Audit of Bile Duct Cytology Reporting at Tallaght Hospital
Brianan McGovern*, Pardeep Maheshwari^, BM Ryan^, Michael Jeffers*
Departments of * Histopathology and ^Gastroenterology, Tallaght Hospital, Dublin 24
Biliary brush cytology can be notoriously difficult to interpret. Recently the Papanicolou Society recommended a 6-tier system to standardise disease categorisation in biliary cytopathology reporting. We wanted to assess reporting in Tallaght Hospital and to compare to international norms.
1. To determine the prevalence of each diagnostic category (non diagnostic, benign, atypical, suspicious, malignant) in our sample group and to correlate with clinical data 2. Review the reporting terminology at AMNCH in view of the proposed standardised terminology for pancreaticobiliary cytology samples 3. Assess inter-observer and intra-observer variation in the context of the proposed major criteria for diagnosis of malignancy
All biliary brushing samples received between January 2012 and March 2013 were identified using the laboratory information system. All patient reports were reviewed. Clinical follow-up for each patient sampled was obtained. Diagnostic cytology slides of all cases were retrieved and reviewed. Results were compared to published data .
100 consecutive sample were reviewed and results are as follows: Fifty five pecent of cases at AMNCH were reported as Benign/Negative as compared to 53.3 % in published data. While Atypical were 22% (11% in published data ) , Malignant 12% (16.5% in Published data), Suspicious for malignancy 9% (18.2% in Published data ) and 2% (0.8% in Published data) were reported as Inedequate sample . Compared to clinical outcomes, there was a sensitivity of 40.4%, specificity of 100%, positive predictive value of 100% andnegative predictive value of 65%. Clear cytology category was given as headline or bottom line resultin only 44% of cases. There was 95% concordance between study pathologists and original reports (5% inter-observer variability).
The prevalence of each diagnostic category for biliary brush cytology at our institution is comparable to published data. Diagnostic sensitivity and specificity rates compare well to the prevalence in the literature. Provision of more clinical and imaging data on request forms could be improved to enhance diagnostic accuracy. On foot of this audit, we are considering implementation of the proposed 6-tier standardised terminology for reporting of bile duct cytology speciemens and introducing standardised request forms for biliary cytology to ensure minimum information for the reporting cytologists