Pancreatic Serous Cystadenomas Fine Needle Aspirations: Improving Diagnostic Yield with Cell Blocks and Inhibin
Marcela Salomao, Helen Remotti, John D Allendorf, John M Poneros, Amrita Sethi, Tamas A Gonda, Anjali Saqi. Columbia University, New York, NY
Background: Serous cystadenomas (SAs) are rare benign neoplasms of the exocrine pancreas. Due to their generally benign prognosis, small and asymptomatic SAs can be followed conservatively. Greater numbers of pancreatic lesions are being detected with increasing and enhanced imaging modalities. Although characteristic imaging findings and chemical analysis of fluid have been described, they are not always recognized prospectively. Similarly, scant cellular yield on fine needle aspirations (FNAs) often leads to either a non-diagnostic or non-specific benign diagnosis. Alpha-inhibin (AI), a highly sensitive marker for SA and not endocrine tumors, is infrequently required for the histological diagnosis due to their characteristic appearance. The aim of this study was to determine if AI immunohistochemical staining can aid in improving the sensitivity and specificity of SA FNA diagnosis.
Design: We performed a retrospective database search for SAs diagnosed in surgical pathology (SP) and endoscopic ultrasound (EUS) FNA specimens. Cases with FNAs and corresponding SPs or follow-up FNAs were selected for the study. The FNAs were evaluated for cellularity, cellular arrangement, cytomorphology(sheets or 3D clusters;) and stroma. Al staining was performed both prospectively and retrospectively on cases with cell blocks (CBs). SP specimens were assessed for architecture (micro- vs macrocystic), cytology (clear vs oncocytic) and stromal predominance.
Results: We identified a total of 12 FNA cases (F:7, M:5, mean age 63.3 yrs), 75% of which had scant cellularity (9/12) and 3 were satisfactory. On smears, the cells were arranged mostly as flat sheets that corresponded to strips of cells on CB sections. The cells were typically small, round to cuboidal and had clear cytoplasm; occasional plasmacytoid cells and oncocytic cells were identified. Some cases had flattened cells, corresponding to attenuated epithelium lining macrocysts on the resection specimens. Stromal fragments were present in 5 FNAs and correlated with the hyalinized stroma in the corresponding SP specimens. AI stain was present in 86% (6/7) of cases and supported the diagnosis of SA.
Conclusions: A diagnosis of SA can significantly alter management of patients with pancreatic masses. Our results indicate that low cellularity and bland cytology is inherent to SAs and performing CBs and AI staining on EUS FNAs can improve the sensitivity and specificity of SAs.
Wednesday, March 6, 2013 1:00 PM
Poster Session VI # 129, Wednesday Afternoon