Man against machine reloaded: performance of a market-approved convolutional neural network in classifying a broad spectrum of skin lesions in comparison with 96 dermatologists working under less artificial conditions

BACKGROUND

Convolutional neural networks (CNNs) efficiently differentiate skin lesions by image analysis. Studies comparing a market-approved CNN in a broad range of diagnoses to dermatologists working under less artificial conditions are lacking.

MATERIALS AND METHODS

One hundred cases of pigmented/non-pigmented skin cancers and benign lesions were used for a two-level reader study in 96 dermatologists (level I: dermoscopy only; level II: clinical close-up images, dermoscopy, and textual information). Additionally, dermoscopic images were classified by a CNN approved for the European market as a medical device (Moleanalyzer Pro, FotoFinder Systems, Bad Birnbach, Germany). Primary endpoints were the sensitivity and specificity of the CNN's dichotomous classification in comparison with the dermatologists' management decisions. Secondary endpoints included the dermatologists' diagnostic decisions, their performance according to their level of experience, and the CNN's area under the curve (AUC) of receiver operating characteristics (ROC).

RESULTS

The CNN revealed a sensitivity, specificity, and ROC AUC with corresponding 95% confidence intervals (CI) of 95.0% (95% CI 83.5% to 98.6%), 76.7% (95% CI 64.6% to 85.6%), and 0.918 (95% CI 0.866-0.970), respectively. In level I, the dermatologists' management decisions showed a mean sensitivity and specificity of 89.0% (95% CI 87.4% to 90.6%) and 80.7% (95% CI 78.8% to 82.6%). With level II information, the sensitivity significantly improved to 94.1% (95% CI 93.1% to 95.1%; P < 0.001), while the specificity remained unchanged at 80.4% (95% CI 78.4% to 82.4%; P = 0.97). When fixing the CNN's specificity at the mean specificity of the dermatologists' management decision in level II (80.4%), the CNN's sensitivity was almost equal to that of human raters, at 95% (95% CI 83.5% to 98.6%) versus 94.1% (95% CI 93.1% to 95.1%); P = 0.1. In contrast, dermatologists were outperformed by the CNN in their level I management decisions and level I and II diagnostic decisions. More experienced dermatologists frequently surpassed the CNN's performance.

CONCLUSIONS

Under less artificial conditions and in a broader spectrum of diagnoses, the CNN and most dermatologists performed on the same level. Dermatologists are trained to integrate information from a range of sources rendering comparative studies that are solely based on one single case image inadequate.

[Artificial intelligence and smartphone program applications (Apps) : Relevance for dermatological practice]

ADVANTAGES OF ARTIFICIAL INTELLIGENCE (AI)

With responsible, safe and successful use of artificial intelligence (AI), possible advantages in the field of dermato-oncology include the following: (1) medical work can focus on skin cancer patients, (2) patients can be more quickly and effectively treated despite the increasing incidence of skin cancer and the decreasing number of actively working dermatologists and (3) users can learn from the AI results. POTENTIAL DISADVANTAGES AND RISKS OF AI USE: (1) Lack of mutual trust can develop due to the decreased patient-physician contact, (2) additional time effort will be necessary to promptly evaluate the AI-classified benign lesions, (3) lack of adequate medical experience to recognize misclassified AI decisions and (4) recontacting a patient in due time in the case of incorrect AI classifications. Still problematic in the use of AI are the medicolegal situation and remuneration. Apps using AI currently cannot provide sufficient assistance based on clinical images of skin cancer.

REQUIREMENTS AND POSSIBLE USE OF SMARTPHONE PROGRAM APPLICATIONS

Smartphone program applications (apps) can be implemented responsibly when the image quality is good, the patient's history can be entered easily, transmission of the image and results are assured and medicolegal aspects as well as remuneration are clarified. Apps can be used for disease-specific information material and can optimize patient care by using teledermatology.

Human surface anatomy terminology for dermatology: a Delphi consensus from the International Skin Imaging Collaboration

BACKGROUND

There is no internationally vetted set of anatomic terms to describe human surface anatomy.

