Adrenal and extra-adrenal retroperitoneal ganglioneuroma: Imaging findings in 13 adults

PURPOSE: To determine the radiologic appearance of ganglioneuromas of the adrenal gland and extra-adrenal retroperitoneum. MATERIALS AND METHODS: A retrospective review was performed of imaging findings in nine patients with ganglioneuroma, two with ganglioneuroma-pheochromocytoma, and two with malignant peripheral nerve sheath tumor (PNST) that arose in a ganglioneuroma. Patients underwent computed tomography (CT) (n = 13), magnetic resonance (MR) imaging (n = 5), and ultrasonography (US) (n = 5). RESULTS: In nine patients with ganglioneuroma, the mass ranged in size from 2 x 4 x 4 cm to 21 x 21 x 22 cm. Imaging findings included attenuation entirely or predominantly less than that of muscle on contrast material-enhanced CT images (n = 9); heterogeneous, predominantly high signal intensity on T2-weighted MR images (n = 5); partial or complete surrounding of one or more major blood vessels with little or no luminal narrowing (n = 4) and calcifications (n = 4) on CT scans; and homogeneous, moderate echogenicity (n 3) on US scans. CT findings in two patients with ganglioneuroma-pheochromocytoma included central necrosis (n = 1) and calcifications (n = 1). In the two patients with malignant PNST that arose in a ganglioneuroma, contrast-enhanced CT showed a large, markedly heterogeneous mass. CONCLUSION: Diagnosis of ganglioneuroma should be considered when typical CT or MR imaging findings are present. Findings in cases of ganglioneuroma-pheochromocytoma and malignant PNST arising in a ganglioneuroma appear to be nonspecific.