Pheochromocytoma diagnosed pathologically with previous negative serum markers

Area of Science:

• Endocrinology
• Oncology
• Nephrology

Background:

• Adrenal masses necessitate catecholamine testing to rule out pheochromocytoma.
• A subset of pheochromocytoma cases are marker-negative, posing diagnostic challenges.

Purpose of the Study:

• To compare patient characteristics and clinical presentations between marker-positive and marker-negative pheochromocytoma.
• To identify potential indicators for diagnosing pheochromocytoma in marker-negative cases.

Main Methods:

• Retrospective chart review of 88 surgically excised pheochromocytoma cases (1995-2013).
• Definition of marker-positive as any abnormal elevation in diagnostic laboratory testing.
• Analysis of patient demographics, tumor characteristics, and presenting symptoms.

Main Results:

• Seven out of 78 cases (9%) were classified as marker-negative pheochromocytoma.
• Marker-negative patients exhibited higher Body Mass Index (BMI) and were more likely to report vertigo/dizziness.
• No significant differences were observed in age or tumor size between the groups.

Conclusions:

• Marker-negative pheochromocytoma is an infrequent but significant diagnostic consideration.
• Vertigo/dizziness in patients with adrenal masses and normal initial labs may warrant further investigation, including MIBG scans or repeat testing.
• Elevated BMI in conjunction with suggestive symptoms should raise clinical suspicion for pheochromocytoma despite negative initial laboratory results.