Imaging in chronic pancreatitis: State of the art review

Misdiagnosis of pancreatic intraductal papillary mucinous neoplasms and the challenge of mimicking lesions: imaging diagnosis and differentiation strategies

The rising prevalence of pancreatic cystic lesions (PCLs), particularly intraductal papillary neoplasms (IPMNs), has been attributed to increased utilization of advanced imaging techniques. Incidental detection of PCLs is frequent in abdominal CT and MRI scans, with IPMNs representing a significant portion of these lesions. Surveillance of IPMNs is recommended due to their malignant potential; however, their overlapping imaging features with benign entities can lead to misdiagnosis, overtreatment, and overutilization of healthcare resources. This paper aims to highlight and differentiate lesions often mistaken for IPMNs, providing insight into their imaging characteristics, diagnostic challenges, and distinctive features while highlighting the incidence of wrong diagnosis for these lesions. These lesions include serous cystadenomas, cystic pancreatic neuroendocrine tumors, mucinous cystic neoplasms, lymphoepithelial cysts, duodenal diverticula, pancreatic schwannomas, chronic pancreatitis, retention cysts, intrapancreatic accessory spleens, pancreatic lipomas, choledochal cysts, and others. Utilizing various imaging modalities, including contrast-enhanced CT, MRI, and EUS, alongside histological and molecular analyses, can aid in accurate diagnosis and appropriate management. Understanding these mimicry scenarios is crucial to avoid unnecessary surveillance, interventions, and the burden they place on both patients and healthcare systems. Improved recognition of these lesions can lead to better patient outcomes and resource allocation.

Radiology of fibrosis part II: abdominal organs

Fibrosis is the aberrant process of connective tissue deposition from abnormal tissue repair in response to sustained tissue injury caused by hypoxia, infection, or physical damage. It can affect almost all organs in the body causing dysfunction and ultimate organ failure. Tissue fibrosis also plays a vital role in carcinogenesis and cancer progression. The early and accurate diagnosis of organ fibrosis along with adequate surveillance are helpful to implement early disease-modifying interventions, important to reduce mortality and improve quality of life. While extensive research has already been carried out on the topic, a thorough understanding of how this relationship reveals itself using modern imaging techniques has yet to be established. This work outlines the ways in which fibrosis shows up in abdominal organs and has listed the most relevant imaging technologies employed for its detection. New imaging technologies and developments are discussed along with their promising applications in the early detection of organ fibrosis.

Clinical outcomes of long-term transmural drainage with double pigtail stents in disconnected pancreatic duct syndrome

Background

Disconnected pancreatic duct syndrome (DPDS) is a common cause of recurrent pancreatic fluid collections (PFCs), often requiring repeat drainage. Following initial drainage with lumen apposing metal stents (LAMS), replacement with transmural double pigtail stents (DPS) has been shown to be a viable drainage modality mitigating the risk of recurrence. The sparsity of literature on the consequences of this strategy requires further investigation. We analyze our outcomes of long-term transmural drainage with DPS in patients with DPDS and assess the safety and efficacy of this technique.

Methods

This retrospective review of a prospectively maintained database from November 2015-May 2022 included all patients with DPDS who underwent removal of LAMS and replacement with long-term transmural DPS. Patient demographics, collection characteristics, drainage technique and outcomes, as well as follow-up data was collected and analyzed using descriptive statistics.

Results

There were 139 patients who underwent endoscopic drainage of PFCs with LAMS during the study period. Seventy-eight patients [walled-off necrosis (n=65) and pseudocysts (n=13)] were found to have DPDS. Of these, 44 patients underwent successful LAMS removal followed by replacement with DPS and were included in the analysis. The median age was 57 years and 14 (32%) were female. The median stent dwell time was 394 days [interquartile range (IQR) 245, 853 days]. Spontaneous stent migration was seen in seven patients (16%), one of whom developed a PFC recurrence which was managed conservatively. The second recurrence was seen in a patient with indwelling DPS which did not require further intervention. There were no locoregional adverse events secondary to long-term indwelling DPS. Among the 28 patients who were followed for a year, three patients developed new-onset diabetes, and chronic pancreatitis (CP) changes in the disconnected segment were seen in eight patients, five of whom required pancreatic enzyme supplementation.

