Presentation, Management, and Outcomes of Patients With Giant Pheochromocytoma

Data on giant pheochromocytomas (PHEOs), defined based on size 10 cm or greater, are scarce.

This work aimed to compare presentation, management, and outcomes of patients with giant vs non-giant PHEOs.

A retrospective cohort study was conducted in a referral center from 2000 to 2023. Consecutive patients with giant PHEOs and randomly chosen patients with non-giant PHEO (referents) were studied at a 1:6 ratio. Outcomes included perioperative complications, metastases, and mortality.

Of 828 patients with PHEOs, 31 (3.7%) had giant PHEO (median size 12 cm, interquartile range [IQR] 10.0-13.5 cm). In comparison to referents (n = 186, median size 4 cm, IQR, 2.9-5.0 cm), 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% of referents. In addition to preoperative α-adrenergic blockade (89%), metyrosine was used in 14 (7%) patients, mostly in patients with giant PHEOs (26% vs 3%; P < .0001). Patients with giant PHEOs 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).

Patients with giant PHEOs 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 PHEOs developed metastases, warranting close follow-up.