Left Adrenal Adenoma (Lipid rich)

• A 45 years old female patient with a history of ovarian carcinoma under follow up.

CT Examination:

• (A) Axial non-enhanced CT images showed a well-defined hypodense left adrenal mass with attenuation value (5 HU).
• (B) coronal contrast-enhanced CT images acquired after 1 minute showed diffuse homogeneous enhancement of the left adrenal mass with increased attenuation value reaching (56 HU).
• (C) Coronal delayed contrast-enhanced CT images acquired 15 minutes later showed significant washout of contrast with reduction of attenuation value reaching (20 HU).

*The non-contrast CT attenuation value was (5 HU), the absolute percentage washout (APW) was (71%) and the relative percentage washout (RPW) was (64%). These values were consistent with lipid-rich adenoma.

MRI Examination:

• (D, E) Axial T1 and T2-weighted MR images showed a well-defined left adrenal mass, displaying isointense signal relative to spleen on T1 and T2WIs.
• (F, G) coronal gradient-echo in-phase and out-of-phase MR images showed significant visual signal loss between in-phase and out-of-phase images (qualitative assessment)
• By quantitative assessment of chemical shift images, the adrenal-to-spleen ratio (ASR) was (0.31) and signal intensity index (SII) was (42%).

*MRI findings were consistent with Adenoma.

-Adrenal adenomas are the most common adrenal gland lesion, and should be considered in the differential diagnosis whenever adrenal masses encountered.

-Triphasic CT with washout protocol and chemical shift MRI are highly accurate imaging modalities for the diagnosis of adrenal adenomas and thus avoid the need for biopsy.