Multiple desmoplastic Spitz nevi with BRAF fusions in a patient with ring chromosome 7 syndrome

Pigment Cell Melanoma Res. 2021 Sep;34(5):987-993. doi: 10.1111/pcmr.12963. Epub 2021 Mar 17.


Patients with non-supernumerary ring chromosome 7 syndrome have an increased incidence of hemangiomas, café-au-lait spots, and melanocytic nevi. The mechanism for the increased incidence of these benign neoplasms is unknown. We present the case of a 22-year-old man with ring chromosome 7 and multiple melanocytic nevi. Two nevi, one on the right ear and the other on the right knee, were biopsied and diagnosed as desmoplastic Spitz nevi. Upon targeted next-generation DNA sequencing, both harbored BRAF fusions. Copy number alterations and fluorescence in situ hybridization (FISH) for BRAF suggested that the fusions arose on the ring chromosome 7. Hence, one reason for increased numbers of nevi in patients with non-supernumerary ring chromosome 7 syndrome may be increased likelihood of BRAF fusions, due to the instability of the ring chromosome.

Keywords: BRAF fusion; BRAF gene; Spitz nevus; Spitz tumor; melanocytic nevi; melanocytic nevus; ring chromosome 7; ring chromosome seven; spitzoid.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Chromosome Disorders* / genetics
  • Chromosome Disorders* / metabolism
  • Chromosomes, Human, Pair 7 / genetics
  • Chromosomes, Human, Pair 7 / metabolism
  • Chromosomes, Human, Pair 7 / physiology
  • Ear Neoplasms* / genetics
  • Ear Neoplasms* / metabolism
  • Ear Neoplasms* / pathology
  • Humans
  • Male
  • Nevus, Epithelioid and Spindle Cell* / genetics
  • Nevus, Epithelioid and Spindle Cell* / metabolism
  • Nevus, Epithelioid and Spindle Cell* / pathology
  • Oncogene Proteins, Fusion* / genetics
  • Oncogene Proteins, Fusion* / metabolism
  • Proto-Oncogene Proteins B-raf* / genetics
  • Proto-Oncogene Proteins B-raf* / metabolism
  • Ring Chromosomes*
  • Skin Neoplasms* / genetics
  • Skin Neoplasms* / metabolism
  • Skin Neoplasms* / pathology


  • Oncogene Proteins, Fusion
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf

Supplementary concepts

  • Chromosome 7 ring syndrome