Endoscopic ultrasonography-guided fine-needle aspiration cytology of surgically confirmed cystic pancreatic neuroendocrine tumors: a Mayo Clinic experience

Longwen Chen; Aziza Nassar; Vishnu Teja Kommineni; Matthew A Zarka; Jun Zhang; Douglas Faigel; Cuong Nguyen; Thorvardur R Halfdanarson; Rahul Pannala

doi:10.1016/j.jasc.2015.04.001

Endoscopic ultrasonography-guided fine-needle aspiration cytology of surgically confirmed cystic pancreatic neuroendocrine tumors: a Mayo Clinic experience

J Am Soc Cytopathol. 2015 Nov-Dec;4(6):335-343. doi: 10.1016/j.jasc.2015.04.001. Epub 2015 Apr 15.

Authors

Longwen Chen¹, Aziza Nassar², Vishnu Teja Kommineni³, Matthew A Zarka⁴, Jun Zhang⁵, Douglas Faigel³, Cuong Nguyen³, Thorvardur R Halfdanarson⁶, Rahul Pannala³

Affiliations

¹ Department of Laboratory Medicine and Pathology, Mayo Clinic, 13400 E. Shea Boulevard, Scottsdale, Arizona. Electronic address: chen.longwen@mayo.edu.
² Department of Laboratory Medicine and Pathology, Mayo Clinic, Jacksonville, Florida.
³ Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, Arizona.
⁴ Department of Laboratory Medicine and Pathology, Mayo Clinic, 13400 E. Shea Boulevard, Scottsdale, Arizona.
⁵ Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, New York.
⁶ Department of Hematology and Oncology, Mayo Clinic, Scottsdale, Arizona.

PMID: 31051748
DOI: 10.1016/j.jasc.2015.04.001

Abstract

Introduction: Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) cytology is widely used to evaluate solid and cystic pancreatic lesions preoperatively. Pancreatic neuroendocrine tumors (PanNETs) are typically solid, but when they are cystic, differentiation from other pancreatic cystic neoplasms can be challenging. We examined cases of cystic PanNETs (cPanNETs) from 3 Mayo Clinic Hospitals focusing on the EUS-FNA cytology.

Materials and methods: A total of 21 EUS-FNA cases of cPanNETs with histology confirmation were identified from the Mayo Clinic Health System database. The patients' demographic data, clinical, radiological, and EUS characteristics were obtained. EUS-FNA cytology and surgical pathology were reviewed.

Results: Among the 21 patients with cPanNETs, only 2 of 21 cases had suggestion of cPanNET on preoperative imaging (computed tomography/magnetic resonance imaging). On EUS, most cPanNETs (16/ of 21) had ≥1 high-risk stigmata or worrisome feature per the Sendai Consensus guidelines. None of the cases had an elevated carcinoembryonic antigen level. EUS-FNA cytology was positive or suspicious for cPanNET in 15 of 21 cases (71.4%). Immunohistochemical stains of neuroendocrine markers were performed on all the positive or suspicious cases and showed positivity for ≥1 neuroendocrine marker. All cases had surgical resection and the diagnosis of cPanNET was confirmed on each case.

Conclusions: Although computed tomography/magnetic resonance imaging has a low specificity for detecting cPanNETs, high-risk features on EUS and low carcinoembryonic antigen levels should raise the suspicion for cPanNET. EUS-FNA cytology along with immunohistochemical stains has a high accuracy in establishing the preoperative diagnosis of cPanNET.

Keywords: Cystic pancreatic neuroendocrine tumor; Endoscopic ultrasonography-guided fine-needle aspiration cytology; Pancreatic cyst; Preoperative diagnosis.