OBJECTIVE

To establish expert consensus on a standardized set of terms that describe clinically relevant human surface anatomy.

METHODS

We conducted a Delphi consensus on surface anatomy terminology between July 2017 and July 2019. The initial survey included 385 anatomic terms, organized in seven levels of hierarchy. If agreement exceeded the 75% established threshold, the term was considered 'accepted' and included in the final list. Terms added by the participants were passed on to the next round of consensus. Terms with <75% agreement were included in subsequent surveys along with alternative terms proposed by participants until agreement was reached on all terms.

RESULTS

The Delphi included 21 participants. We found consensus (≥75% agreement) on 361/385 (93.8%) terms and eliminated one term in the first round. Of 49 new terms suggested by participants, 45 were added via consensus. To adjust for a recently published International Classification of Diseases-Surface Topography list of terms, a third survey including 111 discrepant terms was sent to participants. Finally, a total of 513 terms reached agreement via the Delphi method.

CONCLUSIONS

We have established a set of 513 clinically relevant terms for denoting human surface anatomy, towards the use of standardized terminology in dermatologic documentation.

Dermatoskopie, sequenzielle Videodermatoskopie, Ganzkörperfotografie, künstliche Intelligenz – was bringt uns die Zukunft?

Die Dermatoskopie ist mittlerweile ein fester Bestandteil einer jeden dermatologischen Untersuchung. Mit dieser Technik konnten die Früherkennung von Malignomen der Haut und deren Vorstufen deutlich verbessert und unnötige Exzisionen benigner Hautläsionen reduziert werden. Der Einsatz der Dermatoskopie umfasst mittlerweile auch die Beurteilung von entzündlichen und parasitären Dermatosen sowie Haarerkrankungen. Bei definierten Risikogruppen für ein Melanom sollte der Zwei-Schritte-Algorithmus, bestehend aus Ganzkörperfotografie und Videodermatoskopie, in entsprechenden Zeitintervallen zur Anwendung kommen. Mit dieser Methode können Melanome meist in einem sehr frühen Stadium entdeckt werden, da Veränderungen bestehender Muttermale sowie neu entstandene Läsionen früher festgestellt werden. In den letzten Jahren konnten mehrere Studien nachweisen, dass speziell geschulte neuronale Netzwerke Malignome der Haut, insbesondere Melanome, mit einer sehr hohen Treffsicherheit diagnostizieren können. Wie diese Computer-gestützte Diagnostik mithilfe einer künstlichen Intelligenz in den klinischen Alltag integriert werden kann und welche Vorteile sich hiervon ableiten lassen, ist derzeit noch nicht geklärt.

Diagnostic performance of a deep learning convolutional neural network in the differentiation of combined naevi and melanomas

BACKGROUND

Deep learning convolutional neural networks (CNN) may assist physicians in the diagnosis of melanoma. The capacity of a CNN to differentiate melanomas from combined naevi, the latter representing well-known melanoma simulators, has not been investigated.

OBJECTIVE

To assess the diagnostic performance of a CNN when used to differentiate melanomas from combined naevi in comparison with dermatologists.

METHODS

In this study, a CNN with regulatory approval for the European market (Moleanalyzer-Pro, FotoFinder Systems GmbH, Bad Birnbach, Germany) was used. We attained a dichotomous classification (benign, malignant) in dermoscopic images of 36 combined naevi and 36 melanomas with a mean Breslow thickness of 1.3 mm. Primary outcome measures were the CNN's sensitivity, specificity and the diagnostic odds ratio (DOR) in comparison with 11 dermatologists with different levels of experience.

RESULTS

The CNN revealed a sensitivity, specificity and DOR of 97.1% (95% CI [82.7-99.6]), 78.8% (95% CI [62.8-89.1.3]) and 34 (95% CI [4.8-239]), respectively. Dermatologists showed a lower mean sensitivity, specificity and DOR of 90.6% (95% CI [84.1-94.7]; P = 0.092), 71.0% (95% CI [62.6-78.1]; P = 0.256) and 24 (95% CI [11.6-48.4]; P = 0.1114). Under the assumption that dermatologists use the CNN to verify their (initial) melanoma diagnosis, dermatologists achieve an increased specificity of 90.3% (95% CI [79.8-95.6]) at an almost unchanged sensitivity. The largest benefit was observed in 'beginners', who performed worst without CNN verification (DOR = 12) but best with CNN verification (DOR = 98).

