Long-term outcomes of abdominal paraganglioma

Purpose: Paragangliomas (PGL) are rare neuroendocrine tumors derived from chromaffin cells of the autonomic nervous system. We aim to describe our experience and the long-term outcome of abdominal PGL over the last decade. Methods: A retrospective review of patients diagnosed with PGL in our hospital between November 2005 and June 2017 was conducted. All nonabdominal PGL were excluded and the clinicopathological features and long-term outcomes of the patients were analyzed. Results: A total of 46 patients were diagnosed with abdominal PGL. The average age of diagnosis was 55.4 years and there was no sex predilection. The average tumor size was 5.85 cm and they were predominantly located in the infrarenal position (50%). The mean follow-up period was 42 months (range, 1.8-252 months). All patients with metastases had Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) of >= 4. One patient presented with synchronous metastases while 2 developed local recurrence and distant metastases. One presented with only local recurrence. One patient died 5 years after diagnosis. Conclusion: Abdominal PGL is a rare tumor with excellent long-term prognosis. Recurrence although uncommon, can occur decades after initial diagnosis. Long-term follow-up is therefore recommended for all patients with PGL, especially in patients with PASS of >= 4.