Hepatic siderotic nodules
Hepatic siderotic nodules are a type of regenerative nodule formed in a cirrhotic liver. They occur in hepatic hemosiderosis. The nodules have an increased iron content compared with other regenerative nodules. They may be non-dysplastic or dysplastic.
Pathology
The reason why these nodules concentrate iron is uncertain, but it is attributed to differential iron metabolism in the nodule's cell population from differential transferrin expression . Stainable iron occurs in approximately 25% of all regenerative nodules . Of note, some prefer the term "iron-rich" nodule since the term "siderotic" may have a different meaning in pathology.
Radiographic features
CT
- nodules are potentially hyperattenuating, but the amount of hyperattenuation may be slight, and the finding is non-specific
MRI
- moderate to marked T2/T2* hypointensity due to the T2 shortening effect of iron
- may be T1 hypo-, iso-, or hyperintense
- increased hypointensity on the second echo of an in- and out-of-phase sequence
Imaging cannot reliably differentiate between non-dysplastic or dysplastic siderotic nodules. A siderotic nodule's risk for hepatocellular carcinoma can be classified using LI-RADS. A "probably benign" siderotic nodule fulfills the criteria for an LR2 cirrhosis-associated nodule.
See also