CONCLUSION

The tested CNN more accurately classified combined naevi and melanomas in comparison with trained dermatologists. Their diagnostic performance could be improved if the CNN was used to confirm/overrule an initial melanoma diagnosis. Application of a CNN may therefore be of benefit to clinicians.

Standardization of dermoscopic terminology and basic dermoscopic parameters to evaluate in general dermatology (non-neoplastic dermatoses): an expert consensus on behalf of the International Dermoscopy Society

BACKGROUND

Over the last few years, several articles on dermoscopy of non-neoplastic dermatoses have been published, yet there is poor consistency in the terminology among different studies.

OBJECTIVES

We aimed to standardize the dermoscopic terminology and identify basic parameters to evaluate in non-neoplastic dermatoses through an expert consensus.

METHODS

The modified Delphi method was followed, with two phases: (i) identification of a list of possible items based on a systematic literature review and (ii) selection of parameters by a panel of experts through a three-step iterative procedure (blinded e-mail interaction in rounds 1 and 3 and a face-to-face meeting in round 2). Initial panellists were recruited via e-mail from all over the world based on their expertise on dermoscopy of non-neoplastic dermatoses.

RESULTS

Twenty-four international experts took part in all rounds of the consensus and 13 further international participants were also involved in round 2. Five standardized basic parameters were identified: (i) vessels (including morphology and distribution); (ii) scales (including colour and distribution); (iii) follicular findings; (iv) 'other structures' (including colour and morphology); and (v) 'specific clues'. For each of them, possible variables were selected, with a total of 31 different subitems reaching agreement at the end of the consensus (all of the 29 proposed initially plus two more added in the course of the consensus procedure).

CONCLUSIONS

This expert consensus provides a set of standardized basic dermoscopic parameters to follow when evaluating inflammatory, infiltrative and infectious dermatoses. This tool, if adopted by clinicians and researchers in this field, is likely to enhance the reproducibility and comparability of existing and future research findings and uniformly expand the universal knowledge on dermoscopy in general dermatology. What's already known about this topic? Over the last few years, several papers have been published attempting to describe the dermoscopic features of non-neoplastic dermatoses, yet there is poor consistency in the terminology among different studies. What does this study add? The present expert consensus provides a set of standardized basic dermoscopic parameters to follow when evaluating inflammatory, infiltrative and infectious dermatoses. This consensus should enhance the reproducibility and comparability of existing and future research findings and uniformly expand the universal knowledge on dermoscopy in general dermatology.

Pregnancy as a driver for melanoma

Whether or not pregnancy favours the occurrence and growth of melanoma is a source of controversy in the literature. Several case reports have shown dramatic courses of diseases in pregnancy. We present a case of a 36-year-old woman with multiple naevi with one melanoma detected in 2009 in the first trimester and a second primary melanoma in 2010 in the third trimester of her pregnancy. Both lesions have been present for at least 5 years and have been interpreted as dysplastic naevi. Because of their growth during pregnancy they were removed. No metastatic disease has been found between 2010 and early 2017. This case shows the difficulty of detecting melanomas in pregnancy, particularly when they mimic dysplastic naevi in women with multiple naevi, who are at higher risk. Therefore, we suggest that pregnant women with numerous naevi should be precautious of any changes of their naevi in size, shape and colour. Every suspicious lesion should be either excised or documented/monitored carefully, for example with sequential digital dermoscopy imaging.

The value of reflectance confocal microscopy in diagnosis of flat pigmented facial lesions: a prospective study

BACKGROUND

Flat pigmented facial lesions are difficult to diagnose even with dermatoscopy. It is controversial how additional information obtained by in vivo reflectance confocal microscopy (RCM) impacts the diagnosis and management.

