Clinical Utility of Endoscopic Ultrasound-Guided Fine-Needle Aspiration Biopsy In Mixed Ductal-Neuroendocrine Neoplasms of The Pancreas

Abstract

\n Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy is the first line diagnostic tool used in the evaluation of solid pancreatic masses with high sensitivity and specificity prior to the surgery. Mixed ductal-neuroendocrine neoplasms of the pancreas are rare entity consisting of both ductal adenocarcinoma and neuroendocrine neoplasms, with each component representing at least 30%. Methods: We performed a retrospective analysis of patients with a diagnosis of pancreatic mixed ductal adenocarcinoma and neuroendocrine neoplasms by EUS-FNA specimens at Peking Union Medical College Hospital between 2010-2019 and presented a review of the literature.Results: A total of 3 cases (1 male and 2 females) were evaluated, aged 46, 38 and 62 years, and presented with 3-cm, 2.3-cm and 1.8-cm pancreatic masses, respectively. All the patients presented with abdominal pain and underwent EUS-FNA biopsy. FNA smears revealed a mixture of ductal adenocarcinoma and neuroendocrine neoplasms, identified by immunohistochemistry. According to Ki-67 proliferation index and mitotic count, the tumor grades of the neuroendocrine component were classified as NET G2 in 2 cases (cases 2 and 3) and NEC in 1 (case 1). All of the patients received adjuvant therapy. The diagnosis of patient 1 was confirmed on surgical excision, and she died 5 months after surgery due to hepatic metastases. The other two patients did not undergo surgery, but achieved long – term survival of 3 and 5 years, respectively. To date, 34 cases of pancreatic mixed ductal adenocarcinoma and neuroendocrine neoplasms have been reported in the English language literature including our present three cases. Among them, 5 of 12 patients who underwent preoperative biopsy were diagnosed as combined ductal adenocarcinoma and neuroendocrine neoplasms, of which 3 surgical resection specimens available were identified as mixed ductal-neuroendocrine neoplasms.Conclusion: We suggest that EUS-FNA biopsy is the most effective method for rapid evaluation of pancreatic mixed ductal-neuroendocrine neoplasms with high sensitivity, which is important to determine the most optimum therapy. If the tumor grades of the neuroendocrine component were classified as NET G2 by EUS-FNA biopsy, we propose appropriate adjuvant therapy rather than surgery.