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 .
The right adrenal gland is more commonly affected than the left with a ratio of 3-4:1 .
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 .
Associations
Isolated adrenal gland trauma is uncommon (<5% of all adrenal trauma ) and associated injuries include :
- 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 :
- 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
- diffuse enlargement or replacement of the adrenal gland with less well-defined borders can also be seen and most often relates to laceration
- periadrenal fat stranding is often present
MRI
- T1: hematoma is isointense to muscle, liver, renal cortex
- T2: hematoma is very hyperintense; hyperintense fat stranding
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 . Management is often conservative but may vary depending on hemodynamic stability and the presence of active bleeding .
Complications include :
- 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 .
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