Immediate Assessment of Pancreatic Fine Needle Aspiration Revisited: Is There Any Value in Doing It?

S104 188 Solid Pseudopapillary Tumors of the Pancreas - The Role of Cytology for Diagnosis Sule Canberk, MD1, Ceyda Sonmez, MD1, Nesrin Uygun, MD1, Canser Cakalir, MD1, Osman Faruk Senyuz, MD2, Fatih Gulsen, MD3, Ibrahim Adaletli, MD4. 1The Department of Pathology, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey; 2The Department of Pediatric Surgery, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey; 3The Department of Interventional Radiology, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey; 4The Department of Radiology, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey Introduction: Fine needle aspiration (FNA) biopsy is an established method for accurately diagnosing pancreatic adenocarcinoma and its variants at a high success rate, as well as other rather uncommon solid carcinomas especially when clinical and radiological data are provided. Solid pseudopapillary neoplasm (SPPN) is a rare entity, the histogenesis of which is not well defined. It is an extremely infrequent neoplasm of uncertain malignant potential presenting predominantly in young females with a mean age of 35 years. In our institution, this tumor is frequently diagnosed, and in this paper we reviewed 5 cases. The aim of this paper is to evaluate the fine needle aspiration biopsy of this uncommon pancreatic tumor ‘and correlate it with subsequent resection specimens. Materials and Methods: Of the approximately 650 FNA biopsies performed on pancreas over a period of 12 years from 2000 to 2012, 5 of them are evaluated for SPPN. The cytological material is obtained by percutaneous and/or endoscopic ultrasound guided FNA biopsies. Smears are stained with Diff-Quik and Papanicolaou stains on air-dried and alcohol-fixed slides respectively. A cytopathologist was available for onsite evaluation. Immunocytochemical studies are performed on the cell block sections. The final diagnosis is made regarding both the cytomorphological and immunocytochemical findings. Results: The patients included 3 females and 2 males with an age range between 13 e 41 years (mean age: 35). The tumors, all of which are located in the body/tail of the pancreas, are sized between 2,7 - 5,4 cm. Two patients received partial pancreatectomy afterwards. Aspirates are highly cellular with delicate exaggerated branching papillary structures with central capillaries covered with several layers of plasmacytoid tumor cells. The tumor cells form acinar, rosetoid structures along with the isolated forms dispersed throughout the lesion. The nature of the neoplastic cells are confirmed immunocytochemically by alpha 1-antitrypsin antibody. The age and gender of the patients along with the features of the tumor such as location, cytomorphology, immunocytochemical findings, cytological diagnosis and the histological counterpart whenever available are compactly organized in a table. Conclusions: SPPN can be diagnosed cytologically, but one should keep in mind that on FNAB it can be misdiagnosed as an acinic cell carcinoma or a pancreatic endocrine neoplasm. And since their prognoses are different, identifying them is essential. 189 Immediate Assessment of Pancreatic Fine Needle Aspiration Revisited: Is There Any Value in Doing It? Ghazal Khan1, Ward Reeves1, Jeffrey Mueller1, Richard DeMay1, Irving Waxman2, Tatjana Antic1. 1Pathology, The University of Chicago, Chicago, Illinois; 2Gastrointestinal Interventional Endoscopy, The University of Chicago, Chicago, Illinois Introduction: Endoscopic ultrasound (EUS) guided fine needle aspiration biopsy (FNA) is a primary tool in diagnosing pancreatic malignancies. Potential sampling issue may be mitigated by the attendance of a cytopathologist providing an immediate assessment (IA) and diagnosis. Although many institutions utilize cytopathologists, other less fortunate, do not have that opportunity. It is consent that a minimum of five passes are generally accepted standard to ensure adequacy in the absence of cytopathologist.

