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Published on: March 21, 2018
Methodologic aspects of evaluating brush samples from biliary strictures by cytology and DNA flow cytometry
Annika Bergquist1, Bo Lindberg, Juan Castro
1Department of Gastroenterology and Hepatology, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden. annika.bergquist@medhs.ki.se
Objective:
To present a method of increasing the cell yield from brush samples of the biliary tree for measurement of DNA content by flow cytometry (FCM).
Study Design:
One hundred eight cell specimens from 86 patients were studied by FCM for DNA ploidy and cell cycle composition. All specimens were cytologically classified into benign, suspicious for malignancy and malignant. Two methods for preparation of the cell material were compared.
Results:
Enzymatic treatment of formalin-fixed brushes for release of cell nuclei was superior to mechanical removal of the cells. The fraction of samples not possible to assess was reduced from 27% to 4%, and good quality histograms increased from 21% to 62%. Aneuploidy was detected in 7% of benign and 57% of suspicious malignant samples. Using DNA analysis in addition to cytology as a diagnostic marker for cancer, the sensitivity increased from 12% to 31%.
Conclusion:
FCM of cells from biliary strictures can be used routinely as an adjunct to cytology for DNA analysis.