OBJECTIVE

To examine what in vivo reflectance confocal microscopy of flat pigmented facial lesions adds to clinical examination using dermatoscopy including digital dermatoscopic monitoring.

METHODS

We prospectively collected 70 cases of flat pigmented facial lesions and recorded diagnoses and management decisions by experts based on direct clinical examination aided by dermatoscopy including digital dermatoscopic monitoring and by remote experts who reviewed the corresponding confocal images. The expert confocal readers were blinded to the clinical and dermatoscopic appearance of the lesion.

RESULTS

The sensitivity of dermatoscopy plus digital dermatoscopic monitoring was 95.0% (95% CI 75.13% to 99.87%) and the specificity was 84.0% (95% CI 70.89% to 92.83%). The sensitivity of RCM was 95.0% (95% CI 75.13% to 99.87%) and the specificity was 82.0% (95% CI 68.56% to 91.42%).

CONCLUSION

Although most flat pigmented facial lesions can be managed by clinical examination and dermatoscopy alone, confocal microscopy is a useful adjunct in selected lesions. If RCM is not correlated with clinical and dermatoscopic information, there is risk of overdiagnosis of actinic keratosis, however.

Two years' experience with Web-based teleconsulting in dermatology

A non-commercial teledermatology network based on store-and-forward operation was established in April 2002. The aim was to create an easy-to-use platform for teleconsultation services, where physicians could seek diagnostic advice in dermatology from a pool of expert consultants and where they could present and discuss challenging dermatology cases with special emphasis on diagnosis and therapy. An online moderated discussion forum was added in October 2003. During the first two years, 348 health-care professionals from 45 countries registered to use the Website. A total of 783 requests for consultations were answered; 285 requests concerned pigmented skin lesions, 440 requests were from the whole range of clinical dermatology and 58 requests were about non-melanoma skin cancer. Of a total of 133 requests analysed, 80 (60%) were answered within one day, 47 (35%) within one week, five (4%) within two weeks and one (1%) consultation was answered in more than two weeks. Our experience with a discretionary, non-commercial, multilingual Website for open-access teleconsulting in dermatology appears to be successful. The Website represents an example of user-generated content, together with active interaction between users, who can present and discuss cases with remote colleagues.

Efficacy of superficial and deep regional hyperthermia combined with systemic chemotherapy and radiotherapy in metastatic melanoma

BACKGROUND AND OBJECTIVE

Response rates of cutaneous-subcutaneous or lymph node metastases of melanoma to systemic chemotherapy are rather low. We report our clinical experience with superficial and deep regional hyperthermia in combination with radiotherapy and/or chemotherapy with carboplatin.

PATIENTS/METHODS

We treated 15 patients with metastatic melanoma (6 men, 9 women; age 39-84 years, mean age 60 years) by using superficial or deep regional hyperthermia produced by electromagnetic energy. Superficial hyperthermia was delivered to skin or lymph node metastases in combination with radiochemotherapy in 12 patients, while deep regional hyperthermia was administered with an annular array applicator to lymph node metastases either in combination with radiochemotherapy (1 patient) or with carboplatin alone (2 patients). The clinical response was assessed by clinical evaluation and/or computer tomography and/or ultrasonography at monthly intervals.

RESULTS

Both superficial and deep regional hyperthermia was well tolerated. We observed 5 complete local remissions (34%), 6 partial local remissions (40%) and 2 patients with stable disease (13%). The best results were obtained in cutaneous or retroperitoneal metastases.

CONCLUSIONS

Local response can be achieved in inoperable metastatic melanoma using superficial or deep regional hyperthermia in combination with radiochemotherapy or chemotherapy.

The clinical and dermoscopic features of invasive cutaneous squamous cell carcinoma depend on the histopathological grade of differentiation

BACKGROUND

Little is known about the variability of the dermoscopic criteria of squamous cell carcinoma (SCC) according to the histopathological differentiation grade.

