The number of benign moles excised for each malignant melanoma: the number needed to treat

Fast raster-scan optoacoustic mesoscopy enables assessment of human melanoma microvasculature in vivo

Melanoma is associated with angiogenesis and vascular changes that may extend through the entire skin depth. Three-dimensional imaging of vascular characteristics in skin lesions could therefore allow diagnostic insights not available by conventional visual inspection. Raster-scan optoacoustic mesoscopy (RSOM) images microvasculature through the entire skin depth with resolutions of tens of micrometers; however, current RSOM implementations are too slow to overcome the strong breathing motions on the upper torso where melanoma lesions commonly occur. To enable high-resolution imaging of melanoma vasculature in humans, we accelerate RSOM scanning using an illumination scheme that is coaxial with a high-sensitivity ultrasound detector path, yielding 15 s single-breath-hold scans that minimize motion artifacts. We apply this Fast RSOM to image 10 melanomas and 10 benign nevi in vivo, showing marked differences between malignant and benign lesions, supporting the possibility to use biomarkers extracted from RSOM imaging of vasculature for lesion characterization to improve diagnostics.

Raster-Scanning-Optoacoustic Mesoscopy can be used to image the vasculature in skin cancer lesions but is limited by a long exposure time. Here; the authors increase the speed of the imaging using co-axial illumination and a high-sensitivity ultrasound detector path.

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.

Co-Design of a Trustworthy AI System in Healthcare: Deep Learning Based Skin Lesion Classifier

This paper documents how an ethically aligned co-design methodology ensures trustworthiness in the early design phase of an artificial intelligence (AI) system component for healthcare. The system explains decisions made by deep learning networks analyzing images of skin lesions. The co-design of trustworthy AI developed here used a holistic approach rather than a static ethical checklist and required a multidisciplinary team of experts working with the AI designers and their managers. Ethical, legal, and technical issues potentially arising from the future use of the AI system were investigated. This paper is a first report on co-designing in the early design phase. Our results can also serve as guidance for other early-phase AI-similar tool developments.

A study of dermal melanophages in childhood nevi. Reassessing so-called "pigment incontinence"

In inflammatory dermatoses, dermal melanophages (MLP) are ascribed to "pigment incontinence," with melanin "dropping down" from the epidermis. Although this is analogous to the "dropping down" of melanocytic nevus cells (Abtropfung), MLP in ordinary nevi have not been systematically studied-so "pigment incontinence" may not apply to MLP in nevi. A total of 31 childhood nevi identified by pediatricians and family practitioners were evaluated for the distribution of MLP. We tested the hypothesis that a dermal origin of the melanin in MLP is more likely than dropping down from the epidermis. In our cohort, 90.3% (28/31) of childhood nevi had dermal MLP, a significantly higher frequency, compared to 31/60 ordinary adult nevi (P < 0.0001). Superficial dermis was the most common location (P < 0.001). However, only six specimens had MLP restricted to the superficial dermis, significantly less than predicted by the theory that melanin drops down from the epidermis (P < 0.00001). We also evaluated perivascular MLP, since nerves run together with vessels in neurovascular bundles (NVB), and it has been showed that precursors of melanocytes migrate from the neural crest to the skin as nerve sheath stem cells. Superficial NVB MLP correlated with deep NVB bundle MLP (P < 0.05), suggesting that NVB MLP represent "tombstones" for superficial and deep dermal nevus cells. Deep dermal, deep NVB, and deep periadnexal MLP may be valid biological criteria for diagnosis of congenital type (prenatal) nevi. Viewing prenatal nevi in children as a neurocristopathy fits a major principle of pediatric pathology: childhood diseases should be studied and understood based on what happens during tissue development.

