Citation, DOI & article data
Adrenal cysts are rare lesions that are usually found incidentally on imaging performed for other reasons.
Adrenal cysts are reported to be rare with an incidence of <1% 1.
Patients can present with pain or swelling, although a significant portion (~40%) are incidental findings 1,3. Functional adrenal cysts are very rare 7.
Adrenal cysts can be divided into four categories 1-3:
- endothelial cysts
- epithelial cysts
- including adult polycystic kidney disease (single case report) 4
- parasitic cysts, usually hydatid
Usually thin-walled cystic lesions with anechoic content and posterior beam enhancement. Internal mobile echoes might be seen.
Small adrenal cysts may be difficult to differentiate from adrenal adenomas on unenhanced CT as they may both have densities in the pure fluid range, i.e. -10 to +10. However on post-contrast CT adrenal adenomas tend to enhance, whereas cysts do not 5.
MRI is commonly reserved for those equivocal cases on CT and confirms fluid within the cyst (bright T2 signal) 6.
History and etymology
In 1966, the pathologist Dale G Foster subclassified adrenal cysts into four main types based on histopathological evaluation of 115 cases: epithelial cysts, parasitic cysts, especially hydatid, pseudocysts and endothelial cysts. In this series, endothelial cysts were the commonest type. Although other studies since have found pseudocysts to be more common 7.
- 1. Dimitrios A. Linos, Jon A. van Heerden. Adrenal Glands. ISBN: 9783540268611
- 2. William E. Brant, Clyde A. Helms. Fundamentals of Diagnostic Radiology. ISBN: 9780781761352
- 3. Wedmid A, Palese M. Diagnosis and treatment of the adrenal cyst. Current urology reports. 11 (1): 44-50. doi:10.1007/s11934-009-0080-1 - Pubmed
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- 5. Ricci Z, Chernyak V, Hsu K, Mazzariol FS, Flusberg M, Oh S, Stein M, Rozenblit A. Adrenal cysts: natural history by long-term imaging follow-up. (2013) AJR. American journal of roentgenology. 201 (5): 1009-16. doi:10.2214/AJR.12.9202 - Pubmed
- 6. Gurinder Nandra, Oliver Duxbury, Pawan Patel, Jaymin H. Patel, Nirav Patel, Ioannis Vlahos. Technical and Interpretive Pitfalls in Adrenal Imaging. (2020) RadioGraphics. 40 (4): 1041-1060. doi:10.1148/rg.2020190080 - Pubmed
- 7. Tahri A, Abdellaoui W, Benyakhlef S et al. An Uncommon Presentation of Adrenal Cyst with Subclinical Cushing's Syndrome: A Diagnosis Dilemma. Case Rep Endocrinol. 2021;2021:6662492. doi:10.1155/2021/6662492 - Pubmed
- 8. Sebastiano C, Zhao X, Deng F, Das K. Cystic Lesions of the Adrenal Gland: Our Experience over the Last 20 Years. Hum Pathol. 2013;44(9):1797-803. doi:10.1016/j.humpath.2013.02.002 - Pubmed