Dermoscopy of Melanocytic Neoplasms

Dermoscopic Predictors of Benignity and Malignancy in Equivocal Lesions Predominated by Blue Color

BACKGROUND

Blue color in dermoscopy can be seen in a wide range of benign and malignant lesions, melanocytic or not. Some blue-colored dermoscopic criteria have been associated with specific tumors, such as blue-white veil with melanoma and homogeneous blue with blue nevi. However, when blue color occupies a large part of the lesion's surface, the dermoscopic assessment might be particularly challenging.

OBJECTIVE

To identify dermoscopic predictors associated with benignity and malignancy in tumors characterized by a predominant dermoscopic presence of blue color.

METHODS

We retrospectively screened our institutional database for tumors exhibiting blue color in at least 50% of their surface with available histopathologic diagnosis. Lesions with blue color covering less than 50% of their extent and lesions not histopathologically assessed were excluded. The dermoscopic images were evaluated for the presence of predefined criteria, including the characteristics of the blue color, coexisting colors, and the vascular structures.

RESULTS

Of 91 included tumors, 53 were benign (35 blue nevi, 10 angiomas, and 8 seborrheic keratoses) and 38 malignant (12 melanomas and 26 basal cell carcinomas). Our analysis revealed 3 potent dermoscopic predictors of benignity: extension of blue color in more than 75% of the surface, diffuse distribution of blue color, and absence of vessels, posing a 2.3-fold, 5.6-fold, and 6.7-fold increased probability of benignity, respectively. In contrast, asymmetric distribution of blue color, blue clods, coexistence of gray color and linear vessels were significantly predictive of malignancy, posing a 8.9-fold, 2.8-fold, 13.5-fold, and 10.4-fold increased probability, respectively.

CONCLUSION

In predominantly blue tumors, the probability of malignancy is high when blue color is seen in clods or is asymmetrically distributed and when gray color or linear vessels coexist. In contrast, a diffuse distribution of blue color, its expansion in more than 75% of the surface, and the absence of vessels are highly suggestive of a benign tumor.

Dermatoscopy of combined blue nevi: a multicentre study of the International Dermoscopy Society

BACKGROUND

Combined blue nevi (CBN) may mimic melanoma and are relatively often biopsied for diagnostic reasons.

OBJECTIVE

To better characterize CBN and to compare it with melanoma.

METHODS

We collected clinical and dermatoscopic images of 111 histologically confirmed CBN and contrasted their dermatoscopic characteristics with 132 partly blue coloured melanomas. Furthermore, we compared the accuracy of human experts using pattern analysis with a computer algorithm based on deep learning.

RESULTS

Combined blue nevi are usually flat or slightly elevated and, in comparison with melanoma, more frequent on the head and neck. Dermatoscopically, they are typified by a blue structureless part in combination with either brown clods (n = 52, 46.8%), lines (n = 28, 25.2%) or skin-coloured or brown structureless areas (n = 31, 27.9%). In contrast with melanoma, the blue part of CBN is more often well defined (18.9% vs. 4.5%, P < 0.001) and more often located in the centre (22.5% vs. 5.3%, P < 0.001). Melanomas are more often chaotic (OR: 28.7, 95% CI: 14.8-55.7, P < 0.001), have at least one melanoma clue (OR: 10.8, 95% CI: 5.2-22.2 P < 0.001) in particular white lines (OR: 37.1, 95% CI: 13.4-102.9, P < 0.001). Using simplified pattern analysis (chaos and clues), two raters reached sensitivities of 93.9% (95% CI: 88.4-97.3%) and 92.4% (95% CI: 86.5-96.3%) at corresponding specificities of 59.5% (95% CI: 49.7-68.7%) and 65.8% (95% CI: 56.2-74.5%). The human accuracy with pattern analysis was on par with a state-of-the-art computer algorithm based on deep learning that achieved an area under the curve of (0.92, 95% CI: 0.87-0.96) and a specificity of 85.3% (95% CI: 76.5-91.7%) at a given sensitivity of 83.6% (95% CI: 72.5-91.5%).

CONCLUSION

CBN usually lack melanoma clues, in particular white lines. The accuracy of pattern analysis for combined nevi is acceptable, and histopathologic confirmation may not be necessary in exemplary cases.

Dermatoscopic Features of Combined nevus – a Case Report

Combined nevi (CN), a rare nevus type represent a category of so-called compound tumors. Determined by the presence of two or more different nevus in one biopsy specimen, CN commonly show variable clinical and dermatoscopic features. Therefore, CN could be a diagnostic challenge. We present a 7-year-old Caucasian girl with a pigmented lesion on the arm of no specified duration. Clinical examination showed sharply demarcated pigmented papule. Dermatoscopy revealed a nonchaotic lesion with structureless well defined, minimally eccentric blue area, structureless brown area and brown clods in a symmetric fashion, no vessels and no other clues for melanoma. Histopathology showed a compound common melanocytic nevus, blue nevus in the centre of the lesion with no signs of atypia. Up to now, only 25 cases of CN with dermatoscopic description have been published, withno precise dermatoscopic features established yet. Therefore, studies with larger number of cases are needed for the final conclusions.

Management and dermoscopy of fast-growing nevi in pregnancy: case report and literature review

BACKGROUND

The relationship between pregnancy and a change in melanocytic nevi is still controversial. Moreover, management of the rapid evolution of a nevus in an unauspicious melanocytic lesion can be a clinical challenge in pregnancy.

METHODS

This article examines a case of a fast-growing deep penetrating nevus in a pregnant woman and provides a literature review of articles relative to pregnancy and nevi change, the management of fast-growing pigmented lesions, and the role and usefulness of dermoscopy in these cases.

RESULTS

Recent studies have documented that pregnancy is not associated with any significant change in the size of melanocytic nevi. The management of fast-growing melanocytic lesions during this period compulsorily leans toward excision. Dermoscopy can be useful, providing clinicohistopathologic correlations and a better assignment of the lesion.

CONCLUSION

This case report and review provide important management considerations for nevi during pregnancy. Early intervention with aggressive treatment measures is the best management for fast-growing lesions, and epiluminescence dermoscopy can assist the management, although still remaining a second-level examination, useful for documentation and for a better classification of the lesion.