Adrenal lesion frequency: A prospective, cross-sectional CT study in a defined region, including systematic re-evaluation.
BACKGROUND
incidentally detected adrenal lesions have become a growing clinical problem.


OBJECTIVE
to prospectively estimate and validate the prevalence of incidentally detected adrenal lesions (adrenal incidentaloma) in patients with or without malignant disease undergoing CT.


METHODS
during 18 months all adult patients with incidentally discovered adrenal lesions detected at CT were prospectively reported from the radiology departments of all hospitals in Western Sweden (1.66 million inhabitants). Frequencies of adrenal lesions initially reported at CT and at a systematic re-evaluation were compared. The interobserver variation in blindly assessing adrenal lesions was also analyzed.


RESULTS
adrenal lesions were reported and verified in 339 patients (193 females; mean age 69 years, range 30-94 years). Mean lesion size was 25.8 mm (range 8-94 mm). The mean frequency of originally reported adrenal lesions was 0.9% (range 0-2.4% between hospitals). The systematic re-evaluation of 3801 randomly selected cases showed a mean frequency of 4.5% (range 1.8-7.1% between hospitals). The re-evaluation revealed 177 cases with adrenal lesions, 30% of these were submitted by the local radiologist in accordance with the study design, 23% were described in the local radiology report but not submitted to the study center, while 47% were neither locally reported nor submitted.


CONCLUSIONS
adrenal lesions are under-reported in clinical practice. Prevalence figures for adrenal incidentalomas should therefore be interpreted with caution, especially in multi-center settings.
Hammarstedt
Lilian
L
Department of Radiology, Sahlgrenska University Hospital, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden. lilian.hammarstedt@vgregion.se
Muth
Andreas
A
Wängberg
Bo
B
Björneld
Lena
L
Sigurjónsdóttir
Helga A
HA
Götherström
Galina
G
Almqvist
Erik
E
Widell
Håkan
H
Carlsson
Sture
S
Ander
Stefan
S
Hellström
Mikael
M
D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D000311:Adrenal Glands / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015995:Prevalence; D011446:Prospective Studies; D015203:Reproducibility of Results; D013548:Sweden / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000379:methods*