Impact of in vivo reflectance confocal microscopy on the number needed to treat melanoma in doubtful lesions

Reflectance confocal microscopy versus dermoscopy for the diagnosis of cutaneous melanoma: a head-to-head comparative meta-analysis

This meta-analysis aimed to evaluate the comparative diagnostic performance of reflectance confocal microscopy (RCM) and dermoscopy in detecting cutaneous melanoma patients. An extensive search was conducted in the PubMed and Embase databases to identify available publications up to December 2023. Studies were included if they evaluated the diagnostic performance of RCM and dermoscopy in patients with cutaneous melanoma. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Performance Studies (QUADAS-2) tool. A total of 14 articles involving 2013 patients were included in the meta-analysis. The overall sensitivity of RCM was 0.94 [95% confidence interval (CI), 0.87-0.98], while the overall sensitivity of dermoscopy was 0.84 (95% CI, 0.71-0.95). These results suggested that RCM has a similar level of sensitivity compared with dermoscopy ( P  = 0.15). In contrast, the overall specificity of RCM was 0.76 (95% CI, 0.67-0.85), while the overall specificity of dermoscopy was 0.47 (95% CI, 0.31-0.63). The results indicated that RCM appears to have a higher specificity in comparison to dermoscopy ( P  < 0.01). Our meta-analysis indicates that RCM demonstrates superior specificity and similar sensitivity to dermoscopy in detecting cutaneous melanoma patients. The high heterogeneity, however, may impact the evidence of the current study, further larger sample prospective research is required to confirm these findings.

Real-life practice of reflectance confocal microscopy in France: A prospective multicenter study

BACKGROUND

Studies demonstrating the potential utility of reflectance confocal microscopy (RCM) have been performed under experimental conditions.

OBJECTIVE

To provide an overview of RCM practice in real-life.

METHODS

A multicenter, prospective study carried out in 10 university dermatology departments in France.

RESULTS

Overall, 410 patients were enrolled. One-half of the patients (48%) were referred by private practice dermatologists. They were referred for diagnosis (84.9%) or presurgical mapping (13%). For diagnosis, the lesions were located on the face (62%), arms and legs (14.9%), and trunk (13.6%), and presurgical mapping was almost exclusively on the face (90.9%). Among those referred for diagnosis, the main indication was suspicion of a skin tumor (92.8%). Of these, 50.6% were spared biopsies after RCM. When RCM indicated surgery, histology revealed malignant lesions in 72.7% of cases. The correlation between RCM and histopathology was high, with a correlation rate of 82.76% and a kappa coefficient of 0.73 (0.63; 0.82).

LIMITATIONS

This study was performed in the settings of French tertiary referral hospitals.

CONCLUSION

This study shows that in real-life RCM can be integrated into the workflow of a public private network, which enables a less invasive diagnostic procedure for patients.

Comparison of Extended Skin Cancer Screening Using a Three-Step Advanced Imaging Programme vs. Standard-of-Care Examination in a High-Risk Melanoma Patient Cohort

Modern diagnostic procedures, such as three-dimensional total body photography (3D-TBP), digital dermoscopy (DD), and reflectance confocal microscopy (RCM), can improve melanoma diagnosis, particularly in high-risk patients. This study assessed the benefits of combining these advanced imaging techniques in a three-step programme in managing high-risk patients. This study included 410 high-risk melanoma patients who underwent a specialised imaging consultation in addition to their regular skin examinations in outpatient care. At each visit, the patients underwent a 3D-TBP, a DD for suspicious findings, and an RCM for unclear DD findings. The histological findings of excisions initiated based on imaging consultation and outpatient care were compared. Imaging consultation detected sixteen confirmed melanomas (eight invasive and eight in situ) in 39 excised pigmented lesions. Outpatient care examination detected seven confirmed melanomas (one invasive and six in situ) in 163 excised melanocytic lesions. The number needed to excise (NNE) in the imaging consultation was significantly lower than that in the outpatient care (2.4 vs. 23.3). The NNE was 2.6 for DD and 2.3 for RCM. DD, 3D-TBP, or RCM detected melanomas that were not detected by the other imaging methods. The three-step imaging programme improves melanoma detection and reduces the number of unnecessary excisions in high-risk patients.

Application of dermoscopy and reflectance confocal microscopy in vivo in the evaluation of nevi in children

BACKGROUND

Melanocytic nevi are frequently observed in the pediatric population. While newly acquired nevi can appear during childhood, congenital nevi can continue to grow and clinically change, making patient caregivers concerned. Reflectance confocal microscopy (RCM) in vivo is a noninvasive tool that might enhance the diagnostic accuracy of dermoscopy, reducing the rate of unnecessary surgical procedures. This study aimed to assess the utility of RCM in increasing the diagnostic accuracy of pediatric melanocytic nevi that show pigmentation changes or grow rapidly.

METHODS

Pediatric patients who presented between January 2022 and February 2023 in a single institution with rapidly growing melanocytic nevi or nevi that presented changes in the pigmentation were included in the study. All nevi were evaluated by means of dermoscopy and RCM.

RESULTS

Forty-two patients with a total of 42 melanocytic nevi were included. Most lesions showed a honeycombed pattern (n = 21, 50%). On RCM, only 3 of 42 nevi presented atypical cells within the epidermis (7.1%). Evaluation of the dermoepidermal junction (DEJ) revealed the predominance of the meshwork pattern (n = 22, 52.4%). Notably, features considered significant for atypical melanocytic nevi included 9 nevi with scant atypical melanocytes (21.4%) and 3 nevi with nonedge papillae (7.1%). None of the studied lesions required biopsy among this cohort.

CONCLUSIONS

Most rapidly growing and clinically changing nevi rarely exhibit single atypical cells in the DEJ. The RCM served as a valuable adjunct to dermoscopy, allowing reassurance in the evaluation of these lesions.

[Translated article] Reflectance Confocal Microscopy Terminology in Spanish: A Delphi Consensus Study

The terminology used to describe reflectance confocal microscopy (RCM) findings in both melanocytic and nonmelanocytic lesions has been standardized in English. We convened a panel of Spanish-speaking RCM experts and used the Delphi method to seek consensus on which Spanish terms best describe RCM findings in this setting. The experts agreed on 52 terms: 28 for melanocytic lesions and 24 for nonmelanocytic lesions. The resulting terminology will facilitate homogenization, leading to a better understanding of structures, more standardized descriptions in clinical registries, and easier interpretation of clinical reports exchanged between dermatologists.

Reflectance Confocal Microscopy Terminology in Spanish: A Delphi Consensus Study

The terminology used to describe reflectance confocal microscopy (RCM) findings in both melanocytic and nonmelanocytic lesions has been standardized in English. We convened a panel of Spanish-speaking RCM experts and used the Delphi method to seek consensus on which Spanish terms best describe RCM findings in this setting. The experts agreed on 52 terms: 28 for melanocytic lesions and 24 for nonmelanocytic lesions. The resulting terminology will facilitate homogenization, leading to a better understanding of structures, more standardized descriptions in clinical registries, and easier interpretation of clinical reports exchanged between dermatologists.

