Flat pigmented macules on sun-damaged skin of the head/neck: Junctional nevus, atypical lentiginous nevus, or melanoma in situ?

A facial lentiginous nevus with atypical clinical features in a child: The importance of in vivo reflectance confocal microscopic findings

A 14-year-old girl presented with a facial-pigmented lesion suspicious of melanoma clinically and dermoscopically. In vivo, reflectance confocal microscopy (RCM) findings excluded melanoma by revealing typical epidermal honeycomb and cobblestone patterns. Well-defined follicular contours were seen at the dermal-epidermal junction; there were no elongated, "medusa head-like" follicular protrusions or folliculotropism, which are classical findings seen in lentigo maligna. With this report, we aim to demonstrate the significance of utilizing RCM technology in difficult to diagnose lentiginous pigmented lesions.

A risk-scoring model for the differential diagnosis of lentigo maligna and other atypical pigmented facial lesions of the face: The facial iDScore

BACKGROUND

Due to progressive ageing of the population, the incidence of facial lentigo maligna (LM) of the face is increasing. Many benign simulators of LM and LMM, known as atypical pigmented facial lesions (aPFLs-pigmented actinic keratosis, solar lentigo, seborrheic keratosis, seborrheic-lichenoid keratosis, atypical nevus) may be found on photodamaged skin. This generates many diagnostic issues and increases the number of biopsies, with a subsequent impact on aesthetic outcome and health insurance costs.

OBJECTIVES

Our aim was to develop a risk-scoring classifier-based algorithm to estimate the probability of an aPFL being malignant. A second aim was to compare its diagnostic accuracy with that of dermoscopists so as to define the advantages of using the model in patient management.

MATERIALS AND METHODS

A total of 154 dermatologists analysed 1111 aPFLs and their management in a teledermatology setting: They performed pattern analysis, gave an intuitive clinical diagnosis and proposed lesion management options (follow-up/reflectance confocal microscopy/biopsy). Each case was composed of a dermoscopic and/or clinical picture plus metadata (histology, age, sex, location, diameter). The risk-scoring classifier was developed and tested on this dataset and then validated on 86 additional aPFLs.

RESULTS

The facial Integrated Dermoscopic Score (iDScore) model consisted of seven dermoscopic variables and three objective parameters (diameter ≥ 8 mm, age ≥ 70 years, male sex); the score ranged from 0 to 16. In the testing set, the facial iDScore-aided diagnosis was more accurate (AUC = 0.79 [IC 95% 0.757-0.843]) than the intuitive diagnosis proposed by dermatologists (average of 43.5%). In the management study, the score model reduced the number of benign lesions sent for biopsies by 41.5% and increased the number of LM/LMM cases sent for reflectance confocal microscopy or biopsy instead of follow-up by 66%.

CONCLUSIONS

The facial iDScore can be proposed as a feasible tool for managing patients with aPFLs.

Nevus Spilus With Dermatoheliosis: A Histologic Mimicker of Melanoma in Situ at Melanoma Excision Margins

ABSTRACT

Nevus spilus, or speckled lentiginous nevus, is a relatively common lesion that presents at birth or in early childhood. It consists of a background tan patch, which appears similar to a café au lait macule or lentigo simplex on histology, studded with various types of nevi. Rarely, these nevi can undergo malignant transformation to melanoma. When melanoma develops within a heavily photodamaged nevus spilus, evaluating excision margins may be challenging because the combined histologic features of nevus spilus and severe dermatoheliosis can mimic melanoma in situ. We report a case of an elderly man with extensive sun damage who developed malignant melanoma within an occult nevus spilus, resulting in multiple excisions with false-positive margins.

Tristar Vessels: A Newly Described Dermoscopic Vessel Pattern of Miescher’s Nevus

Purpose: Although it is very common in people over 30 years old, little is known about the validity of dermoscopic criteria to differentiate Miescher’s nevus (MN) from other papulonodular lesions located on the head and neck. The aim of this study is to evaluate the dermoscopic findings in MN on the head and neck in patients over 40 years by using dermoscopy. Methods: In this descriptive cross-sectional study 170 MN were evaluated by using polarized light dermoscopy. frequencies of dermoscopic findings in MN were determined using Statistical Package for Social Sciences for Windows 15.0. Results: The most frequently detected dermoscopic pattern in MN was globular pattern (64.5%), less often homogeneous (32.4%) or cobblestone pattern (2.9%). Globules were observed in 75.3% of MN and dots were seen in 12.4%. They frequently had skin-colored (87.1%) or light-brown (49.4%) homogeneous structureless areas. Elongated comma vessels (47.1%) were the most common vascular findings. Although comma vessels (33.5%) and linear vessels (4.7%) were also observed, 11.2% of MN presented “tristar vessels” (a newly described vascular pattern) that showed regular ‘tristar like ramifications’ in the distal part of the vessels. Conclusions: Firstly identified “tristar vessel pattern” is a dermoscopic description of MN that can be a useful clue to differential diagnosis.

