This lesion was called a hemangioma by the radiologist who interpreted the CT scan
Answers
I would describe this as a heterogeneously enhancing lesion with the dimensions and location in the lateral segment of the left hepatic lobe. The only time I call a liver lesion "hemangioma" is if there is peripheral nodular discontinuous enhancement. In the absence of this characteristic feature, the lesion is indeterminate.
The differential would simply be neoplasm - benign or malignant, including primary liver cancer and metastatic disease. The common primary liver cancers include hepatocellular carcinoma and cholangiocarcinoma.
Since metastatic disease could be gastrointestinal or pancreatic, I would run the bowel very carefully and look at the pancreas for any evidence of neoplasm. I would also look for other metastases. The most commonly missed metastatic sites in the abdomen and pelvis are the liver and spine because those are also the most common locations for metastases. Less common "blind spots" include the paravertebral soft tissue, retroperitoneal and subcutaneous fat (think melanoma and rcc), soft tissue/musculature, and peritoneal surface.
My recommendation would be an MRI of the liver with and without contrast. Hepatocellular carcinoma and cholangiocarcinoma often have characteristic imaging features that can help differentiate these types of cancer. You can also recommend correlation with tumor markers such as alpha-fetoprotein, CEA, and CA 19-9. If the referring physician wants to go to biopsy without an MRI, I would not biopsy a liver lesion without a good quality MRI. If the imaging features are characteristic of hepatocellular carcinoma, the patient does not need a biopsy.
The patient came back over a year later for an MRI of the abdomen when an abdominal ultrasound was performed for other reasons and identified a large liver mass.
Questions
Can you identify each sequence and the relevant finding?
How would you describe this lesion in your report?
What is your diagnosis?
If you were to assign a LIRADS category, what would the category be and why?
Answers
First two images are in-phase and opposed-phase, showing loss of signal in the periphery of the lesion on opposed-phase indicating intracellular lipid.
Second two images are high B value DWI and corresponding ADC map, showing that the lesion restricts.
The next 3 images are arterial phase, portal venous phase, and delayed phase, showing arterial enhancement with washout and pseudocapsule.
The last image is a T2 image showing central necrosis, which some may call a central scar (I don't).
This lesion is hepatocelullar carcinoma; LIRADS 5 based on the size, arterial enhancement, washout and pseudocapsule. A biopsy should not be performed.
The clinical impact of this diagnostic error is that the patient 1) could have undergone surgical resection if the lesion had been identified on the preceding CT scan and 2) can no longer be considered for liver transplant because of the size unless treatment downstages the tumor.
