Biochemical and radiological relationships in patients with pheochromocytoma: lessons from a case control study.
Clin Endocrinol (Oxf)
; 80(6): 790-6, 2014 Jun.
Article
in En
| MEDLINE
| ID: mdl-24494743
ABSTRACT
BACKGROUND:
An elevation of fractionated plasma or urinary metanephrine (MN) or nor-metanephrine (NMN), collectively called metanephrines (MN and NMN), >4-fold above the upper limit of normal (ULN) is usually considered to be diagnostic for pheochromocytoma (PHEO). There are a greater number of false positive results when the elevations are more modest.AIM:
To identify biochemical and radiological features in PHEOs with modest elevations (<4-fold above ULN) of metanephrines.METHODOLOGY:
We retrospectively reviewed the charts of 112 patients with PHEO (10% extra-adrenal) and 208 patients with a non-PHEO adrenal mass operated from 1997-2011, who had metanephrines measured pre-operatively. We divided PHEO into group 1 (n = 90) with metanephrines ≥4-fold ULN and group 2 (n = 22) with metanephrines <4-fold ULN. The non-PHEO group was designated as group 3.RESULTS:
The median (range) tumour size in group 1 and group 2 was 4·8 cm (1·7-22) and 3·0 cm (1·7-5) respectively (P < 0·001). All patients with PHEO in group 2 had a tumour <5 cm in size. The MN fraction was elevated in about 65% of groups 1 and 2; only 2 (1%) patients in group 3 had an elevated urinary MN fraction, and none were associated with an elevated plasma MN fraction. All PHEOs had a pre-contrast attenuation ≥17 Hounsfield Units (HU).CONCLUSIONS:
Modest elevations (<4-fold ULN) of the NMN fraction in an adrenal mass >5 cm are almost always falsely positive. Elevations in plasma and urinary MN fraction are less likely to be false positive. The CT pre-contrast attenuation of PHEOs is >10 HU.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pheochromocytoma
/
Metanephrine
/
Adrenal Gland Neoplasms
Type of study:
Observational_studies
/
Risk_factors_studies
Limits:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Clin Endocrinol (Oxf)
Year:
2014
Type:
Article
Affiliation country:
United States