OBJECTIVES

To evaluate whether specific dermoscopic criteria can predict the diagnosis of poorly differentiated SCC compared with well- and moderately differentiated SCC.

METHODS

Clinical and dermoscopic images of SCCs were retrospectively evaluated for the presence of predefined criteria. Univariate and adjusted odds ratios were calculated. Discriminant functions were used to plot receiver-operator characteristic curves.

RESULTS

Of 143 SCCs included, 48 (33·5%) were well differentiated, 45 (31·5%) were moderately differentiated and 50 (35·0%) were poorly differentiated. Flat tumours had a fourfold increased probability of being poorly differentiated. Dermoscopically, the presence of a predominantly red colour posed a 13-fold possibility of poor differentiation, whereas a predominantly white and white-yellow colour decreased the odds of poorly differentiated SCC by 97% each. The presence of vessels in more than 50% of the tumour's surface, a diffuse distribution of vessels and bleeding were significantly associated with poor differentiation, while scale/keratin was a potent predictor of well- or moderately differentiated tumours.

CONCLUSIONS

Dermoscopy may be regarded as a reliable preoperative tool to distinguish poorly from well- and moderately differentiated SCC. Given that poor differentiation of SCC represents an independent risk factor for recurrence, metastasis and disease-specific death, identifying poorly differentiated tumours in vivo may enhance their appropriate management.

Proposal for a clinical-dermoscopic classification of scalp naevi

BACKGROUND

Recent research suggests that scalp naevi differ with respect to their epidemiology, patient characteristics and morphological patterns, but currently a classification of scalp naevi is lacking.

OBJECTIVES

To investigate the prevalence, together with clinical and dermoscopic features, of scalp naevi detected in persons attending a skin cancer screening programme, and to elaborate a classification of scalp naevi based on their most common morphological patterns.

METHODS

Participants were recruited during the melanoma prevention programme 'sun watch' of Austrian Cancer Aid in Styria. Each participant received a clinical and dermoscopic total-body skin examination including the scalp. For each participant, demographics and clinical characteristics including number of scalp naevi were recorded. Clinical and dermoscopic photographs of at least one scalp naevus per participant were taken and evaluated for specific clinical and dermoscopic features.

RESULTS

In total 867 subjects, including 119 participants (13·7%) with scalp naevi, participated in the study. Compared with those without scalp naevi, subjects with scalp naevi were significantly younger, were more often men and more often exhibited congenital naevi on the body (P < 0·01 for all). Analysis of the clinical and dermoscopic variability of scalp naevi allowed for a proposal to classify scalp naevi into six main groups, namely common, papillomatous, eclipse, congenital, blue and atypical naevus.

CONCLUSIONS

Scalp naevi can be classified into six morphological groups; scalp lesions deviating from these six main patterns should be carefully managed to rule out melanoma.

Assessment of changes in lentigo maligna during radiotherapy by in-vivo reflectance confocal microscopy: a pilot study

BACKGROUND

Radiotherapy is an effective treatment for therapy of lentigo maligna (LM).

OBJECTIVES

To investigate the usefulness of in-vivo reflectance confocal microscopy (RCM) in radiotherapy of LM and document the changes within the lesions during treatment.

METHODS

A total of six lesions in six patients were investigated by RCM before, during and after radiotherapy. For diagnostic assessment three observers with experience in RCM diagnosis, blinded as to the stage of treatment, assessed the RCM images of each lesion and documented the findings by consensus.

RESULTS

Epidermal disarray worsened in three patients during radiotherapy and superficial necrosis was observed in four patients. Large pagetoid round/dendritic cells decreased or even vanished during or after radiotherapy. Dilated vessels and apoptotic cells were seen in all patients during radiotherapy as well as an increase of inflammatory cells in the epidermis and dermis in most of the patients. Dendritic cells with small dendrites were observed during radiotherapy in all patients with an increase in number in three patients. Melanophages appeared in five patients at least once during the examination period. All RCM images were assessed correctly by the three observers.

CONCLUSIONS

Reflectance confocal microscopy is a useful method to visualize changes during and after radiotherapy and might also be used for early detection of potential treatment failures. In addition, it might be helpful in planning radiotherapy.

