The clinical utility of endoscopic ultrasound-guided fine-needle aspiration in the diagnosis and staging of pancreatic carcinoma

Imaging of pancreatic adenocarcinoma with emphasis on multidetector CT

Pancreatic adenocarcinoma is the fourth most frequent cause of cancer-related death. The incidence is increasing and the overall survival has altered little in recent years. Moreover, patients usually present late with inoperable disease and curative resection by standard pancreatico-duodenectomy (Whipple's procedure) is associated with significant morbidity. It should only be attempted in that small group of patients lacking radiological evidence of advanced disease. Despite the recent advances in body magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS), computed tomography (CT) is the mainstay of staging in most centres and the recent development of multidetector CT machines (MDCT) has raised hope of an improvement in preoperative staging. This review focuses on the CT of pancreatic adenocarcinoma with particular emphasis on examination technique and on those criteria that determine resectability.

Blind Whipple Resections for Periampullary and Pancreatic Lesions

Many patients with periampullary mass lesions lack a tissue diagnosis at referral despite advances in body imaging and aggressive biopsy techniques. This review evaluates a consecutive cohort of patients who underwent pancreatoduodenectomy (PD) with and without a diagnosis of malignancy. From 1990 to 2001, 121 patients underwent PD on a gastrointestinal surgical service by a single surgeon with a bias toward “blind” Whipple resections (BWR). Sixty-three per cent of the patients had obstructive jaundice with a mass on CT in 51 per cent. Fifty-three patients (44%) had a preoperative diagnosis of malignancy. Sixty-eight patients (56%) underwent a blind PD based on computed tomography (CT), ERCP, and clinical findings. After PD, 113 patients (94%) had a malignancy (46 pancreatic, 30 ampullary, 13 cholangiocarcinoma, 9 neuroendocrine, 4 duodenal, 10 other). Of the 68 patients (56%) who underwent a blind PD, 61 patients (90%) had a malignancy. Ten per cent of the BWR patients had a pathologic diagnosis of chronic inflammation/pancreatitis. Overall mortality was 3.3% (4 patients), with no deaths in the BWR group. In this review, clinical judgment was correct in 90 per cent of patients undergoing a “blind” PD without a prior diagnosis of malignancy. In patients with “potentially resectable” lesions (based on CT exam), biopsy information does not affect the choice of therapy since a negative biopsy still commits the patients to surgery. Combined CT and/or ERCP data with clinical findings leads most often to a correct diagnosis and procedure. These data question the practice of numerous biopsy attempts in patients with periampullary lesions.

EUS-guided rendezvous drainage of obstructed biliary and pancreatic ducts: Report of 6 cases

BACKGROUND

Only a few cases have been reported of EUS-guided drainage of obstructed pancreatic or bile ducts. An initial experience with EUS-guided rendezvous drainage after unsuccessful ERCP is reported.

METHODS

EUS-guided transgastric or transduodenal needle puncture and guidewire placement through obstructed pancreatic (n=4) or bile (n=2) ducts was attempted in 6 patients. Efforts were made to advance the guidewire antegrade across the papilla or surgical anastomosis. If guidewire passage was successful, rendezvous ERCP with stent placement was performed immediately afterward.

RESULTS

EUS-guided duct access and intraductal guidewire placement was accomplished in 5 of 6 cases, with successful traversal of the obstruction, and rendezvous ERCP, with stent placement in 3 of 6 cases (two biliary, one pancreatic). The procedure was clinically effective in all successful cases (two patients with malignant obstructive jaundice, one with relapsing pancreatitis after pancreaticoduodenectomy). There was one minor complication (transient fever) but no pancreatitis or duct leak after successful or unsuccessful procedures.

CONCLUSIONS

EUS is a feasible technique for allowing rendezvous drainage of obstructed biliary or pancreatic ducts through native papillae or anastomoses after initially unsuccessful ERCP.

Endoscopic ultrasound-guided fine-needle aspiration of lymph nodes: The Hennepin County Medical Center experience

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) allows for the sampling and diagnosis of lesions of the gastrointestinal system and adjacent tissues. It has also proved helpful with the sampling of lymphadenopathy both for the staging of malignancy and for the diagnosis of lymphadenopathy of other causes. We review our experience with EUS-guided FNA of lymph nodes. The cytology files were searched at Hennepin County Medical Center (HCMC) for all cases of lymph nodes sampled by EUS. Clinical history, biopsy site, diagnosis, and follow-up information (including ancillary testing) were reviewed. Between January 1, 2000 and December 5, 2002, 217 lymph nodes from 185 different patients were sampled by EUS at HCMC. Biopsy sites included 62 mediastinal, 9 paraesophageal, and 146 intra-abdominal lymph nodes. Diagnoses were as follows: metastatic non-small cell carcinoma (n = 69); benign, reactive lymph node (n = 76); granulomatous lymphadenopathy (n = 18); malignant lymphoma (n = 7); atypical-suspicious for malignancy (n = 5); metastatic small cell carcinoma (n = 2); necrotic debris (n = 4), and foreign material (n = 1); 35 cases were nondiagnostic (16.1%) in 22 of 185 patients (11.9%). Ancillary tests including flow cytometry, cytogenetics, and cultures were performed. EUS-guided FNA of mediastinal and intra-abdominal lymph nodes provides diagnostic material from which ancillary testing may be performed.

The learning curve for EUS-guided FNA of pancreatic cancer

BACKGROUND

EUS-guided FNA is an effective and safe method for tissue diagnosis of pancreatic cancer. However, EUS-guided FNA is technically challenging and requires special training. The number of cases required to become proficient and the technical steps required to achieve proficiency are unknown.

METHODS

The first 57 EUS-guided FNAs of pancreatic masses by a trained endosonographer were analyzed retrospectively. For 50 masses, the histopathologic diagnosis ultimately was cancer. The sensitivity for the EUS-guided FNA diagnosis of adenocarcinoma was compared in quintiles of 10 procedures.

