LAUSR

Rationale: The function and use of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) has developed in recent years, particularly in distinguishing malignant from benign masses. It is a generally safe method that can be completed without any uncommon complications. Here, although no complications from EUS-FNB were noted, we report about an unexpected catecholamine crisis that occurred after EUS-FNB. Patient’s concerns: A 60-year-old man visited an outpatient clinic with an incidental diagnosis of a retroperitoneal mass on his last abdominopelvic computed tomography (APCT) scan taken at the time of a previous liver abscess treatment. On presentation, the patient showed no symptoms. Diagnoses: A retroperitoneal mass was incidentally discovered on APCT, and risk for lymphoma, gastrointestinal tumor, or neuroendocrine tumor was noted on the APCT reading. Interventions: EUS-FNB was performed on retroperitoneal mass. Outcomes: The procedure was completed without any complications; however, the patient’s condition deteriorated due to hemodynamic instability and cardiovascular collapse. During intensive care unit (ICU) treatment, the biopsy results were found to be paraganglioma. Catecholamine crisis occurred after biopsy of paraganglioma. Lessons: The case presented here gives a caution of complication that may occur after EUS-FNB. Although EUS-FNB is known to be relatively safe, careful evaluation is required when performing biopsy of lesions around the aorta.