Is reflectance confocal microscopy useful in the differential diagnosis of extra facial lentigo maligna? A retrospective multicentric case-control study

BACKGROUND

Extra facial lentigo maligna (EF-LM) arises outside the head and neck area. EF-LM presents the classic histological features of lentigo maligna. The dermoscopic aspects of EF-LM have been poorly studied.

OBJECTIVE

The primary aims of our study were to analyse and describe the clinical, dermoscopic and confocal microscopy features of a series of histologically confirmed EF-LM.

METHOD

We conducted a retrospective and multicentric study. From our database, we selected 48 cases of thin melanomas on photodamaged skin with histological features of EF-LM of which clinical, dermoscopic and confocal microscopy images were available, and a control group of 45 lesions, that can be subjected to differential diagnosis such as solar lentigo, lichenoid keratosis, seborrheic keratosis and melanocytic nevi, of which dermoscopic and confocal microscope images were available.

RESULTS

Extra facial lentigo maligna had a higher prevalence of lentigo-like pigment patterns, angulated lines and zigzag structures. At confocal microscopy, LM-EF cases showed a higher prevalence of pagetoid spreading, round cells, dendritic cells in the epidermis, atypical cells at the dermo-epidermal junction, dendritic cells at the junction, meshwork pattern and elastosis. Our study shows that reflectance confocal microscopy (RCM) has a sensitivity of 90% and a specificity of 97% for the differential diagnosis of this type of melanoma.

CONCLUSIONS

Extra facial lentigo maligna does not have the classic dermoscopic features of superficial spreading melanoma, the most observed dermoscopic criteria are angulated lines and lentigo-like pigment patterns without lentigo-like border. RCM can be a valuable imaging tool for the evaluation of all those suspicion skin lesions at dermoscopy highlighting cellular atypia suggestive for melanoma.

Guidelines for the diagnosis and treatment of basal cell carcinoma: a GRADE approach for evidence evaluation and recommendations by the Italian Association of Medical Oncology

Basal cell carcinoma (BCC) is the most common form of cancer, with a high impact on the public health burden and social costs. Despite the overall prognosis for patients with BCC being excellent, if lesions are allowed to progress, or in a small subset of cases harboring an intrinsically aggressive biological behavior, it can result in local spread and significant morbidity, and conventional treatments (surgery and radiotherapy) may be challenging. When a BCC is not amenable to either surgery or radiotherapy with a reasonable curative intent, or when metastatic spread occurs, systemic treatments with Hedgehog inhibitors are available. These guidelines were developed, applying the GRADE approach, on behalf of the Italian Association of Medical Oncologists (AIOM) to assist clinicians in treating patients with BCC. They contain recommendations with regard to the diagnosis, treatment and follow-up, from primitive tumors to those locally advanced or metastatic, addressing the aspects of BCC management considered as priorities by a panel of experts selected by AIOM and other national scientific societies. The use of these guidelines in everyday clinical practice should improve patient care.

Implementing patient safety and quality improvement in dermatology. Part 1: Patient safety science

Patient safety (PS) and quality improvement (QI) have gained momentum over the last decade and are becoming more integrated into medical training, physician reimbursement, maintenance of certification, and practice improvement initiatives. While PS and QI are often lumped together, they differ in that PS is focused on preventing adverse events while QI is focused on continuous improvements to improve outcomes. The pillars of health care as defined by the 1999 Institute of Medicine report "To Err is Human: Building a Safer Health System" are safety, timeliness, effectiveness, efficiency, equity, and patient-centered care. Implementing a safety culture is dependent on all levels of the health care system. Part 1 of this CME will provide dermatologists with an overview of how PS fits into our current health care system and will include a focus on basic QI/PS terminology, principles, and processes. This article also outlines systems for the reporting of medical errors and sentinel events and the steps involved in a root cause analysis.

Photodynamic Therapy is an Effective Treatment of Facial Pigmented Actinic Keratosis

BACKGROUND

Actinic keratosis (AK), or solar keratosis, is a precancerous condition of the skin, mainly caused by excessive and chronic exposure to ultraviolet radiation. Pigmented AK (pAK) is a rare variant of AK. Photodynamic therapy (PDT) is widely used to treat the classical variant of AK, but very limited data are available on the use of PDT in patients with pAK. The objective of this study was to assess the usefulness of PDT in the treatment of pAK.

METHODS

The study included 16 patients with 20 pAK lesions treated with PDT. All skin lesions were clinically and dermatoscopically assessed for typical features characteristic of pAK. Reflectance confocal microscopy (RCM) was also used to assess keratinocyte atypia, confirm pAK diagnosis, and rule out other disease entities.

RESULTS

After three PDT sessions, the complete resolution of all clinical features of pAK was observed in 80% of the studied lesions. Dermatoscopically, 65% of the lesions achieved 100% response and no cellular atypia was seen in the follow-up RCM images of 85% of lesions.

CONCLUSIONS

Photodynamic therapy is an effective treatment modality for pAK in fair-skinned individuals.

Reflectance Confocal Microscopy and Electrical Impedance Spectroscopy in the Early Detection of Melanoma in Changing Lesions during Long-term Follow-up of Very High-risk Patients

Electrical impedance spectroscopy has clinical relevance in diagnosing malignancy in melanocytic lesions. Sixty-eight lesions with changes during digital follow-up of patients at very high risk of developing melanoma were prospectively included in this study from February to December 2016. Electrical impedance spectroscopy and reflectance confocal microscopy were performed to evaluate their performance in this subset of difficult lesions. Forty-six lesions were considered suspicious on reflectance confocal microscopy and were excised, of these, 19 were diagnosed as melanoma. Fifteen melanomas were detected by electrical impedance spectroscopy, while 4 received a score lower than 4, which suggested no malignancy. The addition of reflectance confocal microscopy improves accuracy while maintaining the same sensitivity. In the case of electrical impedance spectroscopy scores <4, lesions exhibiting changes in follow-up may need short-term monitoring or excision if dermoscopy shows criteria for melanoma. Results of electrical impedance spectroscopy in this subset of very early lesions should be carefully considered due to the risk of false negatives.