Conclusions

Placement of long-term transmural DPS is an effective modality for preventing collection re-accumulation with a favorable safety profile. Randomized prospective studies are essential to investigate the optimal removal timing of indwelling stents to prevent loco-regional complications. Given the realized risk of CP in the disconnected pancreas, follow-up cross sectional imaging may help guide further therapy.

Persistent chronic calcific pancreatitis with intraductal calculi associated with secondary diabetes mellitus type 3 and diabetic ketoacidosis - A case report

Diabetes mellitus type 3 refers to diabetes secondary to an existing disease or condition of the exocrine pancreas and is an uncommon cause of diabetes occurring due to pancreatogenic pathology. It accounts for 15-20% of diabetic patients in Indian and Southeast Asian continents. This is case report of a rare case of type 3 diabetes mellitus (T3DM) presenting with diabetic ketoacidosis (DKA). The patient was admitted for DKA along with complaint of hyperglycemia, blood glucose of 405 mg/dl with HbA1c level of 13.7%. Computed tomography evidence revealed chronic calcific pancreatitis with intraductal calculi and dilated pancreatic duct.

[Modern endoscopic technologies for chronic calcifying pancreatitis]

OBJECTIVE

To evaluate the effectiveness and safety of electrohydraulic lithotripsy of calculi of the main pancreatic duct using ultrathin SpyGlass DS endoscope.

MATERIAL AND METHODS

The study included 29 patients with chronic calcifying pancreatitis and obstructive calculi of the main pancreatic duct. All surgeries were carried out between 2018 and 2023.

RESULTS

Complete removal of calculi (≥5 mm) within one procedure was achieved in 25 (86%) patients.

CONCLUSION

Pancreatoscopy with electrohydraulic lithotripsy using the digital SpyGlass DS system (BostonScientificCorp, Marlborough, MA) is the most effective method for calculi of the main pancreatic duct.

Pancreatic cancer, autoimmune or chronic pancreatitis, beyond tissue diagnosis: Collateral imaging and clinical characteristics may differentiate them

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and is developing into the 2nd leading cause of cancer-related death. Often, the clinical and radiological presentation of PDAC may be mirrored by other inflammatory pancreatic masses, such as autoimmune pancreatitis (AIP) and mass-forming chronic pancreatitis (MFCP), making its diagnosis challenging. Differentiating AIP and MFCP from PDAC is vital due to significant therapeutic and prognostic implications. Current diagnostic criteria and tools allow the precise differentiation of benign from malignant masses; however, the diagnostic accuracy is imperfect. Major pancreatic resections have been performed in AIP cases under initial suspicion of PDAC after a diagnostic approach failed to provide an accurate diagnosis. It is not unusual that after a thorough diagnostic evaluation, the clinician is confronted with a pancreatic mass with uncertain diagnosis. In those cases, a re-evaluation must be entertained, preferably by an experienced multispecialty team including radiologists, pathologists, gastroenterologists, and surgeons, looking for disease-specific clinical, imaging, and histological hallmarks or collateral evidence that could favor a specific diagnosis. Our aim is to describe current diagnostic limitations that hinder our ability to reach an accurate diagnosis among AIP, PDAC, and MFCP and to highlight those disease-specific clinical, radiological, serological, and histological characteristics that could support the presence of any of these three disorders when facing a pancreatic mass with uncertain diagnosis after an initial diagnostic approach has been unsuccessful.

Management of Pancreatic Calculi in Chronic Pancreatitis: A Review Article

Chronic pancreatitis is a slow, irreversible, and progressive inflammatory condition with abdominal pain, loss of parenchyma, fibrosis, and calculus formation. It also causes loss of exocrine and endocrine function. Gallstones and alcohol is the most frequent cause of chronic pancreatitis. It is also caused by other factors, including oxidative stress, fibrosis, and repeated incidence of acute pancreatitis. Chronic pancreatitis is followed by several sequelae, one of them being formation of calculi in the pancreas. The formation of calculi can occur in the main pancreatic duct, branches of the duct, and parenchyma. The cardinal sign of chronic pancreatitis is pain caused by obstruction of pancreatic ducts and its branches leading to ductal hypertension resulting in pain. The main aim of endotherapy includes pancreatic duct decompression. The management options vary based on the type and size of the calculus. The treatment of choice for small-sized pancreatic calculi is endoscopic retrograde cholangiopancreatography (ERCP) followed by sphincterotomy and extraction. The large-sized calculi need fragmentation before extraction, which is done by extracorporeal shock wave lithotripsy (ESWL). Surgery can be an option for patients having severe pancreatic calculi if endoscopic therapy fails. For diagnostic purposes, imaging plays a very important role. The treatment options remain complex if the radiological and laboratory findings overlap. Due to advancements in diagnostic imaging, treatment options have become precise and helpful. It can significantly lower the quality of life along with immediate and long-term problems that pose a serious risk to life. This review comprises the various management options available for removing calculi following chronic pancreatitis, including surgical, endoscopic, and medical therapy.

