Thickness of melanocytes in giant congenital melanocytic nevus for complete surgical excision: clinicopathological evaluation of 117 lesions according to the area and size.

BACKGROUND: Giant congenital melanocytic nevi (GCMN) are usually defined as nevi that exceed 20 cm in maximal diameter or 15% of the total body surface area. There have been reports of life-long malignant change risks arising from GCMN, leading to surgical excision of GCMN. This study aims to evaluate the thickness of melanocytes based on clinical factors in order to provide objective information for the complete resection of the lesion. METHODS: Overall, 75 patients diagnosed with GCMN between 2000 and 2021 were included, and their clinical records were collected retrospectively. 117 pathologic slides obtained during excision were reviewed to measure nevus thickness. Clinical factors were assessed with a generalized estimated equation model for association with nevus thickness. RESULTS: The thickness of nevus was significantly associated with the location and size. Nevus thickness was more superficial in the distal extremity than in the head and trunk (P = 0.003 [head]; P < 0.001 [trunk]; P = 0.091 [Proximal extremity]). Nevi sized 60 cm or more were significantly deeper than those measuring 20-29.9 cm (P = 0.035). An interaction between size and location existed (P < 0.001). Trunk and distal extremity lesions consistently exhibited uniform thickness regardless of lesion size, whereas head and proximal extremity lesions showed variations in thickness based on lesion size. CONCLUSION: GCMNs have differences in thickness according to location and size. Therefore, it is necessary to devise an approach optimized for each patient to treat GCMN. In the study, it was emphasized that the thickness of GCMN is correlated with clinical factors, specifically the location and size of the nevus. Consequently, these findings underscore the need for individualized treatment plans for effective surgical intervention.

PRAME Expression in Melanocytic Proliferations in Special Sites.

The subset of nevi occurring at special sites (eg, acral skin, anogeni-tal region, breast, ear, flexural surfaces) have normal histologic variations that preclude the use of routinely used diagnostic criteria for malignancy. Suggested criteria for differentiating malignant special-site lesions from benign lesions have been described, but there is an unmet need for a validated test aiding in the delineation of benign and malignant lesions at special sites. Preferentially expressed antigen of melanoma (PRAME) expression has been characterized as a relatively specific marker of melanoma, but not within the specific population of special-site lesions. This study aimed to determine if PRAME may serve as a specific marker of melanoma within the population of special-sites lesions.

BioMEL: a translational research biobank of melanocytic lesions and melanoma.

INTRODUCTION: Diagnosing invasive cutaneous melanoma (CM) can be challenging due to subjectivity in distinguishing equivocal nevi, melanoma in situ and thin CMs. The underlying molecular mechanisms of progression from nevus to melanoma must be better understood. Identifying biomarkers for treatment response, diagnostics and prognostics is crucial. Using biomedical data from biobanks and population-based healthcare data, translational research can improve patient care by implementing evidence-based findings. The BioMEL biobank is a prospective, multicentre, large-scale biomedical database on equivocal nevi and all stages of primary melanoma to metastases. Its purpose is to serve as a translational resource, enabling researchers to uncover objective molecular, genotypic, phenotypic and structural differences in nevi and all stages of melanoma. The main objective is to leverage BioMEL to significantly improve diagnostics, prognostics and therapy outcomes of patients with melanoma. METHODS AND ANALYSIS: The BioMEL biobank contains biological samples, epidemiological information and medical data from adult patients who receive routine care for melanoma. BioMEL is focused on primary and metastatic melanoma, but equivocal pigmented lesions such as clinically atypical nevi and melanoma in situ are also included. BioMEL data are gathered by questionnaires, blood sampling, tumour imaging, tissue sampling, medical records and histopathological reports. ETHICS AND DISSEMINATION: The BioMEL biobank project is approved by the national Swedish Ethical Review Authority (Dnr. 2013/101, 2013/339, 2020/00469, 2021/01432 and 2022/02421-02). The datasets generated are not publicly available due to regulations related to the ethical review authority. TRIAL REGISTRATION NUMBER: NCT05446155.