Abstracts The present study reviews the FNA diagnosis of pancreatic adenocarcinoma to evaluate if five passes is a valid, if arbitrary, number. Materials and Methods: 109 consecutive cases of pancreatic adenocarcinoma with IA were identified in the departmental files from January 2010 to September 2011. The results are divided based on the number of passes performed and the first diagnostic pass. Two endoscopists performed all FNAs and three cytopathologists attended. IA was performed on Diff-Quick prepared slides and all cases had a cell block preparation. Results: Of 109 cases 62 (56.9%) had fewer than 5 passes with 61 (55.9%) being diagnosed on pass 5 or less. 47 (43.1 %) cases had more than 5 passes of which 21 (19.3%) were diagnosed on pass 5 or less and 17 (15.5%) required 6 or more passes to be diagnostic. Of those 17 cases 4 were diagnostic at pass 6, 5 at pass 7, 1 at pass 9, 4 at pass 10, 1 at pass 11 and 1 at pass 12. Nine cases (8.2%) were inadequate for diagnosis even after the procedure was terminated. Of those 9, 1 case was inadequate after pass 5, 2 after pass 7, 1 after pass 8, 2 after pass 9, 2 after pass 10 and 1 after pass 14. The cell block preparation contained diagnostic material in 7 of those 9 cases. Conclusions: IA of pancreatic fine needle aspirates is still the most optimal way of assuring that the diagnostic material is obtained. 23.7 % of the present cases did not have diagnostic material on pass 5 or less and even with IA, 8.2 % cases were not diagnostic at the time the procedure was terminated. Among the later were well differentiated adenocarcinomas and cases with hypocellular smears, all but 2 of which were resolved by cell block. 190 Utility of Immunostains in Differentiating Pancreatic Foamy Gland Adenocarcinoma (FGA) from Benign Gastrointestinal Mucosal Contaminants (GIC) in Pancreatic Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) Arbaz Samad, MD, Charanjeet Singh, MD, Stefan Pambuccian, MD. Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota Introduction: FGA has been singled out as a deceptively benign-appearing variant of pancreatic ductal adenocarcinoma (PDA). Histologically it shows foamy cytoplasm, basally located, hyperchromatic and wrinkled (raisinoid) nuclei with cytoplasmic condensation of the luminal borders. EUS-FNA cytologic features include loss of honeycomb architecture, irregular nuclear contours, prominent nucleoli, prominent cell borders, foamy cytoplasm and low nuclear to cytoplasmic ratios. Due to these cytologic features, the cells of FGA closely resemble those of GIC, especially of gastric contaminants. The aim of this study was to evaluate the role of immunohistochemical (IHC) stains in differentiating FGA from GIC. Materials and Methods: All FGA cases diagnosed on EUS-FNA between 1/1/2003 and 12/31/2011 and 5 recent consecutive cases of PDA were retrieved and reviewed and a panel of IHC stains including B72.3, MUC-1, p53, monoclonal CEA, CDX-2, villin, Hep Par-1, p16 and Ki67 was performed on cell block sections. The immunostaining profile of these tumors was compared to that of GIC, which were present in all samples. Results: We identified 10 FGA from 5M/5F patients aged 46-87 (mean 65.7) and 5 PDA from 5 female patients aged 55-85 (mean 68.4). IHC stains that showed some discrimination between FGA and GIC are shown in Table 1. IHC stains for mCEA, villin, CDX2 and Hep Par-1 were not useful in this differential diagnosis; however, membranous staining for B72.3, diffuse nuclear p53 staining and apical MUC-1 immunopositivity were useful to differentiate FGA from GIC as shown in Figure 1. The staining profile of FGA was similar to that of PDA; however the Ki67 proliferative index of FGA was lower than that of PDA and overlapped with that of GIC. Table 1

IHC in FGA, PDA and GIC B72.3 (n, %) MUC1 (n, %) p53 (n, %) p16 (n, %) Ki67 (mean, range)

FGA (nZ10) 7 (70%) PDA (nZ5) 4 (80%) GIC (nZ15) 0

7 (70%) 3 (60%) 0

3 (30%) 5 (100%) 0

3 (30%) 1 (20%) 0

5% (1-15%) 16% (1-25%) 6% (1-20%)