RESULTS

Sensitivity for the diagnosis of pancreatic cancer from first to last quintile were, respectively, 50%, 40%, 70%, 90%, and 80%. There was a significant increase in sensitivity for the first 30 cases after improvement in specific technical skills: shortening of echoendoscope position, scrupulous maintenance of the US view of the needle tip at all times, swift jabbing punctures, sampling multiple areas of the mass in each pass, and performing more than 10 "jiggles" per needle pass. Sensitivity for the diagnosis of pancreatic cancer was greater than 80% for the last 20 of the 57 cases, a level that was maintained for cases 51 through 80.

CONCLUSIONS

The current American Society for Gastrointestinal Endoscopy guideline of 25 supervised EUS-FNA procedures for the diagnosis of pancreatic adenocarcinoma is reasonable.

Endoscopic ultrasound-guided fine needle aspiration biopsy of patients with suspected pancreatic cancer: diagnostic accuracy and acute and 30-day complications

OBJECTIVES

The aims of this study were to evaluate the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with suspected pancreatic cancer, and to assess immediate, acute, and 30-day complications related to EUS-FNA.

METHODS

All patients with suspected pancreatic cancer were prospectively evaluated. A single gastroenterologist performed all EUS-FNAs in the presence of a cytopathologist. Immediate complications were evaluated in all patients. An experienced nurse called patients 24-72 h and 30 days after the procedure. Reference standard for the classification of the final diagnosis included: surgery (n = 48), clinical or imaging follow-up (n = 63), or death from the disease (n = 47).

RESULTS

A total of 158 patients (mean age 62.3 yr) underwent EUS-FNA during the study period. The mean tumor size was 32 x 26 mm. The median number of passes was three (range one to 10). Of these patients, 44% had at least one failed attempt at tissue diagnosis before EUS-FNA. The sensitivity, specificity, PPV, NPV, and accuracy of EUS-FNA in solid pancreatic masses were 84.3%, 97%, 99%, 64%, and 84%, respectively. Immediate self-limited complications occurred in 10 of the 158 EUS-FNAs (6.3%). Of 90 patients contacted at 24-72 h, 78 patients (87%) responded. Of the 90 patients, 20 (22%) reported at least one symptom, all of which were minor except in three cases (one self-limited acute pancreatitis and two emergency room visits, one of which led to admission). In all, 83 patients were contacted at 30 days, and 82% responded. No additional or continued complications were reported.

CONCLUSIONS

EUS-FNA is highly accurate in identifying patients with suspected pancreatic cancer, especially when other modalities have failed. Major complications after EUS-FNA are rare, and minor complications are similar to those reported for upper endoscopy. It seems that follow-up at 1 wk might capture all of the adverse events related to EUS-FNA.

Lower frequency of peritoneal carcinomatosis in patients with pancreatic cancer diagnosed by EUS-guided FNA vs. percutaneous FNA

BACKGROUND

Studies have suggested an increased risk of peritoneal seeding in patients with pancreatic cancer diagnosed by percutaneous FNA. EUS-FNA is an alternate method of diagnosis. The aim of this study was to compare the frequency of peritoneal carcinomatosis as a treatment failure pattern in patients with pancreatic cancer diagnosed by EUS-FNA vs. percutaneous FNA.

METHODS

Retrospective review of patients with non-metastatic pancreatic cancer identified 46 patients in whom the diagnosis was made by EUS-FNA and 43 with the diagnosis established by percutaneous FNA. All had neoadjuvant chemoradiation. Patients underwent restaging CT after completion of therapy, followed by attempted surgical resection if there was no evidence of disease progression.

RESULTS

There were no significant differences in tumor characteristics between the two study groups. In the EUS-FNA group, one patient had developed peritoneal carcinomatosis compared with 7 in the percutaneous FNA group (2.2% vs. 16.3%; p<0.025). No patient with a potentially resectable tumor in the EUS-FNA group had developed peritoneal carcinomatosis.

CONCLUSIONS

Peritoneal carcinomatosis may occur more frequently in patients who undergo percutaneous FNA compared with those who have EUS-FNA for the diagnosis of pancreatic cancer. A concern for peritoneal seeding of pancreatic cancer via percutaneous FNA is warranted. EUS-guided FNA is recommended as the method of choice for diagnosis in patients with potentially resectable pancreatic cancer.

Clinical impact of on-site cytopathology interpretation on endoscopic ultrasound-guided fine needle aspiration

OBJECTIVES

Endoscopic ultrasound-guided fine needle aspiration (EUS-guided FNA) is becoming a preferred modality for diagnosing and staging GI and mediastinal malignancies. Although experts advocate on-site cytopathology assessment for tissue sample adequacy, there are few data to support this claim. Our goal was to determine whether on-site cytopathology interpretation improves the diagnostic yield of EUS-guided FNA.

METHODS

EUS-guided FNA results from two university hospital centers were reviewed and compared. At center 1, where EUS-guided FNA was performed with a cytopathologist on site, the results of 108 consecutive patients were evaluated. At center 2, where a cytopathologist is unavailable, the results of 87 consecutive patients were reviewed. One endoscopist performed all procedures at both institutions. Cytologic diagnoses were categorized as positive or negative for malignancy, suspicious for malignancy, atypical/indeterminate, or unsatisfactory. The number of repeat procedures, needle passes, medication use, target site, age, and sex were compared between the two sites.

RESULTS

Patients at center 2 were older (p = 0.04) and predominantly female (p = 0.03). Pancreas was the most common target site at center 2, whereas thoraco-abdominal nodes were the most common at center 1 (p = 0.0001). Patients at center 1 had a diagnosis of positive or negative for malignancy more frequently (p = 0.001) and were less likely to have an unsatisfactory specimen (p = 0.035) or repeat procedure, although the latter was not significant (p = 0.156).

CONCLUSION

On-site cytopathology interpretation improves the diagnostic yield of EUS-guided FNA. EUS centers should allocate resources to cover for on-site cytopathology evaluation.