Neonatal cutaneous melanoma with cutaneous metastasis: a case report and review of literature.

Malignant melanoma, a rare skin cancer in children, primarily affects individuals over 10 years old. Giant congenital nevi, found in about 1% of newborns, increases the risk. However, the development of melanoma from a pre-existing giant congenital nevus diagnosed during the neonatal period is exceptionally rare. We present a case of congenital melanoma in a newborn, where nodules grew on an existing nevus on the baby's back. Literature on managing such cases was reviewed. This case highlights the importance of considering malignant transformation in congenital nevi and the challenges in their management. Due to limited reported cases over 80 years, conclusive findings on survival and treatment options are difficult to provide. Clinicians should report outcomes to develop a management algorithm for neonatal melanoma. Further studies are needed to enhance understanding of causes and treatment for patients with congenital giant hairy nevi and associated melanoma.

Mosaic RASopathies concept: different skin lesions, same systemic manifestations?

BACKGROUND: Cutaneous epidermal nevi are genotypically diverse mosaic disorders. Pathogenic hotspot variants in HRAS, KRAS, and less frequently, NRAS and BRAF may cause isolated keratinocytic epidermal nevi and sebaceous nevi or several different syndromes when associated with extracutaneous anomalies. Therefore, some authors suggest the concept of mosaic RASopathies to group these different disorders. METHODS: In this paper, we describe three new cases of syndromic epidermal nevi caused by mosaic HRAS variants: one associating an extensive keratinocytic epidermal nevus with hypomastia, another with extensive mucosal involvement and a third combining a small sebaceous nevus with seizures and intellectual deficiency. Moreover, we performed extensive literature of all cases of syndromic epidermal nevi and related disorders with confirmed pathogenic postzygotic variants in HRAS, KRAS, NRAS or BRAF. RESULTS: Most patients presented with bone, ophthalmological or neurological anomalies. Rhabdomyosarcoma, urothelial cell carcinoma and pubertas praecox are also repeatedly reported. KRAS pathogenic variants are involved in 50% of the cases, especially in sebaceous nevi, oculoectodermal syndrome and encephalocraniocutaneous lipomatosis. They are frequently associated with eye and brain anomalies. Pathogenic variants in HRAS are rather present in syndromic keratinocytic epidermal nevi and phacomatosis pigmentokeratotica. CONCLUSION: This review delineates genotype/phenotype correlations of syndromic epidermal nevi with somatic RAS and BRAF pathogenic variants and may help improve their follow-up.

Inflammatory linear verrucous epidermal nevus in groin and labia with claudication: Successfully treated with photodynamic therapy.

SIGNIFICANCE: Inflammatory linear verrucous epidermal nevus (ILVEN) is an uncommon type of epidermal nevus and is refractory to therapy. We report the effectiveness of photodynamic therapy (PDT) for treating ILVEN with claudication in a young girl. ADDITIONAL CONTRIBUTIONS: We thank the patient for granting permission to publish this information. APPROACH: Aminolaevulinic Acid Hydrochloride (ALA) photodynamic therapy (PDT) was applied six times in 1-month interval. RESULTS: Most lesions and pruritus have subsided markedly, with mild scarring and a marked reduction in claudication. CONCLUSIONS: ALA PDT might be an effective and promising treatment for ILVEN in the future.

Reduction of overfitting on the highly imbalanced ISIC-2019 skin dataset using deep learning frameworks.

