Hepatocellular carcinoma with a central scar and a scalloped tumor margin resembling focal nodular hyperplasia in macroscopic appearance.

Background: We sometimes encounter hepatocellular carcinoma (HCC) with a central scar and a scalloped tumor margin resembling focal nodular hyperplasia (FNH) in macroscopic appearance. The fibrolamellar variant sometimes shows this appearance; however, this type of HCC can be clearly differentiated from fibrolamellar variants on the basis of clinical and histopathological findings. The clinical features of patients with this type of HCC need to be clarified.

Methods: From 1988 to 1999, 1,043 patients with HCC underwent hepatectomy at our institution. Histopathological examinations show that fibrolamellar HCC was not included in the series. We selected HCC with a central scar and a scalloped tumor margin resembling FNH in macroscopic appearance. We refer to such tumors as scalloped HCC. We compared the clinical findings and surgical outcomes between patients with scalloped HCC and patients with simple nodular HCC.

Results: Of the 1,043 cases of HCC, 31 (3%) and 571 (55%) were scalloped HCC and simple nodular HCC, respectively. The mean age of the patients with scalloped HCC was 60.7 years, and that of the patients with simple nodular HCC was 62.6 years, without significant difference. The rates of hepatitis C virus infection and liver cirrhosis and serum alpha-fetoprotein levels were significantly lower, and Child-Pugh class and surgical outcomes were significantly better in patients with scalloped HCC than in those with simple nodular HCC. In multivariate analysis, Child-Pugh class (P < 0.001), tumor size (P = 0.046), and gross appearance (P = 0.009) were independent significant prognostic factors.

Conclusion: HCC with a central scar and a scalloped tumor margin resembling FNH occurs in non-cirrhotic patients in their 60s and is associated with a good surgical outcome.