European consensus-based interdisciplinary guideline for melanoma. Part 1: Diagnostics: Update 2022

Cutaneous melanoma (CM) is potentially the most dangerous form of skin tumor and causes 90% of skin cancer mortality. A unique collaboration of multi-disciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organization for Research and Treatment of Cancer (EORTC) was formed to make recommendations on CM diagnosis and treatment, based on systematic literature reviews and the experts' experience. The diagnosis of melanoma can be made clinically and shall always be confirmed with dermatoscopy. If a melanoma is suspected, a histopathological examination is always required. Sequential digital dermatoscopy and full body photography can be used in high-risk patients to improve the detection of early melanoma. Where available, confocal reflectance microscopy can also improve clinical diagnosis in special cases. Melanoma shall be classified according to the 8th version of the American Joint Committee on Cancer classification. Thin melanomas up to 0.8 mm tumor thickness do not require further imaging diagnostics. From stage IB onwards, examinations with lymph node sonography are recommended, but no further imaging examinations. From stage IIC onwards whole-body examinations with computed tomography (CT) or positron emission tomography CT (PET-CT) in combination with brain magnetic resonance imaging are recommended. From stage III and higher, mutation testing is recommended, particularly for BRAF V600 mutation. It is important to provide a structured follow-up to detect relapses and secondary primary melanomas as early as possible. There is no evidence to define the frequency and extent of examinations. A stage-based follow-up scheme is proposed which, according to the experience of the guideline group, covers the optimal requirements, but further studies may be considered. This guideline is valid until the end of 2024.

Ex Vivo Fluorescence Confocal Microscopy in Specimens of the Liver: A Proof-of-Concept Study

Ex vivo Fluorescence Confocal Microscopy (FCM) is a technique providing high-resolution images of native tissues. The method is increasingly used in surgical settings in areas of dermatology and urology. Only a few publications exist about examinations of tumors and non-neoplastic lesions of the liver. We report on the application of FCM in biopsies, surgical specimens and autopsy material (33 patients, 39 specimens) of the liver and compare the results to conventional histology. Our preliminary examinations indicated a perfect suitability for tumor diagnosis (ĸ = 1.00) and moderate/good suitability for the assessment of inflammation (ĸ = 0.4-0.6) with regard to their severity and localization. Macro-vesicular steatosis was reliably detected, micro-vesicular steatosis tended to be underestimated. Cholestasis and eosinophilic granules in granulocytes were not represented in the scans. The tissue was preserved as native material and maintained its quality for downstream histological, immunohistological and molecular examinations. In summary, FCM is a material sparing method that provides rapid feedback to the clinician about the presence of tumor, the degree of inflammation and structural changes. This can lead to faster therapeutic decisions in the management of liver tumors, treatment of hepatitis or in liver transplant medicine.

Ultra-high-frequency ultrasound monitoring of melanomas arising in congenital melanocytic nevi: a case series

The aims of our study were to evaluate with ultra-high-frequency ultrasound (UHFUS) the ultrasound features of congenital melanocytic nevi (CMNs) and malignant melanomas (MMs) arising in CMNs and the correlation between ultrasonographic thickness and histological thickness in MMs. We evaluated 10 patients with small-medium CMNs and 10 patients with MMs arising in small-medium CMNs. We collected patient's data, clinical and dermoscopic features. The UHFUS was performed using a 70 MHz frequency probe to study the ecostructure, shape and vascularization. Breslow thickness was compared with ultrasonographic thickness. In the MMs group the following dermoscopic features were described: hyperpigmentation (n = 9), regression area (n = 6), whitish-blue veil (n = 5), thickened network (n = 5), irregular globules (n = 3), inverse network (n = 2) and striae (n = 1). Hyperpigmentation (n = n = 9), thickened network (n = 7), irregular globules (n = 5), regression area (n = 5), striae (n = 1) and whitish-blue veil (n = 1) were found in the CMNs group. The multicomponent pattern was present in both MMs (n = 4) and in CMNs (n = 5). Moreover, the parameters indicative of suspected malignancy were variously combined in the two groups, without showing significant differences in the statistical analysis; with the exception of the blue veil that correlated with the diagnosis of MM. Ultrasonoghaphic vascularization was an ever-present parameter in MMs (100%), with high intensity of intratumoral signal, as opposed to CMNs. We also found a statistically significant correlation between ultrasound thickness and Breslow thickness. In the future, this technique could implement the diagnostic preoperative phase of MMs arising in CMNs in combination with standard clinical-dermatoscopic evaluation.

Proportion of Thick versus Thin Melanomas as a Benchmarking Tool

BACKGROUND

The ratio of benign moles excised for each malignant melanoma diagnosed (number-needed-to-excise (NNE)) is a metric used to express the efficiency of diagnostic accuracy of melanoma. The literature suggests a progressive effort to reduce the NNE, thus raising concerns about missing early melanoma because the NNE does not capture the most significant outcome for melanoma prognosis, which is linked to the Breslow thickness. A lower NNE could reduce health costs related to melanoma diagnosis only if doing so does not increase the proportion of thicker melanomas.

OBJECTIVES

The diagnostic performance by two tertiary referral centres using the NNE and proportion of thick (Breslow thickness > 1 mm) versus thin (Breslow thickness ≤ 1 mm) excised melanoma (thick/thin ratio: TTR) was compared to determine if a lower NNE is associated with a greater proportion of thicker melanoma. Combining TTR with NNE allows a better estimate of the effectiveness in melanoma diagnosis, assessing both the overall cost for a given pool of excised melanomas and costs due to unnecessary nevi excision at a particular dermatology centre.

METHODS

Demographic data and Breslow thickness of excised melanoma were extracted from patient histologic records at two referral centres for melanoma (Parma Dermatology Unit and Ravenna and Meldola Skin Cancer Unit, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori. IRCCS (IRST)) on all skin tumours excised between 2002 and 2011 and diagnosed as melanoma or melanocytic nevus. NNE and TTR were calculated and compared among the considered variables. Logistic regression was used to assess the contribution of each variable in predicting a higher TTR.

RESULTS

Data from 16,738 excised lesions were analysed. The IRST Unit reported a mean NNE of 4.6, whereas the Parma Unit excised 10.6 nevi for each melanoma. No statistically significant differences existed in the mean (IRST Unit, 0.56 ± 0.89 mm; Parma Unit, 1.07 ± 2.2 mm) and median (range) Breslow thickness (IRST Unit, 0.4 (9) mm; Parma Unit 0.4 (30) mm). The TTR between centres was significantly different (Parma Unit, 24%; IRST Unit, 12%; p < 0.001). Based on logistic regression, the diagnosing centre was the most powerful factor in determining a thickness of >1 mm among diagnosed melanomas (OR = 1.8; 95% CI, 1.2-2.7; p < 0.01), with all other factors being equal. The NNE decreased at both centres from younger-to-older patients, whereas the TTR increased simultaneously; however, the increase in TTR was non-significantly related to NNE reduction after adjusting for confounders (age, gender, and localization).

CONCLUSIONS

A better diagnostic performance is capable of reducing the NNE and TTR, i.e., unnecessary excisions of melanocytic nevi can be reduced without increasing the risk of overlooking melanomas. The TTR, in addition to the NNE, allows stakeholders to better estimate the effectiveness in melanoma diagnosis because both overall costs for a given pool of excised melanomas and costs due for unnecessary nevi excision at a particular dermatology centre can be compared.

