The safety of endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions

Seeding of a Tumor in the Gastric Wall after Endoscopic Ultrasound-guided Fine-needle Aspiration of Solid Pseudopapillary Neoplasm of the Pancreas

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely used as a first-line procedure for the definitive diagnosis of pancreatic solid tumor. Adverse events associated with the EUS-FNA procedure include acute pancreatitis, bleeding, infection, and duodenal perforation. Rarely, pancreatic tumors disseminate in the peritoneal cavity or seed in the gastric wall via the biopsy needle tract after EUS-FNA. Such seeding has been noted primarily in cases of adenocarcinomas and has not been associated with solid pseudopapillary neoplasm (SPN), a rare and potentially malignant tumor of the pancreas. This is the first report of a case of tumor seeding in the gastric wall after EUS-FNA of pancreatic SPN.

Stratifying Intraductal Papillary Mucinous Neoplasms by Cyst Fluid Analysis: Present and Future

A significant proportion of patients with intraductal papillary mucinous neoplasms (IPMNs) undergo surgical resection in order to prevent or treat pancreatic cancer at the risk of significant perioperative morbidity. Efforts have been made to stratify the potential risk of malignancy based on the clinical and radiographic features of IPMN to delineate which cysts warrant resection versus observation. An analysis of the cyst fluid obtained by preoperative endoscopic examination appears to be correlative of cyst type and risk, whereas serum markers and radiographic findings have not yet reached a level of sensitivity or specificity that proves they are clinically meaningful. In this review, we investigate the current cyst fluid analysis studies and present those that have shown promise in effectively stratifying high-risk versus low-risk lesions. While new cyst fluid markers continue to be identified, additional efforts in testing panels and marker composites in conjunction with clinical algorithms have also shown promise in distinguishing dysplasia and the risk of malignancy. These should be tested prospectively in order to determine their role in guiding the surveillance of low-risk lesions and to evaluate the new markers detected by proteomics and genetic sequencing.

Histologic Analysis of Endoscopic Ultrasound-Guided Through the Needle Microforceps Biopsies Accurately Identifies Mucinous Pancreas Cysts

BACKGROUND & AIMS

It is a challenge to accurately assess pancreatic cystic lesions (PCLs) and determine their risk. We compared the yield of tissue acquired with endoscopic ultrasound (EUS)-guided microforceps (through the needle tissue biopsy [TTNB]) with that of samples collected by EUS-guided fine-needle-aspiration (EUS-FNA), and the accuracy of analyses of each sample type in the diagnosis of mucinous PCLs.

METHODS

We performed a prospective open-label study of 114 consecutive adults (56.1% women; mean age, 64.2 y) undergoing EUS-FNA evaluation of PCLs (mean size, 35 mm) at 7 centers, from June 20, 2016, through August 31, 2018. Samples were collected from each cyst by FNA and microforceps; samples collected by FNA were analyzed by cytology and samples collected by TTNB were analyzed by histology. Acquisition yield was defined as the percentage of specimens collected that were adequate for cytologic or histologic analysis. Diagnoses of mucinous cysts were made based on identification of pancreatic mucinous epithelium by cytology analysis of FNA samples or histologic analysis of TTNB samples. Surgical specimens were used as the reference standard when available.

RESULTS

The EUS-guided microforceps were successfully inserted into 97.4% (111 of 114) of PCLs. Tissue acquisition yield was significantly higher with TTNB (95 of 114; 83.3%) than FNA (43 of 114; 37.7%) (P < .001). Sixty-one PCLs were determined to be mucinous based on TTNB analysis (53.5%) vs 11 with FNA analysis (9.6%) (P < .001). Among PCLs categorized as equivocal, based on the level of carcinoembryonic antigen, TTNB analysis found 50% (41 of 82) to be mucinous and FNA analysis found 8.5% (7 of 82) to be mucinous (P < .001). Findings from analyses of samples collected by TTNB were 100% concordant with findings from histologic analysis of surgical specimens (14 of 14), whereas only 3 of 14 findings from analysis of samples collected by FNA were in agreement with findings from surgical specimens (21.4%) (P < .001). Four of 5 mucinous PCLs with advanced neoplasia (80%) were detected with TTNB compared with none with FNA (P = .04). Self-limited intracystic bleeding occurred in 7 patients (6.1%), and acute pancreatitis in 6 patients (5.3%).

CONCLUSIONS

In a multicenter prospective study of patients undergoing EUS-FNA for evaluation of PCLs, we found TTNB collection of tissues for histologic analysis to be safe and feasible, with an acquisition yield of 83.3%. Histologic analysis of samples collected by TTNB identified a larger proportion of mucinous PCLs compared with cytologic analysis of samples collected by FNA-even among samples categorized as equivocal, based on the level of carcinoembryonic antigen. More samples collected by TTNB than FNA were found to have advanced neoplasia. Clinicaltrials.gov no: NCT02979509.

