dermatoscopic features. 6,7,17,18,[33][34][35] As expected, all types of changes considered significant during follow-up were more common in melanoma than in nevi. We found that focal changes in pigmentation and focal changes in structure were significantly more frequent in melanoma than in nevi (with an odds ratio of 2.988 and 5.47, respectively), but no considerable differences in terms of asymmetric enlargement, regression, or changes in pigmentation were demonstrated.…”

Dermoscopic criteria associated with BRAF and NRAS mutation status in primary cutaneous melanoma

“…4 Dermoscopic features have been associated with genetic alterations. 5,6 However, there is no information about the dermoscopic features associated with BRAF and/or NRAS mutations to identify tumours with these alterations and whether this information could be valuable for therapy stratification.…”

Negative Pigment Network Identifies a Peculiar Melanoma Subtype and Represents a Clue to Melanoma Diagnosis: A Dermoscopic Study of 401 Melanomas

“…The description of MM patterns is important both for the recognition of new subgroups and early diagnosis and for the identification of MM subtypes that may be correlated with different biological behaviours (29). New evidence suggests that MM comprises a family of tumours that vary in growth activity (30,31).…”