BACKGROUND: With the rapid growth of Deep Neural Networks (DNN) and Computer-Aided Diagnosis (CAD), more significant works have been analysed for cancer related diseases. Skin cancer is the most hazardous type of cancer that cannot be diagnosed in the early stages. OBJECTIVE: The diagnosis of skin cancer is becoming a challenge to dermatologists as an abnormal lesion looks like an ordinary nevus at the initial stages. Therefore, early identification of lesions (origin of skin cancer) is essential and helpful for treating skin cancer patients effectively. The enormous development of automated skin cancer diagnosis systems significantly supports dermatologists. METHODS: This paper performs a classification of skin cancer by utilising various deep-learning frameworks after resolving the class Imbalance problem in the ISIC-2019 dataset. A fine-tuned ResNet-50 model is used to evaluate the performance of original data, augmented data, and after by adding the focal loss. Focal loss is the best technique to solve overfitting problems by assigning weights to hard misclassified images. RESULTS: Finally, augmented data with focal loss is given a good classification performance with 98.85% accuracy, 95.52% precision, and 95.93% recall. Matthews Correlation coefficient (MCC) is the best metric to evaluate the quality of multi-class images. It has given outstanding performance by using augmented data and focal loss.

Clinical features and management of eyelid margin nevi.

PURPOSE: Acquired melanocytic nevi are common eyelid lesions; however, their clinical presentation is not well documented. METHODS: In this retrospective study, clinical records were reviewed in patients evaluated between 2005 and 2022. RESULTS: Eyelid margin nevi (n = 150) were more commonly excised in female (78%) and Caucasian (86%) patients. Change in appearance/size were frequent presenting complaints, and 17% experienced ocular symptoms. Referring diagnosis included other benign lesions (11.3%), and concern for malignancy (16.7%). Many individuals (38.7%) noted their lesion for ≤5 years. Nevi were distributed across the 4 margins (9% peripunctal), and 88% had a regular base. Visible pigmentation was more common in non-Caucasians (95.2%) than Caucasians (41.1%). Lashes grew through 60.7% of nevi and were often misdirected.Nevi were treated with superficial excision and cauterization. Histologic subtypes included: dermal (86.6%), compound (9.4%), blue (2.7%), junctional (0.7%), lentiginous dysplastic (0.7%). An irregular base (p=0.042) and pigmentation (p=0.056) were more common in compound than dermal nevi. Lash line quality and appearance were improved in the majority of patients returning for follow-up, although postoperative trichiasis, marginal erythema, and residual pigmentation were observed. CONCLUSIONS: Melanocytic nevi commonly involve the eyelid margins and have a variety of presentations and appearances. Existing nevi can change, and new lesions appear throughout adulthood. Stable, benign appearing nevi can be observed. Shave excision provides a diagnosis and improved appearance for symptomatic or suspicious lesions, with few serious complications. Malignant transformation is rare, although evidence for recurrence warrants further evaluation.

Molecular Profiling of Syringocystadenocarcinoma Papilliferum Reveals RAS-Activating Mutations.

CONTEXT.­: Syringocystadenocarcinoma papilliferum (SCACP) is a rare adnexal carcinoma and the malignant counterpart of syringocystadenoma papilliferum (SCAP), which is commonly located on the head and neck and may arise in association with a nevus sebaceus. RAS mutations have been identified in both SCAP and nevus sebaceus. OBJECTIVE.­: To evaluate the clinicopathologic and molecular features of SCACPs, which have not been previously explored. DESIGN.­: We obtained 11 SCACPs from 6 institutions and reviewed the clinicopathologic features. We also performed molecular profiling using next-generation sequencing. RESULTS.­: The cohort comprised 6 women and 5 men with ages ranging from 29 to 96 years (mean, 73.6 years). The neoplasms occurred on the head and neck (n = 8; 73%) and extremities (n = 3; 27%). Three tumors possibly arose in a nevus sebaceus. A total of 4 cases showed at least carcinoma in situ (adenocarcinoma, n = 3; squamous cell carcinoma [SCC], n = 1), and 7 cases were invasive (SCC, n = 5; mixed adenocarcinoma + SCC, n = 2). A total of 8 of 11 cases (73%) had hot spot mutations consisting of HRAS (n = 4), KRAS (n = 1), BRAF (n = 1), TP53 (n = 4), ATM (n = 2), FLT3 (n = 1), CDKN2A (n = 1), and PTEN (n = 1). All 4 cases with HRAS mutations occurred on the head and neck, whereas the KRAS mutation occurred on the extremity. CONCLUSIONS.­: RAS-activating mutations were detected in 50% of the cases, of which most (80%) involved HRAS and occurred on the head and neck, which shows overlapping features with SCAP, supporting that a subset may arise as a result of malignant transformation and likely an early oncogenic event.

