Melanocytic nevi

Spitz tumors represent a heterogeneous group of challenging melanocytic neoplasms, displaying a range of biological behaviors, spanning from benign lesions, Spitz nevi (SN) to Spitz melanomas (SM), with intermediate lesions in between known as atypical Spitz tumors (AST). They are histologically characterized by large epithelioid and/or spindled melanocytes arranged in fascicles or nests, often associated with characteristic epidermal hyperplasia and fibrovascular stromal changes. In the last decade, the detection of mutually exclusive structural rearrangements involving receptor tyrosine kinases ROS1, ALK, NTRK1, NTRK2, NTRK3, RET, MET, serine threonine kinases BRAF and MAP3K8, or HRAS mutation, led to a clinical, morphological and molecular based classification of Spitz tumors...

Melanocytic lesions are instable tumors, the genome of which and its changes determinate their morphology and biological properties. Intermediate lesions share histomorphological features of both, nevi and melanoma. Melanocytomas represent a group of them separated on the basis of recent molecular-biological studies. The article summarizes benign, intermediate, malignant and combined melanocytic skin lesions and offers practical recommendations for diagnosis.

Naevus of Ito and naevus of Ota are benign dermal melanocytoses with similar pathogenic mechanisms of failure in the melanocyte migration to typical locations within the basal layer from neural crest cells and differ in distribution. Bilateral and oral mucosal involvement of naevus of Ota can occur but is infrequent. Naevus of Ito is seldom associated with naevus of Ota and extracutaneous manifestations. A review of the English literature showed 14 cases of naevus of Ota with palatal involvement. None showed bilateral involvement of both naevi with oral involvement...

Cutaneous melanoma (CM) is a candidate for screening programs because its prognosis is excellent when diagnosed at an early disease stage. Targeted screening of those at high risk for developing CM, a cost-effective alternative to population-wide screening, requires valid procedures to identify the high-risk group. Self-assessment of the number of nevi has been suggested as a component of such procedures, but its validity has not yet been established. We analyzed the level of agreement between self-assessments and examiner assessments of the number of melanocytic nevi in the area between the wrist and the shoulder of both arms based on 4548 study subjects in whom mutually blinded double counting of nevi was performed...

BACKGROUND: Acquired melanocytic nevi are common benign skin lesions that require removal under certain circumstances. Shave removal is a straightforward treatment modality with a risk of recurrence. OBJECTIVE: To evaluate the outcome of dermoscopy-guided shave removal of acquired melanocytic nevi in the face of dark-skinned individuals who are more liable to postsurgical complications. METHODS: The study was conducted on 64 patients with acquired facial melanocytic nevi...

BACKGROUND: Increasing melanoma incidence with less increasing mortality is observed in several countries. This discrepancy is not well understood. OBJECTIVE: In this study, our aim was to discuss factors (UV exposure, melanoma treatment, diagnostic activity, overdiagnosis, pathologists' diagnostic threshold and clinicians' propensity to remove suspect skin lesions) that may influence melanoma incidence and mortality in Denmark. METHODS: This was a register study with the number of melanocyte-related lesions and melanoma mortality based on comprehensive national pathology and mortality databases for the period 1999-2019...

BACKGROUND: The diagnosis of subcorneal hematoma (SH) can be challenging because the clinical presentation of SH can resemble melanocytic lesions. Few studies have examined the characteristic dermoscopic features of SH, but a more detailed large-scale study is needed to overcome the diagnostic challenge of differentiating it from acral melanoma. OBJECTIVES: To describe the dermoscopic features of SH. METHODS: We evaluated the clinical and dermoscopic features of 50 SH lesions from 43 patients at the Pusan National University Hospitals (Busan and Yangsan)...

BACKGROUND: Melanocytic nevi are frequently observed in the pediatric population. While newly acquired nevi can appear during childhood, congenital nevi can continue to grow and clinically change, making patient caregivers concerned. Reflectance confocal microscopy (RCM) in vivo is a noninvasive tool that might enhance the diagnostic accuracy of dermoscopy, reducing the rate of unnecessary surgical procedures. This study aimed to assess the utility of RCM in increasing the diagnostic accuracy of pediatric melanocytic nevi that show pigmentation changes or grow rapidly...

BACKGROUND: Melanoma is one of the deadliest skin cancers that originate from melanocytes due to sun exposure, causing mutations. Early detection boosts the cure rate to 90%, but misclassification drops survival to 15-20%. Clinical variations challenge dermatologists in distinguishing benign nevi and melanomas. Current diagnostic methods, including visual analysis and dermoscopy, have limitations, emphasizing the need for Artificial Intelligence understanding in dermatology. OBJECTIVES: In this paper, we aim to explore dermoscopic structures for the classification of melanoma lesions...