Position statement on the definition, incidence, diagnosis and outcome of acute on chronic pancreatitis

BACKGROUND

Acute on chronic pancreatitis (ACP) is a relatively common condition, but there are significant gaps in our knowledge on the definition, incidence, diagnosis, treatment and prognosis.

METHODS

A systematic review that followed PICO (Population; Intervention; Comparator; Outcome) recommendation for quantitative questions and PICo (Population, Phenomenon of Interest, Context) for qualitative research was done to answer 10 of the most relevant questions about ACP. Quality of evidence was judged by the GRADE criteria (Grades of Recommendation, Assessment, Development and Evaluation). The manuscript was sent for review to 12 international experts from various disciplines and continents using a Delphi process.

RESULTS

The quality of evidence, for most statements, was low to very low, which means that the recommendations in general are only conditional. Despite that, it was possible to reach strong levels of agreement by the expert panel for all 10 questions. A new consensus definition of ACP was reached. Although common, the real incidence of ACP is not known, with alcohol as a major risk factor. Although pain dominates, other non-specific symptoms and signs can be present. Serum levels of pancreatic enzymes may be less than 3 times the upper limit of normal and cross-sectional imaging is considered more accurate for the diagnosis in many cases. It appears that it is less severe and with a lower mortality risk than acute pancreatitis.

CONCLUSIONS

Although the evidence base is poor, this position statement provides a foundation from which to advance management of ACP.

Ultrasound Shear Wave Elastography of Normal Pancreas in Adult Subjects

Background and Purpose Transabdominal ultrasound (US)-based shear wave elastography (SWE) provides an attractive method of estimating pancreatic stiffness. There is limited data on the SWE values of the healthy pancreas in Indian subjects. The current study aimed to evaluate SWE of the normal pancreas.

Methods We performed a study from January 2019 to March 2019. We included adult patients who presented for the US of the upper abdomen for vague abdominal symptoms, unrelated to the pancreas. The SWE values were obtained from the pancreatic head and body. The association of pancreatic SWE with age, gender, fatty liver, chronic liver disease, and cholelithiasis was recorded.

Results During the study period, 205 subjects underwent SWE of the pancreas. The mean age of subjects was 41.3 (standard deviation [SD] 15.3) years. There were 93 males and 112 females. The mean SWE value in the head of the pancreas was 8.98 (SD 2.46 kPa), and that in the body region was 8.67 (SD 2.67 kPa). There was a positive correlation of SWE with age. The SWE of the pancreatic body was significantly higher in patients who had a fatty liver on US (p < 0.05). There was no significant association of SWE of the pancreas with gender, presence of chronic liver disease, or gallstones.

Conclusion The normal values of pancreatic SWE are correlated with age and fatty change in the liver.

How Are Imaging Findings Associated with Exocrine Insufficiency in Idiopathic Chronic Pancreatitis?

Aim  The aim is to study the association between imaging findings in chronic pancreatitis and fecal elastase 1 (FE1) in patients with idiopathic chronic pancreatitis (ICP).

Methods  In this retrospective study on a prospectively maintained database of patients with ICP, a radiologist blinded to clinical and laboratory findings reviewed CT and/or MRI. Findings were documented according to recommendations of the Consortium for the Study of Chronic Pancreatitis, Diabetes, and Pancreatic Cancer, October 2018. Low FE1 (<100 μg elastase/g) was considered diagnostic of pancreatic exocrine insufficiency (PEI). Association between imaging findings and FE1 was studied.

