Analysis of factors influencing the diagnostic failure of intraoperative fine needle aspiration cytology in pancreatic cancer.

Intraoperative fine-needle aspiration cytology (IFNAC) of pancreatic lesions provides a safe method of rapid tissue diagnosis. Few studies have included a thorough statistical analysis of the factors influencing the diagnostic failure of IFNAC. IFNAC was performed on 196 patients during surgical procedures for pancreatic and periampullary masses over an 18-year period. The sensitivity was 90.6% and the specificity 100%. There was a 0% puncture-related complication rate. In all, 6 clinicopathological factors were analyzed to elucidate correlations, if any, with IFNAC failure using statistical analysis. Statistical analysis of each of these clinicopathological factor showed that the cases of failure tended to be related to small tumour size (P < 0.0001), well-differentiated grading (P < 0.002) and a nuclear size similar to the surrounding RBCs (P < 0.0001). Age, gender, moderately or poorly differentiated tumours, and multiple punctures proved to be of no statistical significance in our analysis. We suggest that diagnostic failure of IFNAC seems to be caused mainly by a structural factor such as tumour size and an intrinsic one (a cellular low atypism factor such as well-differentiated grading and small nuclear size). However, we would caution that negative IFNAC cannot be relied on to definitively exclude a diagnosis of carcinoma and, in many instances, the justification for pancreatic resection cannot always be based on cytologic findings, but rather on clinical and laparotomy findings.