Assessment of Raman Spectroscopy for Reducing Unnecessary Biopsies for Melanoma Screening

A key challenge in melanoma diagnosis is the large number of unnecessary biopsies on benign nevi, which requires significant amounts of time and money. To reduce unnecessary biopsies while still accurately detecting melanoma lesions, we propose using Raman spectroscopy as a non-invasive, fast, and inexpensive method for generating a “second opinion” for lesions being considered for biopsy. We collected in vivo Raman spectral data in the clinical skin screening setting from 52 patients, including 53 pigmented lesions and 7 melanomas. All lesions underwent biopsies based on clinical evaluation. Principal component analysis and logistic regression models with leave one lesion out cross validation were applied to classify melanoma and pigmented lesions for biopsy recommendations. Our model achieved an area under the receiver operating characteristic (ROC) curve (AUROC) of 0.903 and a specificity of 58.5% at perfect sensitivity. The number needed to treat for melanoma could have been decreased from 8.6 (60/7) to 4.1 (29/7). This study in a clinical skin screening setting shows the potential of Raman spectroscopy for reducing unnecessary skin biopsies with in vivo Raman data and is a significant step toward the application of Raman spectroscopy for melanoma screening in the clinic.

An Analysis of Biopsies for Suspected Skin Cancer at a Tertiary Care Dermatology Clinic in the Western Cape Province of South Africa

BACKGROUND

Skin cancer is a growing health concern worldwide. It is the most common malignancy in South Africa and places a large burden on the public healthcare sector. There is a paucity of published scientific data on skin cancer in South Africa.

OBJECTIVES

To report the findings of biopsies performed in patients with suspected skin cancer attending the Tygerberg Academic Hospital (TAH) Dermatology outpatient department (OPD) in the Western Cape Province of South Africa. Methodology: A retrospective chart review identified all patients who underwent a biopsy for a suspected skin cancer diagnosis between September 2015 and August 2016 at the TAH dermatology OPD.

RESULTS

A total number of 696 biopsies from 390 participants were identified, of which 460 were histologically confirmed as malignant lesions. The proportion of clinically suspected skin cancers that were histologically confirmed as cancer was 68%. The most commonly occurring malignancies were basal cell carcinoma (BCC) (54.8%), squamous cell carcinoma (SCC) (18.9%), squamous cell carcinoma in-situ (SCCI) (8.0%), Kaposi's sarcoma (KS) (6.7%), malignant melanoma (MM) (6.1%), and keratoacanthoma (KA) (4.6%). The number needed to treat (NTT) for all cancers diagnosed and for MM was 1.5 and 4 respectively. BCC (89.3%) and KS (67.7%) was the most common skin cancer in the white and black population respectively. The ratio of BCC to SCC was 2.03.

CONCLUSION

This study provides valuable scientific data on the accuracy of skin cancer diagnosis, distribution and patient demographics in the Western Cape Province of South Africa, on which further research can be based. The study highlights the burden of skin cancer on this specific population group and calls for standardised reporting methods and increased surveillance of skin cancers.

Meta-analysis of number needed to treat for diagnosis of melanoma by clinical setting

OBJECTIVE

To provide a formal statistical comparison of the efficacy of melanoma detection among different clinical settings.

METHODS

A systematic review and meta-analysis of all relevant observational studies on number needed to treat (NNT) in relation to melanoma was performed in MEDLINE. We performed a random-effects model meta-analysis and reported NNTs with 95% confidence intervals (CIs). The subgroup analysis was related to clinical setting.

RESULTS

In all, 29 articles including a total of 398,549 biopsies/excisions were analyzed. The overall NNT was 9.71 (95% CI, 7.72-12.29): 22.62 (95% CI, 12.95-40.10) for primary care, 9.60 (95% CI, 6.97-13.41) for dermatology, and 5.85 (95% CI, 4.24-8.27) for pigmented lesion specialists.

LIMITATIONS

There is heterogeneity in data reporting and the possibility of missing studies. In addition, the incidence of melanoma varies among clinical settings, which could affect NNT calculations.

CONCLUSION

Pigmented lesion specialists have the lowest NNT, followed by dermatologists, suggesting that involving specialists in the diagnosis and treatment of pigmented skin lesions can likely improve patient outcomes.