Real-world experience of implementing the MOLES score in a virtual choroidal naevi clinic at a tertiary referral centre.

INTRODUCTION: The MOLES score has been validated to clinically differentiate choroidal naevi from melanomas by ocular oncologists and community optometrists. However, its utility in a virtual choroidal naevi clinic at a tertiary eye hospital without specialist ocular oncology services has not yet been evaluated. METHODS: A retrospective case review of 385 choroidal lesions in the virtual choroidal naevus clinic at Bristol Eye Hospital during January-March 2020 and April-August 2021 was performed. Choroidal lesions were assessed using the TFSOM-UHHD risk factor index and MOLES score, respectively. For both study periods, clinical outcome and adherence data were analysed. RESULTS: Choroidal lesions scored higher with the TFSOM-UHHD index (median 2) compared to the MOLES score (median 0; p < 0.001). Median required follow-up duration was 2 years for lesions assessed with the TFSOM-UHHD index, and 0 years for those graded with the MOLES score. Overall, 215 patients were appropriately discharged to community optometrists based on their MOLES score. Imaging requirements for the TFSOM-UHHD index and MOLES score protocols were met in 69.1% and 94.8% of cases, respectively. CONCLUSION: The MOLES score was easily implemented in a virtual choroidal naevus clinic, with good adherence. It increased clinic capacity by facilitating appropriate discharges of low-risk naevi to community monitoring, allowing finite and specialist hospital-based services to monitor higher-risk naevi more closely.

Ultrasonographic findings in nevus lipomatosus cutaneous superficialis: What differentiates this tumor from other soft tissue tumors?

Nevus lipomatosus cutaneous superficialis is a rare, benign hamartoma characterized by mature adipocyte proliferation in the dermis. It is frequently difficult to distinguish clinically from soft tissue tumors, including lipoma, neurofibroma, venous malformation, and angiolipoma. Notably, the classical form, which shows multiple and sometimes enlarged nodules, is difficult to differentiate from liposarcoma based on clinical examination, computed tomography, and magnetic resonance imaging findings. Therefore, to ascertain the utility of ultrasonography in diagnosing nevus lipomatosus cutaneous superficialis, sonographic examinations were performed on eight patients with nevus lipomatosus cutaneous superficialis. All patients had ill-defined hyperechoic masses in the dermis or from the dermis to the subcutis, and the posterior echoes were attenuated in seven patients. Color Doppler sonography revealed no blood flow to the lesions. Ultrasound images were created using the reflections of ultrasound waves at interfaces with different acoustic impedances. Therefore, it is assumed that, in nevus lipomatosus cutaneous superficialis, the ultrasound beam is scattered by ectopic mature adipocytes intermingled with collagen bundles, which are shown as hyperechoic masses. Furthermore, the scattering of the ultrasound beam is thought to reduce tissue penetration, which may attenuate the posterior echo.

Dermoscopic Changes in Melanocytic Lesions in 368 Patients With Atypical Nevus Syndrome and Their Association With Melanoma Incidence: A Cohort Study. / Cambios en la dermatoscopia digital en lesiones melanocíticas en 368 pacientes con diagnóstico de síndrome de nevus atípicos y su asociación con el desarrollo de melanoma: estudio de cohorte.

