S72 Abstracts

153

Fine Needle Aspiration Cytology of Colloid Carcinoma of the Pancreas

Maria Laureana Santos-Zabala, MD, Olca Basturk, MD, Carlie Sigel, MD.Memorial Sloan Kettering Cancer Center, New York, New York

Introduction: Colloid carcinoma (CC) is a rare invasive carcinoma of thepancreas believed to arise from intestinal type intraductal papillarymucinous neoplasm (IPMN). The cytologic features of CC are not welldescribed because previous cytology descriptions of invasive carcinomasarising from IPMN do not consistently subtype the invasive carcinoma.Furthermore, current diagnostic criteria may not have been used to diagnosethe histologic correlates for prior descriptions of CC. We describe fineneedle aspiration (FNA) findings for CC using histologically confirmedcases meeting current diagnostic criteria.Materials and Methods: We searched our archive for ultrasound-guidedFNAs of the pancreas with histologic correlation showing CC defined bycontaining >80% extracellular mucin and reviewed corresponding cytologyand histology. The following morphologic parameters were evaluated:cellularity, quantity and quality of mucin, cytoarchitecture, cell size, shape,and nuclear features.Results: Six FNA cases from resected CCs were identified. In 4/6 patientsan associated IPMN of predominantly intestinal type was identified with theCC component comprising <10-100% of the lesions. Two cases wereentirely CC, but one was not entirely submitted for histology and IPMNcould not be excluded. By cyto-histo correlation we determined that 4/6 ofFNAs contained CC while 2 cases showed discrepant features suggestingsampling error. The 4 FNAs containing CC uniformly showed: lowcellularity (tumor cells comprised <20% of smeared material), abundantthick/glassy mucin, degenerating inflammatory cells in mucin, mild nuclearmembrane abnormalities, and disordered honeycomb sheets of mucinouscells. All 4 CC FNAs were originally diagnosed as “suspicious formucinous neoplasm.”Conclusion: The cytologic features of CC are similar to IPMN and may besubject to under-diagnosis due to the well-differentiated cytologic appear-ance, low cellularity, and thick obscuring mucin.

154

A Comparison of Endoscopic Ultrasound Guided Fine NeedleAspiration (EUS-FNA) and Positron Emission Tomography (PET) inPreoperative Diagnosis of Pancreatic Duct Adenocarcinoma

Jinping Lai, MD, PhD, Yong Yue, PhD, Xuemo Fan, MD, PhD,David Frishberg, MD, Maha Guindi, MD, Bonnie Balzer, MD, PhD,Shikha Bose, MD, Joanne Rutgers, MD. Cedars-Sinai Medical Center, LosAngeles, California

Introduction: EUS-FNA is the most commonly used technique toinvestigate and sample pancreatic mass for preoperative diagnosis ofpancreatic ductal adenocarcinoma (PDAC). The role of 18

fluoro-deoxyglu-cose positron emission tomography/computed tomography (PET) in PDACis debated. The sensitivity of PET for the diagnosis of PDAC is reported torange between 68% and 91%, while specificity between 64% and 97%. Thisstudy evaluates the role of EUS-FNA as compared to PET in the preoper-ative evaluation of PDAC.Materials and Methods: Preoperative evaluation by PET and EUS-FNAwas performed on 26 patients with pancreatic solid lesions. All patientsunderwent a subsequent Whipple procedure or partial pancreatic resection.This series included 21 PDACs (8 with neoadjuvant therapy) and fivecontrols (2 low grade neuroendocrine tumors, 2 with sclerosing chronicpancreatitis and 1 gastrointestinal stromal tumor abutting the pancreas).PET was considered positive when the maximum standardized uptake value(SUV) >3. Suspicious and malignant FNA diagnoses were consideredpositive.Results: The 21 PDACs included 5 well differentiated, 12 moderatelydifferentiated and 4 poorly differentiated ductal adenocarcinomas. EUS-FNA correctly diagnosed 20 of 21 PDACs and all 5 of the control cases.One case of well differentiated PDAC was negative on EUS-FNA and on

review contained groups of cytologically benign glandular cells. This casewas negative on PET too. PET was positive in 16 of the 21 PDACs andnegative in all five control cases. Of the five PET-negative PDACs, fourwere moderately differentiated and one was well-differentiated. Thesensitivity, specificity, positive predictive value, negative predictive valueand accuracy for EUS-FNA in diagnosis of PDAC were 95%, 100%, 100%,83% and 96%, respectively, while they were 76%, 100%, 100%, 50% and81% for PET, respectively.Conclusions: Compared to PET, EUS-FNA has a higher sensitivity andaccuracy for preoperative diagnosis of PDAC.

155

Solid Tumor Metastases to the Pancreas Diagnosed by Fine NeedleAspiration: A Single Institution Experience and a Review of theLiterature

Amber Smith, MD, Shelley Odronic, MD,Bridgette Springer, BS, CT(ASCP)CM, Jordan Reynolds, MD. ClevelandClinic, Cleveland, Ohio

Introduction: Pancreatic fine needle aspiration (FNA) is a minimallyinvasive procedure useful for diagnosing pancreatic masses. We describethe experience of a single institution with metastases to the pancreassampled by FNA coupled with a review of the literature.Materials and Methods:We retrospectively searched the medical record forall pancreatic FNAs positive for metastatic disease. Data was gatheredregarding tumor size, focality, previous primary tumor history, anddemographics.Results: There were 2327 patients with pancreatic FNAs performedbetween 1/1/2000 and 3/18/2014. Twenty-two patients were positive formetastases (Age range 59-83, median 68 years, male: female ratio 13:9).The average mass measured 3.7 cm in greatest dimension (range 1.5e6.5cm). The majority of tumors were unifocal (16/22, 72.7%). There were 14renal cell carcinomas, 2 colonic adenocarcinomas, 1 urothelial carcinoma, 1ovarian serous carcinoma, 1 prostatic adenocarcinoma, 1 non-small celllung carcinoma, 1 papillary thyroid carcinoma, and 1 chrondrosarcoma.Rapid on-site adequacy was performed on 13 patients (4 were diagnostic ofmetastasis, 3 were positive for malignant cells, 6 were atypical, none werenegative). The median time between diagnosis of the primary tumor andinitial pancreatic metastasis was 9 years (range: concurrent diagnosis to 21years).Conclusions: The most common metastasis to the pancreas was renal cellcarcinoma which correlates with the current medical literature. However,a variety of other epithelial malignancies were also documented in ourstudy. This study shows that FNA is useful for the diagnosis of metastasesto the pancreas.

156

Acinar Cell Carcinoma of the Pancreas: Cytologic,Immunohistochemical, and Ultrastructural Features

Stephanie Simmons, MD, Isam Eltoum, MD. University of AlabamaBirmingham, Birmingham, Alabama

Introduction: Acinar cell carcinoma is a rare malignant neoplasm of theexocrine pancreas, comprising approximately 1% of all non-endocrinetumors of the pancreas. At our institution, most pancreatic neoplasms arefirst assessed using endoscopic ultrasound guided fine needle aspiration(EUS-FNA). Correct diagnosis is critical, because acinar cell carcinomafollows an aggressive clinical course, but cytologically mimics other moreindolent neoplasms.Materials and Methods: We searched all our cytology records, from 2000to 2013, compiling cases in which acinar cell carcinoma was diagnosed oncytology or histology. All cases were originally stained with periodic acid-Schiff (PAS) and were then submitted for immunohistochemical (IHC)staining for trypsin and chymotrypsin. In addition, the paraffin block wassubmitted for electron microscopy studies.