Cross-sectional study of pigmented lesions of the head and neck in adults aged 40 years and above

The diagnosis of junctional and lentiginous naevi on sun-damaged skin of the head and neck in adults has been questioned in the literature, with the implication that these lesions should be classified as melanoma in situ. This could result in the overdiagnosis and overtreatment of non-malignant lesions. We conducted a cross-sectional study of the histopathological diagnosis of pigmented lesions biopsied from the head and neck of adults ≥40 years of age that were submitted to a large, Queensland-based pathology centre over seven months. Out of 543 lesions assessed, 293 (54.0%) were flat and 250 (46.0%) were raised. Flat naevi consisted of junctional/lentiginous and compound naevi, either with or without dysplasia. Collectively, flat naevi had a prevalence slightly less than that of melanoma (15.0% versus 19.0% among flat lesions, respectively, and 8.1% versus 11.2% among all lesions, respectively). The mean age of biopsy for all junctional/lentiginous naevi was significantly greater than that of all compound naevi (65.0 years versus 52.2 years; P = 0.001). Junctional/lentiginous naevi were significantly more associated with the neck than intradermal naevi (P < 0.001). In conclusion, benign, flat naevi account for a significant proportion of head and neck lesions in adults ≥40 years of age, and their location alone should not outweigh their histopathology when reaching a diagnosis.

Folliculotropism in head and neck lentigo maligna and lentigo maligna melanoma

BACKGROUND

Lentigo maligna (LM) and lentigo maligna-melanoma (LMM) are histotypes of melanoma arising in skin with cumulative solar radiation damage. The extension of atypical melanocytes to the hair follicle (folliculotropism) is a histopathological feature of LM/LMM. Its role has not been totally clarified, but it may be correlated to treatment response in LM or to progression in LMM.

OBJECTIVE

This retrospective, multicentric study aims to identify dermatoscopic features associated with folliculotropism in LMs/LMMs.

PATIENTS AND METHODS

We analyzed cases of head and neck LMs/LMMs diagnosed between 2005-2014 at Melanoma Units, University of Bologna/Modena/Florence/Siena (Italy), Nice (France): 25 LMs and 73 LMMs were included.

RESULTS

Grey circles (44 %) indicated an isthmic/bulb level of involvement, which were completely absent in the infundibular LM lesions (P = 0.041). In the group of LMMs, light/dark brown pseudonetwork and light brown structureless areas were an indicator of diffuse distribution of malignant melanocytes in the follicular units (P < 0.001 and P = 0.001, respectively), while grey circles indicated focal or diffuse distribution (P < 0.001).

CONCLUSIONS

A better understanding of the extension of malignant melanocytes is helpful, aiding clinicians in their decision to perform a radical excision or obtaining a biopsy in the most invasive area of the lesion, which includes potential folliculotropism.

The 2018 World Health Organization Classification of Cutaneous, Mucosal, and Uveal Melanoma: Detailed Analysis of 9 Distinct Subtypes Defined by Their Evolutionary Pathway

CONTEXT.—

There have been major advances in the understanding of melanoma since the last revision of the World Health Organization (WHO) classification in 2006.

OBJECTIVE.—

To discuss development of the 9 distinct types of melanoma and distinguishing them by their epidemiology, clinical and histologic morphology, and genomic characteristics. Each melanoma subtype is placed at the end of an evolutionary pathway that is rooted in its respective precursor, wherever appropriate and feasible, based on currently known data. Each precursor has a variable risk of progression culminating in its fully evolved, invasive melanoma.

DATA SOURCES.—

This review is based on the "Melanocytic Tumours" section of the 4th edition of the WHO Classification of Skin Tumours, published in 2018.

