[343] Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) Biopsy of Solid Pancreatic Lesions: Review of 681 Cases

Guoping Cai, Berrin Ustun, Ahmed Alomari, Gillian H Levy, Malini Harigopal, Harry R Aslanian, Uzma Siddiqui, David Chhieng. Yale University School of Medicine, New Haven, CT

Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy is increasingly used in the diagnosis of pancreatic lesions. Although EUS-FNA has a high specificity in diagnosing malignancy, the reported sensitivity is variable. FNA diagnosis can be achieved by cytomorphologic evaluation alone but ancillary studies may be needed in some cases. Rapid on-site evaluation helps ensure adequate sampling appropriate specimen triage, thus enhancing diagnostic performance. In this study, we retrospectively reviewed our experience in diagnosing solid pancreatic lesions via EUS-FNA biopsy.
Design: The electronic database of cytopathology was searched for pancreatic lesions diagnosed by EUS-FNA during the period from January 2005 to June 2011. We identified 1,143 cases, of which 681 were solid lesions. The final cytology diagnoses included non-diagnostic, negative, indeterminate (atypical and suspicious), neoplasm, and malignant (primary or metastatic). Most cases had rapid on-site evaluation performed. Histopathologic follow-up was available for comparison in 151 cases (22%).
Results: Of 681 cases, 23 cases (3%) were non-diagnostic. Negative, indeterminate, neoplastic, and malignant diagnoses were rendered in 115 (17%), 59 (9%), 58 (9%), and 426 (62%), respectively. Cytologic diagnoses and histopathologic follow-ups were compared in 151 cases (see Table 1). The overall concordance rate for negative, neoplastic and malignant diagnoses was 92%. One of 93 cases that were cytologically diagnosed as malignant showed autoimmune pancreatitis in the follow-up. Neoplastic or malignant diagnosis was seen in 6 of 11 cases that had a negative cytological diagnosis. The calculated sensitivity, specificity, positive predictive value, and negative predictive value were 95%, 83%, 99%, and 45%.

Table 1. Correlation between Cytologic Diagnosis and Histopathologic Follow-up

	Cases	Histopathologic Follow-up
Cytologic Diagnosis	n	Negative	Benign Neoplasm	Malignant
Non-diagostic	2	2 (100%)	0	0
Negative	11	5 (46%)	2 (18%)	4 (36%)
Indeterminate	23	3 (13%)	2 (9%)	18 (78%)
Neoplasm	22	0	19 (86%)	3 (14%)
Malignant	93	1 (1%)	0	92 (99%)
Total	151	11 (7%)	23 (15%)	117 (78%)

Conclusions: In this one of the largest series, we demonstrate that solid pancreatic lesions can be accurately diagnosed by EUS-FNA with 3% non-diagnostic and 9% indeterminate. EUS-FNA has high sensitivity and high positive predictive value in diagnosing pancreatic malignancy. Adequate sampling and awareness of diagnostic pitfalls may help avoid false positive and false negative diagnoses.
Category: Cytopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 57, Tuesday Morning