Clinical usefulness of KRAS mutational analysis in the diagnosis of pancreatic adenocarcinoma by means of endosonography-guided fine-needle aspiration biopsy

AIM

To establish the usefulness of KRAS mutational analysis in the diagnosis of pancreatic adenocarcinoma by comparing this technique with conventional cytology in aspirates obtained by endosonography-guided fine-needle aspiration.

METHODS

All consecutive patients with pancreatic focal lesions undergoing endosonography-guided fine-needle aspiration were included. Samples were obtained with the concurrence of an attendant cytopathologist. Detection of codon-12 KRAS mutations was performed by the restriction fragment length polymorphism-polymerase chain reaction method. The effectiveness of conventional cytology, KRAS mutational analysis and their combination was established with respect to the definitive diagnosis. A cost-effectiveness analysis was also performed.

RESULTS

Thirty-three patients had pancreatic adenocarcinoma and 24 patients had other lesions. A total of 136 samples was obtained. In patients in whom specimens were adequate (93% for cytology; 100% for mutational analysis), the specificity of both techniques was 100%, whereas the sensitivity favoured cytology (97% vs. 73%). When inadequate samples were considered as misdiagnosed, a combination of both techniques reached the highest overall accuracy (cytology, 91%; mutational analysis, 84%; combination of both, 98%).

CONCLUSIONS

Cytology from aspirates obtained by endosonography-guided fine-needle aspiration is the most precise single technique for the diagnosis of pancreatic adenocarcinoma. However, when adequate specimens are not available to reach a cytological diagnosis, the addition of KRAS mutational analysis represents the best strategy.

Endoscopic ultrasound-guided biopsy for the diagnosis of focal lesions of the spleen

OBJECTIVES

Needle biopsy of splenic lesions using computed tomography (CT) or ultrasound (US) is difficult if the size of the lesion is small. It may be dangerous if the lesion is adjacent to the splenic hilum or located peripherally. We used endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to elucidate the tissue diagnosis of splenic abnormalities.

METHODS

EUS-FNA was performed in 12 patients when US- or CT-guided biopsy was inconclusive (n = 5), was not attempted because of small tumor size (0.9-1.4 cm; N = 4), or was considered dangerous (n = 3). A linear echo-endoscope and 22-gauge needles were used for cytology and bacteriology.

RESULTS

The age of the patients was 19-68 yr (median 32 yr). Seven patients were male and five female. The size of the lesions was 0.8-4.2 cm (median 1.4 cm). Cytology was inadequate in one patient. Bacteriology was positive for Staphylococcus aureus and Serratia in one patient each, and cultures were positive for Mycobacterium tuberculosis in two patients. A positive diagnosis was made in 10 of 12 patients (83%). Final diagnoses were tuberculosis in two patients, Hodgkin's disease in two, sarcoidosis in two, abscesses in two, metastatic colon cancer in one, and infarction in one. Suspected recurrence of non-Hodgkin's lymphoma was not confirmed in one case. One patient experienced pain after puncture, but no hematoma was demonstrated on subsequent US examination.

CONCLUSIONS

EUS-FNA cytodiagnosis in patients with unknown splenic lesions seems feasible, even in very small foci, when CT- or US-guided biopsy fails. Additional material for bacteriology may show benign treatable diseases such as abscesses or tuberculosis.

EUS-guided FNA for the diagnosis of gallbladder masses

BACKGROUND

Gallbladder masses can be identified endosongraphically, but FNA for cytologic diagnosis is not routine. This is a review of our experience with EUS-guided FNA of gallbladder masses.

METHODS

Records of patients undergoing EUS were reviewed to identify cases in which FNA of the gallbladder was performed. Reports of EUS procedures, EUS images, cytology results, and clinical records were reviewed.

OBSERVATIONS

Six cases were identified. The final diagnosis was gallbladder carcinoma in 5 and xanthogranulomatous cholecystitis in one. In each case, EUS revealed a hypoechoic mass within the gallbladder wall or gallbladder lumen. Gallbladder wall calcification was observed in 3 of the 5 cases of carcinoma. FNA yielded a specimen that was positive (n = 3) or raised a suspicion (n = 1) for adenocarcinoma in 4 of the 5 proven malignancies. FNA of regional lymph nodes demonstrated metastatic adenocarcinoma in 2 cases. FNA was negative for malignancy in the case of xanthogranulomatous cholecystitis and one case of proven carcinoma. There were no complications.

CONCLUSIONS

EUS-guided FNA of gallbladder masses is safe and can provide a definitive diagnosis of malignancy. Gallbladder carcinoma appears endosonographically as a hypoechoic mass and may be associated with focal wall calcifications.

K-ras gene mutation in the diagnosis of ultrasound guided fine-needle biopsy of pancreatic masses

AIM: To investigate the utility of K-ras mutation analysis of ultrasound guided fine-needle aspirate biopsy of pancreatic masses.

METHODS: Sixty-six ultrasound guided fine-needle biopsies were evaluated by cytology, histology and K-ras mutation. The mutation at codon 12 of the K-ras oncogene was detected by artificial restriction fragment length polymorphisms using BstN I approach.

RESULTS: The presence of malignant cells was reported in 40 of 54 pancreatic carcinomas and K-ras mutations were detected in 45 of the 54 FNABs of pancreatic carcinomas. The sensitivity of cytology and K-ras mutation were 74% and 83%, respectively. The speciality of cytology and K-ras mutation were both 100%. The sensitivity and speciality of K-ras mutation combined with cytology were 83% and 100%, respectively.

CONCLUSION: High diagnostic accuracy with acceptable discomfort of FNAB make it useful in diagnosis of pancreatic carcinoma. Ultrasound guided fine-needle biopsy is a safe and feasible method for diagnosing pancreatic cancer. Pancreatic carcinoma has the highest K-ras mutation rate among all solid tumors. The mutation rate of K-ras is about 80%-100%. The usage of mutation of codon 12 of K-ras oncogene combined with cytology is a good alternative for evaluation of pancreatic masses.

