The smart approach: feasibility of lentigo maligna superficial margin assessment with hand-held reflectance confocal microscopy technology.

BACKGROUND: Lentigo maligna may be challenging to clear surgically. OBJECTIVE: To evaluate feasibility of using superficial skin cuts as RCM imaging anchors for attaining negative surgical margins in lentigo maligna. METHODS: Included patients presented with lentigo maligna near cosmetically sensitive facial structures. We evaluated, with hand-held-RCM, microscopic clearance of melanoma beyond its dermoscopically detected edges. Evaluated margins were annotated using shallow skin cuts. If a margin was positive at 'first-step' RCM evaluation, we sequentially advanced the margin radially outward at that segment by 2-mm intervals until an RCM-negative margin was identified. Prior to final surgical excision, we placed sutures at the outmost skin cuts to allow comparison of RCM and histopathological margin assessments. Primary outcome measure was histopathological verification that RCM-negative margins were clear of melanoma. RESULTS: The study included 126 first-step margin evaluations in 23 patients, median age 70 years (range: 43-91). Seventeen patients (74%) had primary in-situ melanoma and six (26%) invasive melanoma, mean thickness 0.3 mm (range 0.2-0.4 mm). Six cases (26%) showed complete negative RCM margins on 'first-step', 11 (48%) were negative at 'second-step', and four (17%) at 'third-step'. In two additional cases (9%), margins clearance could not be determined via RCM due to widespread dendritic cells proliferation. The RCM-negative margins in all 21 cases proved clear of melanoma on histopathology. Of the 15 cases that returned at 1-year follow-up, none showed any residual melanoma on dermoscopic and RCM examinations. Interobserver reproducibility showed fair agreement between bedside RCM reader and blinded remote-site reader, with Spearman's rho of 0.48 and Cohen's kappa of 0.43; using bedside reader as reference, the remote reader's sensitivity was 92% and specificity 57% in positive margin detection. CONCLUSIONS: Margin mapping of lentigo maligna with hand-held-RCM, using superficial skin cuts, appears feasible. This approach needs validation by larger studies.

Diagnostic accuracy of optical coherence tomography in actinic keratosis and basal cell carcinoma.

BACKGROUND: Early diagnosis of non-melanoma skin cancer (NMSC) is potentially possible using optical coherence tomography (OCT) which provides non-invasive, real-time images of skin with micrometre resolution and an imaging depth of up to 2mm. OCT technology for skin imaging has undergone significant developments, improving image quality substantially. The diagnostic accuracy of any method is influenced by continuous technological development making it necessary to regularly re-evaluate methods. OBJECTIVE: The objective of this study is to estimate the diagnostic accuracy of OCT in basal cell carcinomas (BCC) and actinic keratosis (AK) as well as differentiating these lesions from normal skin. METHODS: A study set consisting of 142 OCT images meeting selection criterea for image quality and diagnosis of AK, BCC and normal skin was presented uniformly to two groups of blinded observers: 5 dermatologists experienced in OCT-image interpretation and 5 dermatologists with no experience in OCT. During the presentation of the study set the observers filled out a standardized questionnaire regarding the OCT diagnosis. Images were captured using a commercially available OCT machine (Vivosight ®, Michelson Diagnostics, UK). RESULTS: Skilled OCT observers were able to diagnose BCC lesions with a sensitivity of 86% to 95% and a specificity of 81% to 98%. Skilled observers with at least one year of OCT-experience showed an overall higher diagnostic accuracy compared to inexperienced observers. CONCLUSIONS: The study shows an improved diagnostic accuracy of OCT in differentiating AK and BCC from healthy skin using state-of-the-art technology compared to earlier OCT technology, especially concerning BCC diagnosis.

Cost-benefit of reflectance confocal microscopy in the diagnostic performance of melanoma.

BACKGROUND: The sub-optimal diagnostic accuracy for melanoma leads to excise a high number of benign lesions, with consequent costs. Reflectance confocal microscopy (RCM) improves diagnostic specificity, thus possibly inducing a reduction in unnecessary excisions and related costs. OBJECTIVE: To estimate the influence of RCM on number of benign lesions needed to excise (NNE) a melanoma, in term of clinical outcomes and costs per patient. PATIENTS AND METHODS: Skin neoplasms excised by the dermatology public service in the Province of Modena were retrieved form centralized pathology database. Differences in NNE between the territorial service (using dermoscopy only) and the University Hospital (adding also RCM to the patients' workflow) were calculated and cost analysis was performed through a micro-costing approach. RESULTS: A large reduction in benign lesions excised at University Hospital was evident, leading to NNE of 6.25 for University Hospital, compared to 19.41 for Territorial Dermatology. Since 4320 unnecessary excisions can be saved every million inhabitants, an overall yearly saving of over 280,000 Eur can be expected from the use of RCM. CONCLUSIONS: The systematic use of RCM was dramatically affecting the number of benign lesions excised, and this can be translated in a significant cost-benefit advantage.