Tumor growth rate of pancreatic serous cystadenomas: Endosonographic follow-up with volume measurement to predict cyst enlargement

BACKGROUND

Serous cystadenomas are benign lesions of the pancreas. Usually they are diagnosed incidentally on cross-sectional imaging studies. Endosonography is a valuable tool in the diagnosis and follow-up of these cystic lesions. Given its benign nature, surgical resection is advised only in symptomatic patients. The interval and length of surveillance is not well established.

METHODS

A retrospective single center study was done. All the patients with a pancreatic serous cystadenoma sent for an endosonographic evaluation, between December 2008 and December 2015 were included. The lesions were follow-up endosonographically at least once, in a 12 months interval. Volume was measured with the formula π/6 × (d1 x d1 x d2). Two groups were evaluated: patients with a volume under 10 mL (Group 1) and those with a volume of 10 mL or more at presentation (Group 2). Growth rate between these two groups was compared.

RESULTS

Thirty-one patients were analyzed, with a mean age of 58.2 years. Patients were mainly women (87%). Twenty-four patients in Group 1 had a mean enlargement of 0.67 ml per year, whereas patients in Group 2 had a mean enlargement of 9.8 ml per year. The growth rate difference between these two groups was statistically significant (p = 0.0001).

CONCLUSION

Asymptomatic patients with pancreatic serous cystadenomas should be follow-up for enlargement. Small volume lesions have a low risk of enlargement compared with high volume and macrocystic serous cystadenomas. Volume at presentation is a feature to analyze when defining surveillance interval.

Current indications and yield of endoscopic ultrasound and ancillary techniques in pancreatic cystic neoplasms

An increase in the diagnosis of pancreatic cystic neoplasm has been described lately. Surgical treatment or surveillance is advised depending on the type of lesion diagnosed. The most accurate diagnostic approach is needed to make the best therapeutic decision. Endoscopic ultrasound is a very valuable tool in the evaluation of pancreatic cystic neoplasm. It generates high-quality images and allows the possibility of sampling the cystic fluid for cytology, microbiological and molecular evaluation. Even with this evaluation, the sensitivity of this approach is not always adequate. New technological resources have been developed to try to improve the diagnostic accuracy of pancreatic cystic neoplasms. The two most promising techniques are needle-based confocal laser endomicroscopy and contrast-enhanced harmonic endoscopic ultrasound. Needle-based confocal laser endomicroscopy allows a microscopic evaluation of mucosal glands and vascular pattern, to differentiate mucinous from non-mucinous lesions. Contrast-enhanced harmonic endoscopic ultrasound is used for the vascular evaluation of the microcirculation of the cyst wall and mural nodule, mainly to make the difference between malignant nodules and mucus plugs. A combination of these different diagnostic techniques can improve the diagnostic accuracy of pancreatic cystic neoplasms to offer the adequate therapeutic decision.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy in the evaluation of pancreatic cystic lesions: a multicenter study

Background and study aims  Accurate diagnosis and classification of pancreatic cysts (PCs) remains a challenge. The aims of this study were to: (1) evaluate the safety and technical success of a novel microforceps for EUS-guided through-the-needle biopsy (TTNB) of PCs; and (2) assess its diagnostic yield for mucinous PCs when compared to FNA cyst fluid analysis and cytology. Patients and methods  This was a multicenter retrospective analysis of 47 patients who underwent EUS-FNA and TTNB for PCs between January 2014 and June 2017. Technical success was defined as acquisition of a specimen adequate for cytologic or histological evaluation. Cyst fluid carcinoembryonic antigen (CEA) was used to initially categorize cysts as non-mucinous (CEA < 192 ng/mL) or mucinous (CEA ≥ 192 ng/mL). Final diagnosis was based on identifiable mucinous pancreatic cystic epithelium on cytology, microforceps histology and/or surgical histology when available. Results  Forty-seven patients with PCs (mean size 30.7 mm) were included. TTNB was successfully performed in 46 of 47 (97.9 %). Technical success was significantly lower with FNA (48.9 %) compared to TTNB (85.1 %) ( P  < .001). For cysts with insufficient amount of fluid for CEA (n = 19) or CEA < 192 ng/mL, the cumulative incremental diagnostic yield of a mucinous PC was significantly higher with TTNB vs. FNA (52.6 % vs 18.4 %; P  = .004). TTNB alone (34.4 %) diagnosed more mucinous PCs than either CEA ≥ 192 ng/mL alone (6.3 %) or when combined with FNA cytology (9.4 %). One episode of self-limited bleeding (2.1 %) and one of pancreatitis (2.1 %) occurred. Conclusions  EUS-TTNB is safe and effective for evaluating PCs. TTNB may help increase the diagnostic yield of mucinous PCs.

