Liver
A 28-year-old woman presents with
vague right upper quadrant abdominal discomfort.
Clinical Question:
A 28-year-old woman presents with vague abdominal discomfort. She has no history of liver disease or known malignancy.
A) Fibrolamellar hepatocellular carcinoma
B) Hepatic adenomatosis
C) Focal nodular hyperplasia (FNH)
D) Hepatic metastases
2. Findings and Diagnosis
Axial (a, b, c) and coronal (d, e, f) CT images reveal multiple hypervascular hepatic masses in a non-cirrhotic liver.
Images a and d are non-contrast, showing multiple iso- to slightly hypodense lesions.
Images b and e demonstrate arterial phase enhancement.
Images c and f (portal venous phase) show rapid washout, with the lesions becoming hypodense relative to the background liver.
These imaging characteristics, along with the absence of cirrhosis and the multifocal distribution, are consistent with hepatic adenomatosis.
Ashley Davidoff MD, TheCommonVein.com (b10832-01cL01)
Correct Answer: B – Hepatic adenomatosis
Why B is Correct:
Hepatic adenomatosis is defined by the presence of multiple hepatic adenomas (≥10), often in a non-cirrhotic liver. The arterial enhancement with rapid washout on portal venous phase is a known imaging pattern, and while it can resemble malignancy, the absence of cirrhosis, young age, and lack of AFP elevation (if tested) support the diagnosis. Some subtypes may carry risk for hemorrhage or malignant transformation, particularly in association with metabolic conditions.
Why the Other Options Are Incorrect:
-
A) Fibrolamellar hepatocellular carcinoma (FL-HCC)
FL-HCC can affect young patients without cirrhosis, but it typically presents as a solitary, large mass, often with a central scar. The presence of multiple lesions makes this diagnosis unlikely. -
C) Focal nodular hyperplasia (FNH)
FNH is usually solitary and shows homogeneous arterial enhancement with no portal venous washout. A central scar may be present and enhance in delayed phases. The multifocal nature and washout pattern do not fit with classic FNH. -
D) Hepatic metastases
Metastases are typically found in patients with a known primary malignancy and often show a hypovascular or rim-enhancing pattern. Although hypervascular metastases exist (e.g., from neuroendocrine tumors), this patient has no known cancer, is young, and lacks systemic signs — making metastases unlikely in this clinical setting.
CT imaging reveals multiple hepatic lesions in a non-cirrhotic liver, demonstrating arterial phase enhancement with rapid washout in the portal venous phase. What is the most likely diagnosis?
CT Enhancement Characteristics of Common Liver Lesions
| Lesion | Arterial Phase | Portal Venous Phase |
|---|---|---|
| Hepatic Adenoma | Intense, homogeneous or heterogeneous enhancement (often due to arterial supply) |
Washout may occur Becomes iso- or hypoattenuating compared to liver |
| Focal Nodular Hyperplasia (FNH) | Intense, homogeneous enhancement (except for central scar) |
Isoattenuating Blends with liver parenchyma; central scar may enhance late |
| Hepatocellular Carcinoma (HCC) | Hyperenhancement (arterial phase “wash-in”) |
Washout appearance Lesion becomes hypoattenuating compared to liver |
Key Differentiating Clues Between Hepatic Adenoma and HCC:
| Feature | Hepatic Adenoma | Hepatocellular Carcinoma (HCC) |
|---|---|---|
| Background liver | Normal liver | Usually cirrhotic or chronically diseased liver |
| Patient population | Young women, OCP use, anabolic steroids | Older adults, chronic hepatitis B/C, alcohol, NASH |
| Enhancement pattern | Arterial hyperenhancement ± washout | Arterial hyperenhancement with classic washout |
| Capsule | Sometimes thin capsule | Often has a capsule, especially in larger tumors |
| Hemorrhage risk | Higher in adenomas | Can also bleed, but less frequently than adenomas |
| Malignant potential | Rare, but certain subtypes (β-catenin) carry risk | Malignant by definition |
| Alpha-fetoprotein (AFP) | Usually normal | May be elevated |