Hypervascular Focus in the Nonhypervascular Nodule (Nodule-in-Nodule) on Dynamic Computed Tomography: Imaging Evidence of Aggressive Progression in Hepatocellular Carcinoma

Objective: The purpose of this study was to investigate the early manifestation of hypervascular hepatocellular carcinomas by means of evaluating the nodule-in-nodule hepatic lesions depicted on dynamic computed tomography. Methods: For 26 lesions with hypervascular foci in nonhypervascular nodules in 23 patients with cirrhotic liver, the size of the lesions was measured during the initial and follow-up studies in patients who had a comparable follow-up computed tomography or magnetic resonance imaging studies (ranging from 46 to 399 days). Results: The mean volume doubling time of the total 26 inner nodules was 36 days, which was significantly shorter than the doubling time for the outer nodules (mean, 257 days for 18 enlarged lesions) (P < 0.001). Conclusions: Because of the rapid progression of the inner hypervascular hepatocellular carcinomas, recognition of nodule-in-nodule lesions is essential for considering short-term follow-up or immediate treatment when managing patients with cirrhosis.