Retroperitoneal ganglioneuroma presenting as an obstructive pyelonephritis: a case report.

Ganglioneuroma is a nerve tumor arising from the sympathetic neural crest. It is a rare benign tumor. Retroperitoneum is its second location after the posterior mediastinum. Usually asymptomatic, it is discovered incidentally on imaging. Surgical resection is the sole treatment. The prognosis is good if the diagnosis is made early with quality R0 surgical excision. We report a case in a 14-year-old female admitted to the emergency department for obstructive pyelonephritis. Imaging features found a retroperitoneal mass with characteristics suggestive of a retroperitoneal ganglioneuroma, which was confirmed by histological study. Ganglioneuroma should be a part of differential diagnoses for any retroperitoneal mass in children and young adults.