Pancreatic carcinomas smaller than 3.0 cm: endosonography (EUS) in diagnosis, staging and prediction of resectability

BACKGROUND

The size of a pancreatic carcinoma determines prognosis and resection. The aim of this study was to review our clinical experience with endoscopic ultrasound (EUS) in diagnosing and staging pancreatic tumours <3.0 in diameter.

METHODS

From February 1997 to October 2000 medical records and results of abdominal ultrasound (US), spiral computed tomography (CT) and EUS with fine-needle aspiration biopsy (FNA) were reviewed in 17 patients operated for histologically proven pancreatic adenocarcinoma measuring

RESULTS

US identified a pancreatic lesion in 11/17 (65%) patients. Spiral CT showed a total of 16/17 (94%) patients with a lesion. EUS identified pancreatic tumour in all patients (100%), and tissue was obtained from 15/17 patients (88%). Mean tumour size was 2.5 cm (range 0.8-3.0 cm). EUS accuracy in evaluating the portal vessels was 78%, superior mesenteric artery 100%, tumour stage (T) 88%, isolated node stage (N) 65% and combined TN staging was 53%. Regarding resectability, EUS sensitivity was 88%, specificity 89%, negative predictive value 89%, positive predictive value 88% and accuracy 88%. Besides cytological material, EUS-FNA histological diagnosis was possible in 12/17 patients (71%). There was only one case of mild post-procedure acute pancreatitis.

CONCLUSION

EUS-FNA is safe and has high diagnostic (100%) and local staging (88%) accuracy in pancreatic cancers <3.0 cm in diameter.

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Key Words

• small pancreatic cancers
• endoscopic ultrasound

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MESH Headings Collapse

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Affiliation(s)

Jc Ardengh Endoscopy Unit of the Division of Gastroenterology, Universidade Federal de São Paulo (UNIFESP)São PauloBrazil Endoscopy Unit, Hospital Albert Einstein (HIAE)São PauloBrazil
Ga de Paulo Endoscopy Unit of the Division of Gastroenterology, Universidade Federal de São Paulo (UNIFESP)São PauloBrazil
Ap Ferrari Endoscopy Unit of the Division of Gastroenterology, Universidade Federal de São Paulo (UNIFESP)São PauloBrazil

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Endoscopic ultrasound guided fine-needle aspiration cytology of pancreatic carcinoma: a 3-year experience and review of the literature

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) of small pancreatic lesions that are undetectable by computed tomography has gained wide acceptance for the procurement of cells for diagnostic purposes. However, this technique is not without difficulty. The authors examined the sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) of this technique in the evaluation of patients with pancreatic biliary duct strictures/masses. The authors were interested in reviewing their cases of pancreatic adenocarcinoma of ductal type and finding the sources of their false-negative cases.

METHODS

A computer search was performed between January 1998 and July 2001. For the last 3 years, a total of 80 cases of suspected ductal adenocarcinoma of the pancreas was identified. Thirty-four patients (42%) underwent a subsequent Whipple procedure or biopsy. Cytologic and histologic correlation was performed in these cases. The rest of the 23 patients (29%) considered to be positive and the 23 patients (29%) considered to be negative underwent no subsequent biopsy and were followed clinically. Cases termed "suspicious" on cytology were considered positive and those termed "atypical cytology" were considered negative in the authors' final calculation. The causes of the false-negative diagnoses were evaluated carefully.

RESULTS

Of the 34 cases followed with subsequent tissue biopsy or surgery; 12 were confirmed to be positive, 12 were confirmed to be negative, and 10 were considered to be false-negative. Previously identified cytomorphologic features of malignancy were used to review all cases. These features were: loss of the honeycomb pattern (100%), anisonucleosis (100%), nuclear contour irregularity (100%), a high nuclear/cytoplasmic ratio (100%), paranuclear chromatin clearing (77%), and the presence of prominent nucleoli in the absence of inflammatory cells (77%). The causes of the 10 false-negative cases were technical difficulty of procuring material in 6 cases, the nature of the lesion in 2 cases, and the scarcity of lesional tissue in 2 cases.

CONCLUSIONS

Using strict cytoarchitectural and cytomorphologic criteria of malignancy for ductal pancreatic lesions previously described in the literature, the sensitivity of this technique at the study institution was 78% with a specificity of 100%. The PPV and NPV of this technique were 100% and 78%, respectively. The most common causes of the false-negative results in descending order were the technical aspect of the procedure, the size and nature of the lesion, and the scarcity of lesional tissue.

Premalignant conditions of the pancreas

Premalignant conditions of the pancreas include benign tumours of the pancreas, intraepithelial neoplasia arising within pancreatic ducts, and tumours of the neuroendocrine cells of the pancreas. In addition, there is a variety of rare genetic conditions that predispose to pancreatic exocrine malignancies such as Peutz-Jeghers syndrome, hereditary non-polyposis colorectal cancer syndrome, familial pancreatitis, germline BRCA2 mutations, and pancreatic endocrine malignancies such as type 1 neurofibromatosis (von Recklinghausen's disease) and multiple endocrine neoplasia type 1. More controversial is the concept of chronic pancreatitis and diabetes mellitus as conditions that increase the risk of pancreatic cancer. However, there is no doubt that smoking is a potentiating factor for pancreatic cancer, especially in people who have familial/genetic risk factors. This review will include the recently proposed new nomenclature and classification system for intraepithelial neoplasia in the pancreatic ducts, an overview of the various familial syndromes that are associated with an increased risk of pancreatic tumours, the surveillance programmes that have been introduced to monitor such families, and methods for early diagnosis.

Endoscopic ultrasound for rectal cancer

The application of EUS has improved the way we evaluate and manage patients with rectal cancer. EUS has substantially greater sensitivity than CT in detecting advanced T stage tumors. Such improved sensitivity results in changes in preoperative therapy that would not otherwise have occurred without EUS. Although the addition of FNA provides little incremental effect on patient management, it carries the most potential for impacting management in those patients with early T stage disease, and its use should be considered in this subgroup of patients. Whether the accurate staging ability of EUS translates into improved outcomes in terms of reduced recurrence rates and ultimately prolonged survival remains uncertain. This will require further long-term outcome studies focusing on the endpoint of tumor recurrence and patient survival.

