Improvement of early recognition of lentigo maligna using dermatoscopy

The HAM10000 dataset, a large collection of multi-source dermatoscopic images of common pigmented skin lesions

Training of neural networks for automated diagnosis of pigmented skin lesions is hampered by the small size and lack of diversity of available datasets of dermatoscopic images. We tackle this problem by releasing the HAM10000 (“Human Against Machine with 10000 training images”) dataset. We collected dermatoscopic images from different populations acquired and stored by different modalities. Given this diversity we had to apply different acquisition and cleaning methods and developed semi-automatic workflows utilizing specifically trained neural networks. The final dataset consists of 10015 dermatoscopic images which are released as a training set for academic machine learning purposes and are publicly available through the ISIC archive. This benchmark dataset can be used for machine learning and for comparisons with human experts. Cases include a representative collection of all important diagnostic categories in the realm of pigmented lesions. More than 50% of lesions have been confirmed by pathology, while the ground truth for the rest of the cases was either follow-up, expert consensus, or confirmation by in-vivo confocal microscopy.

Dermatoscopy of flat pigmented facial lesions-evolution of lentigo maligna diagnostic criteria

Recognition of facial lentigo maligna (LM) is often difficult, particularly at early stages. Algorithms and multivariate diagnostic models have recently been elaborated on the attempt to improve the diagnostic accuracy. We conducted a cross-sectional and retrospective study to evaluate dermatoscopic criteria aiding in diagnosis of flat pigmented facial lesions (FPFL). We examined 46 FPFL in 42 Caucasian patients and found that 4 of 20 dermatoscopic criteria reached the significance level required for features indicating malignancy namely, hyperpigmented follicular openings, obliterated follicular opening, annular-granular structures, and pigment rhomboids. Concomitant presence of at least 2 or 3 of the 4 mentioned criteria was significantly more frequent in LM than in pigmented actinic keratosis (PAK). However, despite more frequently seen in LM, these features were also displayed in some of the PAK and other FPFL, so we found them not specific for LM. Although dermatoscopy enhances the diagnostic accuracy in evaluating FPFL, histopathology remains the gold standard for correct diagnosis, making evident the need for improvements in early noninvasive diagnosis of LM.

Lentigo Maligna - Not Always a Face and Neck Disease of the Elderly

INTRODUCTION

Lentigo maligna (LM) is a rare form of in situ melanoma, frequently seen as a large patch in elderly patients. The aim of this study was to assess clinical and dermoscopic features of LM.

MATERIAL AND METHODS

A retrospective study of LM patients presenting to our center between July 2007 and July 2017 was performed. Demographic data, anatomical location, laterality, diameter, Clark level, Breslow stage, "ABCD" signs and dermoscopic features were registered. Facial versus extrafacial LM were compared.

RESULTS

We found 21 LM, of which 12 had an extrafacial location and 9 a facial location. Half of the extrafacial lesions were located on an upper limb. The median age at diagnosis was 63 years (ranging from 38 to 84 years). Most LM cases were female (16/21) with phototype II (13/21). More than half of the patients (11/21) had a history of a skin neoplasm or actinic keratosis. The median diameter found was 6 mm (interquartile range = 4.5 mm), ranging from 1 to 15 mm. Five lesions were invasive (median Breslow depth of 0.2 mm), and 4 of them were extrafacial.

DISCUSSION

In this study LM was more frequently found in an extrafacial location and as a small patch with a 6-mm diameter medium. The epidemiology of LM/LM melanoma might be changing. Full body examination and dermoscopy are of the utmost importance for the diagnosis. Dermatologists should be aware and search for small lesions outside the face and neck, particularly in middle-aged female patients with photo-damaged skin.

Lentigo maligna: diagnosis and treatment

Lentigo maligna (LM) is an in situ subtype of melanoma, clinically presenting as a pigmented, asymmetric macule that originates mostly on the head and neck and spreads slowly. The diagnosis may be challenging both for clinicians and pathologists. Dermatoscopy and reflectance confocal microscopy represent a useful tool in the differentiation of LM from other pigmented lesions, such as pigmented actinic keratosis, solar lentigines, seborrheic keratosis and lichen planus-like keratosis. Moreover, those non-invasive diagnostic technique may be crucial in the selection of optimal biopsy sites in equivocal lesions, in pre-surgical mapping and in evaluating and monitoring response to non-surgical treatments. Histologic examination remains the gold standard for the diagnosis of LM, showing a lentiginous proliferation of basal atypical melanocytes on a severe sun-damaged skin. The management of LM is constantly evolving. Treatments include surgery (the first choice, when available), radiotherapy and imiquimod cream (in patients not candidates to surgery). Many other possible treatments for LM have been tested, but they are not yet supported by strong evidences. We collected current guidelines and PubMed available reviews, studies and case-reports in order to make an overview on diagnosis and treatment of LM.

