Clinical Outcomes in Patients with Pancreatic Lesions with Suspicious or Indeterminate Cytology on Endoscopic Ultrasound Guided Fine Needle Aspiration (EUS-FNA)

Abstract

Purpose: EUS-FNA has been widely used for the evaluation of solid and cystic pancreatic lesions. However, FNA cytology can be suspicious or indeterminate for malignancy, which may complicate management (require repeat EUS-FNA, surveillance with radiographic imaging, surgical exploration or resection). The aim of this study was to evaluate outcomes in patients with pancreatic lesions with suspicious or indeterminate EUS-FNA cytology. Methods: Our endoscopy database was reviewed from 1/1/02 to 12/31/07 to identify patients with pancreatic lesions who had EUS-FNA that showed suspicious or indeterminate cytology. Malignant or benign outcomes were assessed based on repeat imaging studies showing presence or absence of local invasion or metastasis, surgical pathology and survival for 12 months. Patients with stable imaging or benign surgical pathology or survival for more than 12 months were considered as having benign pancreatic lesions. Conversely, the diagnosis was considered cancer, if there was an increase in size of the lesion, development of local invasion or metastasis on follow-up imaging, cancerous surgical pathology or death within 12 months from causes related to malignancy. Intraductal Papillary Mucinous Neoplasms (IPMN), neuroendocrine tumors, lymphomas, Schwannomas, pseudopapillary tumors and mucinous cystadenomas were grouped separately as ‘other neoplasms’. Results: Among 70 patients with pancreatic masses with suspicious or indeterminate cytology on EUS-FNA, there were 37% males and 63% females. The mean age was 62 years (range 21 to 83). The final diagnosis was adenocarcinoma in 33/70 (47%), benign in 24/70 (35%) and ‘other neoplasms’ in 13/70 (18%). Lesions were solid in 38/70 (54%), cystic in 30/70 (43%) and mixed solid and cystic in 2/70 (3%). The mean size was 29.4 mm (range 5 to 80). Ninety percent of adenocarcinomas were more than 20 mm in size and 67% of benign cases were less than 20 mm. Suspicious cytology was seen in 36/70 (51%) and indeterminate in 34/70 (49%) patients (details shown in table). Majority of solid pancreatic lesions with suspicious cytology were adenocarcinomas (79%). Majority of cystic pancreatic lesions with indeterminate cytology on EUS-FNA (67%) were benign. Conclusion: Our data suggests that solid pancreatic lesions more than 20 mm in size with suspicious cytology on EUS-FNA have a very high likelihood of malignancy. These patients should be treated aggressively as having a malignant diagnosis.Table: Postoplypectomy bleedingTable: Clinical outcomes in patients with pancreatic lesions with suspicious or indeterminate EUS-FNA cytology