Adrenal ganglioneuroma: Features and outcomes of 27 cases at a referral cancer centre

Background: Adrenal ganglioneuroma (AGN) is a rare neurogenic tumour that can mimic other adrenal neoplasms. Limited information, mostly derived from small cases series, is available for AGN. Methods A retrospective review for AGNs seen at a tertiary referral centre describing important features to distinguish AGN from other adrenal neoplasms. Results: Of 53 ganglioneuromas, 27 were AGNs. Median age was 31 years (range, 1.7-64 years) and median tumour size was 8 cm (range, 1.5-20 cm). Seventeen AGNs (63%) were detected incidentally and nine patients (33%) presented with abdominal/back discomfort. Catecholamine levels, available for 21 patients, were normal. On computed tomography (CT), most AGNs were homogenous and well circumscribed with a median density of 32.5 Hounsfield units (HU) on unenhanced CT; 40 HU on postcontrast venous phase; and 66.5 HU on delayed postcontrast phase. On magnetic resonance imaging (MRI), AGNs had hypointense signal on T1-weighted images with heterogeneous hyperintense signal on T2-weighted images. In four patients, there was no tumour growth during median follow-up of 48 months (range, 21-60 months). One patient had malignant peripheral nerve sheath tumour arising from AGN. Thirteen patients with resected AGN had no recurrence during a median follow-up of 50 months (range, 2-135 months). Conclusions: We herein describe the largest AGN series reported to date. Isolated AGNs do not produce catecholamines and have CT imaging characteristics that can help in distinguishing them from other adrenal and para-adrenal neoplasms. The natural history of AGNs is usually benign, although local extra-adrenal extension or malignant transformation can rarely occur.