Melanocytic or Not? Dermoscopy and Reflectance Confocal Microscopy for Lesions Difficult to Diagnose: A Cross-Sectional Diagnostic Accuracy Study

Background

Different techniques for non-invasive skin examination and early diagnosis of skin lesions are available nowadays, being dermoscopy and reflectance confocal microscopy (RCM) the most diffused ones. Several studies supported the complementary use of dermoscopy and RCM that improves diagnostic accuracy when dealing with melanocytic lesions.

Objectives

To analyze RCM diagnostic accuracy in the differential diagnosis between melanocytic and non-melanocytic lesions.

Methods

This is a cohort selected cross-sectional study conducted at the Dermatology Unit of the University of Campania L. Vanvitelli, Naples, Italy, from 2012 to 2020. We searched the image database for all excised lesions for which the clinical and dermatoscopic differential diagnosis was between melanocytic and non-melanocytic and for which an RCM examination was performed. Sensitivity, specificity, and diagnostic accuracy values were estimated.

Results

The study included 53 cases that were found to have disagreement between clinical, histological and RCM diagnosis, of which, in 31 cases the differential diagnosis was melanocytic vs non-melanocytic lesion. The RCM reached a specificity of 87% (95% CI: 0.73-1) and a sensitivity of 62.5% (95% CI: 0.29-0.96) in the present sample. Diagnostic accuracy was 80.6% (95% CI: 0.67-0.94).

Conclusion

RCM has a high specificity in differentiating between difficult-to-diagnose melanocytic and non-melanocytic lesions.

Emerging Minimally Invasive Technologies for the Detection of Skin Cancer

With the increasing incidence of skin cancer, many noninvasive technologies to detect its presence have been developed. This review focuses on reflectance confocal microscopy (RCM), optical coherence tomography (OCT), high-frequency ultrasound (HFUS), electrical impedance spectroscopy (EIS), pigmented lesion assay (PLA), and Raman spectroscopy (RS) and discusses the basic principle, clinical applications, advantages, and disadvantages of each technology. RCM provides high cellular resolution and has high sensitivity and specificity for the diagnosis of skin cancer. OCT provides lower resolution than RCM, although its evaluable depth is deeper than that of RCM. RCM and OCT may be useful in reducing the number of unnecessary biopsies, evaluating the tumor margin, and monitoring treatment response. HFUS can be mainly used to delineate tumor depths or margins and monitor the treatment response. EIS provides high sensitivity but low specificity for the diagnosis of skin malignancies. PLA, which is based on the genetic information of lesions, is applicable for the detection of melanoma with high sensitivity and moderate-to-high specificity. RS showed high accuracy for the diagnosis of skin cancer, although more clinical studies are required. Advances in these technologies for the diagnosis of skin cancer can lead to the realization of optimized and individualized treatments.

Skin strata delineation in reflectance confocal microscopy images using recurrent convolutional networks with attention

Reflectance confocal microscopy (RCM) is an effective non-invasive tool for cancer diagnosis. However, acquiring and reading RCM images requires extensive training and experience, and novice clinicians exhibit high discordance in diagnostic accuracy. Quantitative tools to standardize image acquisition could reduce both required training and diagnostic variability. To perform diagnostic analysis, clinicians collect a set of RCM mosaics (RCM images concatenated in a raster fashion to extend the field view) at 4-5 specific layers in skin, all localized in the junction between the epidermal and dermal layers (dermal-epidermal junction, DEJ), necessitating locating that junction before mosaic acquisition. In this study, we automate DEJ localization using deep recurrent convolutional neural networks to delineate skin strata in stacks of RCM images collected at consecutive depths. Success will guide to automated and quantitative mosaic acquisition thus reducing inter operator variability and bring standardization in imaging. Testing our model against an expert labeled dataset of 504 RCM stacks, we achieved [Formula: see text] classification accuracy and nine-fold reduction in the number of anatomically impossible errors compared to the previous state-of-the-art.

Comparative Analysis of Diagnostic Techniques for Melanoma Detection: A Systematic Review of Diagnostic Test Accuracy Studies and Meta-Analysis

Melanoma has the highest mortality rate among skin cancers, and early-diagnosis is essential to maximize survival rate. The current procedure for melanoma diagnosis is based on dermoscopy, i.e., a qualitative visual inspection of lesions with intrinsic limited diagnostic reliability and reproducibility. Other non-invasive diagnostic techniques may represent valuable solutions to retrieve additional objective information of a lesion. This review aims to compare the diagnostic performance of non-invasive techniques, alternative to dermoscopy, for melanoma detection in clinical settings. A systematic review of the available literature was performed using PubMed, Scopus and Google scholar databases (2010-September 2020). All human, in-vivo, non-invasive studies using techniques, alternative to dermoscopy, for melanoma diagnosis were included with no restriction on the recruited population. The reference standard was histology but dermoscopy was accepted only in case of benign lesions. Attributes of the analyzed studies were compared, and the quality was evaluated using CASP Checklist. For studies in which the investigated technique was implemented as a diagnostic tool (DTA studies), the QUADAS-2 tool was applied. For DTA studies that implemented a melanoma vs. other skin lesions classification task, a meta-analysis was performed reporting the SROC curves. Sixty-two references were included in the review, of which thirty-eight were analyzed using QUADAS-2. Study designs were: clinical trials (13), retrospective studies (10), prospective studies (8), pilot studies (10), multitiered study (1); the remain studies were proof of concept or had undefined study type. Studies were divided in categories based on the physical principle employed by each diagnostic technique. Twenty-nine out of thirty-eight DTA studies were included in the meta-analysis. Heterogeneity of studies' types, testing strategy, and diagnostic task limited the systematic comparison of the techniques. Based on the SROC curves, spectroscopy achieved the best performance in terms of sensitivity (93%, 95% CI 92.8-93.2%) and specificity (85.2%, 95%CI 84.9-85.5%), even though there was high concern regarding robustness of metrics. Reflectance-confocal-microscopy, instead, demonstrated higher robustness and a good diagnostic performance (sensitivity 88.2%, 80.3-93.1%; specificity 65.2%, 55-74.2%). Best practice recommendations were proposed to reduce bias in future DTA studies. Particular attention should be dedicated to widen the use of alternative techniques to conventional dermoscopy.

Clinical Applications of In Vivo and Ex Vivo Confocal Microscopy

Confocal laser scanning microscopy (CLSM) has been introduced in clinical settings as a tool enabling a quasi-histologic view of a given tissue, without performing a biopsy. It has been applied to many fields of medicine mainly to the skin and to the analysis of skin cancers for both in vivo and ex vivo CLSM. In vivo CLSM involves reflectance mode, which is based on refractive index of cell structures serving as endogenous chromophores, reaching a depth of exploration of 200 μm. It has been proven to increase the diagnostic accuracy of skin cancers, both melanoma and non-melanoma. While histopathologic examination is the gold standard for diagnosis, in vivo CLSM alone and in addition to dermoscopy, contributes to the reduction of the number of excised lesions to exclude a melanoma, and to improve margin recognition in lentigo maligna, enabling tissue sparing for excisions. Ex vivo CLSM can be performed in reflectance and fluorescent mode. Fluorescence confocal microscopy is applied for “real-time” pathological examination of freshly excised specimens for diagnostic purposes and for the evaluation of margin clearance after excision in Mohs surgery. Further prospective interventional studies using CLSM might contribute to increase the knowledge about its application, reproducing real-life settings.