Results  In total, 70 patients (M: F = 37:33) with ICP with mean age of 24.2 (SD 6.5) years, range 10 to 37 years and mean disease duration of 5.6 (SD 4.6) years, range 0 to 20 years were included. Mean FE level was 82.5 (SD 120.1), range 5 to 501 μg elastase/g. Mean main pancreatic duct (MPD) caliber was 7 (SD 4) mm, range 3 to 21 mm and mean pancreatic parenchymal thickness (PPT) was 13.7 (SD 5.5) mm, range 5 to 27 mm. There was a significant association between FE1 and MPD size, PPT, type of pancreatic calcification; presence of intraductal stones, side branch dilatation on magnetic resonance cholangiopancreatography and extent of pancreatic involvement ( p <0.05). In total, 79%, 86%, and 78% with moderate to severe MPD dilatation, pancreatic atrophy, and side branch dilatation had low FE1, respectively. But nearly half of those with no or mild structural abnormality on imaging had low FE1.

Conclusion  Significant association between FE1 and specific imaging findings demonstrates its potential as a marker of exocrine insufficiency and disease severity in chronic pancreatitis. But imaging and FE1 are complementary rather than supplementary.

Endoscopic ultrasound diagnostic gain over computed tomography and magnetic resonance cholangiopancreatography in defining etiology of idiopathic acute pancreatitis

BACKGROUND

About 10%-30% of acute pancreatitis remain idiopathic (IAP) even after clinical and imaging tests, including abdominal ultrasound (US), contrast-enhanced computed tomography (CECT) and magnetic resonance cholangiopancreatography (MRCP). This is a relevant issue, as up to 20% of patients with IAP have recurrent episodes and 26% of them develop chronic pancreatitis. Few data are available on the role of EUS in clarifying the etiology of IAP after failure of one or more cross-sectional techniques.

AIM

To evaluate the diagnostic gain after failure of one or more previous cross-sectional exams.

METHODS

We retrospectively collected data about consecutive patients with AP and at least one negative test between US, CECT and MRCP, who underwent linear EUS between January 2017 and December 2020. We investigated the EUS diagnostic yield and the EUS diagnostic gain over different combinations of these cross-sectional imaging techniques for the etiologic diagnosis of AP. Types and frequency of EUS diagnosis were also analyzed, and EUS diagnosis was compared with the clinical parameters. After EUS, patients were followed-up for a median of 31.5 mo to detect cases of pancreatitis recurrence.

RESULTS

We enrolled 81 patients (63% males, mean age 61 ± 18, 23% with previous cholecystectomy, 17% with recurrent pancreatitis). Overall EUS diagnostic yield for AP etiological diagnosis was 79% (20% lithiasis, 31% acute on chronic pancreatitis, 14% pancreatic solid or cystic lesions, 5% pancreas divisum, 5% autoimmune pancreatitis, 5% ductal abnormalities), while 21% remained idiopathic. US, CECT and MRCP, taken alone or in combination, led to AP etiological diagnosis in 16 (20%) patients; among the remaining 65 patients, 49 (75%) obtained a diagnosis at EUS, with an overall EUS diagnostic gain of 61%. Sixty-eight patients had negative US; among them, EUS allowed etiological diagnosis in 59 (87%). Sixty-three patients had a negative CECT; among them, 47 (74%) obtained diagnosis with EUS. Twenty-four had a negative MRCP; among them, 20 (83%) had EUS diagnosis. Twenty-one had negative CT + MRCP, of which 17 (81%) had EUS diagnosis, with a EUS diagnostic gain of 63%. Patients with biliary etiology and without previous cholecystectomy had higher median values of alanine aminotransferase (154 vs 25, P = 0.010), aspartate aminotransferase (95 vs 29, P = 0.018), direct bilirubin (1.2 vs 0.6, P = 0.015), gamma-glutamyl transpeptidase (180 vs 48, P = 0.006) and alkaline phosphatase (150 vs 72, P = 0.015) Chronic pancreatitis diagnosis was more frequent in patients with recurrent pancreatitis at baseline (82% vs 21%, P < 0.001). During the follow-up, AP recurred in 3 patients, one of which remained idiopathic.

CONCLUSION

EUS is a good test to define AP etiology. It showed a 63% diagnostic gain over CECT + MRCP. In suitable patients, EUS should always be performed in cases of IAP. Further prospective studies are needed.

Endoscopic ultrasound diagnostic gain over computed tomography and magnetic resonance cholangiopancreatography in defining etiology of idiopathic acute pancreatitis. World J Gastrointest Endosc 2022;14:376-386. [DOI: 10.4253/wjge.v14.i6.376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

BACKGROUND

About 10%-30% of acute pancreatitis remain idiopathic (IAP) even after clinical and imaging tests, including abdominal ultrasound (US), contrast-enhanced computed tomography (CECT) and magnetic resonance cholangiopancreatography (MRCP). This is a relevant issue, as up to 20% of patients with IAP have recurrent episodes and 26% of them develop chronic pancreatitis. Few data are available on the role of EUS in clarifying the etiology of IAP after failure of one or more cross-sectional techniques.