Endoscopic ultrasonography and endoscopic retrograde cholangiopancreatography imaging for pancreaticobiliary pathology: the gastroenterologist's perspective

With advances in noninvasive radiologic technology, additional adjunctive techniques are developing, and the roles for ERCP and EUS are continuously changing. In a diagnostic setting, ERCP is currently best reserved for patients with a high likelihood of needing endoscopic therapy, and EUS is especially useful for cases in which other imaging techniques have been inconclusive or are of inferior diagnostic capability. In a therapeutic setting, ERCP and EUS retain important roles in the management of both benign and malignant pancreatic and biliary disease. Certainly, technological advances also directly affect these modalities and expanded applications for ERCP and EUS for the pancreas and biliary tract are anticipated.

Comparison of endoscopic ultrasound-guided fine needle aspiration for focal pancreatic lesions in patients with normal parenchyma and chronic pancreatitis

OBJECTIVES

The clinical value of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of pancreatic lesions is uncertain in patients with normal parenchyma and chronic pancreatitis. The aim of this study was to analyze the diagnostic yield and influence of EUS-FNA on the clinical management of patients with pancreatic lesions, in the presence (CP) or absence (NP) of chronic pancreatitis.

METHODS

A total of 207 consecutive patients with NP (n = 133) and CP (n = 74) were examined using linear array echo endoscopes for the procedure and 22-gauge needles.

RESULTS

Adequate specimens were obtained from 200 lesions. A correct final diagnosis was established at histology (n = 108), bacteriology (n = 9), and clinical follow-up (n = 83). Cytology gave 17 false-negative EUS-FNA results (overall sensitivity: 85%). In patients with NP, 60 solid adenocarcinomas were detected, 32 other malignancies, and 38 benign lesions, with 11 false-negative results (sensitivity: 89%). In patients with CP, only seven of 13 malignancies (all solid adenocarcinomas) were identified using FNA (sensitivity: 54%). Overall, malignancy was identified in 116 patients, 32 of whom (27%) had lesions other than primary solid adenocarcinomas. Management was altered in 25 of these patients, which changed the surgical approach in 21%. EUS-FNA influenced the therapeutic approach in 44% of the total patient group.

CONCLUSIONS

EUS-FNA was especially useful in patients with a focal pancreatic lesion with normal parenchyma. Its sensitivity in patients with CP was unacceptably low, and resection of the tumor using standard surgical techniques was still usually required to confirm the correct diagnosis. Diagnostic EUS-FNA influenced clinical management in nearly half of patients.

Diagnosis of cystic neoplasms with endoscopic ultrasound

From the data that are currently available, it appears that EUS can help to reliably distinguish between the majority of benign and neoplastic cystic lesions. In equivocal cases, or cases where a high suspicion for malignancy exists, the use of EUS-guided FNA for obtaining cytology and cystic fluid for analysis of various tumor markers, gives the best diagnostic yield. Occasionally, despite a complete evaluation of a cystic mass, the cyst type may not be determined. The decision regarding further management of these lesions should be based on a combination of factors including symptoms, cyst size, EUS morphology and the patient's overall medical condition. In the case of symptomatic, large, or suspicious lesions where the patient is a good surgical candidate, surgical resection should be performed. However, it becomes more difficult in the case of asymptomatic, small cystic lesions where the patient is not an optimal surgical candidate. In the latter scenario, applying EUS criteria for follow-up of small pancreatic cystic lesions as reported by Ikeda et al can help in the decision-making process. In this study, Ikeda et al reported on 31 patients with pancreatic cystic lesions of unknown etiology that were followed-up with semi-annual EUS exams over a 3-year period. In 87.1% of these lesions, the size was less than 2 cm. Their criteria included 1) a clear thin wall, 2) smooth contour, 3) round or oval shape, 4) no septum or nodules, 5) asymptomatic clinical presentation, and 6) no findings of chronic pancreatitis. The cystic lesions remained stable in 30/31 patients, and only one lesion increased in size. This lesion was resected and was found to be a retention cyst. We are optimistic that the role of EUS in the management of cystic neoplasms will continue to evolve and expand as future studies evaluate the clinical utility of imaging modalities for the optimal practice algorithm for managing these neoplasms.

Endoscopic ultrasound of the pancreas: tissue acquisition and intervention

Endoscopic ultrasound is an established modality for staging gastrointestinal and pancreatic malignancies. Since the development of the linear array echoendoscope, the field of interventional endoscopy has continued to evolve as an adjunctive method to standard endosonography. The ability to sample extraluminal lesions or lymph nodes has overcome the initial limitations of endoscopic ultrasound and provided a list of attractive endoscopic ultrasound-guided therapeutic applications.This review focuses on recent advancements in the field of interventional endosonography related to the diagnosis and therapy of pancreatic diseases. In particular, the article reviews the role of endoscopic ultrasound-guided fine-needle aspiration in diagnosing various pancreatic diseases; the role of endoscopic ultrasound-guided fine-needle injection in delivering neurolytic, chemotherapeutic, or biologic agents; and emerging procedures like endoscopic ultrasound-assisted biliary bypass in the setting of malignant biliary obstruction.

Use of a phased vector array US catheter for EUS

BACKGROUND

Existing EUS catheter probes have limited depth of penetration and lack color flow and Doppler capabilities. This study prospectively assessed the feasibility and safety of using a phased vector array US catheter in the human GI tract.

METHODS

Eleven patients underwent EUS with a steerable 9F phased vector array catheter. Images obtained with the catheter were compared with standard EUS images.

RESULTS

The GI wall layers were equally well imaged with the catheter compared with standard echoendoscopes in 90% of the cases. Images of the liver, spleen, pancreatic parenchyma, and pancreatic duct were of equal quality and resolution with both techniques in the majority of patients. Some deeper structures and blood vessels were better visualized with the catheter. No complications were encountered.

