The value of DNA image cytometry combined with brush routine cytology in diagnosing indeterminate biliary strictures: A large sample size retrospective study

Risk of malignancy in indeterminate biliary tract strictures: Retrospective cohort study

BACKGROUND

Indeterminate biliary strictures, that is, a stricture with benign brush cytology but without clear etiology in clinical or radiological assessment, pose a challenge for clinicians. This study aimed to assess the incidence and risk factors for malignant disease in patients with indeterminate biliary strictures.

METHODS

This is a single-center retrospective study of patients with indeterminate biliary stricture undergoing first endoscopic retrograde cholangiopancreatography (ERCP) and biliary brushing between March 2011 and March 2020. The study included patients with atypical cytology in the first ERCP biliary brushing samples. Main exclusion criteria were primary sclerosing cholangitis, apparent malignancy or tumor in imaging studies, postoperative strictures, chronic pancreatitis, biliary tract stone, and no ≥12-month follow-up or a final pathological diagnosis.

RESULTS

A total of 2279 patients underwent first ERCP procedure because of a biliary tract stricture during the study period, of which 51 patients (2.2%) had an indeterminate biliary stricture and were included. A total of 30 patients (58.8%) had final diagnosis of malignant disease. The patients with final diagnosis of malignant disease were mostly men (n = 19, 63.3%), had jaundice (n = 25, 86.2%), and had significantly higher bilirubin and CA19-9 values than those with benign disease. A total of 25 patients were operated on, of which 21 patients (84%) had malignant disease. Twenty-six patients were followed up only, of whom nine patients (34.6%) had a malignant disease.

CONCLUSION

Indeterminate biliary strictures are uncommon, but two-thirds of the initially indeterminate biliary strictures are malignant. The presence of clinical jaundice and elevated bilirubin and CA19-9 values are associated with increased risk of malignancy.

Digital Image Analysis has an Additive Beneficial Role to Conventional Cytology in Diagnosing the Nature of Biliary Ducts Stricture

BACKGROUND & AIM

Conventional cytological evaluation (CCE) fails to identify nature indeterminate biliary duct stricture (IBDS) in many cases. Digital image analysis (DIA) has the ability to identify and analyze the DNA content of cells. This study assesses the role of DIA in recognizing the nature of IBDS compared to CCE.

METHODS

A prospective observational study was conducted at the Al-Rajhi University Hospital. Fifty patients with IBDS, based on abdominal imaging, were subjected to endoscopic retrograde cholangiopancreatography (ERCP) and brush sampling. These samples were evaluated with CCE and DIA. Follow-up for at least 9 months and cost-analysis had also been done.

RESULTS

Based on the final diagnosis, 32 (64.0%) patients had malignant stricture, and 39 (78.0%) had distal stricture. DIA had 84.40% (95% CI; 67.20-94.70) sensitivity and 94.40% (95% CI; 72.70-99.90) specificity in identifying nature of IBDS, whereas CCE had 19.0% (95% CI; 7.20-36.40) sensitivity and 89.0% (95% CI; 65.30-98.60) specificity. Combination of both modalities had 84.40% (95% CI; 67.20-94.70) sensitivity and 83.30% (95% CI; 58.60-96.40) specificity in identification nature of IBDS. Based on CCE alone, only 6/32 (18.80%) of malignant stricture were diagnosed, and 26/32 (81.20%) were missed. However, DIA alone was able to diagnose 27/32 (84.40%) of malignant stricture, and only 5 cases were missed. Both procedures had detection rate of malignant stricture as DIA alone. Benign stricture was correctly diagnosed in 16/18 (88.80%), 17/18 (94.40%), and 15/18 (83.30%) using CCE alone, DIA alone, and both procedures together, respectively. Cost per detection additional one malignant stricture using DIA required 99.4$.

CONCLUSION

DIA is substantially better than CCE in diagnosing the nature of IBDS but at an increase cost and thus suggests its application in a wider role in clinical practice.

CLINICAL TRIAL NUMBER

NCT04112030.

Determining the Indeterminate Biliary Stricture: Cholangioscopy and Beyond

PURPOSE OF REVIEW

Indeterminate biliary strictures (IDBS) continue to be an area of frustration for clinicians. Standard endoscopic retrograde cholangiopancreatography (ERCP) with conventional brush cytology and/or forceps biopsy has a low sensitivity for distinguishing benign from malignant biliary strictures. A delay in diagnosis of malignancy has consequences for subsequent therapy or surgery. In this article, we review current and emerging technologies that may aid in this diagnostic dilemma.

RECENT FINDINGS

Several technologies have been utilized in IDBS to establish a diagnosis which include peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound with fine needle aspiration, intraductal ultrasound, optical coherence tomography, fluorescence in situ hybridization, next generation sequencing, integrated molecular pathology, and DNA-image cytometry. While cholangioscopy and confocal laser endomicroscopy have become standards of care in expert centers for the evaluation of patients with IDBS, there are several endoscopic and molecular modalities that may also aid in establishing a diagnosis. Further head-to-head prospective diagnostic studies as well as cost-efficacy studies are needed.