Management of Intraductal Papillary Mucinous Neoplasms: Controversies in Guidelines and Future Perspectives

Purpose of review

Management of intraductal papillary mucinous neoplasm (IPMN) is currently based on consensus, in the absence of evidence-based guidelines. In recent years, several consensus guidelines have been published, with distinct management strategies. In this review, we will discuss these discrepancies, in order to guide treating physicians in clinical management.

Recent findings

The detection rate of pancreatic cysts has increased substantially with the expanded use of high-quality imaging techniques to up to 45%. Of these cysts, 24–82% are IPMNs, which harbour a malignant potential. Timely detection of high-risk lesions is therefore of great importance. Surgical management is based on the presence of clinical and morphological high-risk features, yet the majority of resected specimens appear to be low risk.

Summary

International collaboration and incentive large-scale prospective registries of individuals undergoing cyst surveillance are needed to accumulate unbiased data and develop evidence-based guidelines. Additionally, development of non-invasive, accurate diagnostic tools (e.g. biomarkers) is needed to differentiate between neoplastic and non-neoplastic pancreatic cysts and detect malignant transformation at an early stage (i.e. high-grade dysplasia).

Serous pancreatic neoplasia, data and review

AIM

To describe the imaging features of serous neoplasms of the pancreas using ultrasound, endoscopic ultrasound, computed tomography and magnetic resonance imaging.

METHODS

This multicenter international collaboration enhances a literature review to date, reporting features of 287 histologically confirmed cases of serous pancreatic cystic neoplasms (SPNs).

RESULTS

Female predominance is seen with most SPNs presenting asymptomatically in the 5^th through 7^th decade. Mean lesion size was 38.7 mm, 98% were single, 44.2% cystic, 46% mixed cystic and solid, and 94% hypoechoic on B-mode ultrasound. Vascular patterns and contrast-enhancement profiles are described as hypervascular and hyperenhancing.

CONCLUSION

The described ultrasound features can aid differentiation of SPN from other neoplastic lesions under most circumstances.

Incidents and adverse events of endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions

AIM

To evaluate the diagnostic value and safety mainly regarding incidents of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic cystic lesions (PCLs).

METHODS

A total of 150 consecutive patients with suspected PCLs were prospectively enrolled from April 2015 to November 2016. We finally enrolled 140 patients undergoing EUS-FNA. We compared the diagnostic accuracy of EUS-FNA and pathological diagnosis, which is regarded as the gold standard, for PCLs. Patients undergoing EUS-FNA at least 1 wk preoperatively were monitored for incidents and adverse events to evaluate its safety.

RESULTS

There were 88 (62.9%) women and 52 (37.1%) men among 140 patients, with a mean age of 50.1 (± 15.4) years. There were 67 cysts located in the head/uncinate of the pancreas and 67 in the body/tail, and 6 patients had at least 1 cyst in the pancreas. There were 75 patients undergoing surgery and 55 undergoing EUS-FNA with interval at least 1 wk before other operations, with 3 patients undergoing the procedure twice. The accuracy of EUS-FNA in differentiating benign and malignant lesions was 97.3% (73/75), while the accuracy of characterizing PCL subtype was 84.0% (63/75). The incident rate was 37.9% (22/58), whereas only 1 AE was observed in 58 cases.

CONCLUSION

EUS-FNA is effective and safe for diagnosis of PCLs, however procedure-related incidents are common. Caution should be taken in patients undergoing EUS-FNA.

Comparison of endoscopic ultrasound, computed tomography and magnetic resonance imaging in assessment of detailed structures of pancreatic cystic neoplasms

AIM

To evaluate the advantages of endoscopic ultrasound (EUS) in the assessment of detailed structures of pancreatic cystic neoplasms (PCNs) compared to computed tomography (CT) and magnetic resonance imaging (MRI).

METHODS

All patients with indeterminate PCNs underwent CT, MRI, and EUS. The detailed information, including size, number, the presence of a papilla/nodule, the presence of a septum, and the morphology of the pancreatic duct of PCNs were compared among the three imaging modalities. The size of each PCN was determined using the largest diameter measured. A cyst consisting of several small cysts was referred to as a mother-daughter cyst. Disagreement among the three imaging modalities regarding the total number of mother cysts resulted in the assumption that the correct number was the one in which the majority of imaging modalities indicated.

