title: Halo congenital nevus undergoing spontaneous regression. Involvement of T-cell immunity in involution and presence of circulating anti-nevus cell IgM antibodies.
abstract: BACKGROUND
  Halo congenital nevus is a condition in which halo formation is associated with congenital nevocellular nevi. Although several theories have been proposed, the immunologic mechanisms of halo formation and concomitant nevus regression still remain unclear. We presented immunologic findings in a case of halo congenital nevus with unique histologic location of inflammatory cells.
  
  
  METHODS
  Histologically, the present case of halo congenital nevus undergoing spontaneous regression showed a marked inflammatory infiltrate with remnants of original nevus cell nests. In the infiltrating T cells, CD8+ cells outnumbered CD4+ cells and the infiltrate of natural killer cells was not substantial. Direct and indirect immunofluorescence studies demonstrated the presence of IgM antibodies against nevus cells as well as melanoma cells and cultured melanocytes in the patient's serum.
  
  
  CONCLUSIONS
  Our findings suggest that both T-cell-mediated immunity and IgM antibodies may be involved in the regression of halo congenital nevus. However, it is important to point out that our results may simply be epiphenomena and not directly responsible for the destruction of nevus cells.
authors.affiliation: Department of Dermatology, Hamamatsu University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura
authors.forename: K
authors.initials: K
authors.lastname: Yamanaka
authors.forename: H
authors.initials: H
authors.lastname: Wakita
authors.forename: S
authors.initials: S
authors.lastname: Kurokawa
authors.forename: D
authors.initials: D
authors.lastname: Horiguchi
authors.forename: A
authors.initials: A
authors.lastname: Usui
authors.forename: S
authors.initials: S
authors.lastname: Sayama
authors.forename: M
authors.initials: M
authors.lastname: Takigawa
mesh_terms: D000912:Antibodies, Neoplasm / Q000032:analysis / Q000097:blood*; D002675:Child, Preschool; D003165:Complement System Proteins / Q000032:analysis; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000032:analysis / Q000097:blood*; D008297:Male; D008544:Melanocytes / Q000276:immunology; D009365:Neoplasm Regression, Spontaneous; D009508:Nevus, Pigmented / Q000151:congenital* / Q000276:immunology* / Q000473:pathology; D012878:Skin Neoplasms / Q000151:congenital* / Q000276:immunology* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: D000912:Antibodies, Neoplasm; D006684:HLA-DR Antigens; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D003165:Complement System Proteins