An unusual cause of back pain: a case of large nonfunctioning retroperitoneal paraganglioma presented as a large cystic lesion. A case report and review of literature.

Pheochromocytoma arising from outside the adrenal glands is also called paraganglioma. When it occurs below the diaphragm, in the organ of Zuckerkandl or retroperitoneum, it is also called extra-adrenal pheochromocytoma. Paragangliomas are rare tumors which arise from neuroendocrine cells and extra-adrenal paragangliomas (EAPs) account for only 10-15% if all paragangliomas and may present incidentally as a symptomless mass. Typical triad of sweating, headache and fluctuating hypertension if not present makes preoperative diagnosis difficult. Surgical excision is the treatment of choice. Definitive diagnosis is usually made with histological findings. We report a case of large retroperitoneal tumor with size >10 cm which was a high risk depicting malignancy.