title: Blue nevi and variants: an update.
abstract: BACKGROUND
  Blue nevi are a subset of melanocytic proliferations containing cells reminiscent of the embryonal neural crest-derived dendritic melanocytic precursors. They are common specimens in a general pathology practice, but some of their rare variants may pose diagnostic difficulty. Recent molecular studies provide new insights into genetics of blue nevi.
  
  
  OBJECTIVE
  To critically review clinical and histologic features of blue nevi with emphasis on diagnostic problems and rare variants, as well as to provide an update on the pathogenesis of blue nevi.
  
  
  METHODS
  Published peer-reviewed literature and personal experience of the authors.
  
  
  CONCLUSIONS
  Challenging areas in diagnosis of blue nevi include recognition of amelanotic, desmoplastic, atypical, and malignant variants of blue nevus. Recent data show that mutations in genes responsible for common nevi or melanomas such as BRAF , NRAS , or c- kit are rare in blue nevi. Benign and malignant blue nevi harbor frequent mutations in the Gαq class of G-protein α subunits, Gnaq and Gna11 proteins.
authors.affiliation: Department of Pathology, Lahey Clinic, Burlington, Massachusetts, USA. dr.z@DermatopathologyConsultations.com
authors.forename: Artur
authors.initials: A
authors.lastname: Zembowicz
authors.forename: Pushkar A
authors.initials: PA
authors.lastname: Phadke
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D044385:GTP-Binding Protein alpha Subunits / Q000235:genetics; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000378:metabolism / Q000473:pathology*; D009154:Mutation; D018329:Nevus, Blue / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C554062:GNA11 protein, human; C554061:GNAQ protein, human; D044385:GTP-Binding Protein alpha Subunits; D043802:GTP-Binding Protein alpha Subunits, Gq-G11