BACKGROUND AND OBJECTIVE: Atypical nevus syndrome has been described as one of the main risk factors for melanoma. The aim of this study was to analyze dermoscopic changes observed in melanocytic lesions over a follow-up period of 5 years in patients with atypical nevus syndrome. MATERIAL AND METHODS: We conducted a retrospective follow-up study of a cohort of patients seen at a specialized skin cancer and digital body mapping clinic in Medellin, Colombia, between January 2017 and December 2022. We analyzed the dermoscopic changes observed during this period and explored their association with newly diagnosed melanoma. RESULTS: A total of 368 patients (187 women) with a median (interquartile range) age of 43 (37-51) years were included. The dermoscopic features observed at 5 years were an atypical network (222 patients, 60.3%), asymmetric globules (163, 44.2%), white-gray regression areas (105, 28.5%), lesion regression (72, 19.5%), a negative pigment network (59, 16%), asymmetric eccentric pigmentation (28, 7.6%), asymmetric projections (21, 5.7%), and asymmetric vascular patterns (8, 2.1%). Melanoma was diagnosed in 12.2% of patients during follow-up. Features significantly associated with a shorter time to melanoma onset were grayish-white areas (P <.001), asymmetric globules (P=.011), asymmetric eccentric pigmentation (P=.047), and a negative pigment network (P=.001). CONCLUSIONS: The main dermoscopic features of melanocytic lesions in patients with atypical nevus syndrome associated with progression to melanoma were grayish-white areas, asymmetric globules, asymmetric spots, and a negative pigment network.

Unusual conjunctival melanocytic proliferations. Report of five cases and review of the literature.

Indeterminate melanocytic proliferations of the conjunctiva have both benign and malignant features that previously made these lesions nearly impossible to categorize in existing classification schemes. With the evolution of immunohistochemistry and molecular genetics, however, subclassifications have emerged that allow for a more tailored diagnosis and management. These conjunctival melanocytic proliferations include deep penetrating nevus, granular cell nevus, and nevoid melanoma. There remains a small subset of conjunctival melanocytic proliferations that defy precise characterization as nevi, primary acquired melanosis, or melanomas despite currently available ancillary diagnostic modalities and remain indeterminate. We highlight these unusual types of nevi and melanomas, with an update on their morphologic, immunohistochemical, and molecular genetic characteristics.

[Translated article] Dermoscopic Changes in Melanocytic Lesions in 368 Patients With Atypical Nevus Syndrome and Their Association With Melanoma Incidence: A Cohort Study.

BACKGROUND AND OBJECTIVE: Atypical nevus syndrome has been described as one of the main risk factors for melanoma. The aim of this study was to analyze dermoscopic changes observed in melanocytic lesions over a follow-up period of 5 years in patients with atypical nevus syndrome. MATERIAL AND METHODS: We conducted a retrospective follow-up study of a cohort of patients seen at a specialized skin cancer and digital body mapping clinic in Medellin, Colombia, between January 2017 and December 2022. We analyzed the dermoscopic changes observed during this period and explored their association with newly diagnosed melanoma. RESULTS: A total of 368 patients (187 women) with a median (interquartile range) age of 43 (37-51) years were included. The dermoscopic features observed at 5 years were an atypical network (222 patients, 60.3%), asymmetric globules (163, 44.2%), white-gray regression areas (105, 28.5%), lesion regression (72, 19.5%), a negative pigment network (59, 16%), asymmetric eccentric pigmentation (28, 7.6%), asymmetric projections (21, 5.7%), and asymmetric vascular patterns (8, 2.1%). Melanoma was diagnosed in 12.2% of patients during follow-up. Features significantly associated with a shorter time to melanoma onset were grayish-white areas (P<.001), asymmetric globules (P=.011), asymmetric eccentric pigmentation (P=.047), and a negative pigment network (P=.001). CONCLUSIONS: The main dermoscopic features of melanocytic lesions in patients with atypical nevus syndrome associated with progression to melanoma were grayish-white areas, asymmetric globules, asymmetric spots, and a negative pigment network.

Lipid fingerprint-based histology accurately classifies nevus, primary melanoma, and metastatic melanoma samples.

