Sonographic pattern of focal nodular hyperplasia of the liver.

Focal nodular hyperplasia of the liver (FNH) is a histologically defined benign hepatic tumour, possibly associated with the use of oral contraceptives. The present study deals with the question whether FNH can be distinguished from other lesions of the liver by ultrasonography alone or by a combination of real-time sonography and radiologic procedures. Therefore 18 cases of FNH, 16 females and 2 males, are presented. We retrospectively reviewed the diagnostic results of real-time sonography, hepatic scintigraphy, computed tomography with dynamic CT-densitometry, and angiography on these 18 patients. Ultrasonography enables the identification of the lesion in all of the 18 cases. FNH appears to show varying degrees of echogenicity (slight hypoechoic in 6 cases, isoechoic in 6 cases, and slight hyperechoic in 4 cases). In most of the patients the tumour had similar acoustic characteristics as the surrounding normal liver. By ultrasonography alone there is no possible differentiation of FNH from other hepatic tumours. Both the echo pattern of FNH and the results of the ultrasonically guided cytopuncture are unspecific.