title: Nasopharyngeal carcinoma heterogeneity of DNA content identified on cytologic preparations.
abstract: OBJECTIVE
  To evaluate tumor heterogeneity of DNA content in nasopharyngeal carcinoma (NPC) performed on cytologic specimens.
  
  
  METHODS
  Image cytometric analysis of DNA ploidy status of 40 NPCs was performed on nasopharyngeal brushing smears stained with the Feulgen method after hematoxylin eosin staining. If the DNA distribution pattern from the same tumor exhibited diploid, aneuploid or/and tetraploid peaks or some combination of these patterns, the presence of tumor heterogeneity of DNA content was identified.
  
  
  RESULTS
  Thirty-four cases (85%) had a nondiploid DNA pattern among the 40 NPCs. Twenty-eight cases exhibited tumor heterogeneity of DNA content (70%). Of the 28 tumors, 13 (46%) had a combination of diploid and tetraploid patterns, 10 (37%) had a combination of diploid and aneuploid patterns, 3 cases (11%) had a combination of tetraploid and aneuploid patterns, and 2 cases had two aneuploid stem lines. The relationship between DNA ploidy pattern and tumor histologic and cytologic morphology was also examined.
  
  
  CONCLUSIONS
  There is a high incidence of DNA content heterogeneity in NPC. The relevance of tumor heterogeneity to the biologic behavior of NPC awaits further study. DNA quantification with image cytometry on destained cytologic preparations is feasible and reliable.
authors.affiliation: Department of Anatomical and Cellular Pathology, Chinese University of Hong Kong, Hong Kong. mhchen@mailserv.stu.edu.cn
authors.forename: C
authors.initials: C
authors.lastname: Maohuai
authors.forename: A R
authors.initials: AR
authors.lastname: Chang
authors.forename: D
authors.initials: D
authors.lastname: Lo
mesh_terms: D000782:Aneuploidy; D004273:DNA, Neoplasm / Q000032:analysis; D018740:Genetic Heterogeneity; D006801:Humans; D019044:Image Cytometry / Q000379:methods*; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000473:pathology*
chemical_list: D004273:DNA, Neoplasm