European Radiology: Relationship between histopathological components of mixed hepatocellular carcinoma-cholangiocarcinoma and MRI features and prognosis

Mixed liver carcinoma-cholangiocarcinoma (cHCC-CCA) is a primary liver cancer defined by well-defined components of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA
).
The 2019 WHO classification updated the diagnostic terminology to include HCC and CCA components regardless of the proportion of
the two.
Without supportive histomorphological analysis, immunohistochemistry alone is not sufficient to diagnose cHCC-CCA
.

At this stage, the results of research on whether cHCC-CCA survival rate is worse than iCCA are not consistent, but it is generally believed that cHCC-CCA has a worse
survival rate than HCC 。 Recently, more attention has been paid to the substantial role of clinicopathological and imaging features as prognostic factors for relapse-free survival (RFS) and overall survival (OS) in patients with cHCC-CCA, such as alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), microvascular invasion (MVI), peritumor enhancement and delayed enhancement
during the aneurysm.
In addition, the liver imaging reporting and data system (LI-RADS ver.
2018), including LR-4 (possibly HCC), LR-5 (definitely HCC), and LR-M (non-HCC malignancies), are also used as predictors
of RFS and OS for cHCC-CCA.
However, whether the histopathological component of cHCC-CCA predicts the prognosis of RFS and OS is also unknown
.

Recently, a study published in the journal European Radiology distinguished the MR characteristics of LI-RADS based on the different proportions of HCC components in histopathology, and investigated the value
of the proportion of HCC components in predicting the prognosis of cHCC-CCA patients.

This study included 106 patients
with histopathologically confirmed cHCC-CCA.
MR imaging features and clinicopathological outcomes were retrospectively evaluated and compared between two subgroups with different proportions of HCC components.

Relapse-free survival (RFS) and overall survival (OS) were assessed using the Kaplan-Meier survival curve and compared
using a log-rank test.
At the same time, the proportion of HCC components was evaluated using Cox regression analysis to assess the predictors
of RFS and OS.

Liver Imaging Reporting and Data System (LI-RADS) category 4/5 was more common in cHCC-CCA with 50%, 70% (OR=5.
559, p=0.
018), 70% (OR=4.
031, p=0.
008), and 90% (OR=6.
282, p=0.
012) of HCC components ≤> 50%, 70%, and 90% of HCC components
。 In addition, 70% of HCC components > cHCC-CCA (HR: 0.
241, p = 0.
023) had a better OS prognosis
than HCC components ≤ 70%.

Figure A Diffusion-weighted image (b-value=500s/^mm2) shows a 2.
0 cm high signal (arrow) in the sixth segment of the liver.

b T1 weighted imaging shows uniform low signal (arrows).

c Arterial phase images show non-marginal strengthening (arrows).

d Portal vein phase image showing clearance and capsular strengthening (arrows).

This lesion is classified as LR-5

This study shows that cHCC-CCA classified as LR-4/5 is mainly composed of HCC components, and that 70% of cHCC-CCA with HCC component > has better OS
than cHCC-CCA with ≤ HCC component .
These findings suggest that the proportion of HCC or CCA components can predict the prognosis
of patients with cHCC-CCA.

Original source:

Changwu Zhou,Xin Lu,Yi Wang,et al.
Histopathological components correlated with MRI features and prognosis in combined hepatocellular carcinoma-cholangiocarcinoma.
DOI:10.
1007/s00330-022-09065-y