Hepatic siderotic nodules

SideroticHepatic 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 nondysplastic 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 nonspecific

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 nondysplastic or dysplastic siderotic nodule. 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

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