II. Epidemiology
- Hepatic Incidentalomas are identified on 15% of CT studies
- Benign Hepatic Lesions are identified in >50% of autopsies in patients without cancer
III. Evaluation
- Lesions requiring no further evaluation
- Hepatic Lesion <5 mm OR
- Low attenuation (20 Hounsfield Units or less)
- Benign imaging features
- Flash-filling (strongly enhancing) lesions consistent with benign Hemangiomas
- Suspicious findings
- Solid Hepatic Lesions >5mm
- Poorly defined margins
- Greater attenuation (>20 Hounsfield Units)
- Interval growth
- Heterogenous lesions
IV. Differential Diagnosis
- Hepatic Adenoma
- Benign tumor in women on Oral Contraceptives (and exacerbated during pregnancy)
- Larger Hepatic Adenomas may bleed or rupture
- Discontinuation of Oral Contraceptives results in regression of tumor
- Switch to nonhormonal Contraception
- Monitor regression with serial liver Ultrasound
- Surgical resection may be considered in some cases
- Large or persistent lesions are associated with an increased risk of malignant transformation
- Focal Nodular Hyperplasia
- Benign Liver Lesions in young women
- Appear as central liver scar on imaging
- Hepatic Cysts
- Simple Liver Cysts often require no further evaluation
- Indeterminate lesions may be followed with serial liver Ultrasound
- Hepatic Cystadenoma
- Rare, benign Liver Lesions that uncommonly undergo malignant transformation
- Consider further evaluation as imaging may not differentiate benign from malignant
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Hepatic Cavernous Hemangioma
- Most common benign Liver Incidentalomas
- Peripheral Nodule enhancement on CT
- Low risk of rupture if <11 cm
- No treatment needed in asymptomatic Liver Hemangiomas
V. Imaging
- Multiphasic Abdominal CT
- Single-phase Abdominal CT can not differentiate Liver Lesions adequately
- Multiphasic Adominal MRI
VI. Diagnostics
- Percutaneous Liver biopsy
- Complication rate <5%
VII. Management
- Surgical resection indications
- Liver Lesions suspicious for Hepatocellular Carcinoma
- Large Liver Lesions at risk for malignant transformation or rupture (e.g. large Hepatic Adenoma)