Usefulness of adrenal scintigraphy in the follow-up of adrenocortical incidentalomas: a prospective multicenter study.
OBJECTIVE
Prognostic factors for progression of benign adrenocortical adenomas (AI) remain poorly known. We assessed the usefulness of (131)I-6-beta-iodomethylnorcholesterol scintigraphy (IMS) to predict the occurrence of adrenal hyperfunction or mass enlargement.


METHODS
Fifty-one consecutive inpatients with unilateral AI and normal 24-h urinary free cortisol (UFC) were enrolled in a multicenter observational prospective study to investigate the relationship between the scintigraphic pattern and the progression of biological abnormalities of the hypothalamo-pituitary-adrenal axis or tumor size.


RESULTS
Biochemically defined 'subclinical' Cushing's syndrome (SCS) was found at baseline in 47% of patients. Unilateral uptake (UU) was significantly associated with SCS (P<0.05). During the follow-up (4.3+/-1.6-year): 53% of patients showed unchanged hormonal evaluation, 29% displayed intermittent SCS and 18% showed definitive hormonal progression of SCS but without overt biochemical hypercortisolism. UU was associated with persistence of SCS and hormonal progression (P<0.01). In multivariate analysis, UU and impaired 1 mg dexamethasone suppression were independently associated with hormonal progression. Three patients with UU developed clinical CS despite persistently normal UFC. Tumor size increased in 10% patients and was not associated with any scintigraphic pattern.


CONCLUSIONS
Evolution of SCS toward overt biochemical CS in patients with AI is a rare event during a 4-year follow-up. UU is predictive for the occurrence of SCS, its persistence and progression within the spectrum of SCS. Further studies aiming to establish the clinical consequences of SCS are needed to recommend IMS as a complementary evaluation in patients with AI and biochemical SCS.
Fagour
Cédric
C
Department of Endocrinology, University Hospital of Bordeaux, Hôpital Haut Leveque, Avenue de Magellan, 33600 Pessac, France.
Bardet
Stéphane
S
Rohmer
Vincent
V
Arimone
Yannick
Y
Lecomte
Pierre
P
Valli
Nathalie
N
Tabarin
Antoine
A
D000236:Adenoma / Q000000981:diagnostic imaging* / Q000453:epidemiology; D000306:Adrenal Cortex Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D033162:Incidental Findings; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging / Q000379:methods*; D012307:Risk Factors
D007457:Iodine Radioisotopes