Tips for difficult to diagnose hypomelanotic melanomas on reflectance confocal microscopy.

Amelanotic/hypomelanotic melanoma (AHM) represents a clinical diagnostic challenge. Dermoscopy improves AHM diagnosis thanks to visualization of little pigment and vascular pattern. Reflectance confocal microscopy (RCM) increases further the diagnostic accuracy of AHM but few and small studies have described in detail RCM features of AHM. We evaluated dermoscopic and RCM features of nine cases of difficult to diagnose hypomelanotic melanomas (HMs) to find clues for their diagnosis. The RCM score was suggestive of melanoma in all cases. The major criteria of nonedged papillae and/or cytological atypia at the dermo-epidermal junction were seen in all cases. Among the minor criteria, roundish pagetoid cells, including hyporeflective pagetoid cells, were found in four out of nine lesions. Dermoscopically, four out of nine HMs did not show prevalent suspicious criteria while revealing suspicious RCM features that were visible only after careful RCM examination by zooming mosaic images. RCM can improve HM diagnostic accuracy but only after extensive evaluation of images. Atypical cells were less reflective and the architectural irregularity was less visible than in pigmented melanoma and zooming was needed to identify both features.

In vivo reflectance confocal microscopy of halo nevi.

INTRODUCTION: Halo nevi named also Sutton's nevi are uncommon melanocytic lesions occurring especially among adolescents. There are two effective diagnostic methods: dermoscopy and in vivo reflectance confocal microscopy (RCM), which can help us to observe many structural elements and characteristic features of Sutton's nevi. OBJECTIVES: The aim of this study was to describe reflectance confocal microscopy features of halo nevi. METHODS: Eleven patients with fourteen halo nevi were examined by FotoFinder Medicam 800 dermoscope and reflectance confocal microscope Viva Scope 1500 between May of 2018 and September of 2019. RESULTS: Dermoscopic examination revealed 78.6% nevi with a globular pattern, while 21.4% showed a homogenous pattern. In RCM, a typical honeycombed pattern was observed in 57.1% of nevi. 42.9% of nevi showed a disarray of the epidermis and presence of dendritic cells. 35.7% of all lesions presented roundish atypical cells in the epidermis. Roundish pagetoid cells in the dermo-epidermal junction were detected in 14.2% of nevi. Non-edged papillae were observed in 50% of lesions. In each nevus, there were dilated vessels. 50% of nevi revealed dense nests in the periphery, although in case of one lesion the dishomogeneous nests were observed. CONCLUSIONS: Halo nevi are important "melanoma simulators" in confocal microscopy.

A Comparative Study of Pigmented and Non-pigmented Basal Cell Carcinoma in Reflectance Confocal Microscopy.

BACKGROUND/AIM: Basal cell carcinoma (BCC) is a common skin cancer, especially in the elderly population. The probability of BCC development increases past the age of 55. Dermoscopy and reflectance confocal microscopy (RCM) are two modern tools useful in the diagnosis of BCC. PATIENTS AND METHODS: This is a retrospective study conducted on a group of 21 patients with a confirmed diagnosis of BCC. All patients were examined by dermoscopy and RCM. Dermoscopic images were taken using a videodermoscope. RCM was performed in three layers: epidermal, dermoepidermal junction (DEJ), and superficial dermal layer. In each layer, a few RCM criteria of basal cell carcinoma diagnosis were taken into consideration. RESULTS: Dermoscopy of pigmented BCCs revealed blue globules of pigment (p<0.05), gray and blue ovoid nests, which were absent in the entire non-pigmented carcinomas group. In RCM, the epidermis showed no differences between pigmented and non-pigmented carcinomas, however, significant differences were observed at the DEJ. In pigmented BCCs, cordlike structures and plump atypical cells were observed (p<0.05), while in non-pigmented carcinomas, dark silhouettes were present (p<0.05). CONCLUSION: To our knowledge, that is the first study comparing features between pigmented and non-pigmented BCC by RCM. Pigmented and non-pigmented BCCs presented different features in both dermoscopy and RCM. Furthermore, RCM revealed more discriminating features at the DEJ than dermoscopy, thus can be more efficient in the differential diagnosis of difficult BCC.

Dermoscopic Findings in the Presurgical Evaluation of Basal Cell Carcinoma. A Prospective Study.

BACKGROUND: Surgery is the best treatment for basal cell carcinoma (BCC); however, incomplete excisions are possible. OBJECTIVE: Assessment of the accurateness of dermoscopy and clinical evaluation in the detection of borders of BCC and description of dermoscopic findings in clinically healthy tissue surrounding BCC. MATERIALS AND METHODS: Eighty-eight lesions with clinical dermoscopic diagnosis of BCC were examined clinically and dermoscopically, to delineate the correct site of surgical incision, demarcating the respective margins with colred dermographic pencils. Specific dermoscopic features were searched in the skin adjacent to the demarcated clinical margin. RESULTS: In 29 of 88 lesions, clinical and dermoscopic margins of the tumor coincided. In the remaining 59 (67%), 10 (16.9%) presented, in the lesion area identified under dermoscopy, classical criteria for BCC and 57 (96.6%) nonclassical criteria. Differences between clinical and dermoscopic margins were significantly more frequent in superficial BCCs (p = .006). The frequency was not significantly different (p = .85) in relation to body sites. CONCLUSION: Dermoscopy improves the identification of margins for surgical excision in BCC. The observation of nontraditional dermoscopic criteria of BCC, mainly pink-white areas and short telangiectasias in the area between clinically and dermoscopically detected margins, helps to define the actual tumoral margins and to achieve a really radical excision.