Dermoscopy and the experienced clinicians

For several decades, melanoma diagnosis was based on symptoms rather than clinical features. In fact, until the 1970s melanoma was widely not recognized and only diagnosed when presenting as a large, ulcerated, and bleeding nodule. Today it is well known that ulceration and bleeding are symptoms of an advanced stage; thus, it comes not as a surprise that the prognosis of melanoma at that time was very poor. This paper was developed to recognize dermoscopy as an integrative part of the clinical examination, bearing in mind that naked eye diagnosis can change after dermoscopy outcomes, and to help clinicians avoid the concept: "If in doubt, cut it out".

Diagnostic effectiveness of dermoscopy performed by plastic surgery registrars trained in melanoma diagnosis

BACKGROUND

Dermoscopy improves sensitivity and specificity and helps in the early detection of melanoma and nonmelanoma skin cancers (NMSC). Because of the multidisciplinary approach to melanoma, plastic surgeons may be required to perform dermoscopy evaluation. For this reason, in some university hospitals, plastic surgeons in training might perform these evaluations. To assess the validity of digital dermoscopy conducted by plastic surgery registrars, the authors collected the diagnoses of excised lesions from a dermoscopy outpatient clinic, comparing results with literature.

METHODS

A total of 1094 consecutive dermoscopy evaluations performed at Padova University Hospital between 2015 and 2018 were included in the study. All examinations were carried out by 3 plastic surgery registrars who received comparable training on dermoscopy. Excised lesions were classified according to pathological reports.

RESULTS

Four hundred sixty-six lesions were excised, and of them, 224 (48%) were considered pathological or atypical lesions: 34 melanomas (15%), 83 dysplastic or uncertain significance nevi (37%), and 107 NMSC and their precursors (48%). Considering only the 347 pigmented lesions, 34% were malignant or dysplastic lesions. The number needed to treat (NNT) was 10. The nevi-to-melanoma ratio (NMR) was 8, and the malignant melanoma-to-melanoma in situ ratio (MM:MMIS ratio) was 0.36.

CONCLUSIONS

This retrospective study tested the performance of specifically trained plastic surgery registrars in the detection of malignant skin lesions. Compared to literature, the analysis reflects a good sensibility for melanoma, especially in early curable stages. Moreover, our study underlines quite a high number of total excisions, which could be explained by the "surgical imprinting" of plastic surgery registrars.

Evaluation of the Number-Needed-to-Biopsy Metric for the Diagnosis of Cutaneous Melanoma: A Systematic Review and Meta-analysis

Importance

To date, no concerted effort has been made to date to evaluate the literature on number-needed-to-biopsy (NNB) metrics, particularly to account for the differences in clinician type and melanoma prevalence in certain geographic locations.

Objective

To review and synthesize worldwide data for NNB for the diagnosis of cutaneous melanoma.

Data Source

MEDLINE, Embase, and PubMed databases were searched for English-language articles published worldwide from January 1, 2000, to November 28, 2018.

Study Selection

A total of 46 studies were included that addressed NNB for at least 3681 clinicians worldwide and included 455 496 biopsied tumors and 29 257 melanomas; primary care practitioner (PCP) data were only available from Australia.

Data Extraction and Synthesis

Articles were screened for eligibility, and possible overlapping data sets were resolved. Data extracted included clinician specialization, use of dermoscopy, geographic region and location-specific health care system, study design, number of benign tumors, number of melanomas, and NNB. The review followed the PRISMA guidelines.

Main Outcome and Measures

The NNB for the diagnosis of cutaneous melanoma.

Results

A total of 46 studies were included that addressed NNB for at least 3681 clinicians worldwide and included 455 496 biopsied tumors and 29 257 melanomas; primary care practitioner (PCP) data were only available from Australia. The reported NNB ranged from 2.2 to 287, and the weighted mean NNB for all included publications was 15.6. The exclusion of publications structured as all biopsied tumors, owing to variable data characterization, resulted in reported NNB ranging from 2.2 to 30.5, with a global weighted mean NNB of 14.8 for all clinicians, 7.5 for all dermatologists, 14.6 for Australian PCPs, and 13.2 for all US-based dermatological practitioners, including dermatologists and advanced practice professionals. The summary effect size (ES) demonstrates that a mean 4% of biopsies demonstrated melanoma for study stratum A (all biopsied skin tumors, ES, 0.04; 95% CI, 0.03-0.05), and a mean 12% of biopsies demonstrated melanoma for study strata B (melanocytic tumors on pathology review, ES, 0.12; 95% CI, 0.10-0.14) and C (clinical concern for melanoma, ES; 0.12; 95% CI, 0.09-0.14).

