The meaning of equivocal pancreatic cytology in patients thought to have pancreatic cancer

Introduction Fine needle aspirations (FNAs) and endoscopic retrograde cholangiopancreatography (ERCP)-guided brushings (BRUSH) are useful tools in the differentiation between malignant and benign disease of the pancreas. Once the decision to obtain a cytologic confirmation of oneʹs clinical suspicion is made, the interpretation of the findings, especially an equivocal or negative cytology finding, can be unclear. This study seeks to evaluate the utility of cytologic studies in the evaluation of a patient with suspected pancreatic malignancy. Methods A retrospective review of 224 cytologic reports, including 174 FNAs and 50 BRUSHs, from all pancreatic FNAs and BRUSHs performed between January 1989 and June 1995, was performed. Subsequent confirmation of the cytologic diagnosis was made either by histologic or strict clinical criteria. Results Forty-three percent of the cytologic reports were read as malignant, all others reported as suspicious, atypical, or negative. All cytology studies read as malignant and all FNAs reported as suspicious were histologically or clinically confirmed to be malignant. Of those reported as atypical or negative, 55% and 49% were confirmed to be malignant. Both FNA and BRUSH were 100% specific, 75% sensitive, and 80% accurate. Conclusions We conclude that a cytological diagnosis of malignant or suspicious is reliable and useful for further therapy planning in the patient suspected to have a pancreatic malignancy. The reason for the cytologic tests was a strong clinical suspicion, therefore, a high incidence of cancer was found in the patients with atypical or negative readings. A diagnosis of atypical or negative is equivocal and requires further diagnostic maneuvers, frequently including surgery, to make the definitive diagnosis.