Adrenal vein thrombosis

Adrenal vein thrombosis refers to the occlusion of the main central adrenal vein with or without extension to the capsular veins, resulting in hemorrhage and coagulative necrosis of the adrenal glands.

Epidemiology

Adrenal vein thrombosis is a rare condition with no reported incidence rates in the literature. It may occur at any age and there is a female predilection ^1,2.

Risk factors

• hypercoagulable states
• disseminated intravascular coagulation ^3,4
• surgical procedures
• following adrenal venography
• metastatic disease
• trauma
• Waterhouse-Friderichsen syndrome
• inferior vena cava (IVC) or renal vein thrombosis
• severe infections
• chronic respiratory diseases
• hypothermia
• stress and age-related capillary fragility ³.

Clinical presentation

The clinical presentation is not specific and patients may present with:

• severe flank pain ¹
• subcostal region guarding 
• in the case of bilateral adrenal venous infarction, patients may present with hypotension and shock due to acute adrenal insufficiency ⁵

Radiographic features

US

Ultrasound is not the best modality to assess adrenals, but it may show adrenal enlargement with hyperechoic adrenal parenchyma.

CT

Multiphased abdominal CT is the first imaging investigation performed given the non-specific clinical presentation, it may show:

• diffuse edema with enlargement of the adrenal gland
• hyperdensities within the adrenal parenchyma corresponding to central adrenal hemorrhage
• poor enhancement of the surrounding cortex corresponding to adrenal cortical necrosis
• a rim of surviving outer cortex may be seen ⁵
• periadrenal fat stranding
• overflowing thrombi from the right adrenal vein into the inferior vena cava is a common feature ¹
• partial thrombi from the left adrenal vein may overflow into the left renal vein
• although adrenal veins may be visualized on CT, direct visualization of the thrombi in the main central vein is not a described feature
• It is usually associated with other concurrent venous thromboembolism (e.g. cerebral venous thrombosis)

Treatment and prognosis

Anticoagulation therapy with heparin is the mainstay treatment in the acute stage.

Glucocorticoid therapy and electrolyte replacement may be needed in case of bilateral adrenal infarction with acute adrenal insufficiency.

Complications

When bilateral, adrenal venous thrombosis can lead to dramatic adrenal insufficiency.

Differential diagnosis

• adrenal neoplasms
  • the pattern of enhancement usually differentiates them from venous infarction.
• adrenal hemorrhage