RESULTS

A total of 52 females and 16 males were evaluated. The median size of the cysts was 42.5 mm by EUS, 42.0 mm by CT and 38.0 mm by MRI; there was no significant difference in size as assessed among the three imaging techniques. The diagnostic sensitivity and ability of EUS to classify PCNs were 98.5% (67/68) and 92.6% (63/68), respectively. These percentages were higher than those of CT (73.1%, P < 0.001; 17.1%, P < 0.001) and MRI (81.3%, P = 0.001; 20.3%, P < 0.001). EUS was also able to better assess the number of daughter cysts in mother cysts than CT (P = 0.003); however, there was no significant difference between EUS and MRI in assessing mother-daughter cysts (P = 0.254). The papilla/nodule detection rate by EUS was 35.3% (24/68), much higher than those by CT (5.8%, 3/52) and MRI (6.3%, 4/64). The detection rate of the septum by EUS was 60.3% (41/68), which was higher than those by CT (34.6%, 18/52) and by MRI (46.9%, 30/64); the difference between EUS and CT was significant (P = 0.02). The rate of visualizing the pancreatic duct using EUS was 100%, whereas using CT and MRI it was less than 10%.

CONCLUSION

EUS helps visualize the detailed structures of PCNs and has many advantages over CT and MRI. EUS is valuable in the diagnosis and assessment of PCNs.

Can endoscopic ultrasound-guided needle-based confocal laser endomicroscopy replace fine-needle aspiration for pancreatic and mediastinal diseases?

New applications of confocal laser endomicroscopy (CLE) have been developed, such as needle-based CLE (nCLE) for pancreatic masses, pancreatic cystic tumors, and lymph nodes. nCLE is feasible during endoscopic ultrasound (EUS) examination, and preliminary results are very encouraging and suggest this technology may be used in future as a useful adjunct in cases of inconclusive EUS-guided fine-needle aspiration. The aim of this paper is to give an update in this new technology and to define its place in the diagnosis of pancreatic masses and mediastinal diseases.

Effects of premedication with Pronase for endoscopic ultrasound of the stomach: A randomized controlled trial

AIM

To analyze the effects of premedication with Pronase for endoscopic ultrasound (EUS) examination of the stomach.

METHODS

This was a prospective, randomized and controlled clinical study. All patients were randomly assigned to either the Pronase group or placebo group. The pretreatment solution was a mixed solution of 20000 U of Pronase and 60 mL sodium bicarbonate solution in the Pronase group, while an equal amount of sodium bicarbonate solution was administered to the placebo group. All operators, image evaluators and experimental recorders in EUS did not participate in the preparation and allocation of pretreatment solution. Two blinded investigators assessed the obscurity scores for the EUS images according to the size of artifacts (including ultrasound images of the gastric cavity and the gastric wall). Differences in imaging quality, the duration of examination and the usage of physiological saline during the examination process between the Pronase group and the control group were compared.

RESULTS

No differences existed in patient demographics between the two groups. For the gastric cavity, the Pronase group had significantly lower mean obscurity scores than the placebo group (1.0476 ± 0.77 vs 1.6129 ± 0.96, respectively, P = 0.000). The mean obscurity scores for the gastric mucosal surface were significantly lower in the Pronase group than the placebo group (1.2063 ± 0.90 vs 1.7581 ± 0.84, respectively, P = 0.001). The average EUS procedure duration for the Pronase group was 11.60 ± 3.32 min, which was significantly shorter than that of the placebo group (13.13 ± 3.81 min, P = 0.007). Less saline was used in the Pronase group than the placebo group, and the difference was significant (417.94 ± 121.38 mL vs 467.42 ± 104.52 mL, respectively, P = 0.016).

CONCLUSION

The group that had Pronase premedication prior to the EUS examination had clearer images than the placebo group. With Pronase premedication, the examination time was shorter, and the amount of saline used during the EUS examination was less.

EUS for pancreatic cystic neoplasms: The roadmap to the future is much more than just a few shades of gray

Pancreatic cystic and neoplasms are being diagnosed with increasing frequency. Accurate diagnosis and determination of benign versus malignant lesions is crucial for determining need for surveillance versus surgery or endoscopic therapy as well as avoiding unnecessary surgery in cysts with no malignant potential. Tumor markers such as KRAS and GNAS hold promise, but which molecular marker or a combination of markers is most useful and cost effective remains to be seen. Advanced imaging with confocal laser endomicroscopy can serve as an optical biopsy and play a part in the diagnostic algorithm. Microforceps aided biopsy of pancreatic cyst wall and tumor contents hold great promise as they allow direct tissue acquisition. Much progress has been made in the role of EUS guided evaluation of pancreatic cystic neoplasms over the last several years, and with the advances enumerated above, the future is more than just a few shades of gray. Future studies should include prospective multi-arm trials of microforceps biopsy versus conventional EUS-FNA and use of biochemical and molecular markers, confocal laser endomicroscopy or a combination thereof to determine best approach to pancreatic cystic neoplasms. In Osler's words, 'Medicine is a science of uncertainty and an art of probability'. Incorporation of advanced imaging and molecular markers into a new diagnostic algorithm with subsequent validation through retrospective and prospective studies has the potential to increase diagnostic accuracy and guide optimal management of patients and improve outcomes.