Diagnostic Ultrasound - Abdomen and Pelvis

Adrenal Hemorrhage
Diagnoses: Adrenal Gland
• Heterogeneous mass (when myeloid cells predominate)
Adrenal Metastases
• Most frequently occurring hemorrhagic adrenal neoplasm
• Lung cancer most common hemorrhagic metastasis; RCC,
breast, colon, and melanoma also possibilities
• Melanoma: Intrinsic T1 hyperintense may mimic
hemorrhage; appears hypervascular with contrast
Adjacent Neoplasm
• Renal cell carcinoma, angiomyolipoma, hepatocellular
carcinoma, atypical hepatic hemangioma
Adrenal Lymphoma
• Nonspecific US appearance with increased density on CT
• Typically bilateral and in setting of systemic disease
PATHOLOGY
General Features
• Etiology
○ Nontraumatic pathogenesis: Vascular dam of abundant
supply (3 arteries) and limited drainage (1 vein)
– Stress or adrenal tumor → ↑ adrenocorticotrophic
hormone → ↑ arterial blood flow + limited venous
drainage → hemorrhage
– Stress or tumor → ↑ catecholamines → adrenal vein
spasm → stasis → thrombosis → hemorrhage
– Coagulopathies → ↑ venous stasis → thrombosis →
hemorrhage
○ Causes
– Blunt abdominal trauma (right gland > left gland)
– Anticoagulation therapy
– Antiphospholipid antibody syndrome & disseminated
intravascular coagulopathy
– Stress: Recent surgery, sepsis, burns, hypotension,
steroids, pregnancy
– After liver transplantation (commonly seen in right
gland due to ligation of right adrenal vein)
– Primary adrenal or metastatic tumors:
Pheochromocytoma, metastases, adenoma,
myelolipoma, adrenal carcinoma
– Adrenal hyperplasia
– Complication of venous sampling or biopsy
– Neonates (most common adrenal mass in infancy)
□ Difficult labor or delivery; asphyxia or hypoxia
□ Renal vein thrombosis
□ Hemorrhagic disorders; meningococcal septicemia
(Waterhouse-Friderichsen syndrome)
Gross Pathologic & Surgical Features
• Hematoma, enlarged gland, peri-adrenal stranding
Microscopic Features
• Necrosis of all 3 cortical layers + medullary cells
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Nonspecific: Abdominal, flank, or back pain, nausea, and
vomiting
○ Fever, tachycardia, hypotension
○ Acute abdomen
– Guarding, rigidity, rebound tenderness
○ Confusion, disorientation, shock in late phase
○ Acute adrenal insufficiency
– Fatigue, anorexia, nausea, & vomiting
○ Waterhouse-Friderichsen syndrome: Rapidly developing
adrenal failure that can lead to death
– Petechial and purpuric rash, disseminated
intravascular coagulation, fever, septic shock
○ Rarely, asymptomatic; incidental finding (imaging)
Demographics
• Age
○ Occurs in any age group but more common in neonates
– Incidence: 1.7-3% per 1,000 births
○ Nontraumatic (40-80 years); traumatic (20-30 years)
• Gender
○ M:F = 2:1
• Epidemiology
○ Autopsy studies: 0.3-1.8% of unselected cases
○ 15% of individuals who die of shock
○ 2% of orthotopic liver transplantations
Natural History & Prognosis
• Complications
○ Adults: Adrenal crisis; neonate: death (> blood loss)
○ Prerenal azotemia, adrenal abscess, shock
• Prognosis
○ Depends on etiology rather than extent of hemorrhage
○ Often self-limiting, resolving over time
○ 16-50% of patients with bilateral hemorrhage develop
life-threatening adrenal insufficiency
○ Overall mortality rate: 15%
– Waterhouse-Friderichsen syndrome: 55-60%
Treatment
• Medical: Correct fluid, electrolytes, & treat underlying cause
• Surgical: Adrenalectomy (open or laparoscopic)
○ Surgery not typically required, except in adrenal tumors
DIAGNOSTIC CHECKLIST
Consider
• Check for history of trauma, anticoagulant therapy,
coagulopathies, malignancies, stress, recent surgery,
adrenal tumor
• Change over time is suggestive of acute adrenal
hemorrhage; check prior examinations or follow-up studies
for evolution
Image Interpretation Pearls
• US: Avascular adrenal lesion of variable echogenicity with
relevant clinical features
• CT/MR: CT density and MR signal intensity vary with age of
hematoma
SELECTED REFERENCES
1. Hammond NA et al: Imaging of adrenal and renal hemorrhage. Abdom
Imaging. ePub, 2015
2. Jordan E et al: Imaging of nontraumatic adrenal hemorrhage. AJR Am J
Roentgenol. 199(1):W91-8, 2012
3. To'o KJ et al: Imaging of traumatic adrenal injury. Emerg Radiol. 19(6):499-
503, 2012
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