CONCLUSIONS.—

Melanomas were divided into those etiologically related to sun exposure and those that are not, as determined by their mutational signatures, anatomic site, and epidemiology. Melanomas on the sun-exposed skin were further divided by the histopathologic degree of cumulative solar damage (CSD) of the surrounding skin, into low and high CSD, on the basis of degree of associated solar elastosis. Low-CSD melanomas include superficial spreading melanomas and high-CSD melanomas incorporate lentigo maligna and desmoplastic melanomas. The "nonsolar" category includes acral melanomas, some melanomas in congenital nevi, melanomas in blue nevi, Spitz melanomas, mucosal melanomas, and uveal melanomas. The general term melanocytoma is proposed to encompass "intermediate" tumors that have an increased (though still low) probability of disease progression to melanoma.

Ivermectin inhibits HSP27 and potentiates efficacy of oncogene targeting in tumor models

HSP27 is highly expressed in, and supports oncogene addiction of, many cancers. HSP27 phosphorylation is a limiting step for activation of this protein and a target for inhibition, but its highly disordered structure challenges rational structure-guided drug discovery. We performed multistep biochemical, structural, and computational experiments to define a spherical 24-monomer complex composed of 12 HSP27 dimers with a phosphorylation pocket flanked by serine residues between their N-terminal domains. Ivermectin directly binds this pocket to inhibit MAPKAP2-mediated HSP27 phosphorylation and depolymerization, thereby blocking HSP27-regulated survival signaling and client-oncoprotein interactions. Ivermectin potentiated activity of anti-androgen receptor and anti-EGFR drugs in prostate and EGFR/HER2-driven tumor models, respectively, identifying a repurposing approach for cotargeting stress-adaptive responses to overcome resistance to inhibitors of oncogenic pathway signaling.

Neck Melanoma: Clinical, Dermoscopic and Confocal Features

BACKGROUND

The head and neck are considered one single anatomical unit. No data on clinical, dermoscopic and confocal aspects of neck melanoma are currently available.

OBJECTIVES

To identify clinical, dermoscopic and confocal diagnostic features of neck melanomas.

METHODS

Consecutive malignant (cases) and benign (controls) melanocytic skin lesions located on the neck, excised as suspected of being melanoma from March 2011 to February 2018, were retrospectively retrieved. Dermoscopic criteria of the 7-point checklist, integrated by other melanoma features (such as grey colour and irregular hyperpigmented areas) were assessed. Reflectance confocal microscopy (RCM) images were examined when available.

RESULTS

282 lesions located to the head and neck area were biopsied to rule out melanoma. Thirty-one out of 282 (11%) lesions were located on the neck: 21 melanomas and 10 naevi. Melanoma patients were older than patients with naevi (mean age: 60.4 vs. 37.9 years, p < 0.001). Neck melanomas were more frequently located on sun-damaged skin compared to naevi (76.2 vs. 30%, p = 0.02). Dermoscopically, neck melanomas were characterized by irregular dots/globules, grey colour and regression (76.2, 81 and 46.7% of cases) and showed criteria of lentigo maligna melanoma (LMM) in 52.4% of cases. Regression, grey colour, irregular hyperpigmented areas and criteria of LMM typified melanomas on sun-damaged skin, whereas tumours located on non-sun-damaged areas were often characterized by irregular pigmentation (blotches). RCM, implemented to dermoscopy, correctly diagnosed 10/12 melanomas and 3/5 naevi.

CONCLUSION

Neck melanoma has peculiar clinical and dermoscopic aspects that could help clinicians to distinguish it from naevi and to diagnose melanoma earlier.

Eyelid Melanoma in the United States: A National Cancer Database Analysis

BACKGROUND

Eyelid melanoma (EM) is a rare condition that accounts for <1% of all cutaneous melanomas. In this analysis, patients diagnosed with EM in the United States were compared to those with other melanomas in the head and neck.

METHODS

The National Cancer Database was used to select patients with head and neck melanoma from 2004 to 2015.