Dermoscopy pathology correlation in melanoma

Dermoscopy is a widely used technique whose role in the clinical (and preoperative) diagnosis of melanocytic and non-melanocytic skin lesions has been well established in recent years. The aim of this paper is to clarify the correlations between the "local" dermoscopic findings in melanoma and the underlying histology, in order to help clinicians in routine practice.

Actinic Keratosis and Non-Invasive Diagnostic Techniques: An Update

Actinic keratosis represents the earliest manifestation of non-melanoma skin cancer. Because of their risk of progression to invasive squamous cell carcinoma, an earlier diagnosis and treatment are mandatory. Their diagnosis sometimes could represent a challenge even for expert dermatologists. Dermoscopy, confocal laser microscopy and optical coherence tomography could help clinicians in diagnosis.

Synchronous conjunctival melanoma and lentigo maligna melanoma

Lentigo maligna has an extensive and neoplastic character. It typically progresses slowly and may eventually develop into an invasive melanoma, which is called lentigo maligna melanoma. Ocular melanoma is the second most common type of melanoma. The uvea is the most common site of origin of ocular melanomas, while conjunctival melanoma accounts for about 1-5% of cases. In this article, we describe a rare case of synchronic conjunctival melanoma and lentigo maligna on the face.

Enhancing Skin Cancer Diagnosis with Dermoscopy

Dermoscopy increases the sensitivity for skin cancer detection, decreases the number of benign lesions biopsied for each malignant diagnosis, and enables the diagnosis of thinner melanomas compared with naked eye examination. Multiple meta-analyses have identified that dermoscopy improves the diagnostic accuracy for melanoma when compared with naked eye examination. In addition, studies have established that dermoscopy can aid in the detection of keratinocyte carcinomas. Dermoscopy triage algorithms have been developed to help novices decide when a biopsy or a referral is most appropriate. In this article, the authors illustrate the dermoscopic features that assist in identifying melanoma and keratinocyte carcinomas.

Lentigo maligna of the face: A quantitative simple method to identify individual patient risk probability on dermoscopy

BACKGROUND/OBJECTIVES

The clinical and dermoscopic differential diagnosis of flat pigmented facial lesions represents a great challenge for the clinicians. Our aim was to report a quantitative method based on dermoscopic features to better classify pigmented facial lesions.

METHODS

This is a retrospective case-series study that analysed the dermoscopic features of 582 pigmented facial lesions.

RESULTS

The individual patient probability of lentigo maligna (LM) was predicted by a multivariate model, with an accuracy of 0.72. According to the odds ratio at the multivariate analysis, an individual scoring index was assigned to each criterion, and a value of 4.56 was identified as optimal cut-off point. Up to a score of 2.5, the probability that a lesion is an LM is 0. The probability increases from 10 to 50% for a score ranging between 4.5 and 6. It is about 90% for a score of 7.

CONCLUSION

The optimal cut-off point obtained and the curve that identifies the probability of a patient having a LM could improve the classification and the management strategies of equivocal pigmented facial lesions.

Lentigo Maligna, Macules of the Face, and Lesions on Sun-Damaged Skin: Confocal Makes the Difference

Distinguishing lentigo maligna (LM) and lentigo maligna melanoma (LMM) from background pigmented non-melanoma lesions is challenging. The field of solar damage can obscure clinical assessment, and diagnostic ambiguities are created due to the overlap of the clinical features of LM with other benign lesions. Moreover, margin assessment on histology is limited by the resemblance between melanocytic hyperplasia of actinically damaged skin and scattered atypical melanocytes of LM/LMM. Dermoscopy has made a significant contribution but is often not sufficient for diagnosis and margin assessment. Confocal microscopy has become an important complementary tool in enhancing the management of these complex lesions.