Segmentation of cellular patterns in confocal images of melanocytic lesions in vivo via a multiscale encoder-decoder network (MED-Net)

In-vivo optical microscopy is advancing into routine clinical practice for non-invasively guiding diagnosis and treatment of cancer and other diseases, and thus beginning to reduce the need for traditional biopsy. However, reading and analysis of the optical microscopic images are generally still qualitative, relying mainly on visual examination. Here we present an automated semantic segmentation method called "Multiscale Encoder-Decoder Network (MED-Net)" that provides pixel-wise labeling into classes of patterns in a quantitative manner. The novelty in our approach is the modeling of textural patterns at multiple scales (magnifications, resolutions). This mimics the traditional procedure for examining pathology images, which routinely starts with low magnification (low resolution, large field of view) followed by closer inspection of suspicious areas with higher magnification (higher resolution, smaller fields of view). We trained and tested our model on non-overlapping partitions of 117 reflectance confocal microscopy (RCM) mosaics of melanocytic lesions, an extensive dataset for this application, collected at four clinics in the US, and two in Italy. With patient-wise cross-validation, we achieved pixel-wise mean sensitivity and specificity of 74% and 92%, respectively, with 0.74 Dice coefficient over six classes. In the scenario, we partitioned the data clinic-wise and tested the generalizability of the model over multiple clinics. In this setting, we achieved pixel-wise mean sensitivity and specificity of 77% and 94%, respectively, with 0.77 Dice coefficient. We compared MED-Net against the state-of-the-art semantic segmentation models and achieved better quantitative segmentation performance. Our results also suggest that, due to its nested multiscale architecture, the MED-Net model annotated RCM mosaics more coherently, avoiding unrealistic-fragmented annotations.

Improving the prevention and diagnosis of melanoma on a national scale: A comparative study of performance in the United Kingdom and Australia

We undertook this study in light of an uncontrolled rise of melanoma incidence and mortality rates in the United Kingdom (UK). We aim to assess the effectiveness of prevention and early melanoma diagnosis in the UK's National Health Service (NHS) in comparison to the Australian system that has limited the melanoma rise. We compare the prevention campaigns against skin cancer and the stage at which melanoma is diagnosed. We analyse key drivers of early diagnosis. Overall, Australia has performed better than the UK and provides an example for the UK's NHS for better preventing melanoma and diagnosing it. Technologies under development, such as tele-dermatology and artificial intelligence applications, could aid in making melanoma early diagnosis easier, more cost-efficient, and lessen the burden on health systems. Diagnoses also provide the data to help public health officials target prevention programs.

Reflectance confocal microscopy evaluation of pigmented lesions on tattooed skin

The evaluation of pigmented lesions on tattooed skin poses a diagnostic challenge for dermatologists, as a nevus may be partially or completely obscured by tattoo pigment. Because of incidences of melanoma arising from tattooed skin, the current gold standard is to biopsy these lesions. Reflectance confocal microscopy (RCM) is a noninvasive imaging modality used in the diagnosis and management of skin diseases that may allow for diagnosis, while preserving the tattoo design. Retrospective chart review was conducted to identify pigmented lesions on or near tattooed skin that were evaluated with RCM. Confocal characteristics and diagnoses were recorded and analyzed. Nineteen lesions from 15 patients were retrospectively reviewed. Tattoo pigment did not hinder evaluation and diagnosis of pigmented lesions on RCM. About 94.7% of lesions were diagnosed as benign melanocytic nevi by an expert confocal reader. One lesion was confocally diagnosed as melanocytic nevus with atypia but was found to be an inflamed melanocytic nevus on histology. Tattoo pigment particles were differentiated from other hyper-refractile entities by an expert confocal reader based on size, morphology, and clinical correlation. RCM may provide a solution to the diagnostic challenge of pigmented lesions on or near tattooed skin.

Ex vivo confocal microscopy performs real-time assessment of renal biopsy in non-neoplastic diseases

BACKGROUND

Ex vivo confocal microscopy is a technique for tissue examination, which generates images of fresh samples with an optical resolution comparable to those obtained by conventional pathology. The objective of this study was to evaluate the feasibility of using ex vivo confocal microscopy in fusion mode (reflectance and fluorescence) and the H&E-like digital staining that is obtained for the analysis of non-neoplastic kidney biopsies.

METHODS

Twenty-four renal samples acquired from autopsies were scanned in a 4th generation ex vivo confocal microscopy device. The imaging process was completed in an average of three minutes.

RESULTS

Confocal images correlated very well to the corresponding conventional histological sections, both in normal tissue and in chronic lesions (glomerulosclerosis, fibrosis and tubular atrophy). The ex vivo confocal microscopy protocol did not add artifacts to the sample for the ulterior study with light microscopy, nor to the histochemical or immunohistochemical studies.

CONCLUSION

The ease and speed of grayscale and fluorescence image acquisition, together with the quality of the H&E-like digitally stained images obtained with this approach, suggest that this technique shows promise for use in clinical nephrology and renal transplantation.

Speckle-free, near-infrared portable confocal microscope

We have developed a portable confocal microscope (PCM) that uses an inexpensive near-infrared LED as the light source. Use of the spatially incoherent light source significantly reduced the speckle contrast. The PCM device was manufactured at the material cost of approximately $5000 and weighed only 1 kg. Lateral and axial resolutions were measured as 1.6 and 6.0 µm, respectively. Preliminary in vivo skin imaging experiment results showed that the PCM device could visualize characteristic cellular features of human skin extending from the stratum corneum to the superficial dermis. Dynamic imaging of blood flow in vivo was also demonstrated. The capability to visualize cellular features up to the superficial dermis is expected to facilitate evaluation and clinical adoption of this low-cost diagnostic imaging tool.

Non-invasive clinical and microscopic evaluation of the response to treatment with clobetasol cream vs. calcipotriol/betamethasone dipropionate foam in mild to moderate plaque psoriasis: an investigator-initiated, phase IV, unicentric, open, randomized clinical trial

BACKGROUND

Treatment response for psoriasis is typically evaluated using clinical scores. However, patients can relapse after clinical clearance, suggesting persistent inflammation. Dermoscopy, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) can non-invasively improve treatment response assessment.

OBJECTIVES

To compare the clinical and non-invasive microscopic features in a psoriatic target lesion treated with clobetasol cream or calcipotriol/betamethasone dipropionate foam (Cal/BD foam).

METHODS

Prospective, unicentric, open, randomized clinical trial comparing clinical data [total clinical score (TCS)] and microscopic data (dermoscopy, RCM and OCT) in psoriasis patients treated with clobetasol or Cal/BD foam.