CONCLUSION

The steerable phased vector array US catheter is a safe device when used in the GI tract and offers images comparable with those obtained with a dedicated echoendoscope. Further studies are needed to determine the accuracy of tumor staging and clinical utility of this device.

Endoscopic ultrasound

Indications and the clinical utility of endosonography have evolved as new technology, such as linear array echoendoscopes and EUS-guided fine needle aspiration, has emerged. The most noteworthy of the EUS applications are for cancer staging; including rectal, pancreatic, lung, and esophageal malignancies. There is little doubt that EUS is a powerful tool for cancer imaging, but its clinical impact in patient care and management has yet to be validated in prospective outcome studies. Other imaging modalities such as positron emission tomography (PET), dual-phased helical CT, and MR imaging technology will undoubtedly provide increasingly accurate diagnostic and staging information for gastrointestinal diseases. EUS imaging alone may assume a less significant role in relation to these noninvasive modalities in the future. EUS-guided FNA, as well as therapeutic EUS applications, will likely continue to expand in scope and play an important role in clinical medicine for many years to come.

Quantitative analysis of K-ras gene mutation in pancreatic tissue obtained by endoscopic ultrasonography-guided fine needle aspiration: clinical utility for diagnosis of pancreatic tumor

OBJECTIVES

Endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) has become established in the diagnosis of pancreatic cancer. The combination of pathological diagnosis and analysis for mutant K-ras gene was investigated to improve the accuracy of diagnosis.

METHODS

EUS-FNA was performed in 34 patients with pancreatic masses (26 adenocarcinomas and eight chronic pancreatitis). Mutant ras gene was analyzed semiquantitatively in the specimens obtained by EUS-FNA as well as in pancreatic juice obtained by ERCP.

RESULTS

Mutant gene was detected at high amounts (more than 2% of total ras genes) in 20 of 26 (77%) specimens of EUS-FNA and in 12 of 19 (63%) of pancreatic juice in cases with pancreatic carcinoma. Cytological diagnosis of malignancy by EUS-FNA was found in 16 of 26 (62%) patients with pancreatic cancer. Accurate diagnosis of the carcinoma was 21 of 26 (81%) by combined cytology and molecular method of EUS-FNA, and increased to 23 of 26 (88%) by adding molecular analysis of pancreatic juice. In contrast, mutant gene was absent or low level despite suspicious cytology in patients with benign pancreatic lesion.

CONCLUSION

Quantitative analysis of mutant ras gene supplemented conventional cytology of EUS-FNA and ERCP. Detection of mutation at high amounts may represent pancreatic cancer, whereas its absence increased the possibility of benign lesion.

Endoscopic ultrasound-guided fine-needle aspiration biopsy: a study of 103 cases

BACKGROUND

Endoscopic ultrasound (EUS) provides detailed imaging of both intramural and extramural structures within the abdomen and mediastinum. However, EUS is limited in its ability to differentiate an inflammatory/reactive process from a malignancy. Fine-needle aspiration biopsy (FNAB), coupled with EUS, allows for the sampling of the target lesion under ultrasound guidance in real time. To better evaluate the clinical utility and efficiency of EUS-FNAB, a retrospective analysis of the first 103 EUS-FNABs performed at our institute was undertaken.

METHODS

EUS-FNABs was performed in 80 patients with 103 lesions. Both air-dried and alcohol-fixed smears were prepared and stained with Diff-Quik (American Scientific Products, McGraw Park, IL) and Papanicolaou stains, respectively. In addition, ThinPrep slides (Cytyc, Boxborough, MA) and cell blocks, when additional material was available, were also prepared. Immunohistochemical stains were performed on cell blocks wherever required. Cytologic diagnoses were then correlated with the final diagnoses. The latter was based on histologic examination of biopsies/resected pathology materials (n = 54) and clinical follow up (n = 48). Follow-up information was not available for one lesion.

RESULTS

Of 103 EUS-FNABs, 42 FNABs were from the pancreas, 38 from the lymph nodes (10 mediastinal and 28 intraabdominal), 10 from the gastrointestinal tract, 7 from the liver, 4 from the adrenal gland, 1 from the biliary tract, and 1 from a retroperitoneal mass. The mean number of passes to obtain diagnostic materials was 3.3. Of 103 EUS-FNABs, 45, 9, 6, and 37 were reported as malignant, suspicious, atypical, and benign, respectively. Six FNABs were nondiagnostic. The authors did not encounter any false-positive cases. There were three false-negative cases (two pancreatic carcinomas and one gastrointestinal stromal tumor of the stomach). No complications were encountered. The sensitivity, specificity, and accuracy were 71%, 100%, and 81%, respectively. If the FNABs that were classified as suspicious were considered as malignant, the sensitivity, specificity, and accuracy were 86%, 100%, and 91%, respectively.

CONCLUSIONS

EUS-FNAB is a safe and accurate diagnostic procedure for the evaluation of intramural and extramural lesions of the gastrointestinal tract. In the majority of cases, it obviates the need for more invasive diagnostic procedures to obtain a tissue diagnosis.

Accuracy of endoscopic ultrasound in diagnosing and staging pancreatic carcinoma

BACKGROUND

The role of endosonography in diagnosing and staging pancreatic adenocarcinoma is evolving. The aim of this review is to present recently published material comparing the performance of endosonography relative to other imaging modalities when evaluating a patient with a suspected or known carcinoma of the pancreas.

METHODS

Medline was searched using the terms 'endosonography' and 'pancreas neoplasms'. References from retrieved papers were reviewed to identify other reports. Emphasis was placed on peer-reviewed material published within the past 3 years that included comparison with other imaging modalities.

RESULTS

Despite advances in cross-sectional imaging modalities, endosonography remains the most sensitive and specific method to identify pancreatic mass lesions. Resectability determination of pancreatic carcinoma is best done with dual-phase helical CT, although endosonography may have slightly improved accuracy for lymph node assessment. Endosonography-guided fine-needle aspiration biopsy has high sensitivity (93%) and specificity (100%) when employed in patients with masses in whom pancreatic cancer is suspected but prior biopsies are negative.