Conclusions and Relevance

The existing NNB for cutaneous melanoma appeared to vary widely worldwide, lacking standardization in the metric and its reporting, and according to clinician characteristics as well; the NNB of US-based clinicians may warrant further exploration.

Current and future applications of confocal laser scanning microscopy imaging in skin oncology

Confocal laser scanning microscopy (CLSM) is a modern imaging technique that enables the in vivo or ex vivo characterization of skin lesions located in the epidermis and superficial dermis with a high quasi-microscopic resolution. Currently, it is considered to be the most promising imaging tool for the evaluation of superficial skin tumors. The in vivo mode adds the advantage of noninvasive, dynamic, in real-time assessment of the tumor associated vasculature and inflammation. It offers the possibility to repeatedly examine the same skin area without causing any damage and to monitor disease progression and treatment outcome. Furthermore, this novel technology allows the evaluation of the entire lesion and can be used to guide biopsies and to define tumor margins before surgical excision or other invasive therapies. CLSM diagnostic features may differentiate between the various histologic subtypes of skin tumors and therefore helps in choosing the best therapeutic approach. In this study, we present the CLSM characteristic features of the most common melanocytic and non-melanocytic skin tumors, as well as future possible CLSM applications in the study of experimental skin tumorigenesis on animal models.

Characterisation and validation of Mel38; A multi-tissue microRNA signature of cutaneous melanoma

Background

Histopathologic examination of melanocytic neoplasms can be challenging and subjective, with no specific circulating or tissue-based biomarkers currently available. Recently, a circulating 38-microRNA profile of melanoma (Mel38) was described. In this study, Mel38 expression and its impact on downstream mRNA regulation in solid tissue is examined.

Methods

Mel38 was applied to archival, clinically-annotated, solid-tissue genomic datasets representing benign naevi, primary and metastatic melanoma. Statistical analysis of the signature in relation to disease status, patient outcome and molecular pathways was performed.

Results

Mel38 is able to stratify genomic data from solid tissue biopsies on the basis of disease status and differences in melanoma-specific survival. Experimentally-verified messenger-RNA targets of Mel38 also exhibit prognostic expression patterns and represent key molecular pathways and events in melanoma development and progression.

Conclusion

The Mel38 microRNA profile may have diagnostic and prognostic utility in solid tissue as well as being a robust circulating biomarker of melanoma.

Improving clinical diagnosis of early-stage cutaneous melanoma based on Raman spectroscopy

Background

Clinical diagnosis of early melanoma (Breslow thickness less than 0.8 mm) is crucial to disease-free survival. However, it is subjective and can be exceedingly difficult, leading to missed melanomas, or unnecessary excision of benign pigmented skin lesions. An objective technique is needed to improve the diagnosis of early melanoma.

Methods

We have developed a method to improve diagnosis of (thin) melanoma, based on Raman spectroscopy. In an ex vivo study in a tertiary referral (pigmented lesions) centre, high-wavenumber Raman spectra were collected from 174 freshly excised melanocytic lesions suspicious for melanoma. Measurements were performed on multiple locations within the lesions. A diagnostic model was developed and validated on an independent data set of 96 lesions.

Results

Approximately 60% of the melanomas included in this study were melanomas in situ. The invasive melanomas had an average Breslow thickness of 0.89 mm. The diagnostic model correctly classified all melanomas (including in situ) with a specificity of 43.8%, and showed a potential improvement of the number needed to treat from 6.0 to 2.7, at a sensitivity of 100%.

Conclusion

This work signifies an important step towards accurate and objective clinical diagnosis of melanoma and in particular melanoma with Breslow thickness <0.8 mm.

