Infantile Hepatic Hemangioma
Based on the imaging characteristics described—T2 hyperintensity, absent arterial enhancement, and robust portal venous phase enhancement with Eovist—this is most consistent with an infantile hepatic hemangioma.
Diagnostic Reasoning
The imaging pattern you describe is characteristic of a slowly enhancing hemangioma on gadoxetate disodium (Eovist)-enhanced MRI:
- T2 hyperintensity: Classic for hemangiomas due to their blood-filled vascular spaces
- Absent arterial enhancement: Indicates slow blood flow through the lesion
- Robust portal venous phase enhancement: Represents progressive filling of the vascular spaces over time
Key Supporting Evidence
Hemangiomas on Eovist-enhanced MRI demonstrate two distinct enhancement patterns 1:
- Rapidly enhancing hemangiomas (>50% intralesional arterial enhancement)
- Slowly enhancing hemangiomas (≤50% intralesional arterial enhancement)
Your case fits the slowly enhancing pattern, which characteristically shows:
- Progressive incomplete enhancement during portal venous phase
- Continued progressive enhancement into transitional phase
- No pseudo-washout (unlike rapidly enhancing hemangiomas which can show pseudo-washout in 26-40% of cases) 1
Pediatric Context
Gadoxetate disodium is increasingly used in pediatric liver imaging and has proven utility in characterizing pediatric liver lesions 2. Infantile hemangiomas are the most common benign liver tumors in young children, and Eovist-enhanced MRI can effectively characterize them 3, 2.
The hepatocyte-specific properties of Eovist (dual excretion pathway—50% renal, 50% hepatobiliary) 4 allow for both vascular phase imaging and hepatobiliary phase assessment, though hemangiomas themselves do not contain hepatocytes and therefore do not take up the contrast agent.
Critical Pitfalls to Avoid
1. Misinterpreting Pseudo-Washout
Some hemangiomas (particularly rapidly enhancing ones) can show pseudo-washout on transitional phase imaging 1, 5. This occurs because:
- Hepatic parenchyma continues to increase in signal intensity through the hepatobiliary phase (due to hepatocyte uptake)
- Portal vein and hemangioma signal intensity falls in transitional phase
- This creates relative washout that can mimic malignancy 5
However, your case shows robust portal venous enhancement without arterial enhancement, making pseudo-washout unlikely.
2. Distinguishing from Other Lesions
In a 30-month-old with an enlarging liver mass, the differential includes:
- Hepatoblastoma (most common malignant pediatric liver tumor)—typically shows arterial enhancement
- Mesenchymal hamartoma—can be T2 hyperintense but usually cystic/multicystic
- Focal nodular hyperplasia—rare in this age group, shows arterial enhancement and hepatobiliary phase uptake
The absence of arterial enhancement essentially excludes hepatoblastoma and FNH, which are hypervascular lesions.
Diagnostic Confidence
MRI with gadoxetate has 95-99% accuracy for hemangioma diagnosis 6. The combination of:
- T2 hyperintensity
- Progressive enhancement from arterial to portal venous phase
- Robust portal venous enhancement
- Age-appropriate presentation
...provides high diagnostic confidence for infantile hemangioma without need for biopsy.
Management Implications
Most infantile hepatic hemangiomas:
- Are asymptomatic and discovered incidentally
- May enlarge during the first year of life (proliferative phase)
- Typically involute spontaneously over subsequent years
- Require imaging follow-up rather than intervention unless symptomatic
The "enlarging" nature you describe is consistent with the natural proliferative phase of infantile hemangiomas, which typically occurs in the first 12-18 months of life and can extend to 30 months.