Adrenal gland trauma

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 hemorrhage 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 hemothorax
• liver, spleen and/or renal laceration
• rib, pelvic or spinal fractures
• head injury

Adrenal gland traumatic hemorrhage may also present with ¹: 

• posterior pararenal space hemorrhage
• IVC compression
• psoas muscle hematoma
• thickening of the diaphragmatic crus

Radiographic features

CT

• hematoma 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: hematoma is isointense to muscle, liver, renal cortex
• T2: hematoma is very hyperintense; hyperintense fat stranding ³

Treatment and prognosis

Adrenal gland trauma is important to recognize 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 hemodynamic stability and the presence of active bleeding ⁶.

Complications include ^1,4:

• acute adrenal insufficiency (if bilateral)
• delayed hemorrhage
• calcification
• pseudocyst formation
• thrombus from IVC compression (rare)

Differential diagnosis

Differentials to consider include:

• pre-existing adrenal mass
• hemorrhage into the existing adrenal tumor
• 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.