title: Melanonychia, melanocytic hyperplasia, and nail melanoma in a Hispanic population.
abstract: OBJECTIVE
  Longitudinal melanonychia (LM) is a common dermatologic problem encountered in everyday practice. Its diagnostic approach is critical as it can be an early sign of nail melanoma. Racial melanonychia is the entity most frequently associated with LM. Because there are no clinical data regarding these associations in a Mexican population, we conducted a prospective study.
  
  
  METHODS
  A total of 68 consecutive patients given the clinical diagnosis of LM were included and a nail biopsy was performed to determine its cause.
  
  
  RESULTS
  Racial melanonychia was found in 48 cases (68%), 4 cases (5.7%) were associated with benign melanocytic hyperplasia, and 4 cases (5.7%) had a nail apparatus malignancy.
  
  
  CONCLUSIONS
  Dermatoscopy and immunohistochemical stains were not used. Incisional transverse nail matrix biopsies were performed when melanonychia affected the middle portion of the nail plate.
  
  
  CONCLUSIONS
  LM is most commonly associated with racial melanonychia in the Mexican population, but in nearly 6% of cases it may be linked with nail apparatus malignancy. To our knowledge, this is the first time a study of this nature was performed in a mestizo Hispanic population.
authors.affiliation: Department of Dermatology and Cutaneous Surgery, Hospital General Dr. Manuel Gea González, Mexico City, Mexico.
authors.forename: Judith
authors.initials: J
authors.lastname: Dominguez-Cherit
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Roldan-Marin
authors.forename: Patricia
authors.initials: P
authors.lastname: Pichardo-Velazquez
authors.forename: Celeste
authors.initials: C
authors.lastname: Valente
authors.forename: Veronica
authors.initials: V
authors.lastname: Fonte-Avalos
authors.forename: Maria Elisa
authors.initials: ME
authors.lastname: Vega-Memije
authors.forename: Sonia
authors.initials: S
authors.lastname: Toussaint-Caire
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000453:epidemiology; D008297:Male; D008544:Melanocytes / Q000473:pathology*; D008545:Melanoma / Q000453:epidemiology*; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D009260:Nail Diseases / Q000453:epidemiology*; D010859:Pigmentation Disorders / Q000453:epidemiology*; D012878:Skin Neoplasms / Q000453:epidemiology*