RESULTS

A total of 137,233 patients met the criteria of the study. Among them, 2694 were diagnosed with EM (2%) and 134,539 in other head and neck locations (98%). Regarding the patients with EM, the mean age was 68.56 years (standard deviation 14.04). A greater number of them were treated in Academic/Research Programs (53.6%), insured by Medicare (55.7%), tumor in situ (52.2%), stage 0 (49%), and without ulceration (75.9%). The mean time to treatment commencement was 18.96 days for EM compared to 14.4 days for other melanoma in the head and neck regions (P < 0.001). There was a greater proportion of EM in female patients (odds ratio [OR] 2.371 [2.191-2.566], P < 0.001), compared to male; age greater than 80 years (OR 1.622 [1.360-1.934], P < 0.001) compared to 0 to 49 years. Moreover, EM was an independent predictor for treatment in Academic/Research Programs (OR 1.258 [1.160-1.365], P < 0.001) and diagnosis at autopsy (OR 1.414 [1.083-1.847], P = 0.011) compared to other melanoma in the head and neck region.

CONCLUSION

These novel findings have the potential to guide clinical decision making in head and neck melanoma management.

Melanoma of the eyelid and periocular skin: Histopathologic classification and molecular pathology

Cutaneous melanoma, a potentially lethal malignancy of the periocular skin, represents only a small proportion of the roughly 87,000 new cases of cutaneous melanoma diagnosed annually in the United States. Most of our understanding of melanoma of the eyelid skin is extrapolated from studies of cutaneous melanoma located elsewhere. Recent years have witnessed major breakthroughs in molecular biology and genomics of cutaneous melanoma, some of which have led to the development of targeted therapies. The molecular insights have also kindled interest in rethinking how cutaneous melanomas are classified and assessed for risk. We provide a synopsis of the epidemiology, histopathologic classification, and clinical experience of eyelid melanoma since 1990 and then review major advances in the molecular biology of cutaneous melanoma, exploring how this impacts our understanding of classification and predicting risk.

Abundance of the benign melanocytic universe: Dermoscopic-histopathological correlation in nevi

The broad universe of "melanocytic nevi" includes a variety of different subtypes, which can be classified either due to their morphology, epidemiology, genetic alterations or risk for developing melanoma. Regarding morphology, on the one hand macroscopic/clinical and on the other hand histopathological appearance were used to subdivide in the past, often resulting in confusion and poor interobserver agreement, while nowadays dermoscopy presents the clinician's precious bridge between naked-eye examination and histopathological diagnostics, allowing prediction of the lesions' histopathology, follow up and monitoring over time without need of excision. The non-invasive dermoscopic examination relies on the assessment of colors, patterns and the distribution of both within a cutaneous lesion. Until today, the correspondence of certain dermoscopic colors and patterns to certain histopathological correlates has been reported for a huge amount of different cutaneous lesions. Moreover, the correspondence of certain dermoscopic features to certain body sites, age groups and pigmentary traits, but also to specific genetic alterations in lesions, has been broadly investigated. Dermoscopy has led us to a new understanding of melanocytic nevi's biology and evolution and, last but not least, to a new classification system, which we want to present herein.

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.

Reviewing Challenges in the Diagnosis and Treatment of Lentigo Maligna and Lentigo-Maligna Melanoma

Lentigo maligna (LM) and lentigo-maligna melanoma (LMM) are pigmented skin lesions that may exist on a continuous clinical and pathological spectrum of melanocytic skin cancer. LM is often described as a "benign" lesion and is accepted as a melanoma in situ; LM can undergo malignant transformation to particularly aggressive melanoma. LMM is an invasive melanoma that shares properties of LM, as well as exhibiting the metastatic potential of malignant melanoma. Unfortunately, LM/LMM diagnosis based on dermoscopy is rather ambiguous, and these lesions are often mistaken for junctional dysplastic nevi over sun-damaged skin, pigmented actinic keratosis, solar lentigo, or seborrheic keratosis. Diagnosis must be made on biopsy using distinct dermatopathologic features. These include a pagetoid appearance of melanocytes, melanocyte atypia, non-uniform pigmentation/distribution of melanocytes, and increased melanocyte density in a background of extensive photodamage. Advancements in immunohistochemical staining techniques, including soluble adenylyl cyclase (antibody R21), makes diagnosis easier and allows the definition of borders down to a single cell. After a pathologic diagnosis, there are a variety of treatment options, both surgical and non-surgical. Although surgical removal with a wide excision border is the preferred treatment due to decreased recurrence rates, experimental combination therapies are gaining popularity. However, no matter the treatment, LM/LMM carries a high recurrence rate, and patients must be monitored rigorously for recurrence as well as the appearance of additional skin lesions/cancers.

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.