Abstract
The differentiation of melanocytic hyperplasia in severe sun-damaged skin (MH) from early stages of Lentigo Maligna (ELM) may be very difficult. Some histopathologic criteria have been proposed helping to classify lesions as malignant or not. But, more distinctive changes of melanoma may not occur for years (pagetoid cells, adnexal spreading, formation of nests of melanocytes and descent of neoplastic cells into the dermis). The exact threshold for malignancy is still controversial and so the management of these lesions remain discussed.
We retrospectively evaluated consecutive cases of pigmented lesions with pathology report as MH or ELM from the confocal databases of the main melanoma centre of Sydney, Australia from 2005 and 2015. Only cases with > 1 year follow up and recorded dermoscopic and RCM images were reviewed.
We reviewed 11 histopathologic features that were correlated to 13 RCM features and sensitivity and specificity for each RCM criterion were studied. We also analysed the dermoscopic features of each lesion using previously described criteria for LM.
51 cases were retrieved in this period. 40 cases had > 1 year follow up but in 3 cases the dermoscopic images could not be retrieved. There was a significant female predominance (25 cases) and mainly located on upper face (front, peri-oricular and scalp) and lower face (cheeks, peri-oral and chin). The most frequent dermoscopic feature was asymmetric hyperpigmented follicular opening and on RCM most cases showed <5 atypical cells in 3 fields and mild cellular pleomorphism. We discuss correlation with pathology and outcomes.