Table 1.

 Diagnostic criteria used to type 274 focal liver lesions subjected to fine needle biopsy

Diagnosis	Pathological criteria (reference)	Other requirements
HCC (histology)	Multiple liver cell plates in trabecular, solid, or acinar patterns surrounded by a network of sinusoidal vessels with stroma; scanty reticular architecture; invasion of veins in portal tract15	None
HCC (cytology)	Nuclear hyperchromasia; increased nuclear-cytoplasmic ratio; trabecular pattern; nucleolar prominence; atypical naked nuclei; bizarre mitotic figures16	None
Dysplastic nodules (mild dysplasia)	Plates ⩽2 cells thick; intact reticular architecture; no infiltrative edge; large cell dysplasia in some cases17	Confirmation by second imaging study*+clinical and US follow up
Dysplastic nodules (severe dysplasia)	Plates ⩽3 cells thick; foci of decreased reticulum staining; irregular edges; small cell dysplasia and/or isolated glandular structures in some cases17	Confirmation by second imaging study*+clinical and US follow up
Regenerative nodules	Hyperplastic hepatocytes relative or similar to the surrounding liver, generally uniform in structure, with elements of portal tracts regularly distributed inside; absence of cellular and nuclear atypia18	Confirmation by second imaging study*+clinical and US follow-up
Non-Hodgkin’s lymphoma	Atypical lymphoid cells, mono- or polymorphic, whose monoclonal origin was confirmed by immunocytochemical techniques19	None
Haemangioma	Abundant endothelial cells surrounded by stroma in the absence of other types of cells	Confirmation by second imaging study*+clinical and US follow up

*Contrast enhanced computed tomography or contrast enhanced magnetic resonance (see methods for criteria and details).

HCC, hepatocellular carcinoma; US, ultrasound.