Venous Doppler findings are commonly detectable also in focal nodular hyperplasia with modern ultrasound equipments

Background: Previous studies showed that the presence of intratumoral vessels with a venous Doppler spectrum is often depicted in hepatocellular adenoma (HCA) but less in focal nodular hyperplasia (FNH). Based on this finding, Doppler imaging has been used for differential diagnosis between FNH and HCA with important consequences in the management of the two types of focal liver lesions. In particular, in some cases, the decision to perform liver resection in follow up patients with a subcapsular focal liver lesion of unclear interpretation between FNH or Adenoma at ce MR or ce CT, has been oriented versus adenoma by the presence of intratumoral venous signals, while the post surgical biopsy estabilished the diagnosis of FNH.

Aim: To explore the features of FNH at Doppler ultrasonography, analysing in particular the presence of intratumoral venous flow in patients with established diagnosis of FNH.

Methods: Thirty-three consecutive patients (26 women, 7 men; age, mean±SD: 40±13) with 45 FNHs underwent color Doppler ultrasonography and spectral analysis according to a standardized protocol with Esaote Technos MPX and Mylab70XVG equipments. The diagnosis of FNH was established by the presence of typical arterial Doppler signals, typical behaviour at contrast-enhanced ultrasound (CEUS) associated with typical features at least in another imaging technique (ceCT or ceMR). In one case the diagnosis was established by histological examination.

Results: Of the 33 patients, 24 had a single solitary focus and 9 had multiple foci. Tumor diameter ranged between 1.2 and 8.9cm (mean±SD 3.2±1.6cm). The central feeding artery with the typical arterial spectrum characterized by high frequency and low resistance index was detected in all 45 lesions whereas the spoke-wheel sign was observed in 20 cases (44.4%). Vessels with a venous Doppler spectrum were detected inside or at the periphery of 33 lesions with typical arterial findings (73.3%).

Conclusions: The detection of an lesional venous flow in a focal liver lesion suspected to be an hypervascular benign lesion, cannot be considered a typical feature of HCA since it has been detected in an high percentage of FNH in association with the classical arterial spectrum.