Flat scalp melanoma dermoscopic and reflectance confocal microscopy features correspond to histopathologic type and lesion location

Abstract

Background Dermoscopy and Reflectance Confocal Microscopy (RCM) features of scalp melanoma according to lesion location and histopathology have not been fully investigated.Objectives To reveal dermoscopic and RCM features of scalp melanoma according to lesion location and histopathology. MethodsWe retrospectively retrieved images of suspicious, atypical excised, flat melanocytic lesions of the scalp, assessed on dermoscopy and RCM at five centres, from June 2007 to April 2020. Lesions were classified according to histopathological diagnoses of nevi, lentigo maligna melanoma (LM/LMM) or superficial spreading melanoma (SSM). Clinical, dermoscopic and RCM images were evaluated; LM/LMM and SSM subtypes were compared through multivariate analysis.Results Two hundred forty-seven lesions were included. In situ melanomas were mostly LM (81.3%), while invasive melanomas were mostly SSM (75.8%). Male sex, baldness and chronic sun-damaged skin were associated with all types of melanomas and in particular with LM/LMM. LMs were mostly located in the vertex area and SSM in the frontal (OR: 8.8; P < 0.05, CI 95%) and temporal (OR: 16.7; P < 0.005, CI 95%) areas. The dermoscopy presence of pseudonetwork, pigmented rhomboidal structures, obliterated hair follicles and annular-granular pattern were associated with LM diagnoses, whereas bluish-white veil was more typical of SSM. Observations on RCM of atypical roundish and dendritic cells in the epidermis were associated with SSM (42.4%) and dendritic cells with LM (62.5%) diagnoses. Folliculotropism on RCM was confirmed as a typical sign of LM.Conclusions Flat scalp melanomas reveal specific dermoscopic and RCM features according to histopathologic type and scalp location.

Dermoscopy of Lentiginous Melanomas and Equivocal Benign Pigmented Macules of the Scalp: A Case-Control Multicentric Study

“…A study by Garbarino et al [22] more recently analysed the dermoscopic features of 97 scalp melanomas, including 64 LM. A high prevalence of features associated with both facial and extrafacial skin “architecture,” such as irregular pigment network (34.4%), irregular pseudo-network (59.4%), rhomboidal structures (37.5%), and annular-granular pattern (57.8%) was reported, similarly to our study.…”

A cross-sectional study of clinical, dermoscopic, histopathological, and molecular patterns of scalp melanoma in patients with or without androgenetic alopecia

“…In the Stanganelli et al 24 publication, the authors did not find a correlation between androgenetic alopecia and Breslow thickness, while Benati et al 33 found thicker melanomas in bald patients than in those with hair. Garbarino et al 49 analyzed 97 flat SMs and found that superficial spreading melanoma was most often invasive while the LM subtype was most often in situ. The authors hypothesized that LM demonstrates slower growth and easier diagnosis because it is visible to clinical examination 49 .…”

“…Garbarino et al 49 analyzed 97 flat SMs and found that superficial spreading melanoma was most often invasive while the LM subtype was most often in situ. The authors hypothesized that LM demonstrates slower growth and easier diagnosis because it is visible to clinical examination 49 . In our study, melanomas in patients with androgenetic alopecia and elastosis were associated with lower Breslow thickness.…”

Dermoscopy of melanoma according to different body sites: Head and neck, trunk, limbs, nail, mucosal and acral

“…vascular pattern, irregular streaks, irregular pigmentation, irregular dots and globules and regression structures. [25][26][27] Nodular melanoma on the scalp may be either pigmented or amelanotic and is mostly thick/invasive and frequently demonstrates an unspecific pattern. For Recently, the blueblack (BB) rule has been introduced to increase dermoscopic diagnostic accuracy of pigmented NM (Figure 2).…”

“…In detail, early disease (LM) and more advanced disease (LMM) are associated with atypical pseudonetwork with increasing hyperpigmentation and obscuration of follicular openings as the lesions' Breslow thickness increases. Additionally, LM may display any of the well‐known dermoscopic melanoma features summarized in the 7‐point checklist, including atypical network, blue‐white veil, atypical vascular pattern, irregular streaks, irregular pigmentation, irregular dots and globules and regression structures 25–27 …”