Diagnostic Role of Bile Cytology in suspected hilar cholangiocarcinoma: Bile Aspiration Cytology and Brush Cytology

Aims Cholangiocarcinomas, broadly known as bile duct cancers, are enigmatic and difficult to diagnose and treat. Despite their rarity, these cancers have poor prognosis and are generally detected at advanced stages. Definitive histology and/or cytology are required to confirm a diagnosis of malignancy before aggressive management.

The aim of this study is to examine endoscopic biliary tract cytology under Endoscopic Retrograde Cholangiopancreatography (ERCP) as a diagnostic tool in suspected cholangiocarcinoma. This current analysis has been conducted to assess the sensitivity of bile aspiration cytology (BAC) and the accuracy of bile duct brush cytology. It also evaluated the comparative effectiveness of BAC and brushing for cytology in the diagnosis of cholangiocarcinoma. [1] [2] [3] [4]

Methods Data were reviewed from 2018 to November 2023 by analyzing 1600 ERCP through our endoscopic department. Data on 34 patients with suspected hilar cholangiocarcinoma who underwent BAC through a drainage catheter and/or brushings during ERCP were retrospectively collected. A total of 47 biliary samples including 17 bile aspirations and 30 biliary brushings were analyzed by cytological examination. The diagnostic performance of bile aspiration associated with biliary brushing during ERCP was compared to brush cytology alone.

Results 34 patients with suspected hilar cholangiocarcinomas (18 males, 16 females) were included. The mean age was 65 years. Cytological diagnosis was adenocarcinoma in 18 patients, atypical (category III) in 9 and benign biliary strictures in 5 patients. In 6 cases, cytology bile examination was not carried out due to ERCP failure. The number of cytological samplings ranged from 1 to 3 times. 41% was obtained by only brush cytology, 9% by bile aspiration cytology (BAC) and in 32% of cases, samplings were obtained by combination of bile aspiration in addition to brushing. No complications related to the cytological procedure occurred. The overall brush cytology findings for malignancy were as follows: positive predictive value 46%, negative predictive value 24% and accuracy of 20%. Positive results for bile duct aspiration was approximately 6%. The two sample-combination bile aspiration+brushing under ERCP gave a negative predictive value of 45% and a diagnostic accuracy of 54%. When suspicious results were added to malignant results as positive result, the positive diagnostic yield was 65%.

Conclusions Biliary cytology is a straightforward technique that helps in performing and optimizing the sensitivity of ERCP to provide a definitive diagnosis. The findings have shown that the combination of bile aspiration and brush cytology significantly increase accuracy compared to brushing alone in diagnosing malignant bile duct cancer. Inclusion of significant atypia as malignant results may improve the diagnostic performance of cholangiocarcinomas.

Publication History

Article published online:
15 April 2024

• References

• 1 Navaneethan U, Njei B, Lourdusamy V, Konjeti R, Vargo JJ, Parsi MA.. Comparative effectiveness of biliary brush cytology and intraductal biopsy for detection of malignant biliary strictures: a systematic review and meta-analysis. Published online 2014
• 2 Sugimoto S, Matsubayashi H, Kimura H, Sasaki K, Nagata K, Ohno S, Uesaka K, Mori K, Imai K, Hotta K, Takizawa K, Kakushima N, Tanaka M, Kawata N, Ono H.. Diagnosis of bile duct cancer by bile cytology: usefulness of post-brushing biliary lavage fluid. Published online 2015
• 3 Roth GS, Bichard P, Fior-Gozlan M, Roth H, Auroux J, Risse O, Letoublon C, Laverrière MH, Bricault I, Leroy V, Decaens T.. Performance of bile aspiration plus brushing to diagnose malignant biliary strictures during endoscopic retrograde cholangiopancreatography. 2016; 04 (09) E997-E1003
• 4 Juvvala, Kavitha MBBS1; Bajwa, Maria MD2; Bank, Leslie MD, FACG3; Marhaba, Ali MD1. Brush Cytology During ERCP for the Diagnosis of Biliary and Pancreatic Malignancies 2018