Clinical performance of the Nevisense system in cutaneous melanoma detection: an international, multicentre, prospective and blinded clinical trial on efficacy and safety

BACKGROUND

Even though progress has been made, the detection of melanoma still poses a challenge. In light of this situation, the Nevisense electrical impedance spectroscopy (EIS) system (SciBase AB, Stockholm, Sweden) was designed and shown to have the potential to be used as an adjunct diagnostic tool for melanoma detection.

OBJECTIVES

To assess the effectiveness and safety of the Nevisense system in the distinction of benign lesions of the skin from melanoma with electrical impedance spectroscopy.

METHODS

This multicentre, prospective, and blinded clinical study was conducted at five American and 17 European investigational sites. All eligible skin lesions in the study were examined with the EIS-based Nevisense system, photographed, removed by excisional biopsy and subjected to histopathological evaluation. A postprocedure clinical follow-up was conducted at 7 ± 3 days from the initial measurement. A total of 1951 patients with 2416 lesions were enrolled into the study; 1943 lesions were eligible and evaluable for the primary efficacy end point, including 265 melanomas - 112 in situ and 153 invasive melanomas with a median Breslow thickness of 0·57 mm [48 basal cell carcinomas (BCCs) and seven squamous cell carcinomas (SCCs)].

RESULTS

The observed sensitivity of Nevisense was 96·6% (256 of 265 melanomas) with an exact one-sided 95% lower confidence bound estimated at 94·2% and an observed specificity of 34·4%, and an exact two-sided 95% confidence bound estimated at 32·0-36·9%. The positive and negative predictive values of Nevisense were 21·1% and 98·2%, respectively. The observed sensitivity for nonmelanoma skin cancer was 100% (55 of 48 BCCs and seven SCCs) with an exact two-sided 95% confidence bound estimated at 93·5-100·0%.

CONCLUSIONS

Nevisense is an accurate and safe device to support clinicians in the detection of cutaneous melanoma.

Mobile teledermatology helping patients control high-need acne: a randomized controlled trial

BACKGROUND

Acne is an important health issue with a major psychological impact in addition to the physical problems it causes.

OBJECTIVES

To investigate the superiority of mobile teledermatology in the care of patients with high-need facial acne in comparison to outpatient services with particular attention to treatment efficacy, safety, and patient compliance. Further, patient satisfaction with remote care was evaluated.

METHODS

Sixty-nine consecutive patients (f: 25, m: 44, median age: 19 years, range: 13-37 years) were randomly allocated to either the teleconsultation (TCA) or the outpatient consultation (OCA) arm of the trial to receive isotretinoin treatment in weight and severity-dependent dosages over 24 weeks. Acne grading was performed by one examiner using the Global Acne Severity Scale (GEA) and the total lesion counting (TLC).

RESULTS

Due to noncompliance issues, 17 of 69 (24.6%) patients were excluded from the study, of who 10 had been assigned to the TCA (10/34; 29.4%) and 7 to the OCA (7/35; 20%). Both, in the TCA (GEA-score: ∆ = 2.25; TLC: ∆ = 89.08) and in the OCA (GEA-score: ∆ = 2.0; TLC: ∆ = 91.21) excellent and almost equivalent therapeutic outcomes were achieved. In the TCA, however, less patients experienced adverse reactions (P = 0.55). Even though additional live supervision would have been appreciated in some teledermatology cases, patients were satisfied with the mobile service and no consultation request was created.

CONCLUSION

Mobile teledermatology is an efficient, safe and well-accepted tool among patients with high-need acne constituting at least a valuable adjunct to outpatient care services. Further larger studies would be useful to confirm our findings.

Analysis of clinical, dermoscopic and histopathological features of primary melanomas of patients with metastatic disease--a retrospective study at the Department of Dermatology, Medical University of Graz, 2000-2010

BACKGROUND

Incidence rates of malignant melanoma have been increasing worldwide and metastatic melanoma is still a significant problem despite widespread prevention programmes.

