Extrafacial Lentigo Maligna: A Clinical And Dermoscopic Analysis According to Localization.

INTRODUCTION: Whether extrafacial lentigo maligna (EFLM) differs clinically and/or dermoscopically according to location has not been analyzed in depth. OBJECTIVES: To evaluate clinical and dermoscopic characteristics regarding different localization in a series of EFLM. METHODS: We conducted a retrospective analysis of clinical and dermoscopic characteristics of 69 histologically proven EFLM retrieved from the database of two private institutions. RESULTS: Of the 69 EFLM included in the study, 25 (36.2%) were located in posterior trunk (PT), 16 (23.2%) in anterior trunk (AT), 15 (21%) in upper extremities (UE), and 13 (18.8%) in lower extremities (LE). Mean diameter among localization were as follows: 14.3 mm in PT, 11.8 mm in AT, 14 mm in UE, and 10 mm in LE (p 0.44). The most frequent dermoscopic criteria were angulated lines and tan structureless areas (70%), followed by atypical pigment network (60%), both with similar distribution among groups. Angulated lines pattern was the most frequent global pattern, observed in 55% of cases. Tan structureless/granularity pattern and patchy peripheral pigmented islands pattern were seen in 15.6% and 11.6% cases, respectively. No statistically significant differences were observed in the distribution of global dermoscopic pattern in the different localizations. CONCLUSIONS: From the clinical point of view, EFLM did not differ in terms of patient's age and diameter regarding localization. Upon dermoscopy, we found no significant differences in the overall dermoscopic pattern in the different localizations.

Pigmented lesion on the face: which is the chance of being melanoma using reflectance confocal microscopy features?

Facial melanoma presents itself as a brownish macula, being difficult to differentiate it from benign pigmented lesions of the face on clinical examination. Reflectance confocal microscopy (RCM) assists in diagnosing facial lesions in which dermoscopy has limitations, allowing to increase the diagnostic accuracy. The study aimed to analyze the RCM features of pigmented isolated lesions of the face for diagnosing melanoma. Also, we sought to establish the chance of a pigmented lesion on the face being a melanoma using RCM criteria. In this retrospective and prospective study, 105 clinical pigmented lesions on the face underwent RCM, and cytoarchitectural features in the epidermis, the dermo-epidermal junction (DEJ), and dermis were described. For statistical analysis, the exact chi-square test was applied to the RCM criteria. The odds ratio was estimated using univariate logistic regression. Finally, we used the multiple logistic regression method for creating a nomogram to predict the chance of a lesion being a melanoma. After univariate and multivariate logistic regression, atypical round nucleated cells within the epidermis, pagetoid spread, and follicular dendritic cells presented as statistically significant features. Then, a complex nomogram was created to give the chance of a pigmented lesion on the face being a melanoma. The presence of these three features resulted in a 98% probability for melanoma. This study allowed to estimate the diagnosis of melanoma on the face, using RCM, practicable and feasible in the daily routine, through the presence of some RCM nomogram criteria.

Clinical size is a poor predictor of invasion in melanoma of the lentigo maligna type.

BACKGROUND: There are no well-defined clinical factors to predict the risk of occult invasion in melanoma of the lentigo maligna type (LM) before complete histopathologic analysis. OBJECTIVE: To evaluate whether clinical size was a predictor of invasion in LM and subclinical extension. METHODS: Consecutive cases of LM were recorded in a prospectively maintained database from 2006 to 2019. Patient and tumor data were recorded during initial evaluation. The LM clinical area was calculated in square millimeters (length × width). All patients were treated with staged excision. RESULTS: We included 600 patients. The mean age was 65.9 years (standard deviation, 12.3; range, 27-95 years); 62.8% (n = 377) were men. The mean LM clinical area was 128.32 mm2 for in situ lesions versus 200.14 mm for invasive lesions (P = .1). Based on quantile regression, the median margin required for complete removal increased with LM clinical area. LIMITATIONS: The study was performed in a tertiary cancer center with possible referral bias and more complex cases. CONCLUSIONS: LM can present with variable clinical size, which may correlate with subclinical extension; however, the presence of invasion is not well estimated by LM clinical area.