Automated decision support in melanocytic lesion management

An automated melanocytic lesion image-analysis algorithm is described that aims to reproduce the decision-making of a dermatologist. The utility of the algorithm lies in its ability to identify lesions requiring excision from lesions not requiring excision. Using only wavelet coefficients as features, and testing three different machine learning algorithms, a cohort of 250 images of pigmented lesions is classified based on expert dermatologists’ recommendations of either excision (165 images) or no excision (85 images). It is shown that the best algorithm utilises the Shannon4 wavelet coupled to the support vector machine, where the latter is used as the classifier. In this case the algorithm, utilising only 22 othogonal features, achieves a 10-fold cross validation sensitivity and specificity of 0.96 and 0.87, resulting in a diagnostic-odds ratio of 261. The advantages of this method over diagnostic algorithms–which make a melanoma/no melanoma decision–are twofold: first, by reproducing the decision-making of a dermatologist, the average number of lesions excised per melanoma among practioners in general can be reduced without compromising the detection of melanoma; and second, the intractable problem of clinically differentiating between many atypical dysplastic naevi and melanoma is avoided. Since many atypical naevi that require excision on clinical grounds will not be melanoma, the algorithm–in contrast to diagnostic algorithms–can aim for perfect specificities without clinical concerns, thus lowering the excision rate of non-melanoma. Finally, the algorithm has been implemented as a smart phone application to investigate its utility in clinical practice and to streamline the assimilation of hitherto unseen tested images into the training set.

Screening for malignant melanoma-a critical assessment in historical perspective

Screening for melanoma has been advocated for many years because early detection and excision have been regarded as the most important measure to lower mortality from that neoplasm. In the past decade, concern has been raised by epidemiologists that screening might result in excision chiefly of "inconsequential cancer," i.e., melanomas that would never have progressed into life-threatening tumors, a phenomenon referred to by the misleading term "overdiagnosis." Without any firm evidence, that speculation has been embraced worldwide, and incipient melanomas have been trivialized. At the same time, efforts at early detection of melanoma have continued and have resulted in biopsy of pigmented lesions at a progressively earlier stage, such as lesions with a diameter of only 2, 3, or 4 mm. Those tiny lesions often lack sufficient criteria for clinical and histopathologic diagnosis, the result being true overdiagnoses, i.e., misdiagnoses of melanocytic nevi as melanoma. This is especially true if available criteria for histopathologic diagnosis are diminuished even further by incomplete excision of lesions. The reliability of histopathologic diagnosis is far higher in excisional biopsies of lesions that were given some more time to develop changes that make them recognizable. Biopsy of pigmented lesions with a diameter of 6 mm has been found to result in a far higher yield of melanomas. In addition to better clinical judgment, slight postponement of biopsies bears the promise of substantial improvement of the reliability of histopathologic diagnosis, and of alleviating true overdiagnoses.

Melanoma screening: Informing public health policy with quantitative modelling

Australia and New Zealand share the highest incidence rates of melanoma worldwide. Despite the substantial increase in public and physician awareness of melanoma in Australia over the last 30 years–as a result of the introduction of publicly funded mass media campaigns that began in the early 1980s –mortality has steadily increased during this period. This increased mortality has led investigators to question the relative merits of primary versus secondary prevention; that is, sensible sun exposure practices versus early detection. Increased melanoma vigilance on the part of the public and among physicians has resulted in large increases in public health expenditure, primarily from screening costs and increased rates of office surgery. Has this attempt at secondary prevention been effective? Unfortunately epidemiologic studies addressing the causal relationship between the level of secondary prevention and mortality are prohibitively difficult to implement–it is currently unknown whether increased melanoma surveillance reduces mortality, and if so, whether such an approach is cost-effective. Here I address the issue of secondary prevention of melanoma with respect to incidence and mortality (and cost per life saved) by developing a Markov model of melanoma epidemiology based on Australian incidence and mortality data. The advantages of developing a methodology that can determine constraint-based surveillance outcomes are twofold: first, it can address the issue of effectiveness; and second, it can quantify the trade-off between cost and utilisation of medical resources on one hand, and reduced morbidity and lives saved on the other. With respect to melanoma, implementing the model facilitates the quantitative determination of the relative effectiveness and trade-offs associated with different levels of secondary and tertiary prevention, both retrospectively and prospectively. For example, I show that the surveillance enhancement that began in 1982 has resulted in greater diagnostic incidence and reduced mortality, but the reduced mortality carried a significant cost per life saved. I implement the model out to 2028 and demonstrate that the enhanced secondary prevention that began in 1982 becomes increasingly cost-effective over the period 2013–2028. On the other hand, I show that reductions in mortality achieved by significantly enhancing secondary prevention beyond 2013 levels are comparable with those achieved by only modest improvements in late-stage disease survival. Given the ballooning costs of increased melanoma surveillance, I suggest the process of public health policy decision-making–particularly with respect to the public funding of melanoma screening and discretionary mole removal–would be better served by incorporating the results of quantitative modelling.