OBJECTIVES

We made a systemic review of all metastasized melanoma patients treated at the Department of Dermatology, Medical University of Graz in the years 2000-2010 and looked at the kind of melanoma type, e.g. if it has been slowly growing superficial spreading melanoma (SSM) or fast growing nodular melanoma (NM).

METHODS

Histological slides and clinical images of patients treated at our department between 2000 and 2010, who received chemotherapy because of proven metastatic disease were analysed with regard to growth type of their primary tumours.

RESULTS

A total of 88 patients met the inclusion criteria. Mean age of all patients was 57 years (median 59 years, SD ± 15 years). Of these 88 patients 51 patients (58%) (28 male patients and 23 female patients) had SSM; mean age 58 years (median 58 years, SD ± 14 years) and 37 patients (42%) (18 male patients and 19 female patients) had NM; mean age 56 years (median 61 years, SD ± 17 years). Mean Breslow thickness in the SSM group was 2.26 mm (median: 1.6 mm, SD ± 2.11 mm). In the NM group, mean Breslow thickness was 4.59 mm (median: 3.50 mm, SD ± 4.07 mm). When separated by gender, 46 melanomas were seen in the male group (28 SSM and 18 NM) and 42 melanomas in the female group (23 SSM and 19 NM).

CONCLUSIONS

Our results showed that more than half of the patients with metastatic disease had SSMs and not, as suspected, NMs. As SSMs are growing over a longer period to become invasive and potentially metastatic, there might be a chance to focus primary and secondary prevention programmes not only on fast growing tumours but also on slowly changes of tumours.

Excised melanocytic lesions in children and adolescents - a 10-year survey

BACKGROUND

Early recognition and prompt excision is to date the only available strategy for reducing mortality from melanoma. Little is known about the accuracy of melanoma detection in children and adolescents.

OBJECTIVES

To assess the accuracy of melanoma detection in a paediatric population.

METHODS

From the Department of Dermatology, Medical University of Graz, Austria, we reviewed the dermatopathology reports of naevi and melanomas excised in patients younger than 20 years over a 10-year period (1998-2007). Patients were subdivided into four age groups: 0-4, 5-9, 10-14 and 15-19 years.

RESULTS

Accuracy in melanoma detection was tested using the number needed to excise (NNE) value that is obtained by dividing the total number of excised lesions by the number of melanomas. A total of 22564 lesions were reviewed, disclosing 22526 naevi and 38 melanomas, for an overall NNE value of 593.8. Five melanomas were excised in children aged 10-14 years (NNE 1141) and 33 in children aged 15-19 years (NNE 479.8), whereas no melanomas were found among 1026 lesions excised in children younger than 10 years. In children aged 0-4 years, congenital and Spitz/Reed naevi accounted for 34.5% and 20% of lesions, respectively. These percentages decreased progressively when moving to older age groups (P<0.0001). In contrast, the percentage of dermal and compound naevi rose in direct proportion with age, being 3.4% and 20.7%, respectively, in the youngest age group, and 36.7% and 31.9%, respectively, among the oldest patients (P<0.0001).

CONCLUSIONS

The overall NNE value in paediatric patients over the 10-year study period was 593.8, meaning that about 594 lesions were excised to find one melanoma. This value is 20 times higher than the rates found in adult patients.

A simple scoring system for the diagnosis of palmo-plantar pigmented skin lesions by digital dermoscopy analysis

BACKGROUND

Many research groups have recently developed equipments and statistical methods enabling pattern classification of pigmented skin lesions. To differentiate between benign and malignant ones, the mathematical extraction of digital patterns together with the use of appropriate statistical approaches is a challenging task.

OBJECTIVE

To design a simple scoring model that provides accurate classification of benign and malignant palmo-plantar pigmented skin lesions, by evaluation of parameters obtained by digital dermoscopy analysis (DDA).

PATIENTS AND METHODS

In the present study we used a digital dermoscopy analyser to evaluate a series of 445 palmo-plantar melanocytic skin lesion images (25 melanomas 420 nevi). Area under the receiver operator curve, sensitivity and specificity were calculated to evaluate the diagnostic performance of our scoring model for the differentiation of benign and malignant palmo-plantar melanocytic lesions.

