Extra-adrenal nonfunctional retroperitoneal paraganglioma: case report and review of the literature.

An extra-adrenal paraganglioma is a rare tumor derived from the chromaffin cells of sympathetic ganglia. This report documents a rare case of nonfunctional extra-adrenal paraganglioma in a 20-year-old woman with persistent flank pain. Ultrasonography and computed tomography revealed a solid mass with calcification in center, measuring 7 x 6 x 6 cm, and localized in the left upper para-aortal retroperitoneal region. Absence of typical clinical symptoms made a correct preoperative diagnosis unlikely. Tumor was successfully removed through a midline laparotomy incision, and pathological analysis of the surgical specimen revealed a paraganglioma. After 12 months, the patient is still in a good health, asymptomatic, and without evidence of tumor recurrence. This case emphasizes the necessity to include extra-adrenal paraganglioma in the differential diagnosis and management of retroperitoneal tumors, despite its rarity.