Reflectance Confocal Microscopy in Lentigo Maligna

Lentigo maligna is the most common type of facial melanoma. Diagnosis is complicated, however, as it shares clinical and dermoscopic characteristics with other cutaneous lesions of the face. Reflectance confocal microscopy is an imaging technique that permits the visualization of characteristic features of lentigo maligna. These include a disrupted honeycomb pattern and pagetoid cells with a tendency to show folliculotropism. These cells typically have a dendritic morphology, although they may also appear as round cells measuring over 20μm with atypical nuclei. Poorly defined dermal papillae and atypical cells may be seen at the dermal-epidermal junction and can form bridges resembling mitochondrial structures. Other characteristic findings include junctional swelling with atypical cells located around the follicles, resembling caput medusae. Reflectance confocal microscopy is a very useful tool for diagnosing lentigo maligna.

Dermoscopy of difficult-to-diagnose Melanomas

Dermoscopy is a non-invasive procedure that allows the evaluation of cutaneous lesions, and is considered to be a useful tool that improves the diagnostic accuracy of melanoma. Many dermoscopic criteria of melanoma have been established and several algorithms have been created for melanoma detection. However, the recognition of some melanomas remains challenging. Melanomas on specific body sites, melanomas in patients with multiple atypical moles, and nodular melanomas represent the most difficult-to-recognize melanoma subtypes, since they typically lack the “classic” melanoma-specific criteria. This paper provides an update on dermoscopy of difficult-to-diagnose melanomas by summarizing the newest data. Lastly, we highlight the importance of digital dermoscopy in the follow-up of melanocytic lesions for the detection of incipient melanomas while maintaining a low excision rate.

Diagnosis and treatment of melanoma. European consensus-based interdisciplinary guideline - Update 2016

Cutaneous melanoma (CM) is potentially the most dangerous form of skin tumour and causes 90% of skin cancer mortality. A unique collaboration of multi-disciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organisation of Research and Treatment of Cancer was formed to make recommendations on CM diagnosis and treatment, based on systematic literature reviews and the experts' experience. Diagnosis is made clinically using dermoscopy and staging is based upon the AJCC system. CMs are excised with 1-2 cm safety margins. Sentinel lymph node dissection is routinely offered as a staging procedure in patients with tumours >1 mm in thickness, although there is as yet no clear survival benefit for this approach. Interferon-α treatment may be offered to patients with stage II and III melanoma as an adjuvant therapy, as this treatment increases at least the disease-free survival and less clear the overall survival (OS) time. The treatment is however associated with significant toxicity. In distant metastasis, all options of surgical therapy have to be considered thoroughly. In the absence of surgical options, systemic treatment is indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies should be considered. BRAF inhibitors like dabrafenib and vemurafenib in combination with the MEK inhibitors trametinib and cobimetinib for BRAF mutated patients should be offered as first or second line treatment. Therapeutic decisions in stage IV patients should be primarily made by an interdisciplinary oncology team ('Tumour Board').

Extrafacial Lentigo Maligna: A Report on 14 Cases and a Review of the Literature

Lentigo maligna is the most common form of in situ melanoma. It is most often found on the head and neck, and its clinical and dermoscopic features in this location have been extensively described in the literature. We present a series of 14 patients diagnosed with extrafacial lentigo maligna and lentigo maligna melanoma at Hospital General de Valencia and Hospital de Manacor in Spain, and describe the clinical, dermoscopic, and histologic features observed. Most of the melanomas were located on the upper limbs; the next most common locations were the trunk and the lower limbs. The dermoscopic patterns were consistent with facial lentigo maligna and superficial spreading melanoma. Extrafacial lentigo maligna is uncommon. It has similar clinical and histologic features to facial lentigo, but dermoscopy may show a mix of patterns typically seen in lentigo maligna and superficial spreading melanoma. This difference in dermoscopic features is essentially due to anatomical differences between skin on the face and on other parts of the body.

Dermoscopic and clinical features of head and neck melanoma

BACKGROUND

The dermoscopic criteria of extrafacial melanomas are well-known.

OBJECTIVE

To determine the frequency of dermatoscopic findings in head and neck melanomas (HNM) and to assess the distinguishing dermoscopic criteria of facial and extrafacial melanoma.

METHODS

This observational study included 108 patients with HNM (63% male, mean age 64 years). Participants underwent individual dermoscopic imaging of clinically melanoma. All lesions were excised, and histopathological examination was performed on all specimens.

