EUS for Pancreatic Neuroendocrine Tumors

Background: Pancreatic neuroendocrine tumors are rare tumors with malignant potential. EUS has been shown to be superior to other imaging methods in the preoperative localization and diagnosis.

Purpose: To evaluate the clinical presentation and EUS morphology, we examined histologically confirmed pancreatic neuroendocrine tumors retrospectively.

Patients and Methods: We underwent EUS for nineteen patients that a subsequently histologically confirmed pancreatic neuroendocrine tumors from April 2006 to July 2010. We examined the clinical presentation and EUS features retrospectively.

Results: Nineteen resected patients (6 men and 13 women; mean age 55.3 years; range 26–79 years) underwent EUS; of whom 6 (31.6%, 5 insulinomas and 1 glucagonoma) were functional pancreatic neuroendocrine tumors presented with abdominal pain, peptic ulcer disease, and hypoglycemia. Tumor locations were 8 in head, 9 in body, 2 in tail. Mean tumor size was 16.2mm (range 7–53mm). Echogenic features were solid in 16, mixed in 2 and cystic in 1. Margins were regular in 17 and irregular in 2. Echogenicity were hypoecoic in 15, isoechoic in 3 and hyperecoic in 1. Inner echogenic features were homogeneous in 18 and heterogeneous in 1. Tumor locatins and echogenic features were similar in functional and nonfunctional pancreatic neuroendocrine tumors. Two cases were patients with negative CT findings, although they could be detected by EUS.

Conclusions: EUS is sensitive tool, especially in cases of small lesions in which other imaging modalities have failed.