AIM

To evaluate the diagnostic gain after failure of one or more previous cross-sectional exams.

METHODS

We retrospectively collected data about consecutive patients with AP and at least one negative test between US, CECT and MRCP, who underwent linear EUS between January 2017 and December 2020. We investigated the EUS diagnostic yield and the EUS diagnostic gain over different combinations of these cross-sectional imaging techniques for the etiologic diagnosis of AP. Types and frequency of EUS diagnosis were also analyzed, and EUS diagnosis was compared with the clinical parameters. After EUS, patients were followed-up for a median of 31.5 mo to detect cases of pancreatitis recurrence.

RESULTS

We enrolled 81 patients (63% males, mean age 61 ± 18, 23% with previous cholecystectomy, 17% with recurrent pancreatitis). Overall EUS diagnostic yield for AP etiological diagnosis was 79% (20% lithiasis, 31% acute on chronic pancreatitis, 14% pancreatic solid or cystic lesions, 5% pancreas divisum, 5% autoimmune pancreatitis, 5% ductal abnormalities), while 21% remained idiopathic. US, CECT and MRCP, taken alone or in combination, led to AP etiological diagnosis in 16 (20%) patients; among the remaining 65 patients, 49 (75%) obtained a diagnosis at EUS, with an overall EUS diagnostic gain of 61%. Sixty-eight patients had negative US; among them, EUS allowed etiological diagnosis in 59 (87%). Sixty-three patients had a negative CECT; among them, 47 (74%) obtained diagnosis with EUS. Twenty-four had a negative MRCP; among them, 20 (83%) had EUS diagnosis. Twenty-one had negative CT + MRCP, of which 17 (81%) had EUS diagnosis, with a EUS diagnostic gain of 63%. Patients with biliary etiology and without previous cholecystectomy had higher median values of alanine aminotransferase (154 vs 25, P = 0.010), aspartate aminotransferase (95 vs 29, P = 0.018), direct bilirubin (1.2 vs 0.6, P = 0.015), gamma-glutamyl transpeptidase (180 vs 48, P = 0.006) and alkaline phosphatase (150 vs 72, P = 0.015) Chronic pancreatitis diagnosis was more frequent in patients with recurrent pancreatitis at baseline (82% vs 21%, P < 0.001). During the follow-up, AP recurred in 3 patients, one of which remained idiopathic.

CONCLUSION

EUS is a good test to define AP etiology. It showed a 63% diagnostic gain over CECT + MRCP. In suitable patients, EUS should always be performed in cases of IAP. Further prospective studies are needed.

Missed Case of Pancreatogenic Diabetes Diagnosed Using Ultrasound

Nonalcoholic pancreatogenic diabetes mellitus (type 3c DM) is an often-misdiagnosed entity usually seen in young men of tropical countries. Although most of the patients present with abdominal pain and symptoms of exocrine pancreatic insufficiency, there is still a subset that does not present with these classical symptoms, which emphasizes the need for special diagnostic considerations. The significance of identifying this subset of diabetic lies not only in the change in management of the disease but also in early detection for pancreatic carcinoma that is more common among those patients. In our case, ultrasound with X-ray played a vital role in diagnosis, prompting us to consider it as an essential part of the investigation panel in all newly diagnosed nonobese diabetic individuals.

Efficacy of endovascular embolization of arterial pseudoaneurysms in pancreatitis: A systematic review and meta-analysis

BACKGROUND

There is a significant variability in the reported outcomes following endovascular embolization of arterial pseudoaneurysms in pancreatitis. The objective of this systematic review and meta-analysis is to evaluate the efficacy of endovascular embolization of pancreatitis-related pseudoaneurysms.

