Abstract: Background and purpose: Adrenal schwannoma is extremely rare, mostly benign, lack of special characteristics in clinical and imaging presentation. The aim of this study was to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of adrenal schwannoma, in order to improve the accuracy of diagnosis. Methods: The CT and MRI features of 8 patients with pathology-proven adrenal schwannoma were reviewed. Among the 8 patients, 4 patients underwent CT scanning, 3 patients underwent MR scanning, 1 patient underwent both CT and MR scanning. Results: The tumors were located at the left adrenal in 5 cases and at the right in 3 cases. Tumors showed no signs of endocrine activity in all cases. All tumors were well-circumscribed, oval or lobulated masses, 2 cases with calcification, 5 cases with cystic change, 2 cases with intratumoral hemorrhage. CT or MR enhancement showed moderate, heterogeneously delayed enhancement in 7 cases with enhanced capsule. Four cases showed rabbit tail sign. Conclusion: The imaging and pathological features of adrenal schwannoma have certain characteristics. The CT and MRI features, such as intact capsule, cystic degeneration, rabbit tail sign, calcification and progressive enhancement, are helpful to improve the accuracy of diagnosis of adrenal schwannoma.

Key words: Adrenal schwannoma, Tomography, X-ray computed, Magnetic resonance imaging