Histopathologic characteristics of incidental hepatocellular carcinoma after liver transplantation

Liver transplantation for patients with hepatocellular carcinoma (HCC) is an accepted therapeutic modality, depending on the size and number of nodules. Since a high incidence of incidental HCC at transplantation has been reported, our aim was to evaluate the histopathologic characteristics of these patients.

This retrospective analysis from March 1998 to June 2009 included liver transplantation patients without increased alpha-fetoprotein or nodules on imaging methods. We included patients with HCC on anatomopathologic exam, excluding those presenting with HCC on the presurgery evaluation through clinical, laboratory and imaging methods.

Among the 277 transplanted subjects, 27 showed incidental HCC. The alpha-fetoprotein average level was 8.52 mg/dL (1.6-28.2). One patient presented with adenomatosis and focus of HCC. Histopathologic analyses showed: mean tumor size was 0.9 cm (range = 0.4-3.5); average number of tumors in each explanted liver 1.85 (range = 1-7) nodules; and three (11.1%), microvascular invasion (11.1%). The TNM staging showed 17 (63%) stage I and 6 (22%) stage II. The Edmondson and Steiner classification showed 19 (70%) subjects in degree II.

The histopathologic presentation of incidental HCC after liver transplantation showed tumors in early stage with microvascular invasion in some cases.