Diagnostic Accuracy of Hyperpigmented Microcircles in Dermatoscopy of Non-Facial Non-Acral Melanomas: A Pilot Retrospective Study using a Public Image Database

Abstract

<b><i>Background:</i></b> Grey perifollicular circles are a dermatoscopic clue to melanoma, especially in facial skin. So far, no other adnexal clues than follicular have been investigated in this diagnosis. <b><i>Objectives:</i></b> The study aimed to analyse the prevalence of hyperpigmented periadnexal microcircles (HMs) in melanoma and its common simulators at non-facial non-acral sites, analyse the relation between the presence of HM, regression and hypopigmentation, and evaluate the diagnostic accuracy of this structure in melanoma. <b><i>Methods:</i></b> International Skin Imaging Collaboration (69,445 images) was searched in April 2020 for the pathology-confirmed dermatoscopic images with metadata including sex, age bin, and declared non-acral non-facial anatomic site. The final study sample (5,408 images, 1,326 of which were melanomas) was evaluated by expert dermatoscopist blinded to the diagnosis and labelled for the presence of ≥3 HM distributed centrally (cHM) or peripherally (pHM), hypopigmentation, and classic dermatoscopic regression structures. A subset of 40 images was labelled by 7 raters (2 residents, 5 experts) to assess interobserver agreement. We compared the presence of pHM with the presence of regression as well as performed a set of independent χ<sup>2</sup> tests to evaluate the discriminatory power and its fragility. Performance of the models was assessed using measures of discrimination and calibration. <b><i>Results:</i></b> HM were significantly more prevalent in melanomas than in non-melanomas and nevi. Fair/good interobserver agreement for HM was reached for all the raters, and moderate/good for experts only (single rater/average, respectively). Regardless of regression/hypopigmentation status, pHM were significantly more common in melanoma than in non-melanomas or nevi and were observed significantly more often in melanomas on sun-damaged skin (upper extremity, posterior torso). No significant differences between the groups were found for cHM. pHM proved a high odds ratio in the tests as to the classical indicators such as classic dermatoscopic regression structures. <b><i>Conclusion:</i></b> pHM could be considered a novel dermatoscopic clue to melanoma.

Exploring Small-Diameter Melanomas: A Retrospective Study on Clinical and Dermoscopic Features

“…Caution is important when interpreting architectural disorder in small lesions to avoid overdiagnosis of melanoma [ 20 ]. Especially in cases with a diameter of ≤4 mm, diagnostic disagreements among pathologists are not unlikely [ 15 ]. To address this complex issue, Ferrara et al [ 21 ] propose a collaborative “consensus diagnosis” approach among pathologists, emphasizing the necessity of pooling collective expertise to resolve diagnostic uncertainties.…”

“…The dermoscopic structures assessed for their presence or absence are outlined in Table 1 . The selection of dermoscopic features was based on the available literature [ 15 , 16 , 17 , 18 , 19 ], ensuring a comprehensive analysis of the lesions in the study. Given the ongoing debates in the current literature regarding the standardization of dermatoscopic structure terminology, with some authors using descriptive terms and others employing metaphoric terms, we sought to minimize interpretational subjectivity among the authors.…”

Multiple Primary Melanoma: A Five-Year Prospective Single-Center Follow-Up Study of Two MC1R R/R Genotype Carriers

“…We retrieved thirty melanoma-specific dermoscopic structures from literature [23,36,38,45,[78][79][80][81][82][83][84][85][86]. The attending dermatologist selected up to six present melanoma-specific dermoscopic clues for each case (58 SPMs).…”

An Extensive Investigation into the Use of Machine Learning Tools and Deep Neural Networks for the Recognition of Skin Cancer: Challenges, Future Directions, and a Comprehensive Review

“…Despite the elevated peril of melanoma, there is a strong likelihood of survival with prompt detection and treatment. Hence, it is important to conduct research in the challenging field of early detection of melanoma; for more details and information the reader can follow the discussion in references [14][15][16]. Briefly, most cancer instances fall into the non-melanoma group, which includes sebaceous gland carcinoma (SGC), basal cell carcinoma (BCC), and squamous cell carcinoma (SCC).…”