title: Spitz nevus versus malignant melanoma: spitz nevi predominate on the thighs in patients younger than 40 years of age, melanomas on the trunk in patients 40 years of age or older.
abstract: BACKGROUND
  To determine whether location and gender in addition to patient age might be useful in discriminating parameters between malignant melanoma (MM) and Spitz nevus (SN); 1228 cases of MM and 967 cases of SN were analyzed.
  
  
  METHODS
  Computerized records were studied and compared as to frequency and density, and the results were statistically analyzed.
  
  
  RESULTS
  Spitz nevi (SNs) were found to predominate on the thighs (32.6 % of the cases in women, 19.9 % of the cases in men); in persons younger than 40 years of age, in both genders they were found 8.1 times more frequently than MM in this location. In contrast, MMs on the trunk in persons 40 years of age or older in both genders were 7.4 times more frequent compared with SN.
  
  
  CONCLUSIONS
  There has been no follow-up of the patients, and the question whether SN are benign tumors was not assessed.
  
  
  CONCLUSIONS
  The only locations that appear to be of additional diagnostic help when differentiating between these two tumors are the thighs in patients younger than 40 years of age, suggesting SN, and the trunk in patients 40 years of age or older, suggesting MM.
authors.affiliation: Laboratory of Dermatohistopathology, Munich, Germany. CSchmoeckel@t-online.de
authors.forename: Christian
authors.initials: C
authors.lastname: Schmoeckel
authors.forename: Gregor
authors.initials: G
authors.lastname: Wildi
authors.forename: Torsten
authors.initials: T
authors.lastname: Schäfer
mesh_terms: D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000175:diagnosis*; D018332:Nevus, Epithelioid and Spindle Cell / Q000175:diagnosis*; D018570:Risk Assessment; D012737:Sex Factors; D012878:Skin Neoplasms / Q000175:diagnosis*; D013848:Thigh