[Management of benign melanocytic lesions as a melanoma prevention. Systematic review]

There is a growing concern and awareness of skin cancer. As a result, possibly unnecessary surgeries of melanocytic lesions are carried out as a prophylactic measure. We performed a systematic review of the medical literature to identify primary studies on the effectiveness and cost-effectiveness of surgery treatment of benign melanocytic lesions for melanoma prevention. We included 19 primary studies on surgical treatment of acquired melanocytic lesions and one economic evaluation. Indicators, such as number needed to treat and the malignancy ratio, depend on several factors such as specialty and experience of the physician, pressure from the patient or patient characteristics. Early diagnosis of melanoma is critical in preventing skin cancer. However, primary studies show through several indicators that there are factors that increase the proportion of lesions treated unnecessarily. Effectiveness can be improved by careful use of techniques to identify suspicious lesions and educational programs for physicians, especially in primary care.

BAM! Utilizing the frequency of Benign, Atypical and Malignant diagnoses for quality improvement in the histopathologic diagnosis of melanocytic neoplasms

BACKGROUND

Healthcare quality measures are metrics that quantify medical outcomes. There is a need for performance indicators in the diagnosis of melanocytic neoplasms. We sought to determine whether the atypical to malignant diagnosis ratio (AMR) and benign to malignant diagnosis ratio (BMR) could identify differences between practitioners within a group as well as individual diagnostic drift.

METHODS

Diagnoses of melanocytic neoplasms from 2013 and 2014 by two dermatopathologists were prospectively subclassified as benign, atypical or malignant and reported on a monthly basis to the pathologists. Case diagnoses of melanocytic neoplasms from 2012 and 2009 were retrospectively subclassified as benign, atypical or malignant for comparison.

RESULTS

A total of 33,169 cases were used in this study. Interpathologist AMR and BMR were significantly different. One pathologist demonstrated a significant increase in AMR over time.

CONCLUSION

AMR and BMR metrics are potential performance indicators that can measure pathologist uncertainty, identify diagnostic drift and provide a surrogate measure of the relative risk level of laboratory patient populations. If applied to multiple laboratories, AMR and BMR metrics could help inform physicians' choice of dermatopathology laboratory and provide a method for comparative analysis between laboratories.

Practical application of new technologies for melanoma diagnosis: Part I. Noninvasive approaches

Confirming a diagnosis of cutaneous melanoma requires obtaining a skin biopsy specimen. However, obtaining numerous biopsy specimens-which often happens in patients with increased melanoma risk-is associated with significant cost and morbidity. While some melanomas are easily recognized by the naked eye, many can be difficult to distinguish from nevi, and therefore there is a need and opportunity to develop new technologies that can facilitate clinical examination and melanoma diagnosis. In part I of this 2-part continuing medical education article, we will review the practical applications of emerging technologies for noninvasive melanoma diagnosis, including mobile (smartphone) applications, multispectral imaging (ie, MoleMate and MelaFind), and electrical impedance spectroscopy (Nevisense).

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

BACKGROUND

The number needed to treat (NNT) ratio is an effective method for measuring accuracy in melanoma detection. Dermoscopy reduces the number of false positives and subsequently unnecessary excisions. In vivo reflectance confocal microscopy (RCM) is a noninvasive technique that allows examination of the skin with cellular resolution.

OBJECTIVES

To assess the impact of RCM analysis on the number of equivocal lesions, assumed to be melanocytic, excised for every melanoma.