RESULTS

Drawing on histopathological analysis, lentigo maligna melanoma or lentigo maligna was diagnosed in 60 lesions, superficial spreading melanoma in 18, nodular in 10, desmoplastic in 8, superficial spreading melanoma in situ in 12. The most frequent location for head and neck melanoma was the cheek (60 patients, 55.6%). Eight prominent dermatoscopic features were observed in facial melanoma: annular-granular pattern (18%); rhomboidal structures (29%); pseudonetwork (29%); asymmetrical, pigmented, follicular openings (51%); obliterated hair follicles (8%); red rhomboidal structures (18%); increased density of the vascular network (32%); scar-like depigmentation (59%).

CONCLUSIONS

HNM has specific dermoscopic features, and classical extrafacial dermoscopic rules are less useful for diagnosis of facial melanoma. In our study, further characteristic dermatoscopic findings were detected in facial melanoma such as low frequencies of irregular dots, 2 or fewer colors in lesions, the presence of pseudonetwork, increased density of the vascular network, red rhomboidal structures, in addition to dermatoscopic findings of extrafacial melanoma. Thus, it is concluded that the prediction and identification of HNM may be evident with the help of these signs.

Diagnosis and management of lentigo maligna: a review

Lentigo maligna is a melanocytic neoplasm occurring on sun-exposed skin, usually on the head and neck, of middle-aged and elderly patients. It is thought to represent the in situ phase of lentigo maligna melanoma. The ill-defined nature and potentially large size of lesions can pose significant diagnostic and treatment challenges. The goal of therapy is to cure the lesions in order to prevent development of invasive disease, and surgical excision is the treatment of choice to achieve clear histological margins. Nonsurgical treatment modalities have been reported; however, evidence is lacking to support their use. Age, general health, and comorbidities need to be taken into account when deciding the right treatment modality for each individual patient.

Reflectance confocal microscopy correlates of dermoscopic patterns of facial lesions help to discriminate lentigo maligna from pigmented nonmelanocytic macules

BACKGROUND

The clinical recognition of lentigo maligna (LM) and LM melanoma can be very challenging due to the overlapping features it shares with other pigmented macules of the skin. Noninvasive diagnostic techniques can assist in the differential diagnosis.

OBJECTIVES

To identify reflectance confocal microscopy (RCM) indicators for LM through the identification of in vivo microscopic substrates of the main dermoscopic features seen in flat pigmented lesions of the face.

METHODS

Retrospective analysis of 60 pigmented lesions (LM, invasive melanoma, solar lentigo/flat seborrhoeic keratosis, lichen planus-like keratosis, pigmented actinic keratosis) was carried out. The main dermoscopic patterns and RCM features were described. A new method for correlating RCM with dermoscopic patterns was developed.

RESULTS

Pseudonetwork (37 of 60 lesions) and annular granular structures (37 of 60 lesions) were the most frequent dermoscopic patterns, followed by pigmented blotches (27 of 60 lesions). Upon RCM examination, pseudonetwork and blotches differed in melanomas and other nonmelanocytic lesions. These differences included the intraepidermal proliferation of atypical cells (predominantly dendritic-shaped with adnexal tropism) and the presence of a meshwork pattern at the junction. Also, annular granular structures exhibited dendritic cells almost exclusively in melanoma, with no difference between melanomas and nonmelanocytic lesions for the junctional and upper dermal pattern (characterized by dermal inflammation). Fingerprinting was mostly present in nonmelanocytic lesions or corresponded to an overlap with solar lentigo in melanomas.

CONCLUSIONS

RCM is useful for identifying the histological substrate of dermoscopic features in pigmented lesions of the face. It can provide a better definition of the lesion areas, enabling an improved diagnostic approach.

Clinical and dermoscopic characteristics of melanomas on nonfacial chronically sun-damaged skin

BACKGROUND

Melanomas on chronically sun-damaged skin (CSDS) can be difficult to identify and often manifest morphologic features that overlap with benign lesions.

OBJECTIVE

We describe and analyze the clinical and dermoscopic characteristics of melanomas on nonfacial CSDS.

METHODS

Melanoma cases on nonfacial CSDS were retrospectively identified from the biopsy specimen logs of 6 melanoma clinics. Clinical and dermoscopic images were combined into 1 database. Demographics, clinical, dermoscopic, and histopathologic information were analyzed. Descriptive frequencies were calculated.