RESULTS

We included 36 adult patients (22 men). At week 4, more patients treated with Cal/BD foam achieved TCS ≤1 than with clobetasol (63.2% vs. 18.8%, P = 0.016). Treatment satisfaction was higher with Cal/BD foam (P < 0.03). Microscopically, Cal/BD foam induced more reduction in epidermal thickness at week 4 (P < 0.049). Dilated horizontal blood vessels were more common with clobetasol than with Cal/BD foam at week 8 (69.2% vs. 31.2%, P = 0.159). If epidermal hyperplasia was noted at baseline, the response was poorer with clobetasol (P = 0.029).

LIMITATIONS

Small sample size, open study, imaging sampling bias.

CONCLUSION

Cal/BD foam is more effective than clobetasol, has better patient satisfaction and induces greater reduction in the hyperkeratosis/acanthosis, regardless of baseline epidermal hyperplasia.

Reporting regression with melanoma in situ: reappraisal of a potential paradox

Melanoma in situ (MIS) is a form of radial growth phase melanoma in which the proliferation of malignant cells is confined to the epidermis. Histologic features are invaluable in recognition of MIS. Regression occurs when the host's immune system attacks the primary melanocytic tumor cells via tumor infiltrate lymphocytes, resulting in a fibrotic component. Various criteria have been proposed to assess the extent of histologic regression. Some authors define regression based on histologic features of the dermis, which is inappropriate for MIS. Specific dermatoscopic findings of regression in MIS have been reported including peppering, grey-blue areas, white areas, and blue-whitish veils. Many studies assess the impact of histologic regression on invasive melanoma prognosis, but no studies to-date have considered the effect of histologic regression exclusively in patients with MIS. The literature to-date does not suggest evaluation and management should be modified if histologic regression is present in MIS. Studies specifically investigating the effect of histologic regression on MIS prognosis are needed to inform evidence-based practices.

Reflectance confocal microscopy: Principles, basic terminology, clinical indications, limitations, and practical considerations

Reflectance confocal microscopy (RCM) is a noninvasive imaging tool used for in vivo visualization of the skin. It has been extensively studied for use in the evaluation of equivocal cutaneous neoplasms to decrease the number of biopsy procedures in patients with benign lesions. Furthermore, its applications are broadening to include presurgical cancer margin mapping, tumor recurrence surveillance, monitoring of ablative and noninvasive therapies, and stratification of inflammatory disorders. With the approval of category I Current Procedural Terminology reimbursement codes for RCM image acquisition and interpretation, use of this technology has been increasingly adopted by dermatologists. The first article in this 2-part continuing medical education series highlights basic terminology, principles, clinical applications, limitations, and practical considerations in the clinical use of RCM technology.

Utilizing Machine Learning for Image Quality Assessment for Reflectance Confocal Microscopy

In vivo reflectance confocal microscopy (RCM) enables clinicians to examine lesions' morphological and cytological information in epidermal and dermal layers while reducing the need for biopsies. As RCM is being adopted more widely, the workflow is expanding from real-time diagnosis at the bedside to include a capture, store, and forward model with image interpretation and diagnosis occurring offsite, similar to radiology. As the patient may no longer be present at the time of image interpretation, quality assurance is key during image acquisition. Herein, we introduce a quality assurance process by means of automatically quantifying diagnostically uninformative areas within the lesional area by using RCM and coregistered dermoscopy images together. We trained and validated a pixel-level segmentation model on 117 RCM mosaics collected by international collaborators. The model delineates diagnostically uninformative areas with 82% sensitivity and 93% specificity. We further tested the model on a separate set of 372 coregistered RCM-dermoscopic image pairs and illustrate how the results of the RCM-only model can be improved via a multimodal (RCM + dermoscopy) approach, which can help quantify the uninformative regions within the lesional area. Our data suggest that machine learning-based automatic quantification offers a feasible objective quality control measure for RCM imaging.

Dermoscopy comparative approach for early diagnosis in familial melanoma: influence of MC1R genotype

BACKGROUND

MC1R polymorphisms interact with CDKN2A mutations modulating melanoma risk and contribute to a less suspicious clinical and dermoscopic appearance of melanomas. Different strategies, including dermoscopic comparative approach and digital monitoring, are used for the melanoma diagnosis in this context.

OBJECTIVE

To analyse the diagnostic accuracy of the morphologic approach and comparative approach in dermoscopy, and to detect melanoma in familial melanoma (FamMM) patients according to different genetic backgrounds.

METHODS

Two independent readers evaluated 415 lesions belonging to 25 FamMM: 26 melanomas (62% in situ, 36% early invasive) and 389 naevi, blinded for dermoscopic and histopathologic diagnosis, following two different steps. First step-Randomized: all lesions were randomly located in one single folder. Second step-Comparative approach: the lesions were clustered by patient. Sensitivity, specificity and number needed to excise (NNE) for melanoma diagnosis were calculated for both diagnostic strategies. Sensitivity and specificity were also assessed regarding the genetic background.

RESULTS

The comparative approach showed lower sensitivity compared to the morphologic approach (69.2 and 73.1 vs. 76.9 both readers) but better specificity (95.9 and 95.1 vs. 84.3 and 90.2, respectively). NNE was better in the comparative approach. The readers had more difficulties diagnosing lesions from CDKN2A mutation carriers with red hair colour (RHC) MC1R variants.

CONCLUSION

The comparative approach can be useful in high-risk patients to decrease the NNE. Early melanomas in CDKN2A carriers with RHC polymorphisms are more difficult to diagnose even with the comparative approach and benefit from the detection of changes during digital dermoscopy monitoring for early diagnosis.

Reflectance confocal microscopy terminology glossary for melanocytic skin lesions: A systematic review

BACKGROUND

There is lack of uniformity in the reflectance confocal microscopy (RCM) terminology for melanocytic lesions.

OBJECTIVE

To review published RCM terms for melanocytic lesions and identify redundant, synonymous terms.

METHODS

A systematic review of original research articles adhering to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines was conducted until August 15, 2018. Two investigators gathered all published RCM terms used to describe melanoma and melanocytic nevi. Synonymous terms were grouped based on similarity in definition and in histopathologic correlation.

RESULTS

Out of 156 full-text screened articles, 59 studies met the inclusion criteria. We identified 209 terms; 191 (91.4%) corresponding to high-magnification/cellular-level terms and 18 (8.6%) corresponding to low-magnification/architectural patterns terms. The overall average use frequency of RCM terms was 3.1 times (range, 1-31). By grouping of individual RCM terms based on likely synonymous definitions and by eliminating terms lacking clear definition, the total number of RCM terms could be potentially reduced from 209 to 40 terms (80.8% reduction).

LIMITATIONS

Non-English and non-peer-reviewed articles were excluded.

CONCLUSIONS

This systematic review of published RCM terms identified significant terminology redundancy. It provides the basis for subsequent terminology consensus on melanocytic neoplasms.

