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JAAD Case Reports Mar 2017
PubMed: 28280767
DOI: 10.1016/j.jdcr.2017.01.003 -
Dermatology Research and Practice 2011Despite recent advances, the biology underlying nevogenesis remains unclear. Activating mutations in NRAS, HRAS, BRAF, and GNAQ have been identified in benign nevi....
Despite recent advances, the biology underlying nevogenesis remains unclear. Activating mutations in NRAS, HRAS, BRAF, and GNAQ have been identified in benign nevi. Their presence roughly correlates with congenital, Spitz, acquired, and blue nevi, respectively. These mutations are likely to play a critical role in driving nevogenesis. While each mutation is able to activate the MAP kinase pathway, they also interact with a host of different proteins in other pathways. The different melanocytic developmental pathways activated by each mutation cause the cells to migrate, proliferate, and differentiate to different extents within the skin. This causes each mutation to give rise to a characteristic growth pattern. The exact location and differentiation state of the cell of origin for benign moles remains to be discovered. Further research is necessary to fully understand nevus development given that most of the same developmental pathways are also present in melanoma.
PubMed: 21754924
DOI: 10.1155/2011/463184 -
Urology Annals Oct 2014Prostatic melanosis is a very rare, benign lesion characterized by the presence of melanin in the epithelium of the prostate gland and stromal dendritic cells, requiring...
Prostatic melanosis is a very rare, benign lesion characterized by the presence of melanin in the epithelium of the prostate gland and stromal dendritic cells, requiring no additional treatment. It constitutes the melanocytic lesions of the prostate together with blue nevus and malignant melanoma. We present a case with prostatic melanosis because it is rarely seen and its distinction from malignant melanoma is clinicopathologically very important.
PubMed: 25371626
DOI: 10.4103/0974-7796.141010 -
Ear, Nose, & Throat Journal Dec 2021Blue nevus is a type of uncommon benign pigmented lesion in the skin or the mucosa of human body which is featured by pigmented dendritic melanocytes and spindled...
Blue nevus is a type of uncommon benign pigmented lesion in the skin or the mucosa of human body which is featured by pigmented dendritic melanocytes and spindled melanocytic cells. Sinonasal blue nevus is extremely rare. We reported a sinonasal blue nevus case with the background of pituitary adenoma, type 2 diabetes mellitus, and hypertension (including endoscopic and histological pictures). Further, the existing literature about blue nevus is reviewed. This paper puts a spotlight on the potential correlation between blue nevus with the endocrine system disorder and provides support for further experimental research.
PubMed: 34892997
DOI: 10.1177/01455613211064014 -
Indian Dermatology Online Journal 2016Reticulin staining has been suggested as an inexpensive tool in the differential diagnosis of melanoma versus benign nevi. In the present study, reticulin immunostaining...
INTRODUCTION
Reticulin staining has been suggested as an inexpensive tool in the differential diagnosis of melanoma versus benign nevi. In the present study, reticulin immunostaining patterns in malignant melanomas, benign intradermal nevi, and blue nevi were observed. The concordance in evaluation of the pattern between observers was also done.
MATERIALS AND METHODS
A retrospective search was performed in the computer database of the Ackerman Academy of Dermatopathology for "melanoma," "melanocytic nevus," and "blue nevus". Fifty-six melanomas (30 of nodular subtype and 26 of superficial spreading subtype), 54 benign compound nevi, and 27 blue nevi were selected for the study. Patterns of reticulin staining in the dermis and the basement membrane in these melanocytic lesions were evaluated and the concordance between the two groups of authors was assessed. Statistical evaluation was performed with the Statistica(®) 10 program, Tulsa, OK. Concordance of the pattern evaluation was evaluated using Cohen's kappa coefficient.
RESULTS
Melanomas show a variable basement membrane pattern some of which show flat, thin and smooth pattern. Benign nevi almost never showed this flat pattern at the basement membrane zone. In the dermis, melanomas showed reticulin fibers surrounding groups of melanocytic cells while nevi predominantly had reticulin fibers around individual cells. There was greater agreement in evaluating the dermal component compared to the basement membrane pattern.
CONCLUSION
The dermal reticulin staining pattern may be of some value in the diagnosis of melanocytic lesions, but poor concordance in evaluation of the basement membrane zone pattern limits its usefulness.
PubMed: 26955582
DOI: 10.4103/2229-5178.174312 -
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