Adrenal ganglioneuroma resected for suspicious malignancy: multicenter review of 25 cases and review of the literature

PURPOSE: We reviewed the experience with adrenal ganglioneuroma (AGN) pathologically confirmed following adrenalectomy in medium- to high-volume medical centers. METHODS: The medical records of all adrenalectomy cases in 4 medical centers between 2006 and 2020 were retrospectively reviewed for demographics, clinical, radiological and laboratory findings, surgical treatment, pathology results, and outcomes. RESULTS: Twenty-five out of 875 adrenalectomy cases (2.9%) were pathologically confirmed as AGN. Those patients' average age was 40.5 years (range, 4–76 years), 13 (52.0%) were males, and 18 lesions (72.0%) were right-sided. One patient had a family history of neurofibromatosis, and another had a succinate dehydrogenase gene mutation. Abdominal/back pain attributed to mass effect was the most common symptom. All 25 patients underwent abdominal computerized tomography scanning in which the average maximal tumor diameter was 6.61 cm. The mean pre- and postcontrast Hounsfield units (HU) values were 35.2 and 59, respectively; and the mean late-phase HU value was 71.1. Twenty-two patients (88.0%) underwent minimally invasive surgery. The average tumor diameter recorded in the final pathology report was 7 cm. Isolated AGN was diagnosed in 21 cases (84.0%), and the additional components reported for the remaining 4 cases included pheochromocytoma (2), ganglioneuroblastoma (1), and neurofibroma (1). The average follow-up length was 16.8 months (range, 1–136 months), during which there was no recurrence or death. CONCLUSION: AGN is a rare, slow-growing, large benign tumor with radiological characteristics similar to those seen in malignant tumor. Final diagnosis is established by pathology after surgical resection, preferably minimally invasive, with an overall excellent prognosis.