Today we'll talk about malignancies
of the hepatobiliary system.
So we'll begin with a case.
A 45-year-old man with chronic hepatitis
B presents to clinic for a routine follow up.
He was adopted from China and has
been diagnosed with hepatitis B as an infant.
Since then, he has been
on Tenofivir without issues.
He has been feeling well
without any new symptoms.
Vitals are normal , his
abdominal exam is benign.
He has no ascites, jaundice,
scleral icterus or hepatomegaly.
A screening ultrasound last
month, showed two new liver masses.
A follow-up triple-phase CT scan showed
two lesions both less than 2 cm in size
with arterial enhancement
and venous washout.
What is the most likely diagnosis?
So before we answer that question,
let's look at some key items in this case.
He has a history of chronic
hepatitis B from vertical transmission
and he is from a region where
hepatitis B is known to be endemic.
He has no signs of cirrhosis on exam.
And his imaging is concerning
for potentially a malignancy
although at this point, we don't know whether it's
a primary liver tumor or metastasis to the liver.
In addition, there is this added feature of
having arterial enhancement with venous washout,
we'll talk about what that means in a bit.
So let's now speak about
hepatocellular carcinoma, or HCC.
Most cases, around 80% will
arise in the context of cirrhosis,
so recall that with chronic
inflammation, you can eventually lead to
permanent scarring of
the liver with the cirrhosis
and this predisposes
people to then develop HCC
The highest incidence of HCC can be found in
regions in Africa, China, Taiwan and Hongkong.
Symptoms include abdominal pain, weight
loss, loss of appetite or anorexia and fatigue
The diagnosis can be
confirmed by imaging alone.
So you may do triple-phase CT
scan, which we'll discuss a bit later.
You may also do a contrast-enhanced MRI.
And only for equivocal cases, when the diagnosis
is unclear, you may need to do a liver biopsy.
So, what is a triple-phase CT scan?
This refers to three phases: arterial,
portal venous and delayed phases of contrast
So we take images of the liver on CT at specific
times after giving contrast intravenously.
HCC has a particular appearance
on a triple-phase CT scan.
So, on the left side, you see two masses within
the liver that are showing arterial enhancement,
meaning they are brighter than the
rest of the tissue surrounding them.
In panel B, on the right side, you
see now venous phase washout.
So this is when we time the CT, at
some point after the IV contrast is given,
when the contrast is beginning
to wash out in the veins
so now you can see those two masses
that used to be bright are now darker in color
than the rest of the liver
parenchyma around them.
And this is what's called,
typical appearance of HCC
with arterial enhancement
and venous phase washout.
As a quick high-yield aside, remember
that hepatitis B is the one infection
that can cause hepatocellular carcinoma
without first progressing to cirrhosis
So with hepatocellular carcinoma,
the key thing is to prevent this diagnosis.
So to that end, we screen all patients with cirrhosis
with a liver ultrasound every 6 months to look for HCC.
Keep in mind also that those patients who
have hepatitis B can develop HCC without cirrhosis
so all patients with hepatitis B should
also be screened at the same frequency.
Here, you can see an example of a liver
ultrasound and if you look closely at the image
towards the top, there is a well-circumscribed
circular lesion that is concerning potentially for HCC.
The treatment options, like with most cancers depends
greatly on the size and the number of lesions.
So your options include first, surgical
resection that can be done for small lesions,
and in patients who don't
have decompensated cirrhosis.
There are other non-surgical options including
transarterial chemoembolization or TACE for short.
This involves injecting chemical material directly
into the arteries that are supplying the HCC mass
and thereby cutting off the blood
supply and shrinking the tumor.
Another method we can do is
called radiofrequency ablation or RFA.
This is done for larger lesions or
when patients have multiple lesions.
There are also medications like
Sorafinib that targets the angiogenesis
or the growth of blood vessels
that are supplying the HCC tumor.
This is particularly used
for very vascular tumors
or if they have extrahepatic spread
of the tumor in the context of cirrhosis.
Lastly, liver transplantation can be
an option for select patients with HCC.
So, who gets referred
for liver transplantation?
Why not transplant everyone
who has hepatocellular cancer?
The answer is quite complicated
and it depends on several criteria.
One of the systems we
use is the Milan criteria.
So, this is a system that has been devised to show that
those who have a tumor up to 3 tumors all less than 3 cm
or 1 tumor less than 5 cm without any invasion of the
tumor into the vascular structures or outside of the liver.
We know that these people
have an excellent 5-year prognosis.
So, these are the people that we can
refer for liver transplantation evaluation.
So now we can return to our case.
Our 45-year-old man with a history of
chronic hepatitis B from vertical transmission.
He luckily has no signs of cirrhosis on exam,
although, since he has hepatitis
B, he may still have cancer.
And his imaging findings
are concerning for cancer.
The answer really comes from
the last part of the case that tells you
that it appears to be arterially
enhancing with venous washout.
So the most likely diagnosis
is hepatocellular carcinoma.
You should always suspect this diagnosis in anyone
with a chronic hepatitis with a new liver mass.
What really clinches the diagnosis
here is the typical appearance of
with venous phase washout
and thus you do not need to do a biopsy.