Pheochromocytoma diagnosed pathologically with previous negative serum markers.

BACKGROUND AND

OBJECTIVES

Patients presenting with adrenal masses require workup with catecholamine or metabolite measurements to rule out pheochromocytoma. There is a select portion of patients with marker negative pheochromocytoma. The aim of this study is to compare patient characteristics and presentations between marker positive and marker negative tumors.

METHODS

We performed an IRB-approved retrospective chart review of 88 cases of pheochromocytoma excised at our institution from 1995 to 2013. We considered any abnormal elevation in diagnostic test to be marker-positive.

RESULTS

Seventy-eight cases had laboratory results available. Among these, seven had no elevations in laboratory testing. There was no difference in age or tumor size, but marker-negative patients had higher BMI than marker-positive patients. Marker negative patients were more likely to present with vertigo/dizziness (P = 0.003). Neither was more likely to have a genetic syndrome associated with risk of pheochromocytoma.

CONCLUSIONS

Marker-negative pheochromocytoma is uncommon, representing 9% of cases in our series. Of patients with adrenal masses or presentation suggesting catecholamine excess with normal labs, those with vertigo/dizziness may warrant a metaiodobenzylguanidine scan or repeat testing to avoid missing pheochromocytoma. Clinicians may need a high degree of suspicion for pheochromocytoma in patients with negative testing and elevated BMI.