Learning objectives
To review the main aspects of imaging evaluation of adrenal anomalies.
To recognize mimics that can simulate adenomas.
To define challenges that can potentially be characterized in CT and MRI.
Background
Adrenal lesions pose a significant challenge in diagnostic imaging due to their diverse etiologies and varied presentations. While radiologists often focus on identifying lesions associated with adrenal tumors, there's a crucial need to consider other potential causes. Differential diagnosis plays a pivotal role in distinguishing between benign and malignant lesions, which can range from adrenal adenomas and myelolipomas to metastases and adrenal hemorrhage. Optimal imaging techniques coupled with careful analysis are imperative to prevent diagnostic errors and ensure appropriate patient management.
Findings and procedure details
A: BENIGN CONDITIONS1. Adenoma: the most common benign adrenal tumor, characterized by well-demarcated round or oval masses with homogeneous density. Typically, these adenomas exhibit low attenuation values (<10 HU)(Figure 1) on CT scans, distinguishing them from other adrenal lesions. A 15-minute post-contrast CT protocol is often employed to differentiate adenomas from non-adenomas, particularly in cases where lipid content is poor, in which is calculated the absolute percentage washout (APW), that above 60% shows a high probability of adenoma (EDEU Formula):
APW = (60s Enhanced HU...
Conclusion
Adrenal anomalies can be potentially missed in routine exams and its broad number of differential diagnoses can be mischaracterized by CT and MRI. In this context, the role of the radiologist in identifying and differentiating is essential to a better clinical strategy.
Personal information and conflict of interest
L. D. S. Moreno:
Nothing to disclose
A. C. F. Rodrigues:
Nothing to disclose
R. d. a. Omena:
Nothing to disclose
E. G. d. Oliveira Neto:
Nothing to disclose
M. V. A. Soares:
Nothing to disclose
References
Federle MP, Jeffrey RB Jr, Woodward PJ, Borhani AA, DeCrescenzo A, Laing FC. Diagnostic Imaging: Abdomen. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2011.
Midya A, Chandra S, Gachabayov M, Philpotts L. Adrenal Imaging: A Comprehensive Review. Radiol Clin North Am. 2020;58(4):697-715.
Morgan DE, Giordano TJ, Lacy MQ, Kasperbauer JL. Adrenal Incidentaloma: A Practical Review of Radiologic Evaluation and Management. Radiol Clin North Am. 2019;57(6):1127-1139.
Patel MR, Callstrom MR. Computed Tomography- and Ultrasound-Guided Ablation of Adrenal Gland Tumors. Semin Intervent Radiol. 2021;38(1):82-89.
Patel MR, Singh...