[352] Fine Needle Aspiration Diagnosis of Mucinous Cystic Neoplasms and Intraductal Papillary Mucinous Neoplasms of the Pancreas: Cytomorphology, CEA Level and K-ras Mutation Status

Xiangbai Chen, Berrin Ustun, Jane Bernstein, Harry Aslanian, David Chhieng, Guoping Cai. Yale School of Medicine, New Haven, CT

Background: Mucinous cystic neoplasm (MCN) and intraductal papillary mucinous neoplasm (IPMN) are the two most common mucinous lesions in the pancreas. Recognition of these lesions preoperatively is important due to their association with variable dysplasia and invasive carcinoma. However, accurate diagnosis could be difficult based on cytomorphologic features alone and may require clinical correlation and ancillary studies. In this retrospective study, we review the results of cytological diagnosis, CEA level and K-ras mutation status in MCNs and IPMNs.
Design: The Cytopathology archives were searched for cystic or solid/cystic pancreatic lesions diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy at our institution from January 2005 to July 2011. The cases were included in the study only when there was surgical follow-up with diagnosis of either MCN or IPMN. The cytological diagnosis and the results of CEA level and K-ras mutation status, if performed, were retrospectively reviewed.
Results: A total of 61 cases were identified, including 25 MCN and 36 IPMN cases diagnosed on surgical follow-up. The MCN cases had low-grade dysplasia, moderate dysplasia, or high-grade dysplasia/invasive carcinoma in 21, 1, and 3 cases, respectively. Low-grade dysplasia, moderate dysplasia and high-grade dysplasia/invasive carcinoma were present in 17, 10, and 9 IPMN cases. Based on cytomorphologic features, mucinous neoplasm was recognized in 11 of 25 MCN cases (44%) and in 26 of 36 IPMN cases (72%) including a malignant diagnosis in 3 MCNs and 6 IPMNs. Elevated CEA level (>= 192 ng/ml) was seen in 11 of 14 MCN cases (79%) and 6 of 7 IPMN cases (86%) while K-ras mutation was identified in 7 of 13 MCN cases (54%) and 8 of 15 IPMN cases (53%). By combing cytomorphologic features with CEA level and K-ras, the sensitivity for identification of mucinous neoplasm was increased from 44% to 68% in MCNs and from 72% to 83% in IPMN cases.

Table 1. Cytomorphology, CEA Level and K-ras Mutation in Mucinous Neoplasms
Surgical DiagnosisCytological DiagnosisCEA LevelK-ras Mutation
 NegativeNeoplasmMalignant<192 ng/ml>=192 ng/mlNegtaivePositive
MCN (n=25)148331167
IPMN (n=36)102061678

Conclusions: Our data demonstrate that EUS-FNA has a higher sensitivity for identifying IPMNs than MCNs based on cytomorphologic features. Adjunctive ancillary studies such as CEA level and K-ras mutational analysis increase the sensitivity, especially for identification of MCNs.
Category: Cytopathology

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 78, Tuesday Afternoon


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