title: Superficial urothelial (umbrella) cells. A potential cause of abnormal DNA ploidy results in urine specimens.
abstract: OBJECTIVE
  To determine the DNA ploidy distribution in urothelial superficial (umbrella) cells and to assess the value of the image analysis operator's experience.
  
  
  METHODS
  DNA ploidy was assessed in 12 cytologically negative bladder washes stained with Feulgen stain. All 12 cases were evaluated independently by three operators with different levels of cytopathology experience and different goals. Operator 1 (experienced) selected only nuclei of urothelial cells, avoiding nuclei of superficial cells; operator 2 (experienced) selected only nuclei of superficial cells; operator 3 (inexperienced) selected the largest and most-atypical-looking nuclei. Each operator measured a total of 100 nuclei per case.
  
  
  RESULTS
  Operator 1 found all cases to be diploid (97% of nuclei on average). Operators 2 and 3 showed a wide range of results. Almost half the nuclei (47%) analyzed by operator 2 were in the diploid region, a third (35%) were in the tetraploid region, and the remaining (18%) ones had a DNA index (DI) in the range of 1.2-1.8 or > 2.5. Operator 3 obtained the most abnormal results. Only 9% of the nuclei were diploid, while 37% were in the tetraploid region, 18% were in the hyperploid region, and 35% had a DI in the range of 1.2-1.8. Differences among results obtained by each operator were statistically significant.
  
  
  CONCLUSIONS
  The nuclei of superficial (umbrella) cells often have abnormal DNA content, which may cause abnormal DNA ploidy results in cytomorphologically normal bladder washes. Consequently, the nuclei of superficial cells should be avoided in the evaluation of urine samples. DNA analysis of urine specimens requires selection of nuclei only of deep urothelial cells by an experienced operator.
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, Illinois 60153, USA. ewojcik@luc.edu
authors.forename: E M
authors.initials: EM
authors.lastname: Wojcik
authors.forename: R J
authors.initials: RJ
authors.lastname: Brownlie
authors.forename: T J
authors.initials: TJ
authors.lastname: Bassler
authors.forename: M C
authors.initials: MC
authors.lastname: Miller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002455:Cell Division; D002467:Cell Nucleus; D004273:DNA, Neoplasm / Q000652:urine*; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011003:Ploidies; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000473:pathology / Q000652:urine*; D019459:Urothelium / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm