Teaching Case

A 70-year-old male patient with no relevant medical history came to our hospital for general revision.

An abdominal CT with intravenous contrast was performed. In this study, a well-defined mass of the left adrenal gland was discovered. In the non-contrast phase (Fig. 1) the mass appeared with predominately low density. On portal phase the mass showed brisk peripheral enhancement with a nodular pattern (Fig. 2), which increased in late phase images.
An abdominal MRI with gadolinium was also done. On T2-weighted images, the mass showed a homogeneous hyperintense signal (Fig. 3), and in pre-contrast T1-weighted images, the mass was slightly more hypointense (Fig. 4) than the liver.
In the early phase T1-weighted sequence with gadolinium, the mass showed an enhancing pattern similar to that observed in the TC; In the early phase the mass had a peripheral nodular enhancement (Fig. 5) which progressively increased in size on the delayed images with incomplete filling of the adrenal mass.

Detection of adrenal lesions has increased with the expanding use of cross-sectional imaging. Up to 9% of general population present adrenal abnormalities [1] that are normally discovered incidentally.
Most frequent adrenal incidental benign lesions are adrenal adenomas (41%) and adrenal myelipomas (9%) [2]. The typical presentation of adrenal adenomas on non-contrast CT, is as small, well-defined, low density (less than 10 HU), homogeneous lesions.
Adrenal haemangiomas are certainly uncommon, benign, non-functioning tumours often discovered incidentally on imaging studies. They are more frequent in patients in between the ages of 50 and 70 years, with a 2:1 female-to-male ratio [3].
Adrenal haemangiomas usually arise from the adrenal cortex and appear as well-delimited, encapsulated masses. They do not produce hormones and they use to be asymptomatic. If they have a huge size, they may cause pressure related symptoms. On histological examination, they most frequently present enlarged masses of blood-filled sinusoidal channels that have displaced normal adrenal tissues [4]. The presence of vascular cavities at the periphery is an important feature, which accounts for the characteristic peripheral nodular contrast enhancement pattern.
On non-enhanced CT, haemangiomas usually present as solid masses with central areas of low attenuation, representing areas of necrosis or fibrosis, particularly in large tumours. They usually show higher HU values than typical adenomas. After intravenous administration of contrast, the peripheral nodular enhancement reveals contrast-filled vascular cavities we previously speak of. Centripetal enhancement pattern is found less frequently than in hepatic haemangiomas [3], but is highly specific for haemangioma.
The appearance of adrenal haemangioma on MRI is distinctive. On non-contrast T1-weighted images is typically more hypo-intense than liver. Sometimes, a hyper-intense focus in the centre of the mass could be seen, representing haemorrhage. On T2-weighted images adrenal haemangiomas show marked high signal intensity due to dilated vascular spaces. As with CT imaging, administration of gadolinium produces a characteristic nodular and peripheral enhancement pattern that increases on delayed T1-weighted imaging.
When typical imaging findings are not present, malignant adrenal tumor must be considerated. In these patients, PET exam or biopsy should be performed to achieve the diagnosis.
Asymptomatic typical adrenal haemangiomas smaller than 3.5 cm could be treated conservatively and they may be monitored with regular imaging (CT) [5]. Masses with a diameter greater than 3.5 cm have a significant risk of spontaneous haemorrhage and should be treated surgically. Moreover, surgical resection could be also necessary to exclude malignant adrenal disease or if pressure related symptoms are present.