CONCLUSIONS

Endosonography can aid in diagnosing patients with pancreatic neoplasms through definitive inclusion or exclusion of a mass lesion as well as biopsy confirmation of malignancy. The role of endosonography in determination of resectability has been eclipsed by dual-phase helical CT.

Pancreatic tissue sampling guided by EUS, CT/US, and surgery: a comparison of sensitivity and specificity

BACKGROUND

Needle aspiration of the pancreas is performed to differentiate pancreatic malignancy, focal chronic pancreatitis, and metastasis to the pancreas. Biopsies may be directed by using EUS, CT, US, or surgery. This study retrospectively compared the accuracy of EUS-guided, CT/US-guided, and surgical tissue sampling of the pancreas over a 5-year period.

METHODS

The records of patients undergoing pancreatic tissue sampling were reviewed for a final clinical diagnosis based on the results of cytology, histology, and clinical history. The sensitivity, specificity, and accuracy of each technique were calculated.

RESULTS

One hundred forty-nine tissue samples (68 EUS-guided, 70 CT/US-guided, 11 surgical) from 128 patients were compared. There was no significant difference in accuracy rates for EUS (76.4%), CT/US (81.4%), and surgically guided (81.8%) specimens. EUS was used when masses were smaller (2.6 +/- 0.1 cm) as compared with CT/US (3.4 +/- 0.2 cm, p < 0.001) and surgery (2.9 +/- 0.4 cm, p = 0.49). In univariate analyses, factors associated with greater accuracy regardless of technique were as follows: (1) older age, (2) larger size of the mass, and (3) participation by a cytologist during the procedure. A subsequent multivariate logistic regression analysis, in which the examination of the effect of each factor controls for the effect of each of the other factors, found that only older age was a significant predictor of accuracy.

CONCLUSION

EUS-guided tissue sampling of pancreatic masses is as accurate as CT/US-guided sampling and surgical biopsies.

A prospective, blinded assessment of the impact of preoperative staging on the management of rectal cancer

BACKGROUND & AIMS

The influence of preoperative staging of rectal carcinoma on therapeutic decisions is uncertain. The use of fine-needle aspiration (FNA) of perirectal nodes in this setting has not been evaluated. The aim of this prospective, blinded study of patients with rectal cancer was to assess the impact of preoperative staging on treatment decisions and compare the tumor (T), nodal (N) staging performance characteristics of pelvic computed tomography (CT), rectal endoscopic ultrasonography (EUS), and EUS FNA.

METHODS

Eighty consecutive patients with newly diagnosed rectal cancer were prospectively evaluated. Therapy decisions were recorded after sequential disclosure of staging information to the patient's surgeon.

RESULTS

In 31% of patients (95% confidence interval, 21%-42%), EUS staging information changed the surgeon's original treatment plan based on CT alone. The further addition of FNA changed therapy in one patient. T staging accuracy was 71% (CT) and 91% (EUS) (P = 0.02); N staging accuracy was 76% (CT), 82% (EUS), and 76% (EUS FNA) (P = NS).

CONCLUSIONS

Preoperative staging with EUS results in more frequent use of preoperative neoadjuvant therapy than if staging was performed with CT alone. The addition of FNA only changed the management of one patient, whereas FNA did not significantly improve N staging accuracy over EUS alone. FNA seems to offer the most potential for impacting management in those patients with early T stage disease, and its use should be confined to this subgroup of patients. EUS is more accurate than CT for determining T stage of rectal carcinoma.

Endoscopic ultrasound-guided fine-needle aspiration in 179 cases: the M. D. Anderson Cancer Center experience

BACKGROUND

Recently, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has emerged as a diagnostic adjunct for small pancreatic lesions and abdominal and mediastinal lymph node diseases.

DESIGN

During a 21-month period, we performed 179 EUS-FNAs in 166 consecutive patients; these data are the subject of this study. An average of 2.6 needle passes were obtained and aspiration was performed most commonly in the pancreas (162 cases, 91%). The FNA smears were reviewed using six diagnostic categories (negative for malignancy/nondiagnostic [NND], atypia, suspicious for malignancy, benign tumor/cyst, neuroendocrine neoplasm [NEN], and carcinoma). The review diagnosis was correlated with the histologic diagnosis made on resection or surgical biopsy specimens in 70 cases. Up to 17 months of clinical follow-up were sought for the cases with a negative or inconclusive FNA diagnosis and no diagnostic tissue confirmation (81 cases).

RESULTS

The review FNA diagnoses were as follows: NND (49 cases), atypia (17 cases), suspicious for malignancy (12 cases), benign tumor/cyst excluding NEN (10 cases), NEN (6 cases), carcinoma (85 cases). Follow-up methods included resection (49 cases), surgical biopsy (21 cases), repeat FNA or brushing cytology (28 cases), and clinical follow-up only (81 cases). Of the 49 NND cases, 23 (47%) had positive follow-up results (i.e., false-negative diagnosis) that were confirmed by tissue diagnosis (resection/surgical biopsy in 11 cases [48%] and repeat FNA/brushing in 12 cases [52%]). These included pancreatic/ampullary adenocarcinoma in 20 cases, esophageal squamous carcinoma in 1 case, and NEN in 2 cases. Follow-up also revealed carcinoma in all 12 suspicious cases and 13 pancreatic adenocarcinomas and 1 microcystic adenoma in 14 of the 17 atypical cases. Overall, repeat computed tomography (CT)-guided FNA samples yielded a definite diagnosis in four atypical and seven NND cases, whereas EUS-FNA results provided a definite diagnosis in three cases in which CT-guided FNA failed and in two cases in which ampullary biopsy failed. No false-positive cases were identified. The false-negative rate due to inadequate sampling was 13.2%. Sensitivity (including cases with inadequate cellularity and nondiagnostic aspirates) was 81.7% and specificity was 100%. None of the factors evaluated (lesion characteristics, aspiration site, and tumor type) significantly influenced diagnostic results.

