dysplastic hepatic nodules

Dysplastic liver nodules are focal nodular regions (≥1 mm) without definite evidence of malignancy.

Epidemiology

They have been found in cirrhotic patients with a prevalence of 14% (size >1.0 cm) to 37% (size >0.5 cm) .

Associations

Pathology

Dysplasia indicates:

  • nuclear atypia
  • increased fat or glycogen in the cluster of dysplastic cells
Classification

They are broadly divided depending on the presence of cytologic and architectural atypia :

Radiographic features

Ultrasound

Cirrhotic changes are present but the nodules may not be visualized on ultrasound. A few cases have shown hypo- and hyperechoic nodules and the echogenicity relates to the fat content in the nodule.

CT

Usually hypoattenuating, however, they may be iso- or hyperattenuating to the hepatic parenchyma.

  • multiphase contrasted images: they may show early arterial uptake but the contrast does not wash out on delayed phase (unlike HCC)
MRI
  • T1: although the signal intensity may vary broadly, most of them have high T1 signal 
  • IP-OOP: shows fat accumulation characterized by signal drop on the out-of-phase sequence
  • T2: iso- to hypointense
  • DWI: no restricted diffusion
  • T1 C+ (Gd)
    • high-grade nodules show early contrast enhancement without washout on delayed phase
  • T2* C+ (SPIO)
    • low-grade nodules appear hypointense

Treatment and prognosis

They are considered premalignant and hence follow-up is necessary. Percutaneous ablation therapy can be considered .

Differential diagnosis

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