Cystic neuroendocrine tumor in the pancreas detected by endoscopic ultrasound and fine-needle aspiration: a case report.

ABSTRACT

BACKGROUND: Pancreatic neuroendocrine tumors are typically solid neoplasms but in very rare cases present as cystic lesions. The diagnosis of cystic tumors in the pancreas is extremely difficult and the use of endoscopic ultrasound and fine-needle aspiration might be helpful in the work-up of patients with cystic neuroendocrine tumors in the pancreas. CASE PRESENTATION A 78-year-old Caucasian man was admitted with a history of epigastric pain. Laboratory tests were normal. The patient underwent transabdominal ultrasound, computed tomography and magnetic resonance cholangiopancreatography demonstrating an unclear cystic mass in the head of the pancreas. The patient was referred for endoscopic ultrasound. Endoscopic ultrasound showed a hypoechoic lesion (42 × 47 mm) in the head of the pancreas with regular borders and large cystic components. The main pancreatic duct was normal without any connection to the cystic process. The lesion underwent fine-needle aspiration (22 Gauge). Cytological examination demonstrated cohesive groups of plasmacytoid cells staining positively for synaptophysin and chromogranin A, which is suggestive of a neuroendocrine tumor. CONCLUSIONS: Differential diagnosis of cystic lesions in the pancreas is very difficult with conventional radiology, such as computed tomography and magnetic resonance imaging. This unusual case with a pancreatic cystic neuroendocrine tumor highlights the clinical importance of endoscopic ultrasound in the work-up of patients with unclear lesions in the pancreas.