METHODS

Searches of MEDLINE, EMBASE, and SCOPUS databases were performed through July 1, 2019 in accordance with PRISMA guidelines. All studies with ≥10 patients reporting technical success, clinical success, complications, and mortality were included. Generalized linear mixed method with random effects model was used for assessing pooled incidence rates and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 29 studies (n = 840 with 638 pseudoaneurysms) were included. The pooled incidence rates of pseudoaneurysms in acute and chronic pancreatitis were 0.05% and 0.03%, respectively (odds ratio, 0.91, 95% CI-0.24-3.43). The most common site of pseudoaneurysm was splenic artery (37.7%). The most common embolization agent was coil (n = 415). The follow up period was 54.7 months (range, 21 days to 40.5 months). Pooled technical success rate was 97% (95% CI-92-99%, I2 83%). Clinical success rates at ≤3 months, 3-12 months, and >12 months were 82% (95% CI-70-90%, I2 42%), 86% (95% CI-75-92%, I2 44%), and 88% (95% CI-83-91%, I2 0%), respectively. There was no significant difference in the technical or clinical success between acute and chronic pancreatitis on subgroup analysis. Mortality was lower in chronic pancreatitis (OR 4.27 (95% CI 1.35-13.53, I2 0%)). Splenic infarction was the most common complication (n = 47).

CONCLUSION

Endovascular embolization is associated with a high technical and clinical success.

Role of ultrasound shear wave elastography in preoperative prediction of pancreatic fistula after pancreaticoduodenectomy

BACKGROUND

Majority of predictors of postoperative pancreatic fistula (POPF) use intraoperative variables. We aimed to study the role of preoperative ultrasound shear wave elastography (USWE) to predict POPF.

METHODS

The consecutive patients who underwent pancreaticoduodenectomy (PD) between January 2019 to March 2020 were prospectively enrolled. All patients underwent USWE assessment at the pancreatic neck level. Intraoperative variables including pancreatic texture, pancreatic duct diameter, blood loss and histological grading of fibrosis were also recorded. Associations between USWE and intraoperative variables and histological grading with the development of POPF were analyzed.

RESULTS

Of the 62 patients assessed, 50 patients (mean age: 53 ± 14 years; 31 males) were included. POPF and clinically relevant POPF (CRPOPF) were observed in 22 (44%) and 7 (14%) patients respectively. Soft pancreas was an independent predictor of CRPOPF (p = 0.04). The mean USWE valve was significantly lower in patients with CRPOPF as compared to no CRPOPF (9.7 Kpa vs. 12.8Kpa, p = 0.016). At receiver operating characteristic curve analysis, USWE value of 12.65Kpa yielded sensitivity and specificity of 100% and 47%, respectively, for prediction of CRPOPF. USWE showed significant correlation with intraoperative pancreatic texture (Spearman's rank correlation coefficient (ρ) = 0.565, p = 0.001).

CONCLUSION

USWE helps in preoperative prediction of CRPOPF. This may further help to customize management strategy in high risk patients.

Interventional radiological management of hepatobiliary disorders in pregnancy

Hepatobiliary disorders are common in pregnancy and pose a management challenge. Minimally invasive interventional radiological (IR) techniques allow safe and effective management of these disorders. However, the available literature is scarce. Radiological interventions in this group of patients mandate a clear understanding of the risks of radiation to the fetus. The IR physician involved in the care of these patients should be aware of the measures to minimize the exposure to ionizing radiation. Additionally, the risk-benefit ratio should be clearly defined in a multidisciplinary discussion involving IR physicians, obstetricians, and gastroenterologists. This review is an effort to address issues related to the application of IR procedures for hepatobiliary disorders in pregnant patients.

Challenging biliary strictures: pathophysiological features, differential diagnosis, diagnostic algorithms, and new clinically relevant biomarkers - part 1

It is frequently challenging to make the correct diagnosis in patients with biliary strictures. This is particularly important as errors may have disastrous consequences. Benign-appearing strictures treated with stents may later be revealed to be malignant and unnecessary surgery for benign strictures carries a high morbidity rate. In the first part of the review, the essential information that clinicians need to know about diseases responsible for biliary strictures is presented, with a focus on the most recent data. Then, the characteristics and pitfalls of the methods used to make the diagnosis are summarized. These include serum biomarkers, imaging studies, and endoscopic modalities. As tissue diagnosis is the only 100% specific tool, it is described in detail, including techniques for tissue acquisition and their yields, how to prepare samples, and what to expect from the pathologist. Tricks to increase diagnostic yields are described. Clues are then presented for the differential diagnosis between primary and secondary sclerosing cholangitis, IgG4-related sclerosing cholangitis, cholangiocarcinoma, pancreatic cancer, autoimmune pancreatitis, and less frequent diseases. Finally, algorithms that will help to achieve the correct diagnosis are proposed.