Unilateral or bilateral, round or oval, well-defined mass

Variable echogenicity depending on stage of hemorrhage

Variable appearance depending on age of hemorrhage

US: Nonspecific, avascular hypoechoic, hyperechoic, or heterogeneous lesion

CT/MR: Can better characterize hemorrhagic contents of lesion, increasing specificity

Acute hematoma: Hyperechoic

Subacute hematoma: Mixed echogenicity ± central hypoechoic area

Chronic hematoma: Hypo- or anechoic cyst-like lesion

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  Curvilinear calcification, internal echoes/layering debris

Adreniform enlargement of adrenal gland

Displacement & mass effect on kidney and IVC

Avascular on color Doppler

US for initial screening & detection followed by CT/MR for further characterization

Left adrenal gland can be difficult to see on US, and small lesions may be obscured

Adrenal adenoma

Pheochromocytoma

Myelolipoma

Primary adrenal, metastatic, or adjacent tumors

Adjacent neoplasm

Adrenal lymphoma

Blunt abdominal trauma (right gland > left gland)

Nontraumatic pathogenesis: Vascular dam of abundant arterial supply and limited venous drainage

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  Anticoagulation therapy, recent surgery, sepsis, burns, hypotension, steroids, pregnancy

  
  
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  Hemorrhage in primary adrenal or metastatic tumors: Pheochromocytoma, myelolipoma, adrenal carcinoma

Nontraumatic pathogenesis: Vascular dam of abundant supply (3 arteries) and limited drainage (1 vein)

Relatively uncommon condition but potentially catastrophic event due to adrenal insufficiency

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  Can result in adrenal insufficiency

More common in neonates than children and adults

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  Most common cause of adrenal mass in infancy

  
  
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  Usually seen during 1st week of life

Bilateral in 15% of individuals who die of shock

Occurs secondary to traumatic (more common) and nontraumatic causes

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  Traumatic hemorrhage: Blunt abdominal trauma

  
  
  
  
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    25% of patients with blunt abdominal trauma have adrenal hemorrhage

    
    
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    Unilateral in 80% of cases: Right (85%), left (15%)

  
  
  
  
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  Nontraumatic hemorrhage (often bilateral)

  
  
  
  
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    Stress, bleeding disorders, adrenal tumors

    
    
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    Neonatal stress (birth asphyxia), idiopathic

    
    
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    Meningococcal septicemia (Waterhouse-Friderichsen syndrome)

  
  

Abdominal, flank, or back pain, nausea, and vomiting, fever, tachycardia, hypotension

Acute adrenal insufficiency

Waterhouse-Friderichsen syndrome: Rapidly developing adrenal failure that can lead to death

Occurs in any age group but more common in neonates

Left adrenal gland can be difficult to image, use spleen or fluid-filled stomach as acoustic window