Hepatic adenomas and focal nodular hyperplasia: dynamic CT study.

A retrospective, multi-institutional study was carried out on a series of 50 histologically proved benign hepatic tumors. The 27 hepatic adenomas (HAs) and 23 cases of focal nodular hyperplasia (FNH) were studied with ultrasonography (US) and dynamic computed tomography (CT). Angiography was performed in 26 cases (15 HAs, 11 FNHs); scintigraphy was not used because of its cost. US scans proved nonspecific. CT scans demonstrated hemorrhage in five HAs and were useful in characterizing tumoral vascularity and any intratumoral features such as necrosis or central fibrous scar. The presence of arterial vessels (five patients) in the projection of this central fibrous scar is suggestive of FNH. Dynamic CT scans did not show the type of tumor in most cases. In cases with lesions greater than 3 cm for which doubt as to the diagnosis persists, combined use of morphologic data, scintigraphy, dynamic CT scanning, and angiography can guide the therapeutic decision: surgery or follow-up CT study after use of oral contraceptives is stopped.