RESULTS

One hundred eighty-six cases met the inclusion criteria: 142 melanomas in situ (76%) and 39 invasive (21%; mean thickness, 0.49 mm). Lentigo maligna was the most common histopathologic subtype (n = 76; 40.9%). The most frequent dermoscopic structures were granularity (n = 126; 67.7%) and angulated lines (n = 82; 44%). Vascular structures were more frequent in invasive melanomas (56% vs 12% of in situ melanomas). Most manifested 1 of 3 dermoscopic patterns: patchy peripheral pigmented islands, angulated lines, and tan structureless with granularity pattern.

LIMITATIONS

This was a retrospective study, and evaluators were not blinded to the diagnosis. In addition, interobserver concordance and sensitivity and specificity for dermoscopic structures were not evaluated.

CONCLUSION

Outlier lesions manifesting dermoscopic structures, such as granularity, angulated lines, or vessels and any of the 3 described dermoscopic patterns should raise suspicion for melanoma.

Interventions for melanoma in situ, including lentigo maligna

BACKGROUND

Malignant melanoma is a form of skin cancer associated with significant mortality once it has spread beyond the skin. Melanoma in situ (MIS) is the earliest histologically recognisable stage of malignant melanoma and represents a precursor of invasive melanoma. Lentigo maligna (LM) represents a subtype of pre-invasive intraepidermal melanoma associated specifically with chronic exposure to ultraviolet (UV) radiation. Over the past two decades, the incidence of MIS has increased significantly, even more than the invasive counterpart. There are several treatment options for MIS, but no consensus exists on the best therapeutic management of this condition.

OBJECTIVES

To assess the effects of all available interventions, surgical and non-surgical, for the treatment of melanoma in situ, including LM.

SEARCH METHODS

We searched the following databases up to November 2014: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2014, Issue 10), MEDLINE (from 1946), Embase (from 1974), LILACS (from 1982), African Index Medicus (from inception), IndeMED of India (from inception), and Index Medicus for the South-East Asia Region (IMSEAR) (from inception). We scanned the references of included and excluded studies for further references to relevant trials and searched five trials registries. We checked the abstracts of major dermatology and oncology conference proceedings, and we shared our lists of included and excluded studies with industry contacts and other experts in the field of melanoma to try to identify further relevant trials.

SELECTION CRITERIA

We included randomised controlled trials (RCT) on the management of MIS, including LM, that compared any intervention to placebo or active treatment. We included individuals, irrespective of age and sex, diagnosed with MIS, including LM, based on histological examination.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated possible studies for inclusion; extracted data from the included study using a standard data extraction form modified for our review; assessed risk of bias; and analysed data on efficacy, safety, and tolerability. They resolved any disagreements by discussion with a third author. We collected adverse effects information from included studies.

MAIN RESULTS

Our search identified only 1 study eligible for inclusion (and 1 ongoing study in active recruitment stage), which was a single centre, open label, parallel group, 2-arm RCT with 90 participants, who had 91 histologically proven LM lesions.Forty-four participants, with 44 LM lesions, were treated with imiquimod 5% cream 5 days per week plus tazarotene 0.1% gel 2 days/week for 3 months, and 46 participants, with 47 LM lesions, were treated with imiquimod 5% cream 5 days per week for 3 months. Two months after cessation of topical treatment, the initial tumour footprint was excised using 2 mm margins via a staged excision. This study was open label, and analysis was not intention-to-treat, leading to a high risk of incomplete outcome data.Our primary outcome 'Histological or clinical complete response' was measured at 5 months in 29/44 participants (66%) treated with imiquimod plus tazarotene (combination therapy) and 27/46 participants (59%) treated with imiquimod (monotherapy). The difference was not statistically significant (risk ratio (RR) 1.12, 95% confidence interval (CI) 0.81 to 1.55, P value = 0.48).With regard to our secondary outcomes on recurrence and inflammation, after a mean follow up of 42 months, no local recurrences were observed among complete responders. Difference in overall inflammation score between the 2 groups was significant (mean difference (MD) 0.6, 95% CI 0.2 to 1, P value = 0.004), with the mean overall inflammation score being significantly higher in the combination group.The study authors did not clearly report on side-effects. Because of adverse effects, there was a dropout rate of 6/44 participants (13.7%) in the combination group compared with 1/46 (2.2%) in the imiquimod monotherapy group (due to excessive inflammation) before the cessation of topical treatment (first 3 months), but this was not statistically significant (RR 6.27, 95% CI 0.79 to 50.02, P value = 0.08).

