Accuracy of dermoscopic criteria for the differentiation between superficial basal cell carcinoma and Bowen's disease

BACKGROUND

The dermoscopic features of superficial basal cell carcinoma (sBCC) and Bowen's disease (BD) have been extensively investigated, and dermoscopy was shown to significantly improve their recognition. However, incorrectly diagnosed cases still exist, with a considerable number of sBCCs dermoscopically interpreted as BD. Our aim was to investigate the dermoscopic variability in sBCC and BD on different anatomic sites, to identify potent dermoscopic predictors for each diagnosis and to investigate the potential source of the inaccurate clinico-dermoscopic diagnosis of some sBCCs.

METHODS

Dermoscopic images of histopathologically diagnosed sBCC and BD were evaluated by three independent investigators for the presence of predefined criteria. Subsequently, three independent investigators with expertise in dermoscopy classified the tumours as sBCC or BD based on the dermoscopic image. Diagnostic accuracy scores were calculated and crude and adjusted odds ratios, and 95% confidence intervals were calculated by univariate and conditional multivariate logistic regression, respectively.

RESULTS

A total of 283 lesions were included in the study (194 sBCCs and 89 BD). The main dermoscopic predictors of BD were dotted vessels (7.5-fold) and glomerular vessels (12.7-fold). The presence of leaf-like areas/spoke-wheel areas/concentric structures (OR = 0.027) and arborizing vessels (OR = 0.065) has predicted sBCC. Multivariate risk factors for sBCC misclassification were the location on lower extremities (OR = 5.5), the presence of dotted vessels (OR = 59.5) and the presence of large ulceration (OR = 6.4). In contrast, the presence of brown-coloured pigmentation was a protective predictor for misdiagnosis (OR = 0.007). Finally, a subgroup analysis of lesions located on lower extremities revealed two additional potent predictors of sBCC: superficial fine telangiectasia (SFT) and whity shiny blotches/strands.

CONCLUSIONS

Dotted and glomerular vessels are strong predictors of BD. When located on the lower extremities, sBCC may also display dotted vessels, rendering its recognition problematic. On the latter anatomic site, clinicians should consider SFT and whity shiny blotches/strands as additional sBCC predictors.

Dermoscopic features of melanocytic skin lesions in Greek children and adolescents and their association with environmental factors and skin types

BACKGROUND

Acquired naevi often present in childhood and increase in number and size during early and middle life. As naevi represent potential mimickers of melanoma, the knowledge of their epidemiologic and morphologic characteristics is essential.

OBJECTIVE

In this study, we intend to determine the prevalence of dermoscopic patterns of naevi, as well their association with environmental and constitutional factors.

METHODS

Cross-sectional data derived from a population-based cohort of children and adolescents aged 6-18 years, from 12 different schools in Thessaloniki, Greece. For each participant, a consent form and a questionnaire were completed, which included data on age, sex, phototype, sun sensitivity, sun exposure, sunscreen use and previous sunburn history. All naevi, their body distribution, and their dermoscopic patterns were recorded.

RESULTS

Two thousand and five hundred and five (2505) subjects were enrolled into the study (47.8% males and 52.2% females). The mean number of MN counted in a single person was 29.11 (SD = ±23.863). TNC increased continuously with higher age. Males were found to have a significantly increased number on the trunk (11.7 ± 11.2 and 10.0 ± 8.7, respectively, P < 0.001) and face and neck (6.2 ± 5.3 and 5.1 ± 4.3, respectively, P < 0.001) while females on the upper (10.3 ± 10.1 and 9.3 ± 9.4, respectively, P = 0.008) and lower extremities (2.8 ± 3.4 and 2.5 ± 3.2, respectively, P = 0.008). Globular pattern was the most frequent dominant pattern in lower age groups, and its percentage fell as age increased. On the contrary, the reticular pattern was more often documented in individuals in adolescence.

CONCLUSION

This first study of MN in our young population aims to be the basis of further investigation for the MM preventive policy of our state.