Probably, the most important factor for the survival of a melanoma patient is early detection and precise diagnosis. Although in most cases these tasks are readily carried out by pathologists and dermatologists, there are still difficult cases in which no consensus among experts is achieved. To deal with such cases, new methodologies are required. Following this motivation, we explore here the use of lipid imaging mass spectrometry as a complementary tool for the aid in the diagnosis. Thus, 53 samples (15 nevus, 24 primary melanomas, and 14 metastasis) were explored with the aid of a mass spectrometer, using negative polarity. The rich lipid fingerprint obtained from the samples allowed us to set up an artificial intelligence-based classification model that achieved 100% of specificity and precision both in training and validation data sets. A deeper analysis of the image data shows that the technique reports important information on the tumor microenvironment that may give invaluable insights in the prognosis of the lesion, with the correct interpretation.

Nevus lipomatosus superficialis: A series of six cases.

Nevus lipomatosus still imposes diagnostic, categorization, and etiologic challenges. Even though an intradermal adipose tissue is a histopathologic prerequisite, the lesions are clinically divided into classic multiple forms and a solitary variant, which some consider a separate so-called lipofibroma clinicopathologic entity. This further complicates the true prevalence, classification and etiopathogenesis of nevus lipomatosus. Case reports and series studies have reflected either consistent or variable and sometimes conflicting clinicopathologic findings. A few have reported electron microscopic findings. Immunohistochemistry is lacking. We report two multiple and four solitary forms of nevus lipomatosus in six patients, highlighting their salient histopathologic features and immunohistochemical profile. Both forms showed intradermal groups of perivascular S100+ lipogenic and CD34+ mesenchymal cells intermixed with scattered CD1a+ and FXIIIa+ dendrocytes, CD3 lymphocytic and CD117 mast cells in a fibromyxoid milieu. Epidermal nevoid and comedonal follicular alterations, attenuated dermal connective tissue and adnexal structures were variably present in both forms. We compared our findings with seven series of studies reporting classic and solitary forms. Both forms showed similar histopathologic findings, comparable clinicopathologic features, predominantly pelvic, and shoulder girdle distribution patterns in bimodal age onsets. Even though some lipomatous skin lesions clinically and histopathologically overlap with nevus lipomatosus, certain findings are helpful distinguishing features. Small intradermal islands of lipocytic fibroplasia have characteristic perivascular milieu that may function as a niche of preadipose CD34 mesenchymal stem cells. They are most likely represented in the dermis of the pelvic and shoulder areas in certain individuals prone to maintain these embryonic reservoirs, which are clinically manifested at different ages. Some may have unifocal or multifocal residues reflecting multiple and solitary forms.

The Skin Molecular Ecosystem Holds the Key to Nevogenesis and Melanomagenesis.

Early detection of melanoma is critical to good patient outcomes, but we still know little about the mechanisms of early melanoma development. Normal epidermis has many of the sequence variants and genetic architecture disruptions found in both benign nevi, melanomas, and other skin cancers, yet continues to behave more or less normally. One hypothesis is that many melanocytes in this context are "tumor competent" but are regulated by the microenvironment provided by the surrounding keratinocytes to inhibit progress to nevi or melanoma. There is evidence of accumulating disorder in several measures of the genomic and epigenomic landscape from normal skin through nevi to melanoma that may be key to promoting nevogenesis and melanomagenesis.

Cutaneous Horn Presentation in Porokeratotic Eccrine Ostial and Dermal Duct Nevus. A Brief Review and Case Report.

ABSTRACT: Porokeratotic eccrine ostial and dermal duct nevus is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia. Different clinical presentations have been reported in the literature. Here, we report a case of a 6-year-old girl diagnosed with porokeratotic eccrine ostial and dermal duct nevus confirmed by histopathologic study. Atypical lesions are described as whitish, warty-looking neoformations located in the anterolateral region of the right hip (cutaneous horn).