8/22/2019 Utility of EUS-FNA in the Diagnosis of Pancreatic Neuroendocrine Tumors: Correlation with Histopathology in 76 Pa

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T1602

Utility of EUS-FNA in the Diagnosis of Pancreatic

Neuroendocrine Tumors: Correlation with Histopathology

in 76 PatientsShireen A. Pais, Kathleen Mcgreevy, Julia K. Leblanc, Stuart Sherman,Lee Mchenry, John M. DewittIntroduction: Pancreatic neuroendocrine tumors (NETs) are rare neoplasms thatare classified as functional (F-NET) or nonfunctional (NF-NET) depending on thepresence or absence of excess hormone production. Endoscopic ultrasound (EUS)-guided fine needle aspiration (EUS-FNA) is often used to diagnose NETs but there

are limited data on its sensitivity for this indication. Aim: To determine thesensitivity of EUS-FNA for the diagnosis of a NET. Methods: We retrospectivelyidentified all patients from 7/95 to 11/06 who underwent EUS for suspected orsubsequently confirmed pancreatic NET. Patients with excluded with: 1) extra-pancreatic tumors alone; 2) EUS-FNA of a pancreatic tumor was not performed.The diagnosis of a NETwas confirmed by: 1) EUS-FNA with or without confirmatoryimmunochemistry (ICC) with synaptophysin and chromogranin of? 1 pancreaticmass or metastatic site; or 2) an alternative biopsy method and/or surgical resectionof the pancreas or other metastatic site. Results: 92 patients (56 male; median age:57 yrs, range: 23-83 yrs) with 34 (37%) F-NETand 58 (63%) NF-NETs were identified.By EUS, the tumors were located in the pancreatic head, body, tail or weremultifocal in 38 (41%), 27 (29%), 19 (21%) and 8 (9%), respectively. Of these 92, 76(83%) underwent EUS-FNA of a pancreatic mass, 36 (47%) of whom also had a EUS-FNA of an alternative (nonpancreatic) site including the liver (n Z 15; 16%),another lesion in the pancreas (n Z 7; 8%), or lymph node (n Z 9; 10%;peripancreatic in 5, celiac in 3 and mediastinal in 1). Immunohistochemistry wasperformed in 51/76 (67%) EUS-FNA specimens and the results were: ICC-positive(n Z 44), ICC-negative (n Z 5), not interpretable (n Z 1) or inadequate forinterpretation (n Z 1). Surgery was performed in 41 (54%): distal pancreatectomy(nZ 16), Whipple procedure (n Z 10), enucleation (n Z 10) and subtotal (nZ 2)or total pancreatectomy (n Z 1). The remaining two who underwent surgery hadan exploratory laparotomy only. 66 patients had a confirmed diagnosis of NET andthe sensitivity of EUS-FNA is shown in Table 1. The results of the false-negative EUS-FNA biopsies of the pancreas (n Z 12) were interpreted as: normal in 2, suspiciousin 2, nondiagnostic in 5, adenocarcinoma in 2, and a solid pseudopapillary tumor in1. Conclusion: EUS-FNA is a sensitive method for the diagnosis of pancreatic NETsbut yield is lower in tumors smaller than 15 mm in diameter.

Sensitivity of EUS-FNA for the diagnosis of NETs

ALL(n Z 76)

F-NET(n Z 28)

NF-NET(n Z 48)

Lesions less than orequal to 15 mm

(n Z 21)

Sensitivity(confidenceintervals%)

84% (74-90) 78% (60-90) 89% (75-95) 62% (41-79)