In vivo confocal microscopy of dermoscopic suspicious lesions in patients with xeroderma pigmentosum: A cross-sectional study

BACKGROUND

Xeroderma pigmentosum (XP) is a rare genetic disease characterized by extreme photosensitivity, resulting in a higher incidence of cutaneous tumors. Reflectance confocal microscopy (RCM) is a noninvasive imaging method for diagnosing cutaneous lesions.

OBJECTIVE

To explore the application of RCM in the follow-up of patients with XP.

METHODS

Patients with XP underwent RCM for suspicious lesions from January 2010 through April 2019. Lesions with malignant RCM features were excised, and the results were compared with their histopathologic features. Benign lesions on RCM were monitored every 3 months. We recorded the confocal features that were related to malignancy and specifically to melanoma.

RESULTS

A total of 61 suspicious lesions from 13 patients with XP were included. Thirty-three lesions (54%) were malignant (14 melanomas, 15 basal cell carcinomas, and 4 squamous cell carcinomas). Nonvisible papillae (OR, 11.8; 95% CI, 2.6-53.1; P = .001) and atypical cells at the dermoepidermal junction (OR, 11.7; 95% CI, 2.7-50.3; P = .001) were independent predictors of malignancy.

LIMITATIONS

There were limited numbers of patients and lesions. Most cases were retrospectively included, and some did not have a histologic analysis.

CONCLUSIONS

RCM is a valuable tool in the follow-up of patients with XP, reducing the need for excisions by 35%.

Basal cell carcinoma characterization using fusion ex vivo confocal microscopy: a promising change in conventional skin histopathology

BACKGROUND

Ex vivo confocal microscopy (CM) works under two modes, fluorescence and reflectance, allowing the visualization of different structures. Fluorescence CM (FCM) requires a contrast agent and has been used for the analysis of basal cell carcinomas (BCCs) during Mohs surgery. Conversely, reflectance CM (RCM) is mostly used for in vivo diagnosis of equivocal skin tumours. Recently, a new, faster ex vivo confocal microscope has been developed which simultaneously uses both lasers (fusion mode).

OBJECTIVES

To describe the BCC features identified on reflectance, fluorescence and fusion modes using this novel device. To determine the best mode to identify characteristic BCC features. To develop a new staining protocol to improve the visualization of BCC under the different modes.

METHODS

From September 2016 to June 2017, we prospectively included consecutive BCCs which were excised using Mohs surgery in our department. The lesions were evaluated using ex vivo CM after routine Mohs surgery. The specimens were first stained with acridine orange and then stained using both acetic acid and acridine orange.

RESULTS

We included 78 BCCs (35 infiltrative, 25 nodular, 12 micronodular, 6 superficial). Most features were better visualized with the fusion mode using the double staining. We also identified new CM ex vivo features, dendritic and plump cells, which have not been reported previously.

CONCLUSIONS

Our results suggest that nuclei characteristics are better visualized in FCM but cytoplasm and surrounding stroma are better visualized in RCM. Thus, the simultaneous evaluation of reflectance and fluorescence seems to be beneficial due to its complementary effect. What's already known about this topic? Ex vivo fluorescent confocal microscopy (FCM) is an imaging technique that allows histopathological analysis of fresh tissue. FCM is faster - at least one-third of the time - than conventional methods. FCM has a sensitivity of 88% and a specificity of 99% in detecting basal cell carcinomas (BCCs). What does this study add? Reflectance and fluorescence modes can be used simultaneously in a new ex vivo CM device. Each mode complements the other, resulting in an increase in the detection of BCC features in fusion mode. A combined staining using acetic acid and acridine orange enhances the visualization of tumour and stroma without damaging the tissue for further histopathological analysis.

Improvement of diagnostic confidence and management of equivocal skin lesions by integration of reflectance confocal microscopy in daily practice: Prospective study in 2 referral skin cancer centers

BACKGROUND

Reflectance confocal microscopy (RCM) allows accurate, noninvasive, in vivo diagnosis for skin cancer. However, its impact on physicians' diagnostic confidence and management is unknown.

OBJECTIVES

We sought to assess the physicians' diagnostic confidence and management before and after RCM of equivocal skin lesions.

METHODS

Prospective, 2-center, observational study. During clinical practice, 7 dermatologists recorded their diagnostic confidence level (measured in a scale from 0 to 10), diagnosis, and management before and after RCM of clinically/dermoscopically equivocal lesions that raised concern for skin cancer. We also evaluated the diagnostic accuracy before and after RCM.

RESULTS

We included 272 consecutive lesions from 226 individuals (mean age, 53.5 years). Diagnostic confidence increased from 6.2 to 8.1 after RCM (P < .001) when RCM confirmed or changed the diagnosis. Lesion management changed in 33.5% cases after RCM (to observation in 51 cases and to biopsy/excision in 31 cases). After RCM, the number needed to excise was 1.2. Sensitivity for malignancy before and after RCM was 78.2% and 85.1%, respectively. Specificity before and after RCM was 78.8% and 80%, respectively.

LIMITATIONS

Small sample size, real-life environment, and different levels of expertise among RCM users.

CONCLUSION

Physicians' diagnostic confidence and accuracy increased after RCM when evaluating equivocal tumors, frequently resulting in management changes while maintaining high diagnostic accuracy.

A roadmap for the clinical implementation of optical-imaging biomarkers

Clinical workflows for the non-invasive detection and characterization of disease states could benefit from optical-imaging biomarkers. In this Perspective, we discuss opportunities and challenges towards the clinical implementation of optical-imaging biomarkers for the early detection of cancer by analysing two case studies: the assessment of skin lesions in primary care, and the surveillance of patients with Barrett's oesophagus in specialist care. We stress the importance of technical and biological validations and clinical-utility assessments, and the need to address implementation bottlenecks. In addition, we define a translational roadmap for the widespread clinical implementation of optical-imaging technologies.

Non-invasive imaging in dermatology and the unique potential of raster-scan optoacoustic mesoscopy

In recent years, several non‐invasive imaging methods have been introduced to facilitate diagnostics and therapy monitoring in dermatology. The microscopic imaging methods are restricted in their penetration depth, while the mesoscopic methods probe deeper but provide only morphological, not functional, information. ‘Raster‐scan optoacoustic mesoscopy’ (RSOM), an emerging new imaging technique, combines deep penetration with contrast based on light absorption, which provides morphological, molecular and functional information. Here, we compare the capabilities and limitations of currently available dermatological imaging methods and highlight the principles and unique abilities of RSOM. We illustrate the clinical potential of RSOM, in particular for non‐invasive diagnosis and monitoring of inflammatory and oncological skin diseases.

Reflectance confocal microscopy made easy: The 4 must-know key features for the diagnosis of melanoma and nonmelanoma skin cancers

BACKGROUND

Reflectance confocal microscopy (RCM)-based skin cancer diagnosis requires proficiency.

OBJECTIVE

To identify a short list of key RCM features of skin cancers and test their diagnostic utility.

