RISKY ENDOSCOPIC ULTRASONOGRAPHY-GUIDED FINE-NEEDLE ASPIRATION FOR ASYMPTOMATIC RETROPERITONEAL TUMORS

Abstract
Paraganglioma, a sporadically occurring rare tumor should be included in the differential diagnosis of retroperitoneal tumors, such as malignant lymphomas, gastrointestinal stromal tumors, sarcoma and carcinoma of unknown primary site. A 58‐year‐old Japanese woman presented with a large retroperitoneal tumor detected by ultrasonography (US). She had no medical history of hypertension. Computed tomography showed a mass, 7 cm in diameter, located between the pancreas and the inferior vena cava. It was unclear whether the mass originated from the duodenum or the mesentery. Endoscopic ultrasonography (EUS) demonstrated a large solid paraduodenal mass. Doppler US revealed sparse vascularity in the tumor. With the differential diagnosis of retroperitoneal tumor, we carried out EUS‐FNA. At the time of the third needle puncture, transient severe hypertension was noted, with a blood pressure measurement of 269/130 mmHg. Data obtained from urine and blood examinations after EUS‐fine‐needle aspiration indicated a diagnosis of paraganglioma.