RESULTS

Model performance reached a very high value (0.983). The DDA parameters selected by the model that proved statistically significant were: area, peripheral dark regions, total imbalance of colours, entropy, dark area and red and blue multicomponent. When all seven model variables were used in a multivariate mode, setting sensitivity at 100% to avoid false negatives, we estimated a minimum specificity of about 80%.

CONCLUSIONS

Simplicity of use and effectiveness of implementation are important requirements for the success of quantitative methods in routine clinical practice. Scoring systems meet these requirements. Their outcomes are accessible in real time without the use of any data processing system, thus allowing decisions to be made quickly and effectively.

Agreement of dermatopathologists in the evaluation of clinically difficult melanocytic lesions: how golden is the 'gold standard'?

BACKGROUND

The 'gold standard' for the diagnosis of melanocytic lesions is dermatopathology. Although most of the diagnostic criteria are clearly defined, the interpretation of histopathology slides may be subject to interobserver variability.

OBJECTIVES

The aim of this study was to determine the variability among dermatopathologists in the interpretation of clinically difficult melanocytic lesions.

METHODS

This study used the database of MelaFind®, a computer-vision system for the diagnosis of melanoma. All lesions were surgically removed and sent for independent evaluation by four dermatopathologists. Agreement was calculated using kappa statistics.

RESULTS

A total of 1,249 pigmented melanocytic lesions were included. There was a substantial agreement among expert dermatopathologists: two-category kappa was 0.80 (melanoma vs. non-melanoma) and three-category kappa was 0.62 (malignant vs. borderline vs. benign melanocytic lesions). The agreement was significantly greater for patients ≥40 years (three-category kappa = 0.67) than for younger patients (kappa = 0.49). In addition, the agreement was significantly lower for patients with atypical mole syndrome (AMS) (kappa = 0.31) than for patients without AMS (kappa = 0.76).

LIMITATIONS

The data were limited by the inclusion/exclusion criteria of the MelaFind® study. This might represent a selection bias. The agreement was evaluated using kappa statistics. This is a standard method for evaluating agreement among pathologists, but might be considered controversial by some statisticians.

CONCLUSIONS

Expert dermatopathologists have a high level of agreement when diagnosing clinically difficult melanocytic lesions. However, even among expert dermatopathologists, the current 'gold standard' is not perfect. Our results indicate that lesions from younger patients and patients with AMS may be more problematic for the dermatopathologists, suggesting that improved diagnostic criteria are needed for such patients.

[Trivial injury to the sole of the foot]

A 67-year-old male patient noticed a foreign body sensation following a trivial trauma to the sole of the left foot approximately 4 months before presentation. The existing skin alteration had been self-treated with pumice stone and an unidentifiable wart tincture. The examination revealed an approximately 2 cm in diameter macula on the left heel with a zonal construction. The periphery was formed by a polycyclic dark brown ring which enclosed a reddish skin colored macula with several minute erosions. Dermatoscopy revealed an unspecific pattern with polymorphic vessels in the center. The peripheral ring showed radially running streaks as well as a parallel track-like pattern in one region. Histology revealed this to be an acral melanoma. A melanoma should always be included in the differential diagnostic considerations of atypical acral lesions. A biopsy should always be carried by unclear clinical and light microscopical findings out to enable a final diagnosis.

New trends in dermoscopy

The dermatologists, in their educational training, learn to observe, recognize and classify lesions in order to obtain those stereotypes that allow them to make the diagnosis. For this reason, they have not felt the need to develop means to flank examination. For some years, however, this sort of prejudice is disappearing and also dermatology has begun to make use of semiotics instrumental. Among the most tried and tested equipment in clinical practice, worth remembering the dermoscopy and digital dermoscopic analysis. The recent availability of digital cameras and phones equipped with the latest generation of optical systems capable of capturing images of pigmented lesions in epiluminescence, has further expanded the range of tools at our disposal.