METHODS

We identified key RCM features through consensus among 6 experts using a modified Delphi method. To test the diagnostic utility of these RCM key features, 10 novice RCM readers evaluated a subset of 100 RCM cases from a retrospective data set of benign and malignant skin neoplasms.

RESULTS

From 56 features reported in the literature, the experts identified 18 RCM features as highly valuable for skin cancer diagnosis. On the basis of consensus definitions, these RCM features were further clustered into 2 melanoma-specific key features (atypical cells and dermoepidermal junction disarray), 1 basal cell carcinoma-specific key feature (basaloid cords/islands), and 1 squamous cell carcinoma-specific key feature (keratinocyte disarray). The novice reading study showed that the presence of at least 1 of the 4 key features was associated with an overall sensitivity for skin cancer diagnosis of 91%, with a sensitivity for melanoma of 93%, a sensitivity for basal cell carcinoma of 92%, and a sensitivity for squamous cell carcinoma of 67%, and an overall specificity of 57%.

LIMITATIONS

The consensus was based on only six RCM experts and the validation study was retrospective.

CONCLUSIONS

A consensus terminology short list identifying the 4 RCM key features for skin cancer diagnosis may facilitate dissemination of RCM to novice users.

The use of in vivo reflectance confocal microscopy for the diagnosis of melanoma

INTRODUCTION

The use of reflectance confocal microscopy (RCM) for imaging the skin non-invasively raised constantly during the last decade. One of the main field of application is skin cancer diagnosis, and in particular melanoma diagnosis. Several studies have investigated the diagnostic accuracy of RCM as compared to dermoscopic examination, and its value in enhancing early diagnosis of dermoscopic difficult melanomas. Areas covered: The purpose of this paper was to review the principles behind RCM image acquisition as well as to describe and discuss key RCM features of melanoma. Moreover, we conducted a literature search in order to highlight the current available evidence about RCM sensitivity and specificity in the diagnosis of melanoma. Expert commentary: During the last decade, we assisted at the increasing interest in non invasive imaging tools for the diagnosis of skin cancer. RCM is one of the most studied of a series of diagnostic methods that are emerging in the field of melanoma imaging. Most probably in the future, RCM will be more frequently available in tertiary referral centres, thus the knowledge of the pros and contra of the tool and its clinical applicability is of upmost importance in order to allow correct referrals with the final aim of improving diagnostic accuracy.

Diagnostic accuracy of ex vivo fluorescence confocal microscopy in Mohs surgery of basal cell carcinomas: a prospective study on 753 margins

BACKGROUND

Frozen histological sections are used for intraoperative margin assessment during Mohs surgery. Fluorescence confocal microscopy (FCM) is a new tool that offers a promising and faster alternative to frozen histology.

OBJECTIVES

To evaluate prospectively in a clinical setting the accuracy of FCM vs. frozen sections in margin assessment of basal cell carcinoma (BCC).

METHODS

Patients with BCC scheduled for Mohs surgery were prospectively enrolled. Freshly excised surgical specimens were examined by FCM and then frozen sections were evaluated. Permanent sections were obtained, in order to validate the sample technique. A blind re-evaluation was also performed for discordant cases. Sensitivity and specificity levels, as well as positive and negative predictive values (PPV and NPV, respectively), were calculated and receiver-operating characteristic curves generated.

RESULTS

We enrolled 127 BCCs in as many patients (40·2% females). Seven hundred and fifty-three sections were examined. All BCCs were located in the head and neck area. In evaluating the performance of FCM vs. frozen sections, sensitivity was 79·8%, specificity was 95·8%, PPV was 80·5% and NPV was 95·7% [area under the curve 0·88, 95% confidence interval 0·84-0·92 (P < 0·001)]. Forty-nine discordant cases were re-evaluated; 24 were false positive and 25 false negative. The performance of FCM and frozen sections was also evaluated according to the final histopathological assessment.

CONCLUSIONS

We found high levels of accuracy for FCM vs. frozen section evaluation in intraoperative BCC margin assessment during Mohs surgery. Some technical issues prevent the wide use of this technique, but new devices promise to overcome these limitations.

Diagnostic accuracy of reflectance confocal microscopy for pigmented skin lesions presenting dermoscopic features of cutaneous melanoma

Introduction

The incidence and mortality of melanoma are rising rapidly. Despite ongoing research and the introduction of new therapeutic methods, advanced melanoma is still considered incurable. Early detection and surgical excision of the tumor increases patients’ survival. Since the diagnostic protocol includes surgical excision of all suspicious lesions, it is burdened with a high rate of unnecessary excisions that cause unwanted scarring. This is why the development of accurate diagnostic techniques is crucial. The most common diagnostic tool in early diagnosis of cutaneous melanoma is dermoscopy, though there are emerging new techniques, such as reflectance confocal microscopy and optical coherence tomography.

Aim

To evaluate diagnostic accuracy of reflectance confocal microscopy as a secondary examination in melanocytic lesions previously diagnosed as melanomas by means of dermoscopy.

Material and methods

Forty-six melanocytic lesions presenting dermoscopic features of cutaneous malignant melanoma were examined by means of reflectance confocal microscopy.

Results

The RCM evaluation showed sensitivity at the level of 100% and specificity at 62%.

Conclusions

It can be estimated that double evaluation of melanocytic lesions by dermoscopy and reflectance confocal microscopy may allow up to 62% of unnecessary excisions to be avoided.

Malignant melanoma clinically mimicking pyogenic granuloma: comparison of clinical evaluation and histopathology

Amelanotic melanomas (AMMs) account for a small proportion of all melanomas. They pose a risk of delayed diagnosis and, consequently, poor prognosis. AMMs may atypically present as a pyogenic granuloma-like lesion. This study sought to investigate the prevalence and clinical and histological features of AMM masquerading as pyogenic granuloma. The database of a tertiary medical center was screened for all patients pathologically diagnosed with melanoma in 2005-2016. Those with a suspected primary (i.e. pre-excision) clinical diagnosis of pyogenic granuloma were identified, and their demographic, clinical, histologic, and outcome data were collected from the medical files. Of 2038 patients diagnosed with melanoma, 10 (∼0.5%) had a pyogenic granuloma-like AMM. The mean±SD age at lesion presentation was 56±18.9 years and the mean time from lesion appearance to diagnosis was 91.5±117.1 months. Nine tumors were located on the skin surface, and one on the oral mucosa. The mean lesion size was 19.6±14.1 mm and the mean Breslow's depth was 6.47±3.1 mm; all tumors presented in the vertical growth phase. Seven (70%) patients had lymph node involvement or metastasis at diagnosis. Two patients died of the disease within 1 year of diagnosis. Given the potential lethality of AMM and the benign nature of pyogenic granuloma, clinician recognition of pyogenic granuloma-like AMMs is crucial. In the presence of a pyogenic granuloma-like lesion, findings of older patient age and large tumor size should raise the index of suspicion and prompt a biopsy study, thereby ensuring early and accurate treatment.