Ambiguous melanocytic tumors with loss of 3p21

Am J Surg Pathol. 2014 Aug;38(8):1088-95. doi: 10.1097/PAS.0000000000000209.


Germline loss-of-function mutations in BAP1 are associated with the development of cutaneous melanocytic tumors with some histopathologic characteristics seen in Spitz nevi. Similar melanocytic tumors occurring in a sporadic setting have been demonstrated to have biallelic loss of BAP1. In some of these sporadic tumors, loss of BAP1 occurs through mutation of 1 allele and genomic loss of the other. We screened our database of comparative genomic hybridization profiles of ambiguous melanocytic tumors to identify cases with a single genomic event involving loss of the BAP1 locus. The prevalence of tumors with a single genomic event involving loss of BAP1 was 6.7% in our study population. We further characterized the BAP1 status in 17 of these tumors with available additional material, confirming loss of BAP1 in all cases. We describe BAP1 loss in a blue nevus-like melanoma and further expand the histopathologic spectrum of spitzoid melanocytic neoplasms with BAP1 loss.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Chromosomes, Human, Pair 3 / genetics*
  • Comparative Genomic Hybridization
  • Female
  • Germ-Line Mutation
  • Humans
  • Male
  • Melanoma / genetics*
  • Middle Aged
  • Skin Neoplasms / genetics*
  • Tumor Suppressor Proteins / genetics*
  • Ubiquitin Thiolesterase / genetics*
  • Young Adult


  • BAP1 protein, human
  • Tumor Suppressor Proteins
  • Ubiquitin Thiolesterase