Adrenal (Excluding Mineralocorticoids)

MON-535 - Distinct Clinical Profile and Increased Hypertensive Risk in Composite Pheochromocytomas - Results From a Two-Center Cohort Study

Monday, June 15, 2026

9:00 AM - 2:00 PM CT

Late-Breaking Poster Presenter(s)

Karolina Zawadzka, MD

Resident doctor
Jagiellonian University Medical College
Krakow, Poland

Co-Author(s)

ER

Ewelina Rzepka, MD

Jagiellonian University Medical College
Krakow, Poland
JC

Jan Calissendorff, MD, PhD, Associate professor

Associate professor
Department of Molecular Medicine and Surgery
Stockholm, Sweden
MU

Magdalena Ulatowska-Białas, MD, PhD

Docent
Jagiellonian University Medical College
Krakow, Poland
CJ

C. Christofer Juhlin, Professor

Karolinska Institutet
Stockholm, Sweden

Senior Author/Primary Investigator(s)

AH

Alicja Hubalewska-Dydejczyk, MD, PhD, Professor

Jagiellonian University Medical College
Krakow, Poland
Henrik Falhammar, MD, PhD, FRACP, Associate Professor

Professor, Senior Endocrinologist
Karolinska Institutet
Stockholm, Stockholms Lan, Sweden

Background: Composite pheochromocytoma-ganglioneuroma is a rare entity in which pheochromocytoma coexists with additional neural crest-derived components, most commonly ganglioneuroma. Its clinical phenotype and prognostic features compared with typical pheochromocytoma remain insufficiently defined.

Methods: We retrospectively analyzed 190 patients with histopathologically confirmed pheochromocytomas, including composite pheochromocytoma-ganglioneuroma cases. Clinical characteristics and outcomes were compared between patients with composite tumors and those with typical pheochromocytoma.

Results: Among 190 patients, 28 (14.9%) had composite tumors and 160 had typical pheochromocytomas. Patients with composite tumors were older compared with those with typical pheochromocytomas (median 67 vs 56 years; p=0.015). On unenhanced CT, composite tumors demonstrated lower attenuation (median 30 vs 35 HU; p=0.01) and were less often detected as adrenal incidentalomas. In multivariable analysis, independent of age, the composite phenotype was associated with a higher likelihood of preoperative systolic hypertension (OR 2.47; p=0.049), as well as postoperative elevated blood pressure, both systolic (OR 3.24; p=0.012) and diastolic (OR 4.66; p=0.002). Additionally, it was associated with an increased risk of Ki-67 expression in the 3-5% range (OR 28.68; p=0.026).

Conclusion: Composite tumors are associated with a distinct clinical course compared with typical pheochromocytoma, characterized by a higher burden of elevated blood pressure that persists after surgery and higher Ki-67 levels. These findings support closer postoperative clinical monitoring in this subgroup of patients.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*