title: Acquired patch-type blue nevus with overlying vitiligo: a case report.
abstract: BACKGROUND
  Blue nevi are a group of congenital and acquired dermal melanocytoses characterized by a blue-gray appearance on the skin. The common blue nevus and cellular blue nevus are the most common subtypes. Patch-type blue nevus is rather rare.
  
  
  METHODS
  We describe a 77-year-old Chinese male with a 6 × 8-cm non-palpable blue patch overlaid by a depigmented patch on the back of the left scalp. Histological examination of the blue-gray patch showed numerous spindled and elongated bipolar dendritic melanocytes in the upper reticular dermis and an absence of epidermal melanocytes. Immunohistochemically, these dendritic melanocytes were positive for S-100 and HMB-45. A diagnosis of a patch-type blue nevus with overlying vitiligo was made after the biopsy.
  
  
  CONCLUSIONS
  The patient presents an unusual manifestation of patch-type blue nevi with overlying vitiligo. To the best of our knowledge, these features have not been previously described.
authors.affiliation: Department of Dermatovenereology, West China Hospital, Sichuan University, 610041 Chengdu, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Cheng
authors.forename: Hanjun
authors.initials: H
authors.lastname: Yang
authors.forename: Yuping
authors.initials: Y
authors.lastname: Ran
mesh_terms: D000368:Aged; D006258:Head and Neck Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008297:Male; D058950:Melanoma-Specific Antigens / Q000378:metabolism; D018329:Nevus, Blue / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D009418:S100 Proteins / Q000378:metabolism; D012535:Scalp / Q000473:pathology*; D012878:Skin Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D014820:Vitiligo / Q000150:complications / Q000473:pathology*; D058951:gp100 Melanoma Antigen
chemical_list: D058950:Melanoma-Specific Antigens; C548637:PMEL protein, human; D009418:S100 Proteins; D058951:gp100 Melanoma Antigen