title: Image analysis of peripheral compression artefacts of ThinPrep(®) liquid-based cytology preparations.
abstract: OBJECTIVE
  ThinPrep (TP), one of the Food and Drug Administration-approved liquid-based cytology (LBC) preparations, is widely used for gynaecological and non-gynaecological cytology samples. A unique physical artefact caused by the compression at the periphery in TP slides has not been adequately evaluated to date.
  
  
  METHODS
  We processed four established tumour cell lines (MKN28, MKN45, KG-1 and NB4) and mononuclear cells isolated from whole blood over Ficoll-Plaque for TP preparations. For this part of the study, we included five normal cervical LBC preparations. We then auto-counted and auto-measured the area, mean grey value and Feret's diameter in both the inner disc and peripheral rim of the preparations by image morphometry. In addition, we compared the distribution of atypical cell groups in the peripheral rim and inner disc of 132 lung aspirates, 80 thyroid aspirates, 212 cerebrospinal fluids (CSFs) and 50 gynaecological samples.
  
  
  RESULTS
  The areas and Feret's diameters of the cytoplasm in the peripheral compressed rim area were statistically larger than those of cells in the inner disc. The mean grey values of cells (cytoplasm and nucleus) in the peripheral compression rim were also smaller than those in the inner disc cells, leading to decreases in nuclear and cytoplasmic chromatism. Except for the mean grey values, the differences were not significant in the cervical samples.
  
  
  CONCLUSIONS
  Cellular morphology may be markedly distorted in the peripheral rim, regardless of cell malignancy, which may lead to the misinterpretation of cells during the screening. Accordingly, cytological diagnosis based on the findings within the peripheral rim should take this phenomenon into account. Compressed cells found in the peripheral rim should be interpreted with caution when TP slides are used for cytopathological diagnosis.
authors.affiliation: Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Choi
authors.forename: H S
authors.initials: HS
authors.lastname: Shim
authors.forename: J-W
authors.initials: JW
authors.lastname: Song
authors.forename: S W
authors.initials: SW
authors.lastname: Chae
authors.forename: Y-N
authors.initials: YN
authors.lastname: Lee
authors.forename: J E
authors.initials: JE
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
mesh_terms: D044963:Biopsy, Fine-Needle / Q000379:methods*; D045744:Cell Line, Tumor; D002584:Cervix Uteri / Q000473:pathology; D003581:Cytodiagnosis / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008168:Lung / Q000473:pathology; D008297:Male; D011247:Pregnancy; D013961:Thyroid Gland / Q000473:pathology; D014626:Vaginal Smears