AUTHORS' CONCLUSIONS

There is a lack of high-quality evidence for the treatment of MIS and LM.For the treatment of MIS, we found no RCTs of surgical interventions aiming to optimise margin control (square method, perimeter technique, 'slow Mohs', staged radial sections, staged "mapped" excisions, or Mohs micrographic surgery), which are the most widely used interventions recommended as first-line therapy. The use of non-surgical interventions in selected cases (patients with contraindications to surgical interventions) may be effective and may be considered preferable for experienced providers and under close and adequate follow up.For the treatment of LM, we found no RCTs of surgical interventions, which remain the most widely used and recommended available treatment. The use of non-surgical interventions, such as imiquimod, as monotherapy may be effective and may be considered in selected cases where surgical procedures are contraindicated and used preferentially by experienced providers under close and adequate follow up. The use of topical therapies, such as 5-fluorouracil and imiquimod, as neoadjuvant therapies warrants further investigation. There is insufficient evidence to support or refute the addition of tazarotene to imiquimod as adjuvant therapy; the current evidence suggests that it can increase topical inflammatory response and withdrawal of participants because of treatment-related side-effects.

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.

Amelanotic metastatic cutaneous melanoma

Dermatoscopy of melanocytic lesions has guided the decision of when or not to biopsy a lesion. The use of this tool has increased clinical examination's sensitivity and specificity in 89% and 96% respectively. However, dermatoscopic evaluation of amelanotic or hypomelanotic melanomas, as well as metastases, can be difficult. There is still no standardization for the analysis of these pathologies, which relies mostly on their vascular pattern. We describe the dermatoscopy of acral metastatic amelanotic melanoma.

Diagnosis and management of facial pigmented macules

The differential diagnosis of pigmented macules on the mottled chronic sun-damaged skin of the face is challenging and includes lentigo maligna (LM), pigmented actinic (solar) keratosis, solar lentigo, and lichen-planus-like keratosis. Although dermatoscopy improves the diagnostic accuracy of the unaided eye, the accurate diagnosis and management of pigmented facial macules remains one of the most challenging scenarios in daily practice. This is related to the fact that pigmented actinic (solar) keratosis, lichen-planus-like keratosis, and LM may reveal overlapping criteria, making their differential diagnosis clinically difficult. For this reason, practical rules have been introduced, which should help to minimize the risk for inappropriate diagnosis and management of LM.

Surveillance for treatment failure of lentigo maligna with dermoscopy and in vivo confocal microscopy: new descriptors

BACKGROUND

Nonsurgical treatment (radiotherapy, imiquimod) is increasingly employed for the management of lentigo maligna (LM). While the diagnosis of LM remains difficult, the detection of treatment failure is even more challenging.

OBJECTIVES

To describe the sensitivity and specificity for the diagnosis of LM of individual features and methods using dermoscopy and in vivo reflectance confocal microscopy (RCM) to aid in the detection of treatment failure of LM following nonsurgical treatment.

METHODS

A retrospective study of dermoscopy and RCM images (blinded to the correlation with pathology) in patients with biopsy-confirmed LM who were undergoing nonsurgical treatment in two referral institutions - one in Sydney, Australia, and the other in Barcelona, Spain. Ninety-eight patients were treated nonsurgically for LM during the period 2006-2012. Thirty-one patients had abnormal dermoscopy or RCM evaluation, and had a biopsy that identified LM recurrence in 15 patients and nonmelanoma diagnoses in 16 patients (one Bowen disease, 15 solar changes).

RESULTS

The diagnosis of treatment failure was difficult with dermoscopy, with a sensitivity of 80% and specificity of 56%, even with the interpretation of an expert. The best criterion was asymmetric hyperpigmented follicular openings, but this was present in only 47% of treatment failure LM. Isolated, very fine brown dots ('dust' appearance) correlated highly with the diagnosis of treatment failure LM (73% sensitivity and 88% specificity) and with pagetoid cells seen with RCM. The LM score, comprising six criteria, had a specificity of 94% and sensitivity of 100%.

CONCLUSIONS

These methods and descriptors should help to manage the diagnosis of treatment failure.

