Abstract
Background: Incidentally detected adrenal lesions have become a growing clinical problem.
Purpose: To prospectively estimate and validate the prevalence of incidentally detected adrenal lesions (adrenal incidentaloma) in patients with or without malignant disease undergoing CT.
Material and 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.
Conclusion: Adrenal lesions are under-reported in clinical practice. Prevalence figures for adrenal incidentalomas should therefore be interpreted with caution, especially in multi-center settings.
Acknowledgments
We wish to express our sincere thanks to all the radiology and clinical staff of the participating hospitals for their assistance and support of this study. We are grateful for financial support from the Swedish Cancer Society, the Göteborg Medical Society, the Västra Götaland Region Research Fund, and Government grants under the LUA/ALF Agreement. The research was independent of the funders.
Declaration of interest: All authors certify that there are no actual or potential conflicts of interest in relation to this article. The authors alone are responsible for the content and writing of the paper.
Additional members of the Adrenal Study Group:
Alingsås Hospital, Alingsås: J. Grebo, Dept of Radiology; S. Ljungberg, Dept of Medicine; Capio Lundby Hospital, Gothenburg: A. Gering-Kutti, Dept of Radiology; Carlanderska Hospital, Gothenburg: C. Norrby, M. Rosenkrans, Dept of Radiology; Falköping Hospital, Falköping: M. Larsson, Dept of Radiology; Frölunda Specialist Hospital, Gothenburg: N. Lundh, C. Manucheri, Dept of Radiology; Kungsbacka Hospital, Kungsbacka: E. Nilsson, M. Unger, Dept of Radiology; Kungälv Hospital, Kungälv: J. Gallego, G. Hansen, M. Laesser, Dept of Radiology; Lidköping Hospital, Lidköping: O. Söderman, Dept of Radiology; Lysekil Hospital, Lysekil: M. Frank, Dept of Radiology; Northern Älvsborg Hospital (NÄL), Trollhättan: Å. Bovaller, Z. Francziszty, J. Strömberg, Dept of Radiology; E. Ekerstad, Dept of Medicine; Sahlgrenska University Hospital, Gothenburg: H. Ahlman, Dept of Endocrine Surgery; A. Gaulitz, Dept of Radiology Mölndal; F. Thorén, A. Sakinis, Dept of Radiology Sahlgrenska; P. Lukes, Dept of Radiology Östra; Southern Älvsborg Hospital (SÄS), Borås: B. Arnell, Dept of Radiology; Uddevalla Hospital, Uddevalla: C. Hallberg, H. Östberg, Dept of Radiology; S. Wettre, Dept of Medicine; Varberg Hospital, Varberg: P. Bernland, I. Falk, A. Hogedal, Dept of Radiology; C. Forsberg, Dept of Surgery; Strömstad Hospital, Strömstad: S. Palmblad-Olow, Dept of Radiology; Skövde Hospital (KSS), Skövde: K. Wennerstrand, Dept of Radiology.