Clinical usefulness of dermoscopy in the management of lentigo maligna melanoma treated with topical imiquimod: A case report.

The importance of dermoscopy for diagnosing lentigo maligna melanoma (LMM) is well known. More recently, dermoscopy has been proposed as a useful tool also for the treatment choice and monitoring. Herein, we present an 87-year-old woman, who was successfully treated with imiquimod 5% cream after surgical persistence of residual LMM and for whom dermoscopy was helpful to assist diagnosis and assess tumor persistence after surgery and its response to topical treatment with imiquimod.

Dermal vasculature and melanocytic proliferation index in photodamaged skin in the assessment of lateral margins of lentigo maligna and lentigo maligna melanoma.

Lentigo maligna (LM) is the most common subtype of melanoma on the face. When it invades the dermis it is called lentigo maligna melanoma (LMM). Its histological delimitation is controversial due to subjectivity. Analysis of peritumoral vasculature and proliferation index of melanocytes may help to differentiate tumor areas from tumor-free areas, as neoplasia-induced angiogenesis in such scenarios, as well as the higher proliferation index of melanocytes in melanomas, are well established. This work compares the peritumoral vasculature and melanocyte proliferation index of LM and LMM with that of adjacent non-neoplastic skin and sun-damaged skin (control). Forty-three resection cases of LM and LMM were selected retrospectively. Immunohistochemistry was performed for anti-CD31 and anti-CD105 to assess vascularization. Melanocyte proliferation index double labeling was performed using the anti-Melan-A and anti-Ki-67. The Chalkley optical grid was used to quantify blood vessel hotspots. Doubly labeled cells with anti-Melan-A and anti-Ki-67 were counted at tumor, free margin, and control skin. Microvasculature quantification under the melanomas, for both CD31 and CD105, was greater than at the margins of the same specimens (P < 0.0001; P = 0.0001) and greater than control skin (P = 0.0016; P = 0.0027), with higher density for CD31 than CD105. The mean number of double-labeled proliferating melanocytes at the melanoma periphery was greater than at the adjacent free skin and control skin (P = 0.0011). The control skin samples showed the highest CD31-positive vasculature in the head and neck region, with a positive correlation between melanocytic proliferation index and vasculature. The presence of neovascularization (CD105) and proliferating melanocytes (Ki67+/Melan-A+) are suspicious findings for LM/LMM, helping to outline, diagnose, and evaluate tumor margins.

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.

Inner gray halo, a novel dermoscopic feature for the diagnosis of pigmented actinic keratosis: clues for the differential diagnosis with lentigo maligna.

BACKGROUND: Pigmented actinic keratosis (PAK) is a frequent simulator of lentigo maligna (LM) on the face upon clinical and dermoscopic examination, leading to misdiagnosis and unnecessary excisions. LM and PAK share dermoscopic features, making it difficult to have a confident diagnosis of PAK only with current dermoscopic knowledge. OBJECTIVE: We sought to evaluate sensitivity, specificity, and interobserver reproducibility of a novel dermoscopic feature, inner gray halo (IGH), and establish its histopathological and confocal correlations. METHODS: Dermoscopists blinded to histopathological diagnosis evaluated 58 PAK and 21 LM for the presence of IGH and dermoscopy parameters. Areas exhibiting IGH were marked and imaged with reflectance confocal microscopy before sampling for histopathologic correlation. Reflectance confocal microscopy and transverse histologic sectioning were performed in 14 of 79 cases. RESULTS: IGH was present in 53 of 58 (94.1%) PAK and in 5 of 21 (23.8%) LM in our series (sensitivity 91.4%; specificity 71.4%; positive predictive value 89.8%). Interobserver agreement was excellent (Kappa 0.846). Through transverse and perpendicular histologic sections, a dermoscopic-histologic-confocal correlation of IGH was established. LIMITATIONS: A larger test set is needed to further validate the use of IGH in the differential diagnosis of PAK and facial pigmented lesions. CONCLUSION: IGH is a novel dermoscopic parameter useful for the differentiation of PAK from LM on the face.