Adrenal Gland cyst

Clinical History

A 47-year-old woman in follow up for an endometrial thickening was referred to our service for a check up abdominal ultrasound. In the ultrasound, a hypoechoc nodule was found and the patient uderwent a CT and an MRI in a period of one year.

Imaging Findings

Ultrasound
In the expected location in the right adrenal gland we see a hypoechoic nodule with 17 mm

CT
In the right adrenal gland we see a hypodense nodule with 17 mm with fluid density and no enhancement after contrast administration.

MRI

In the right adrenal gland we see a nodule with 17 mm, with defined margins strongly hyperintense on T2, hypointense in phase and out of phase sequence and hyperintense signal on ADC map.

Discussion

The adrenal glands are routinely observed on non-contrast CT of the abdomen and thorax.
The majority of adrenal lesions detected at CT are benign, namely adenomas.
CT can be a helpful tool in differentiating benign from malignant lesions. Larger lesions tend to be either metastasis or a primary carcinoma. The shape of the adrenal gland can also be helpful in predicting malignancy.
Numerous MR imaging parameters can be used to describe adrenal masses, including T1 and T2 signal, enhancement, and chemical shift characteristics [1]. In general, metastases and carcinomas contain larger amounts of fluid than adenomas and thus appear bright on T2-weighted images.
There is little literature concerning adrenal gland cyst with very few works published after 2000, due to the very low detection rate of this pathology.
Most adrenal cysts are characterized by their simple morphology, although some can be complex and confused with necrotic malignancies [2-4].
When we see adrenal cystic lesions, cystic adrenal neoplasms must be excluded.
Adrenal gland cysts have been classified as pseudocysts, endothelial cysts, epithelial cysts, and parasitic cysts [2, 3].
Adrenal cysts may be observed in association with adrenal carcinoma of the medulla and cortex. Radiologic studies are helpful in the pre-surgical diagnosis of cystic lesions of the adrenal gland [1, 2].
They have low attenuation at CT with wall enhancement when intravenous contrast material is administered. On MRI, these lesions typically appear hypointense on T1-weighted images and hyperintense on T2-weighted images with no soft- tissue component and no internal enhancement [5].
Their origin is from the endothelium in 45% of cases, from pseudocysts in 39%, and from parasitic diseases in less than 10% [6].
An asymptomatic patient after a confident diagnosis should be followed up with imaging studies to assure stability and exclude metastatic disease [6].
Clinically they are frequently asymptomatic, physical manifestations only present with larger lesions.
Any functional, possible malignant or benign lesion with more than 5 cm in diameter deserves surgical treatment. Small benign lesions can be followed up [7]; conservative management is a viable option, although no surveillance protocols have been described.

Take home messages

1- It is important to exclude malignancy in a cystic adrenal lesion.
2- Follow up with imaging studies is helpful and mandatory.
3- CT is an optimal imaging method in the study of the adrenal gland.

Differential Diagnosis List

Final Diagnosis

Adrenal Cyst

URL:	https://eurorad.org/case/14027
DOI:	10.1594/EURORAD/CASE.14027
ISSN:	1563-4086