Dermoscopic findings for the early detection of melanoma: an analysis of 200 cases

INTRODUCTION

Dermoscopy is a complementary technique that has led to major advances in the diagnosis of pigmented skin lesions. The aim of this study was to describe the dermoscopic features of a series of melanomas and analyze the differences between melanomas in situ and invasive melanomas.

MATERIAL AND METHODS

We retrospectively recorded epidemiological, clinical, histologic, and dermoscopic features of a series of 200 primary melanomas. We performed a descriptive and analytical study of the dermoscopic features identified.

RESULTS

The mean age of the patients was 63 years and there was a similar distribution of male and female patients. The most common histologic subtypes were superficial spreading melanoma (62.5%) and lentigo maligna (25.5%); 67% of the melanomas had a Breslow thickness of less than 1mm and 24.5% were melanomas in situ. Overall,the most common global dermoscopic features were the multicomponent pattern (33.5%), the reticular pattern (18%), and the nonspecific pattern (15.5%). The most common local features were structureless homogeneous areas (67.5%), white-blue structures (58%), an atypical pigmented network (55.5%), and irregularly distributed dots and globules (44%). The following features were more common in invasive melanomas than in melanomas in situ: blue, gray, red and white colors, multicomponent and homogeneous patterns, dots and globules, blue-white structures, homogeneous areas, a blue-white veil, white shiny structures, a reverse pigment network, and milky-red areas. The reticular pattern was more common in melanomas in situ.

DISCUSSION

The use of dermoscopy has contributed to the early diagnosis of melanoma. The most common dermoscopic features of melanoma are multiple structures and colors (multicomponent pattern), an atypical reticular pattern (with wide, irregular meshes), and an absence of distinguishing features (nonspecific pattern) associated with the presence of vascular structures.

CONCLUSIONS

Dermoscopy facilitates the diagnosis of melanoma and could be useful for differentiating between melanoma in situ and invasive melanoma.

Dermatoscopy of flat pigmented facial lesions

BACKGROUND

The diagnosis of flat pigmented lesions on the face is challenging because of the morphologic overlap of biologically different lesions and the unknown significance of dermatoscopic patterns.

OBJECTIVE

To better characterize dermatoscopic patterns of various types of flat pigmented facial lesions and to analyse their significance by calculating their relative risks and diagnostic values.

METHODS

We prospectively analysed dermatoscopic images of 240 flat pigmented facial skin lesions collected consecutively from 195 patients (41.5% females, mean age: 61 ± 14 years) between 2007 and March 2012 in a primary skin cancer practice situated in Queensland, Australia.

RESULTS

Histopathologically 114 (47.5%) lesions were malignant (24 lentigo maligna, 21 basal cell carcinomas and 69 pigmented actinic keratoses). Compared with all other patterns the positive predictive value for lentigo maligna was highest for a pattern of circles (31.3%, 95% CI: 11.1-58.6%). A pattern of clods was associated with basal cell carcinoma. If grey structures were present the relative risk for malignancy was 2.2 (95%CI: 1.4-3.4). The best clues to differentiate pigmented actinic keratosis from other lesions were the presence of scale (positive predictive value: 72.2%, specificity: 94.2%), white circles (positive predictive value: 68.8%, specificity: 94.2%) and a sharply demarcated border (positive predictive value: 44.2%, specificity: 86.0%).

CONCLUSIONS

In flat lesions a pattern of circles bears the highest risk for facial melanoma but other patterns do not exclude it. Scale, white circles and a sharply demarcated border are clues to pigmented actinic keratoses. The presence of grey colour is a clue to malignancy regardless of pattern.

Lentigo maligna: review of salient characteristics and management

Lentigo maligna is a melanocytic neoplasm, often regarded as 'melanoma in situ,' which may progress to lentigo maligna melanoma. Lentigo maligna clinically presents as a pigmented, asymmetric macule that originates on the head and neck and spreads slowly. The preferred method for diagnosing lentigo maligna is excisional biopsy. Histology shows proliferation of atypical melanocytes at the epidermal-dermal junction in small nests or single cells. The differential diagnosis includes solar lentigo, seborrheic keratosis, lichen planus-like keratosis, pigmented actinic keratosis, and melanocytic nevus. Stains used in diagnosis include hematoxylin and eosin, HMB-45, MART-1/Melan-A, Mel-5, and S-100. Surgical excision is the preferred treatment for lentigo maligna. Second-line techniques include medical (topical imiquimod) and destructive therapy.