Adrenal gland trauma most commonly results from blunt force trauma.

Epidemiology

Adrenal gland trauma is present on 1-2% of CT imaging in blunt trauma although the occurrence is thought to be much higher as injury has been demonstrated at 28% in one autopsy series ^1-4. 

The right adrenal gland is more commonly affected than the left with a ratio of 3-4:1 ². 

Pathology

Adrenal haemorrhage is the most common injury to the adrenal gland and is thought to be a result of direct compression or increased venous pressures from IVC compression. Laceration of the adrenal gland is less common ^2,3. 

Associations

Isolated adrenal gland trauma is uncommon (<5% of all adrenal trauma ⁴) and associated injuries include ^1,2:

• pulmonary contusions, pneumothorax and/or haemothorax

• liver, spleen and/or renal laceration

• rib, pelvic or spinal fractures

• head injury

Adrenal gland traumatic haemorrhage may also present with ¹: 

• posterior pararenal space haemorrhage

• IVC compression

• psoas muscle haematoma

• thickening of the diaphragmatic crus

Radiographic features

CT

• haematoma presents as a well-defined nodular mass, within either the body or the limb with a density of 50-80 HU ^1,2

• diffuse enlargement or replacement of the adrenal gland with less well-defined borders can also be seen and most often relates to laceration ^1,2

• periadrenal fat stranding is often present ¹

MRI

• T1: haematoma is isointense to muscle, liver, renal cortex

• T2: haematoma is very hyperintense; hyperintense fat stranding ³

Treatment and prognosis

Adrenal gland trauma is important to recognise as mortality is twice as high in blunt trauma patients with adrenal gland injury than without ². Management is often conservative but may vary depending on haemodynamic stability and the presence of active bleeding ⁶.

Complications include ^1,4:

• acute adrenal insufficiency (if bilateral)

• delayed haemorrhage

• calcification

• pseudocyst formation

• thrombus from IVC compression (rare)

Differential diagnosis

Differentials to consider include:

• pre-existing adrenal mass

• haemorrhage into the existing adrenal tumour

• adrenal gland hyperenhancement: usually bilateral with preserved adrenal gland morphology and in the setting of hypotension

Practical points

The presence of a discrete adrenal mass in the context of blunt trauma without injury to other abdominal organs or CT features of injury warrants follow-up investigation ^1,4.