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Cell Jun 2022Giant congenital melanocytic nevi are NRAS-driven proliferations that may cover up to 80% of the body surface. Their most dangerous consequence is progression to...
Giant congenital melanocytic nevi are NRAS-driven proliferations that may cover up to 80% of the body surface. Their most dangerous consequence is progression to melanoma. This risk often triggers preemptive extensive surgical excisions in childhood, producing severe lifelong challenges. We have presented preclinical models, including multiple genetically engineered mice and xenografted human lesions, which enabled testing locally applied pharmacologic agents to avoid surgery. The murine models permitted the identification of proliferative versus senescent nevus phases and treatments targeting both. These nevi recapitulated the histologic and molecular features of human giant congenital nevi, including the risk of melanoma transformation. Cutaneously delivered MEK, PI3K, and c-KIT inhibitors or proinflammatory squaric acid dibutylester (SADBE) achieved major regressions. SADBE triggered innate immunity that ablated detectable nevocytes, fully prevented melanoma, and regressed human giant nevus xenografts. These findings reveal nevus mechanistic vulnerabilities and suggest opportunities for topical interventions that may alter the therapeutic options for children with congenital giant nevi.
Topics: Animals; Heterografts; Humans; Melanoma; Mice; Neoplasm Transplantation; Nevus, Pigmented; Skin Neoplasms
PubMed: 35561684
DOI: 10.1016/j.cell.2022.04.025 -
Indian Pediatrics Oct 2014
Topics: Child; Female; Forehead; Humans; Nevus, Halo; Skin
PubMed: 25362030
DOI: No ID Found -
Tidsskrift For Den Norske Laegeforening... Jan 2021
Topics: Humans; Nevus, Pigmented; Skin Neoplasms
PubMed: 33433097
DOI: 10.4045/tidsskr.20.0605 -
Singapore Medical Journal Nov 2018Although spongiotic (eczematous), psoriatic and cutaneous skin infections are among the most common in dermatology consultations, melanocytic lesions - including the... (Review)
Review
Although spongiotic (eczematous), psoriatic and cutaneous skin infections are among the most common in dermatology consultations, melanocytic lesions - including the different types of nevi and melanomas - are among those that cause a great deal of concern and stress to patients and their clinicians. A diagnosis of benign melanocytic nevus carries a very good prognosis. However, a diagnosis of melanoma might indicate more aggressive treatment, lifelong surveillance and a worse prognosis. Differentiating between these conditions is not always a straightforward process for clinicians and pathologists. Therefore, knowledge of melanoma mimickers is very important for clinicians in general, and dermatologists and pathologists in particular. In this review, we called attention to some of the more frequent benign but unusual melanocytic lesions that are of diagnostic concern for clinicians evaluating these cutaneous proliferations.
Topics: Cell Proliferation; Diagnosis, Differential; Humans; Incidence; Melanoma; Nevus, Pigmented; Prognosis; Risk; Skin; Skin Neoplasms; United States; Melanoma, Cutaneous Malignant
PubMed: 29774360
DOI: 10.11622/smedj.2018041 -
Ugeskrift For Laeger Jul 2022Benign skin tumours are commonly seen by general practitioners. They are important to differentiate from skin malignancies. Most benign skin lesions are diagnosed based...
Benign skin tumours are commonly seen by general practitioners. They are important to differentiate from skin malignancies. Most benign skin lesions are diagnosed based on the history and clinical features. However, if the clinical diagnosis is uncertain, a skin biopsy, e.g. excisional or punch for histopathological examination is necessary to rule out malignancy. Seborrheic keratoses are the most common benign skin tumours with an increasing incidence with age. Other common benign skin lesions include melanocytic naevi, acrochordons and dermatofibromas, which may resemble malignant neoplasms.