METHODS

Consecutive patients (n = 343) presenting with doubtful lesions were considered for enrolment. The lesions were analysed by dermoscopy and RCM, with histopathological assessment considered the reference standard. The main outcome was the NNT, calculated as the proportion of equivocal lesions excised for every melanoma.

RESULTS

Dermoscopy alone obtained a hypothetical NNT of 3·73; the combination of dermoscopy and RCM identified 264 equivocal lesions that qualified for excision, 92 of which were confirmed to be a melanoma, resulting in an NNT of 2·87, whereas the analysis of RCM images classified 103 lesions as melanoma, with a consequent NNT of 1·12. The difference in the reduction of this ratio was statistically significant between the three groups (P < 0·0001). There was no significant improvement in sensitivity when comparing the combination of dermoscopy and RCM with RCM alone (94·6% vs. 97·8%; P = 0·043). However, the differences between specificities were statistically significant (P < 1 × 10(-6) ), favouring RCM alone.

CONCLUSION

The addition of RCM analysis to dermoscopy reduces unnecessary excisions with a high diagnostic accuracy and could be a means for reducing the economic impact associated with the management of skin cancer.

Clinical triage of cutaneous squamous cell carcinoma and basal cell carcinoma to avoid treatment delay: value of an electronic booking system

BACKGROUND

Provisional clinical diagnosis is the first step in planning skin surgery. Different clinical priorities are given to basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). Discriminating between SCC and BCC can be difficult. The rate of misdiagnosis of SCC as BCC is reported as 5.7-87.6%, and can cause treatment delay. We have developed a web-based surgery booking system that requires clinical commitment to a putative differential diagnosis category, rather than a single diagnosis, at the time of consultation. This includes a crucial overlap category of 'SCC or SCC/BCC'.

AIM

To assess whether our system helped avoid treatment delay to patients with SCC, and to measure the number needed to treat (NNT).

METHODS

This was a retrospective analysis from April 2012 to August 2013, comprising all patients undergoing booked excisional surgery in our unit. The clinical triaging category was compared with the histological diagnosis. Sensitivity, specificity, positive predictive value, negative predictive value (NPV), NNT and mean Breslow thickness were calculated.

RESULTS

In total, 1455 lesions were excised, identifying 789 (54.2%) invasive malignancies (86 MM, 115 SCC, 583 BCC, 5 other), 100 in situ lesions and 150 dysplastic lesions. The majority (83.2%) of malignancies were designated into the correct malignant category. Misdiagnosis of SCC as BCC was 5.2%. Sensitivity and NPV for SCC were 94.8% and 99.4%, respectively. NNT was 1.26, 4.12 and 3.19 for BCC, SCC and MM respectively, and 1.73 for all malignancies. Mean invasive Breslow thickness was 1.29 mm [0.78 mm including melanoma in situ (MMIS)], and the MM to MMIS was 1.6.

CONCLUSION

An overlap triage category of 'SCC or SCC/BCC' helps to prevent delay in the treatment for patients with SCC.

[Sequential digital dermatoscopic imaging. How much time is required per patient?]

BACKGROUND

Melanoma screening is possible using the naked eye, a loupe, a dermatoscope or a sequential digital dermatoscopic imaging (SDDI) device. The latter provides photodocumentation and makes it possible to assess changes over time. One potential disadvantage of this method has been felt to be in the time expenditure per patient.

OBJECTIVES

Objective was to prospectively assess the time required for routine melanoma screening, using a SDDI device.

MATERIALS AND METHODS

All patients screened for melanoma using a SDDI system (Mole Max2) in a private dermatology practice during 1 year were included prospectively. The time needed per patient was measured. Suspicious lesions were excised and histologically evaluated. The number needed to treat (NNT) was calculated. Excisions performed exclusively due to cosmetic reasons were not included.

RESULTS

381 patients with 10,356 melanocytic lesions were documented using SDDI and clinically assessed (mean: 27.18 melanocytic lesions per patient; min:1, max:110). Mean time consumption per lesion was 15.4 s. (min:3, max:57) and per patient about 7 min. 98 suspicious lesions were excised, among them13 melanomas; yielding a NNT of 7.54.

