2019 Volume 34 Issue 4 Pages 181-187
A 38 year-old female was evaluated for a pancreatic mass found on abdominal ultrasonographic screening. CT scan revealed an early enhancing tumor in the pancreatic head. MRI revealed that the tumor showed a low signal in the T1 weighted image, a high signal in the T2 weighted image, and a diffusion reduced signal in the diffusion weighted image. EUS showed a 14mm low echoic tumor with a smooth margin and well-defined border near the portal vein. The tumor was strongly enhancing in the early phase of contrast EUS, and EUS-FNA was performed. Cytologic analysis was consistent with a neuroendocrine tumor and a pancreaticoduodenectomy was performed. Hematoxylin and eosin staining showed a Zellballen pattern and immunohistochemical studies were positive for S100 in cells between the tumor clusters, establishing paraganglioma as the final diagnosis. Peripancreatic paraganglioma is rare and it is very difficult to distinguish a paraganglioma from a pancreatic neuroendocrine neoplasm based on imaging studies alone. In an invasive procedure such as EUS-FNA, the blood pressure might be greatly elevated in a patient with a paraganglioma. When EUS-FNA is performed for a tumor rich in blood flow, the differential diagnosis including paraganglioma is very important and we must be ready for acute elevation of blood pressure.
