In our population the tumor recurrence rate was 13,7%,
which is similar to the rates observed in other studies with comparable follow-up period and in which Milan selection criteria were adopted (3,4).
Extrahepatic recurrence was the most common recurrence pattern with respect to tumor location,
comparatively with other studies in which the focus was on the appearance of early recurrence (2,3).
Consistently with previous studies (4),
the median time to recurrence was 12,36 months and late recurrence was less common,
representing only 12,5% of cases.
As a premise to the analysis of the relationship between histopathological and imaging variations from the primary to the recurrent HCC,
we evaluated whether enhancement pattern on pretransplantation imaging and differentiation degree on explanted liver were correlated in our studied population.
Some investigators have recently reported a correlation between histopathologic grade and HCC blood supply in radiological and pathologic analyses (5,
A tendency towards higher grades in tumors with hypervascular pattern was demonstrated (5,7),
however there is some evidence that in the late stage of HCC development,
the arterial blood supply decreases again (7-9).
Despite the fact that in our population a very small number of patients had evidence of atypical hypovascular HCC (4,3%),
a correlation was found between differentiation degree and enhancement pattern (p=0,035).
50% of patients with hypovascular HCC had well-differentiated tumor,
as compared with only 15% of patients with hypervascular HCC.
Comparatively with previous studies,
moderately-differentiated HCCs account for the majority of tumors,
and they are almost exclusively characterized by a typical hypervascular pattern (8).
Focusing on the variations in imaging and histopathological characteristics between the primary and the intrahepatic recurred HCC,
no correlation was found between enhancement pattern changes (from hypervascular to hypovascular,
experienced by two patients) and histopathological changes (from moderate to poor differentiation degree in one patient).
a very small number of patients experienced such changes in our population,
affecting the statistical strength of our results.
further studies are desirable to address the issue of changes in dynamic-imaging enhancement pattern between the primary and the intrahepatic recurred HCC.