University of Missouri Health System Columbia, MO, United States
Mahmoud Mansour, MD1, Lei N. Sun, MD, PhD1, Magda Esebua, MD1, Kanak Das, MD2 1University of Missouri Health System, Columbia, MO; 2University Medical Center, Lubbock, TX
Introduction: Establishing an accurate and timely diagnosis of malignancy in biliary strictures remains a challenging goal in endoscopy. In the era of advanced endoscopy, where various methods can be utilized to obtain tissue samples for diagnoses, it remains unclear if endoscopists should routinely send biliary stents for cytological evaluation.
Methods: We evaluated biliary stents that were sent for cytology from 12/2018 to 10/2020. Stent cytology was recorded as positive, reactive atypia likely to be benign, atypia suspicious for malignancy, or negative. Patient demographics, stent type and duration, and methods used to reach a final diagnosis were obtained by chart review.
Results: A total of 23 biliary stents from 17 patients (11 males, 6 females, mean age 74) were examined. Mean duration for stent placement was 10.3 weeks. 7 out of the 24 stents were metallic. In the 6 patients who were ultimately diagnosed with malignancy, none of the 11 stents sampled (see table, case 13 and 16 had 4 and 3 stents sampled respectively) had positive cytology. Of those 11 stents, 2 showed reactive atypia, and 9 were benign. Sensitivity and specificity of stent cytology were 0% and 100%, respectively. No changes to clinical management were made based on stent cytology. EUS-FNA/B had the highest sensitivity of 67% for detecting malignancy.
Discussion: Historically, stent cytology was thought to have good utility in diagnosing malignancy based on a small series done in 1989 by Leung et al. However, those findings were challenged by the small sample size and the recent development of more advanced techniques, such as endoscopic ultrasound and cholangioscopy, that allow for early and accurate detection of malignancy. More recently, Mutaraman et al. showed in their retrospective analysis of 175 patients in 2019 stent cytology sensitivity of only 1.7%. This poor sensitivity is consistent with the findings in our study.
Our study is limited by the retrospective nature and the small sample size. Only one patient had cholangiocarcinoma, which likely contributed to the low diagnostic yield of stent cytology, as tumors extrinsic to the bile duct, such as pancreatic cancers and ampullary tumors, are expectedly more difficult to sample from within the duct.
The availability of better diagnostic modalities and the low sensitivity make stent cytology of less utility in diagnosing pancreatobilliary malignancy. Larger multicenter studies are needed to better understand the role of biliary stents' cytological analysis.
Case #
Final diagnosis
Stent cytology results
Methods(s) establishing malignant diagnosis
Other methods used to obtain tissue samples
1
Periampullary adenocarcinoma
Benign
Endoscopic biopsy
Brushing, EUS-FNA
2
Benign
Benign
Brushing
3
Benign
Benign
EUS-FNB
4
Benign
Benign
Brushing, EUS-FNB
5
Benign
Benign
Brushing, EUS-FNB
6
Periampullary adenocarcinoma
Benign: Reactive atypia
EUS-FNB, Endoscopic biopsy
Brushing
7
Benign
Benign: Reactive atypia
Brushing, EUS-FNB
8
Benign
Benign: Reactive atypia
EUS-FNA
9
Periampullary adenocarcinoma
Benign
EUS-FNB
Endoscopic biopsy
10
Benign
Benign
Brushing, EUS-FNB, Billiary biopsy
11
Benign
Benign
Brushing
12
Benign
Benign
Brushing
13*
Periampullary adenocarcinoma
Benign
EUS-FNB
Brushing, cholangioscopy
14
Pancreatic adenocarcinoma
Benign: Reactive atypia
EUS-FNA, Brushing
15
Benign
Benign
Brushing, biliary biopsy
16*
Cholangiocarcinoma
Benign
Brushing
EUS-FNB
17*
Benign
Benign
Brushing
Table: EUS: Endoscopic ultrasound. FNB: Fine needle biopsy. FNA: Fine needle aspiration. * Indicates that multiple stents were evaluated for cytology over the course of management. (4 stents for case # 13, 3 stents for case # 16 and 2 stents for case # 17)
Disclosures:
Mahmoud Mansour indicated no relevant financial relationships.
Lei Sun indicated no relevant financial relationships.
Magda Esebua indicated no relevant financial relationships.
Kanak Das indicated no relevant financial relationships.
Mahmoud Mansour, MD1, Lei N. Sun, MD, PhD1, Magda Esebua, MD1, Kanak Das, MD2. P0036 - To Send or Not to Send Biliary Stents for Cytology: The Unanswered Question, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.
