• pancreatic;
  • biliary;
  • bile duct;
  • brushing;
  • cytology

Brushing cytology is frequently utilized for the investigation of pancreatic and biliary strictures but is associated with low diagnostic sensitivity. The Papanicolaou Society of Cytopathology has presented a system for diagnostic classification which includes the categories benign, atypical, suspicious for malignancy and malignant.

We studied a series of 216 pancreatic and biliary brushings with either histologic follow-up or a minimum of 6 months clinical follow-up to determine outcomes for the diagnostic categories (“benign,” “atypical, favor reactive,” “atypical, not otherwise specified,” “atypical, suspicious” and “malignant”).

Eighty-six of the 216 (39.8%) were designated “atypical” with 10 of these designated as “atypical favor reactive.” Forty-five were called “atypical not otherwise specified” and 31 were interpreted as “atypical suspicious for malignancy.” On follow-up, 2 of 10 (20%) “atypical favor reactive” were eventually associated with a malignant diagnosis and 23 of 31 (74.2%) “atypical, suspicious for malignancy” demonstrated a malignant outcome. The remaining 45 brushings in the “atypical” category were “atypical not otherwise specified,” and 62% of these were associated with malignancy on follow-up.

Stratification of the “atypical” category into “atypical favor reactive,” “atypical, not otherwise specified” and “atypical, suspicious for malignancy” improves diagnostic accuracy. The “atypical suspicious for malignancy” category has a follow-up similar to the “malignant” category while the “atypical favor reactive” category is associated with a clinical outcome similar to that of the “benign” category. Diagn. Cytopathol. 2014;42:285–291. © 2013 Wiley Periodicals, Inc.