ABSTRACT
Paraganglioma is an extraadrenal pheochromocytoma originating from chromaffin ceIls distributed in sympathetic nervous systems. This tumor often can produce catecholamines and induce sustained or paroxysmal hypertension, with or without the typical symptams of headache, palpitation and sweating. Paraganglioma without the usual clinical manifestations is not easy to suspect and diagnose. Herein, we report a case of atypical retroperitoneal paraganglioma which was thought to be the pancreas tail mass and result in a paroxysmal adrenergic crisis and fatal dilated cardiomyopathy after the sonographically guided percutaneous biopsy. This rare case warns against the usual practice of percutaneous biopsy for the preoperative diagnosis of intraabdominal or retmperitoneal tumors.