Hepatic siderotic nodules

Hepatic siderotic nodules are a type of regenerative nodule formed in a cirrhotic liver. They occur in hepatic haemosiderosis. The nodules have an increased iron content compared with other regenerative nodules. They may be nondysplasticnon-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 ³. Stainable iron occurs in approximately 25% of all regenerative nodules ³. 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 nonspecificnon-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 nondysplasticnon-dysplastic or dysplastic siderotic nodulenodules. A siderotic nodule's risk for hepatocellular carcinoma can be classified using LI-RADS. A "probably benign" siderotic nodule fulfils the criteria for an LR2 cirrhosis-associated nodule.

See also

• regenerative hepatic nodule
• dysplastic hepatic nodule
• hepatocellular carcinoma
• LI-RADS