Topics: Biopsy; Humans; Nevus, Pigmented; Skin; Skin Diseases; Skin Neoplasms
PubMed: 35959819
DOI: No ID Found -
Pigment Cell & Melanoma Research Nov 2015Melanocytic nevi are a benign clonal proliferation of cells expressing the melanocytic phenotype, with heterogeneous clinical and molecular characteristics. In this... (Review)
Review
Melanocytic nevi are a benign clonal proliferation of cells expressing the melanocytic phenotype, with heterogeneous clinical and molecular characteristics. In this review, we discuss the genetics of nevi by salient nevi subtypes: congenital melanocytic nevi, acquired melanocytic nevi, blue nevi, and Spitz nevi. While the molecular etiology of nevi has been less thoroughly studied than melanoma, it is clear that nevi and melanoma share common driver mutations. Acquired melanocytic nevi harbor oncogenic mutations in BRAF, which is the predominant oncogene associated with melanoma. Congenital melanocytic nevi and blue nevi frequently harbor NRAS mutations and GNAQ mutations, respectively, while Spitz and atypical Spitz tumors often exhibit HRAS and kinase rearrangements. These initial 'driver' mutations are thought to trigger the establishment of benign nevi. After this initial phase of the cell proliferation, a senescence program is executed, causing termination of nevi growth. Only upon the emergence of additional tumorigenic alterations, which may provide an escape from oncogene-induced senescence, can malignant progression occur. Here, we review the current literature on the pathobiology and genetics of nevi in the hope that additional studies of nevi promise to inform our understanding of the transition from benign neoplasm to malignancy.
Topics: Carcinogenesis; Genetic Predisposition to Disease; Humans; Nevus, Pigmented; Skin Neoplasms
PubMed: 26300491
DOI: 10.1111/pcmr.12412 -
The Pan African Medical Journal 2021Congenital melanocytic nevus (CMN) is a proliferation of melanocytes that presents at birth or shortly after birth as light brown to black patches or plaques, covering...
Congenital melanocytic nevus (CMN) is a proliferation of melanocytes that presents at birth or shortly after birth as light brown to black patches or plaques, covering any part of the body occasionally exhibiting hypertrichosis. The estimated prevalence of such large forms is 0.002% of the births, resulting from mutations of genes coding for NRAS and KRAS proteins, usually during the first twelve weeks of pregnancy. Giant CMN also known as "bathing trunk nevus," "giant hairy nevus", and "nevus pigmentosus et pilosus" has highest potential to turn into malignant melanoma. We present a case of a 7 year old boy who came to our clinic with complaints of itching over his left shoulder and back for 4 months duration. He gave history of black patches on those areas since birth that gradually grew in size and attained the current presentation. On examination, well demarcated black patches were noted over his left shoulder, arm, trunk (A) and extending from nape of the neck and the entire back with excessive hair growth (B). A diagnosis of congenital melanocytic nevus was established and since it could potentially evolve into a melanoma, prophylactic surgery with skin grafting was suggested but the patient's parents refused. Hence dermabrasion was done to lighten the dark pigmentation and reduce hair growth within nevi. Parents were counselled about complications of CMN and advised to follow up with a dermatologist regularly. Clinicians should scrupulously examine the child to facilitate timely surgical intervention thereby reducing morbidity and mortality associated with this condition.
Topics: Child; Humans; Infant, Newborn; Male; Melanocytes; Melanoma; Nevus, Pigmented; Skin Neoplasms; Skin Transplantation
PubMed: 34887981
DOI: 10.11604/pamj.2021.40.107.26779 -
Modern Pathology : An Official Journal... Jan 2020In daily clinical practice melanocytic nevi are commonly encountered. Traditionally, both benign and malignant melanocytic tumors have been sub-classified by their... (Review)
Review
In daily clinical practice melanocytic nevi are commonly encountered. Traditionally, both benign and malignant melanocytic tumors have been sub-classified by their histopathologic characteristics with differing criteria for malignancy applied to each group. Recently, many of the mutations that initiate nevus formation have been identified and specific sets of mutations are found in different subtypes of nevi. Whereas a single mutation appears sufficient to initiate a nevus, but is not enough to result in melanoma, specific combinations of mutations have been identified in some melanocytic tumors that are regarded to be of low biologic potential. The term "melanocytoma" has recently been proposed by the World Health Organization to describe those tumors that demonstrate genetic progression beyond the single mutations that are found in nevi but are not frankly malignant. Melanocytomas occupy intermediate genetic stages between nevus and melanoma and likely have an increased risk of malignant transformation as compared to nevi. This review provides an update on the broad spectrum of melanocytic nevi and melanocytomas and outlines their key histopathologic and genetic features.
