Presentation, Management, and Outcomes of Patients with Giant Pheochromocytoma: Retrospective Cohort Study.

Abstract

Context: Data on giant pheochromocytomas (PHEO), defined based on size ≥ 10 cm, are scarce.

Objective: to compare presentation, management, and outcomes of patients with giant vs non-giant PHEOs.

Design: retrospective cohort study, 2000-2023.

Setting: referral center.

Patients: consecutive patients with giant PHEO and randomly chosen patients with non-giant PHEO (referents) at a 1:6 ratio.

Outcomes: perioperative complications, metastases, mortality.

Results: Of 828 patients with PHEO, 31 (3.7%) had giant PHEO (median size 12 cm, IQR 10.0-13.5). In comparison to referents (n=186, median size 4 cm, IQR, 2.9-5.0), patients with giant PHEO had more symptoms of catecholamine excess (median of 2 vs 1, P=.04) and presented with a higher prevalence of severe catecholamine excess (76% vs 30%, P<.0001).Adrenalectomy was performed in 94% of patients with giant PHEOs and 100% referents. In addition to preoperative alpha-adrenergic blockade (89%), metyrosine was used in 14 (7%) patients, mostly in patients with giant PHEO (26% vs 3%, P<.0001). Patients with giant PHEO had a higher perioperative complication rate (31% vs 10%, P=.004).During a median follow-up of 3 years, metastases developed at a higher rate in patients with giant PHEOs (45% vs 4% in referents, P<.0001). Disease-specific mortality was 7% in patients with giant PHEOs and 0% in referents (P=.02).

Conclusion: Patients with giant PHEO as compared to referents were more symptomatic, had a higher degree of catecholamine excess, and had a higher rate of perioperative complications. Almost half of patients with giant PHEO developed metastases, warranting a close follow-up.