The limitations of dermoscopy: false-positive and false-negative tumours

Dermoscopy has been documented to increase the diagnostic accuracy of clinicians evaluating skin tumours, improving their ability to detect skin cancer and better recognize benign moles. However, dermoscopically 'false-positive' and 'false-negative' tumours do exist. False-positive diagnosis usually leads to unnecessary excisions. False-negative diagnosis is much more dangerous, as it might result in overlooking a cancer, with severe undesirable consequences for the patient and the physician. Therefore, management strategies should mainly focus on addressing the risk of dermoscopically false-negative tumours. The most frequent benign tumours that might acquire dermatoscopic characteristics suggestive of malignancy are seborrhoeic keratosis (SK), including solar lentigo, melanoacanthoma, irritated, clonal and regressive SK, angioma (mainly thrombosed angioma and angiokeratoma), dermatofibroma, benign adnexal tumours and naevi (Clark, Spitz, recurrent, combined, sclerosing). The most useful clues to recognize these tumours are the following: solar lentigo - broad network; melanoacanthoma - sharp border; irritated SK - regularly distributed white perivascular halos; clonal SK - classic SK criteria; regressive SK - remnants of SK; targetoid haemosiderotic haemangioma - dark centre and reddish periphery; thrombosed angioma - sharp demarcation; angiokeratoma - dark lacunae; atypical dermatofibromas - palpation; follicular tumours - white colour; sebaceous tumours - yellow colour; Clark naevi - clinical context; Spitz/Reed naevi - age; combined naevi - blue central area; recurrent naevi - pigmentation within the scar; sclerosing naevi - age and location on the upper back; blue naevi - history. Malignant tumours that might mimic benign ones and escape detection are melanoma (in situ, nevoid, spitzoid, verrucous, regressive, amelanotic), squamous cell carcinoma (mainly well-differentiated variants) and rarely basal cell carcinoma (non-pigmented variants). The most useful clues to recognize the peculiar melanoma subtypes are as follows: melanoma in situ - irregular hyperpigmented areas; nevoid melanoma - history of growth; spitzoid melanoma - age; verrucous melanoma - blue-black sign; regressive melanoma - peppering or scar-like depigmentation; amelanotic melanoma - pink colour, linear irregular vessels, dotted vessels. In this article, we summarized the most frequent dermoscopic variations of common skin tumours that are often misinterpreted, aiming to assist clinicians to reduce the number of false diagnoses.

Tracking actinic keratosis of face and scalp treated with 0.015% ingenol mebutate to identify clinical and dermoscopic predictors of treatment response

BACKGROUND

Ingenol mebutate (IngMeb) 0.015% gel is an approved field treatment option for non-hyperkeratotic non-hypertrophic actinic keratosis (AK) of face and scalp. Efficacy of IngMeb has been assessed only on a clinical ground, in the majority of studies. Dermoscopy is a pivotal tool for the diagnosis of AK, while its role in evaluating the response to non-surgical therapies for AK has not been fully defined.

OBJECTIVES

Our study aims to determine whether some dermoscopic features of AK of the face and scalp areas may independently predict the response to IngMeb therapy.

METHODS

Clinical and dermoscopic responses, 1 month after 0.015% IngMeb therapy, were retrospectively evaluated using a per-patient and per-lesion approach. Safety was evaluated through local skin reaction composite score calculation. Demographic, clinical and dermoscopic factors were then evaluated via univariate and multivariate logistic regression analysis to assess independent predictors of response.

RESULTS

Fifty-five patients with 245 AKs were enrolled. Clinically, per-patient response evaluation identified 25 (45.4%) poor/partial and 30 (54.5%) complete responders, corresponding on a per-lesion approach to 66 (26.9%) and 179 (73.1%) AKs, respectively. Dermoscopy reclassified 14 patients in the per-patient and 48 AKs in the per-lesion analysis from complete to poor/partial responders. Multivariate logistic regression analysis showed that AKs dermoscopically characterized by red pseudonetwork and located on the face were independently associated with a complete dermoscopic response to 0.015% IngMeb therapy, while microerosions were negative predictors.

CONCLUSION

Specific dermoscopic features of AK may predict the response to 0.015% IngMeb therapy, together with the location on the face.

Dermoscopic features and patterns of poromas: a multicentre observational case-control study conducted by the International Dermoscopy Society

BACKGROUND

Poromas are benign cutaneous sweat gland tumours that are challenging to identify. The dermoscopic features of poromas are not well characterized.

OBJECTIVE

To determine the clinical-dermoscopic features of poromas.