T1603

Endoscopic Ultrasound Guided Fine Needle Aspiration Biopsy

for Diagnostic Evaluation of Proximal Biliary StricturesBanke Agarwal, Jennifer L. Labundy, Naveen B. Krishna, Brian T. CollinsBackground: Determining the etiology of proximal biliary strictures (PBS) remainsa challenge. Even though endoscopic ultrasound guided fine needle aspiration(EUS-FNA) has potential and is often used in evaluation of PBS, its role in thediagnostic evaluation of PBS is still not clearly established due to a lack of sufficientdata. Patients and Methods: We retropectively studied the performancecharacteristics of EUS-FNA in patients with obstructive jaundice and PBS in ourinstitution from March 2002 to March 2006. Patients with stricture confined abovethe hepatic bifurcation were excluded. Patients with history of liver transplantationwere also not included due to markedly different probability of cancer in thesepatients. EUS examination was performed using a radial echoendoscope followedby a linear echoechoendoscope in all patients. EUS-FNA was performed using 22Gor 25G needles. FNAs were stained by Diff-Quik and Papanicolaou method withimmediate assessment by an attending cytopathologist. EUS-FNA was classified aspositive only if a definitive cytologic diagnosis of malignancy was made. The finalpatient outcome was based on surgical pathology or clinical follow-up of at least 12months. Results: Twenty-one patients qualified for inclusion (13 male, 8 female),with mean age of 61.6 16.3 years (range 23 to 87). The strictures ranged in lengthfrom 10-70 mm. All patients had jaundice at the time of presentation for ERCP andhad a biliary stent in place at the time of EUS-FNA. CTrevealed a hilar mass lesion in9 patients. In 13 patients, a final diagnosis of cancer was made- cholangiocarcinoma

(nZ 12) and enlarged periportal nodes with metastasis (n Z 1). Eight patients hadbenign stricture which included 3 with PSC, 2 with inflammatory pseudo-tumorsand 3 patients without specific etiologic cause. There were 5 false negativediagnoses- 2 patients had cancer detected by surgery and 3 patients developedmetastases. The accuracy of EUS-FNA for diagnosis of cancer was 76.2%, with 61.5%sensitivity, 100% specificity, 61.5% NPV and 100% PPV. Summary and conclusions:EUS-FNA can be a useful tool in obtaining a tissue diagnosis of malignancy inpatients with obstructive jaundice and PBS, when brush cytology of the stricture isnot definitively diagnostic of malignancy. The low negative predictive value of EUSFNA indicates that a negative biopsy can not reliably exclude malignancy. Our studysupports a recently published similar study. Both studies are limited by small cohort

size since proximal strictures are relatively uncommon.

T1604

Value of Endosonography to Predict Symptomatic Stenosis

of the Pancreatic SphincterNittly Chahal-Sekhon, Viktor E. Eysselein, David ChungAims: To evaluate the symptomatic response of Pancreatic Sphincterotomy inpatients with a dilated pancreatic duct as determined by Endosonography. Wehypothesized that a dilated pancreatic duct near the papilla predicts pancreaticsphincter stenosis in patients with pancreatic type pain. Methods: Retrospectivestudy in patients with possible pancreatic-type pain underwent follow-up from 1 to6 months after pancreatic sphincterotomy. Having a dilated pancreatic duct (OorZ 4 mm) near the papilla was assessed by endosonography. Follow-up data wereretrospectively obtained using a structured questionnaire; the main parameter forevaluating treatment success was a significant reduction in pain followingEndosonography. Pain severity before and after pancreatic sphincterotomyperformed by Endoscopic Retrograde Cholangiopancreato-graphy (ERCP) wasdetermined using a scale from 0 to 10, 10 being the most severe. Results: Pancreaticducts (PD) that were measured less than or equal to 2 mm were a designatednormal control group without symptomatic pain. Of 22 patients with painfulpancreatic-type pain, 14 were male & 8 were female with an average of a 1 to 6month follow-up. The pain degree decreased significantly (p ! 0.0001) from8.2 0.3 to 3.0 0.3 (means SEM)in the patients with dilated pancreatic ductafter pancreatic sphincterotomy (see Table below). 27% of the patients hada normal diagnostic study on CT and/or MRCP but on Endosonography thepancreatic duct was actually dilated using a cutoff of 4 mm. Conclusions: Ourpreliminary data suggest that a dilated pancreatic duct on Endosonography inpatients with pancreatic-type pain predicts stenosis of the pancreatic sphincter.Pancreatic sphincterotomy in those patients leads to significant pain relief.Diagnostic imaging methods such as C.T./MRCP revealed a normal pancreatic ductin 27% of patients but had a dilated pancreatic duct on Endosonography. C.T./MRCPare therefore inferior to endosonography in predicting symptomatic pancreaticsphincter stenosis. Thus, Endosonography appears a promising and more accuratemethod for diagnosing symptomatic pancreatic sphincter stenosis.

Pain scale (mean SEM)

Group Before After % Change

Dilated panc. duct 8.2 0.3 3.0))) 0.3 63

)))p ! 0.0001

Abstracts

AB304 GASTROINTESTINAL ENDOSCOPY Volume 65, No. 5 : 2007 www.giejournal.org