Adrenal Gland – Multimodality Imaging
Number:28ESURABS0084
Type:Educational Electronic Presentation
Authors: Pranay Rao, Galen Brennan, Akshya Gupta, Vikram Dogra
Keywords:adrenal gland, malignant, benign, computed tomography, magnetic resonance imaging.
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Educational objective

To familiarize attendees with adrenal pathologies, such as adrenal adenoma, myelolipoma, and metastasis, and uncommon tumors of the adrenal gland such as pheochromocytoma, ganglioneuroma, and adrenal cortical carcinoma. Multimodality diagnostic features of the various adrenal pathologies will be presented.

Topic Review

Adrenal pathology can be categorized in various ways. One way to characterize adrenal pathology is by malignant potential.

 

Adrenal adenomas are commonly encountered benign lesions. They are more common in older patients and those with diabetes or hypertension (2). Non-hyperfunctioning adenomas are almost always detected as an incidental adrenal lesion. Adenomas are usually well-defined, round and homogenous. Calcifications, necrosis, and hemorrhage is rare. Approximately 80% of adrenal adenomas are “lipid-rich” and can be confidently diagnosed with no further imaging or follow-up if the lesion attenuates ≤ 10 Hounsfield Units on non-contrast CT. If suspicion remains, or in the case of a “lipid poor” adenoma, wash-out of > 60% on adrenal protocol CT is diagnostic (Figure 1). On MRI, adenomas are usually relatively...

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Figure 1. Adrenal adenoma. A 2 cm left-sided adrenal gland lesion is shown on pre-contrast, post-contrast, and on delayed post-contrast imaging. This corresponds to an absolute washout of 72% and a relative washout of 75.8%, consistent with an adenoma.
Figure 2. Adrenal adenoma. A 3 cm left adrenal lesion demonstrating convincing signal dropout on out-of-phase imaging consistent with an adrenal adenoma.
Conclusions

The practicing radiologist needs to be aware of the multimodal appearance of various adrenal pathologies to facilitate proper diagnosis and management of disease.