No abstract text is available yet for this article.

Birthmarks in newborns can be classified as vascular, melanocytic or pigmented, or markers of underlying developmental abnormalities of the nervous system. A nevus simplex is a benign capillary malformation. Newborns with a nevus flammeus can be safely treated before one year of age with a pulsed dye laser to reduce the visibility of lesions. Infantile hemangiomas should be treated with systemic beta blockers if there is a risk of life-threatening complications, functional impairment, ulceration, underlying abnormalities, permanent scarring, or alteration of anatomic landmarks...

BACKGROUND/OBJECTIVES: Although excision of melanocytic nevi with high-grade dysplasia is recommended by the World Health Organization (WHO), clinical studies investigating the approach based on the grading dysplasia of melanocytic lesions with peripheral globules (PGs) are lacking. We investigated the grades of dysplasia and their distinguishable dermoscopic and clinical features to provide accurate data for managing these lesions. METHODS: We retrospectively classified histologically confirmed melanocytic lesions with PGs according to the 2018 WHO Classification of Skin Tumours criteria in a university hospital in Turkey...

BACKGROUND: Tissue expansion for treating giant congenital melanocytic nevi (GCMN) is a commonly employed surgical method. However, the procedure's efficacy is often hindered by anatomical and histological characteristics as well as blood supply, particularly in the extremities and trunk. Enhancing expansion efficiency while reducing complications is thus a topic to be investigated, especially for pediatric patients undergoing rapid physical and psychological development with higher risks of non-compliance to medical instructions...

Drivers of Spitz neoplasms include activating point mutations in HRAS and Spitz-associated genomic fusions. It has become evident that some BRAF-mutated melanocytic neoplasms can morphologically mimic Spitz tumors (STs). These have been termed BRAF mutated and morphologically spitzoid (BAMS). In this study, 17 experts from the International Melanoma Pathology Study Group assessed 54 cases which included 40 BAMS and 14 true STs. The participants reviewed the cases blinded to the genomic data and selected among several diagnostic options, including BAMS, ST, melanoma, and other...

PURPOSE: Low frequency EPR can noninvasively detect endogenous free radical melanin in melanocytic skin lesions and could potentially discriminate between benign atypical nevi and malignant melanoma lesions. We recently succeeded in demonstrating the ability of clinical EPR to noninvasively detect the endogenous melanin free radical in skin lesions of patients. However, the signal-to-noise ratio (SNR) was extremely low warranting further research to boost the sensitivity of detection...

Among nevus-associated melanomas, which overall account for 20%-30% of all melanomas, those arising specifically in congenital melanocytic nevi are infrequent, but can be disproportionately frequent in childhood and adolescence. Congenital melanocytic nevi (CMNi) are common benign melanocytic tumors that are present at birth or become apparent in early childhood. They are classified based on the projected adult size. Small and medium-sized CMNi are frequent, whereas large/giant CMNi (over 20 cm in diameter) are rare, but can be associated with high morbidity due to marked aesthetic impairment and the risk of neurocutaneous syndrome or melanoma development...

Pediatric melanomas are rare tumors that have clinical and histological differences from adult melanomas. In adult melanoma, the immunohistochemical marker PRAME is increasingly employed as a diagnostic adjunct. PRAME is also under investigation as a target structure for next-generation immunotherapies including T-cell engagers. Little is known about the characteristics of PRAME expression in pediatric melanoma. In this retrospective study, samples from 25 pediatric melanomas were compared with control groups of melanomas in young adults (18-30 years; n = 32), adult melanoma (>30 years, n = 30), and benign melanocytic nevi in children (0-18 years; n = 30) with regard to the immunohistochemical expression of PRAME (diffuse PRAME expression >75%/absolute expression)...

BACKGROUND: Limited research exists on laser treatment of giant congenital melanocytic nevus (GCMN). OBJECTIVE: We sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response. METHODS AND MATERIALS: Between 2019 and 2022, we enrolled 30 medium-to-giant CMN patients who underwent Er: YAG laser treatment. All patients received biopsies before and after laser treatments...

INTRODUCTION: Conjunctival nevi are benign tumors that are commonly located at the nasal or temporal limbus and rarely in the fornix or tarsus. We report a case of a patient presenting with a solitary compound cystic nevus of the conjunctival fornix in the background of bilateral complexion-associated melanosis. CASE PRESENTATION: A 71-year-old African-American female was referred for evaluation of an incidentally noted melanocytic lesion of the right conjunctival fornix...

Congenital melanocytic nevi (CMN) are special types of moles. CMN happen when extra pigment-making cells (melanocytes) grow in a baby's skin while the baby is forming before birth. They are not caused by anything their parent did or didn't do during pregnancy. These moles are there when the baby is born, stay on the skin for life, and grow as the child grows.