CONCLUSIONS

SDDI can be easily integrated into the daily routine; a variety of systems are available. The time required is reasonable, about 7 min per patient and about 15 s per lesion. The quality of the evaluation is operator-dependent; it can be evaluated by determining the NNT. A major advantage of this diagnostic procedure is the photodocumentation which makes it possible to assess potential progression of a melanocytic lesion.

Histologic outcomes of excised moderate and severe dysplastic nevi

BACKGROUND

Dysplastic nevi (DN) have been a matter of controversy since their initial description in 1978 because of differences in the clinical and histological terminology, and large studies on histological outcomes of excising moderate to severely DN have not previously been described.

OBJECTIVE

To determine the clinical characteristics of DN and histologic outcomes of excised moderate and severe DN.

METHODS

Retrospective chart review of patients with DN or Clark's nevi at the Dermatology Department at Rutgers-Robert Wood Johnson Medical School in Somerset, New Jersey, from January 2009 to June 2012. Three hundred ninety-three lesions from 380 patients were included in this study.

MAIN OUTCOME MEASURE

Histologic results of excised moderate and severe DN.

RESULTS

Thirty-four percent of DN were excised because of the presence of moderate or severe atypia, personal history of melanoma, or both. None of the excised lesions showed evidence of melanoma; 81.6% of excisions showed scar or granulation tissue. Only 14% of excised lesions were found to have residual lesions, and 4.4% showed recurrent nevi.

CONCLUSION

In 134 excisions of moderate to severe DN, no melanoma was identified. Most of the excisions showed scar or granulation tissue. The rate of residual lesions after shave biopsy of moderate or severe DN was lower than after punch biopsy.

Canine olfactory detection of malignant melanoma

Our patient is a 75-year-old man who presented after his pet dog licked persistently at an asymptomatic lesion behind his right ear. Examination revealed a nodular lesion in the postauricular sulcus. Histology confirmed malignant melanoma, which was subsequently excised. Canine olfactory detection of human malignancy is a well-documented phenomenon. Advanced olfaction is hypothesised to explain canine detection of bladder, breast, colorectal, lung, ovarian, prostate and skin cancers. Further research in this area may facilitate the development of a highly accurate aid to diagnosis for many malignancies, including melanoma.

Using the 7-point checklist as a diagnostic aid for pigmented skin lesions in general practice: a diagnostic validation study

BACKGROUND

GPs need to recognise significant pigmented skin lesions, given rising UK incidence rates for malignant melanoma. The 7-point checklist (7PCL) has been recommended by NICE (2005) for routine use in UK general practice to identify clinically significant lesions which require urgent referral.

AIM

To validate the Original and Weighted versions of the 7PCL in the primary care setting.

DESIGN AND SETTING

Diagnostic validation study, using data from a SIAscopic diagnostic aid randomised controlled trial in eastern England.

METHOD

Adults presenting in general practice with a pigmented skin lesion that could not be immediately diagnosed as benign were recruited into the trial. Reference standard diagnoses were histology or dermatology expert opinion; 7PCL scores were calculated blinded to the reference diagnosis. A case was defined as a clinically significant lesion for primary care referral to secondary care (total 1436 lesions: 225 cases, 1211 controls); or melanoma (36).

RESULTS

For diagnosing clinically significant lesions there was a difference between the performance of the Original and Weighted 7PCLs (respectively, area under curve: 0.66, 0.69, difference = 0.03, P<0.001). For the identification of melanoma, similar differences were found. Increasing the Weighted 7PCL's cut-off score from recommended 3 to 4 improved detection of clinically significant lesions in primary care: sensitivity 73.3%, specificity 57.1%, positive predictive value 24.1%, negative predictive value 92.0%, while maintaining high sensitivity of 91.7% and moderate specificity of 53.4% for melanoma.

CONCLUSION

The Original and Weighted 7PCLs both performed well in a primary care setting to identify clinically significant lesions as well as melanoma. The Weighted 7PCL, with a revised cut-off score of 4 from 3, performs slightly better and could be applied in general practice to support the recognition of clinically significant lesions and therefore the early identification of melanoma.