METHODS

Cross-sectional, observational study of 113 poromas and 106 matched control lesions from 16 contributors and eight countries. Blinded reviewers evaluated the clinical and dermoscopic features present in each clinical and dermoscopic image.

RESULTS

Poromas were most commonly non-pigmented (85.8%), papules (35.4%) and located on non-acral sites (65.5%). In multivariate analysis, dermoscopic features associated with poroma included white interlacing areas around vessels (OR: 7.9, 95% CI: 1.9-32.5, P = 0.004), yellow structureless areas (OR: 2.5, 95% CI: 1.1-6.0, P = 0.04), milky-red globules (OR: 3.9, 95% CI: 1.4-11.1, P = 0.01) and poorly visualized vessels (OR: 33.3, 95% CI: 1.9-586.5, P = 0.02). The presence of branched vessels with rounded endings was positively associated with poromas but did not reach statistical significance (OR: 2.4, 95% CI: 0.8-6.5, P = 0.10). The presence of any of these five features was associated with a sensitivity and specificity of 62.8% and 82.0%, respectively.

CONCLUSION

We identified dermoscopic features that are specific to the diagnosis of poroma. Overall, however, the prevalence of these features was low. Significant clinical and dermoscopic variability is a hallmark of these uncommon tumours, which are most prevalent on non-acral sites.

Update on dermoscopy of Spitz/Reed naevi and management guidelines by the International Dermoscopy Society

Spitzoid lesions represent a challenging and controversial group of tumours, in terms of clinical recognition, biological behaviour and management strategies. Although Spitz naevi are considered benign tumours, their clinical and dermoscopic morphological overlap with spitzoid melanoma renders the management of spitzoid lesions particularly difficult. The controversy deepens because of the existence of tumours that cannot be safely histopathologically diagnosed as naevi or melanomas (atypical Spitz tumours). The dual objective of the present study was to provide an updated classification on dermoscopy of Spitz naevi, and management recommendations of spitzoid-looking lesions based on a consensus among experts in the field. After a detailed search of the literature for eligible studies, a data synthesis was performed from 15 studies on dermoscopy of Spitz naevi. Dermoscopically, Spitz naevi are typified by three main patterns: starburst pattern (51%), a pattern of regularly distributed dotted vessels (19%) and globular pattern with reticular depigmentation (17%). A consensus-based algorithm for the management of spitzoid lesions is proposed. According to it, dermoscopically asymmetric lesions with spitzoid features (both flat/raised and nodular) should be excised to rule out melanoma. Dermoscopically symmetric spitzoid nodules should also be excised or closely monitored, irrespective of age, to rule out atypical Spitz tumours. Dermoscopically symmetric, flat spitzoid lesions should be managed according to the age of the patient. Finally, the histopathological diagnosis of atypical Spitz tumour should warrant wide excision but not a sentinel lymph-node biopsy.

Dermoscopic features predicting the presence of mitoses in thin melanoma

BACKGROUND

The latest AJCC classification has included the number of mitoses as a factor for upstaging thin melanomas. Meanwhile, while dermoscopy has often been used to predict melanoma thickness, its value in predicting number of mitoses remains unknown.

OBJECTIVE

Our aim is to evaluate the correlation between dermoscopic features and the presence of mitoses in a consecutive cohort of thin melanomas.

METHODS

A case control study has been performed to identify specific dermoscopic parameters that could differentiate thin melanomas with 1 or more mitoses per mm2 from those without mitoses.

RESULTS

Of 177 melanomas equal to or thinner than 1mm, 131 (74%) lesions had no mitoses and 46 (36%) lesions had at least 1 mitosis×mm2. Dermoscopic features associated with the presence of 1 or more mitoses were the following: peripheral streaks (OR 4.11; 95% CI 1.94-8.71) and black colour (OR 4.70; 95% CI; 2.28-9.68). In contrast, atypical pigment network (OR (0.30; 95% CI 0.15-0.61)) and brown colour (OR 0.36; 95% CI 0.18-0.75) were associated to melanomas without mitoses. The same variables were also associated to the increasing number of mitoses at linear regression.

CONCLUSION

Black colour and peripheral streaks can predict the presence of mitoses in thin melanoma, while atypical pigment network and brown colour are associated to thin melanoma without mitoses.