CONCLUSION

EUS-FNA is a valuable diagnostic and staging tool with high specificity and sensitivity. Negative or nondiagnostic cases on EUS-FNA require further diagnostic work for a definitive diagnosis when clinical or radiographic findings do not correlate with the FNA results.

Endosonography-guided fine needle aspiration biopsy in the evaluation of pancreatic masses

OBJECTIVES

Diagnosis of pancreatic tumors can be problematic. This study aimed to determine the performance of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS FNA) in pancreatic malignancy when prior biopsies performed by CT guidance or ERCP were negative.

METHODS

A total of 185 patients with known or suspected pancreatic masses were prospectively evaluated with EUS FNA. Before EUS FNA, all patients were evaluated with abdominal CT (61 with CT-guided biopsy) and 91 with ERCP (41 had brushings or biopsy).

RESULTS

EUS had greater sensitivity than CT in detecting a mass (99% vs 57%, p < 0.0001). In 58 patients with negative CT-guided biopsies, EUS FNA had 90% sensitivity for malignancy, 50% specificity for benign disease and 84% accuracy. Similarly, in 36 patients with negative ERCP tissue sampling, results for EUS FNA were 94%, 67% and 92%, respectively. Complications were mild and infrequent (0.5%).

CONCLUSION

EUS FNA of pancreatic masses safely and accurately diagnoses pancreatic malignancy when prior biopsy techniques have been unsuccessful.

EUS-guided fine needle aspiration of the liver: indications, yield, and safety based on an international survey of 167 cases

BACKGROUND

The liver is a common site of metastases for various malignancies. EUS-guided fine needle aspiration (EUS-FNA) of liver masses has only been reported in small series from single centers.

METHODS

A retrospective questionnaire was sent by e-mail to 130 EUS-FNA centers around the world regarding indications, complications, and findings of EUS-FNA of the liver.

RESULTS

Twenty-one centers reported 167 cases of EUS-FNA of the liver. A complication was reported in 6 (4%) of 167 cases including the following: death in 1 patient with an occluding biliary stent and biliary sepsis, bleeding (1), fever (2), and pain (2). EUS-FNA diagnosed malignancy in 23 of 26 (89%) cases after nondiagnostic fine needle aspiration under transabdominal US guidance. EUS localized an unrecognized primary tumor in 17 of 33 (52%) cases in which CT had demonstrated only liver metastases. EUS image characteristics were not predictive of malignant versus benign lesions.

CONCLUSION

EUS-guided FNA of the liver appears to be a safe procedure with a major complication rate of approximately 1%. EUS-FNA should be considered when a liver lesion is poorly accessible to US-, or CT-guided FNA should be considered when US- or CT-guided FNA fail to make a diagnosis, when a liver lesion(s) is detected (de novo) by EUS, and for investigation of possible upper GI primary tumors in the setting of liver metastases.

Influence of EUS training and pathology interpretation on accuracy of EUS-guided fine needle aspiration of pancreatic masses

BACKGROUND

Identification, staging, and fine needle aspiration of pancreatic mass lesions are probably the most technically demanding EUS skills. This study evaluated the effect of formal training on the diagnostic accuracy of EUS-guided fine needle aspiration (EUS-FNA) of pancreatic masses and the source of the variability in diagnostic accuracy between initial and later procedures.

METHODS

Sixty-five patients with pancreatic masses underwent EUS-FNA between April 1998 (introduction of EUS-FNA) and August 1999, 20 of whom were examined by 3 endosonographers without prior experience with EUS-FNA. The initial experience of these 3 endosonographers (April to December 1998; group A patients), which included a formal training period of 2 months, and their later experience (January to August 1999; group B patients) were evaluated. Final diagnoses were determined by surgical pathology or clinical follow-up. All EUS-FNA samples were reviewed by 4 blinded pathologists to determine the contribution of pathologist interpretation to varying EUS-FNA accuracy.

RESULTS

After a short training period, there was a significant improvement in EUS-FNA accuracy (33% vs. 91%; p = 0.004). After pathology review, good agreement was identified between original FNA interpretation and that on review (kappa = 0.78; 95% CI [0.5, 1.0]). There were differences between the mean cellularity score (2.8 vs. 1.8, p = 0.01) and mean number of passes (5.1 vs. 2.8, not significant) for correct versus incorrect FNA specimens.

CONCLUSION

Significant improvements in EUS-FNA accuracy can be achieved with a short period of mentored training. EUS-FNA errors during the initial learning phase are primarily due to inadequate specimens. Interpretation of pancreatic EUS-FNA specimens remained consistent before and after training.

A resource utilization projection study of EUS

BACKGROUND

EUS has emerged as standard practice with respect to the diagnosis and staging of GI malignancies. Whether currently available resources are sufficient to meet the potential need for EUS is uncertain. This study examines the hypothetical demand for EUS in the United States.

METHODS

EUS cases performed at 3 centers with well-established expertise in EUS in 1997 were retrospectively reviewed and trends were extrapolated to national cancer statistics. Indications for EUS fell into 3 categories: (1) diagnosis/staging of esophageal, gastric, pancreatic, or rectal cancers (established indications); (2) suspected GI malignancy (obligate "rule out"); and (3) "other" (emerging indications). Hypothetical total numbers of cases in which EUS could be performed in the United States were calculated taking into consideration the expected number of GI malignancies for which EUS would be appropriate (based on cancer statistics for 2000), the fraction unresectable by CT, the fraction of elderly nonsurgical candidates, proportionate "rule out" cases, as well as "other" emerging indications.

RESULTS

The calculated hypothetical number of cases (United States) in which EUS would be indicated is 79,568 per year (10,287 esophagus, 10,666 stomach, 23,069 pancreas, and 35,546 rectal). If "other" indications remained constant at 12%, there would potentially be 89,116 EUS procedures performed per year, with a conservative estimate of 79,572 per year.

CONCLUSIONS

This model suggests that currently available EUS resources are not sufficient to meet hypothetical demand. Future considerations include the number of endoscopy units in which EUS is performed, the capacity of individual units, and the implications for training programs in the United States.