Diagnostic Ultrasound - Abdomen and Pelvis

Hepatic Adenoma
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Diagnoses: Liver
• Vascular, biliary, nodal invasion may be present
Metastases
• Usually multiple and look for primary tumors
PATHOLOGY
General Features
• Etiology
○ ↑ risk in oral contraceptives and anabolic steroid users
○ Pregnancy
– Increased tumor growth rate and tumor rupture
○ Types I and III glycogen storage disease
– Multiple adenomas: 60%
○ Diabetes mellitus
○ Klinefelter syndrome
○ Obesity
• High incidence of
○ Hemorrhage, necrosis, and fatty change
Staging, Grading, & Classification
• 4 molecular/pathological subtypes: Help determine
prognosis and management
○ β-catenin-mutated HCA (10-15%): High risk of
malignant transformation
– Occurs more frequently in men
– Steatosis is rare, inflammation is absent
– Difficult to differentiate from well-differentiated HCC
on pathology
○ Inflammatory HCA (50%): 10% risk of malignant
transformation
– Focal steatosis may be present
– Previously classified as telangiectatic FNH
○ Hepatocyte nuclear factor 1α-inactivated HCA (30-
35%)
– Steatosis characteristically present
– Absence of inflammatory infiltrate
○ Unclassified (< 10%)
Gross Pathologic & Surgical Features
• Well-circumscribed mass on external surface of liver
• Soft, pale, or yellow tan
• Large areas of hemorrhage or infarction
• "Pseudocapsule" and occasional "pseudopods"
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ RUQ pain (40%): Due to hemorrhage
○ Asymptomatic (20%)
• Clinical profile
○ Usually normal liver function tests
Demographics
• Age
○ Young women of childbearing age group
• Gender
○ 98% seen in females (M:F = 1:10)
○ Males on anabolic steroids or with glycogen storage
disease
• Epidemiology
http://radiologyebook.com/
○ Estimated incidence in oral contraceptive users
– 4 adenomas per 100,000 users
○ Multiple adenomas in glycogen storage disease
Natural History & Prognosis
• Complications
○ Hemorrhage: Intrahepatic or intraperitoneal (40%)
○ Rupture: Increased risk in pregnancy
○ Malignant transformation
– 4.3% risk in adenomas larger than 5 cm
– High risk in β-catenin subtype
• Prognosis
○ Usually good
– After discontinuation of oral contraceptives
– After surgical resection of large/symptomatic
○ Poor
– Intraperitoneal rupture
– Rupture during pregnancy
– Adenomatosis (> 10 adenomas)
– Malignant transformation
Treatment
• Adenoma < 6 cm
○ Observation and discontinue oral contraceptives
• Adenoma > 6 cm and near surface
○ Surgical resection
• β-catenin mutated subtype
○ Resection due to increased risk of malignant
transformation
• Avoid pregnancy due to increased risk of rupture
DIAGNOSTIC CHECKLIST
Consider
• Rule out other benign and malignant liver tumors, which
have similar imaging features, particularly HCC or FNH
• Percutaneous biopsy is associated with high risk of bleeding
• Check for history of oral contraceptives and glycogen
storage disease (in case of multiple adenomas)
SELECTED REFERENCES
1. Khanna M et al: Current updates on the molecular genetics and magnetic
resonance imaging of focal nodular hyperplasia and hepatocellular
adenoma. Insights Imaging. ePub, 2015
2. Dhingra S et al: Update on the new classification of hepatic adenomas:
clinical, molecular, and pathologic characteristics. Arch Pathol Lab Med.
138(8):1090-7, 2014
3. Frulio N et al: Evaluation of liver tumors using acoustic radiation force
impulse elastography and correlation with histologic data. J Ultrasound
Med. 32(1):121-30, 2013
4. Bieze M et al: Diagnostic accuracy of MRI in differentiating hepatocellular
adenoma from focal nodular hyperplasia: prospective study of the additional
value of gadoxetate disodium. AJR Am J Roentgenol. 199(1):26-34, 2012
5. Purysko AS et al: Characteristics and distinguishing features of
hepatocellular adenoma and focal nodular hyperplasia on gadoxetate
disodium-enhanced MRI. AJR Am J Roentgenol. 198(1):115-23, 2012
6. Kamaya A et al: Hypervascular liver lesions. Semin Ultrasound CT MR.
30(5):387-407, 2009