Topics: Biomarkers, Tumor; Genetic Predisposition to Disease; Humans; Melanocytes; Mutation; Nevus, Pigmented; Phenotype; Skin Neoplasms
PubMed: 31659277
DOI: 10.1038/s41379-019-0390-x -
BMC Ophthalmology Sep 2022Divided nevus with verrucous hyperplasia will always recur after surgery but non-verrucous divided eyelid nevus rarely recur. This study analyzed the differential...
PURPOSE
Divided nevus with verrucous hyperplasia will always recur after surgery but non-verrucous divided eyelid nevus rarely recur. This study analyzed the differential expression of Ki-67, S100, Melan A and HMB45 and identified the correlation between the clinical and histopathological features of verrucous and non-verrucous divided eyelid nevus.
METHODS
This study included 29 patients, of whom 8 patients had verrucous divided nevus. Immunohistochemistry labeling was used to assess the expression of Ki-67, S100, Melan A and HMB45 after excision. The difference between verrucous and non-verrucous divided eyelid nevus was analyzed.
RESULTS
The patients' ages ranged from 2 to 59 years, with a mean age of 19 years. The lesion size ranged from 1.5 to 2.0 cm in diameter and invaded the eyelid margins and the posterior lamella of the eyelids. Immunohistochemistry labeling showed strong positivity for approximately 98.5% of S100 and positive staining for approximately 27.6% of Ki-67, 72.4% of Melan A and 6.8% of HMB45. However, Ki-67 was significantly upregulated in verrucous divided nevus of the eyelids compared with non-verrucous divided nevus, with approximately 38.8% upregulation in verrucous and 18.3% upregulation in non-verrucous nevus.
CONCLUSIONS
This study correlated the clinic-pathologic features of verrucous divided eyelid nevus by means of statistically analyzing the varied clinical features and pathological impressions. The significant over-expression of S100 may be used as an indicator of divided nevus of the eyelids, and the over-expressed Ki-67 may contribute to the recurrence of verrucous divided nevus. High expression of HMB45 and Melan A may represent malignant transformation.
Topics: Adolescent; Adult; Antibodies, Monoclonal; Child; Child, Preschool; Eyelid Neoplasms; Eyelids; Humans; Ki-67 Antigen; MART-1 Antigen; Middle Aged; Nevus; Nevus, Pigmented; Skin Neoplasms; Young Adult
PubMed: 36057574
DOI: 10.1186/s12886-022-02582-w -
Pediatric Dermatology 1996We report a patient with phakomatosis pigmentovascularis IIb and numerous iris hamartomas. Phakomatosis pigmentovascularis IIb is characterized by the simultaneous...
We report a patient with phakomatosis pigmentovascularis IIb and numerous iris hamartomas. Phakomatosis pigmentovascularis IIb is characterized by the simultaneous occurrence of a nevus flammeus, a mongolian spot, and sometimes a nevus anemicus in the same individual, with systemic involvement. To our knowledge, the association with multiple iris hamartomas has been reported only once. This second patient suggests that the association might be more common. Additional reports will indicate if such an association is more frequent than is now assumed.
Topics: Child, Preschool; Diagnosis, Differential; Female; Hamartoma; Humans; Iris; Nevus, Blue; Nevus, Pigmented; Skin Neoplasms; Syndrome
PubMed: 8919522
DOI: 10.1111/j.1525-1470.1996.tb01184.x