Pediatric Surgery

Hepatoblastoma with Dr. Greg Tiao

March 23, 2022
Hepatoblastoma is the most common malignant liver tumor in the pediatric population. But treatment strategies have changed dramatically over the past 25 years. That’s why today, were going to review the basics-with an expert.

00:27:38-0027:45 “hepatoblastoma, 200-250 cases a year, huge changes in treatment algorithms over the last 20 years”

That’s Dr. Greg Tiao-Pediatric Transplant surgeon at Cincinnati Children’s Hospital Medical Center. He’s going to walk us through everything you need to know about Hepatoblastoma. Stick around. This is the StayCurrent in Pediatric Surgery Podcast….

I’ll start by setting the scene, a child comes into the hospital with an abdominal mass and even though we are specifically talking about hepatoblastoma, we need to have a pretty wide differential diagnosis.

That’s right, hepatoblastoma is the most common malignant liver tumor in children but it’s nowhere near the most common liver tumor or the most common abdominal malignancy.

When I’m recalling the most common abdominal malignancy in children, I recall this being somewhat controversial. But most would consider it to be neuroblastoma

27:15- 27:37 “correct, a bit of a toss up who you talk to, neuroblastoma or wilms. Neuroblastoma is the most common because of all the satellite lesions, but wilms is the more frequent completely intrabdominal”

One thing’s for sure, once you have imaging and determine the tumor is coming from the liver your differential should consider hepatoblastoma in addition to hemangioma, fibronodular hyperplasia, hamartomas, and hepatocellular carcinoma. But common things being common, hemangioma should be pretty high on the list. (show background slide at 25:38)

9:08- 9:15 “right, benign growths, we see a lot of them, hemangiomas”
25:34- 25:36 “most common is hemangioma”

Even though hepatoblastoma is the most common malignant liver tumor in kids, but still pretty rare overall only effecting about 250 kids a year. So you need to be pretty in tune with their range of presentations, and keep a high index of suspicion.

27:53-28:18 “range of presentations… paraneoplastic syndrome” (need to edit out the patient name part 27:57-27:59)

But in any situation –keep in mind than an elevation in Alpha Feto Protein or AFP is a key component in the workup.

28:18-28:26 “AFP is critical to the diagnostic algorithm, and to risk stratification”

Okay, so to summarize: I see a kid and I’m suspicious, he has a large abdominal mass and an AFP in the ten thousands. Now we need axial imaging, mostly experts are relying on MRI to delineate the anatomy and better characterize the extent of liver involvement.
6:00-6:02 “MRI w/ Eovist”

Dr. Tiao, what was that? Eovist?

7:23-7:35 “taken up by hepatocytes, excreted into bile, explanation”

If you’re listening on the stay current app scroll down to the bottom to see examples of these images. The Eovist really does delineate the bilary anatomy.

To establish a diagnosis of hepatoblastoma we really need 4 things. Start with a history, move to your abdominal imaging, check an AFP, and then get a liver biopsy.

The most important interventions for survival is too achieve complete resection, the way that you get there can be varied.

33:49-34:05 “primary goal is to achieve complete tumor, can do it all these ways, procedures with the remnant liver, or liver transplantation”

As you are probably gathering, a lot of these resection algorithms are based on liver anatomy and the Pretext system, but before we get there, Dr. Tiao can you talk to us about how to identify the 8 liver segments on axial imaging?

14:40-14:58 “these segments here, those segments there. Do you know why he labeled in counter clockwise circle?”

Staring at camera shaking head no

15:41-16:02 “he was a French anatomist, injected contrast in portal vessels, labeled counter clockwise because districts of Paris are in the same fashion”

Hm, that actually makes sense in a strange kind of way.

16:44- 17:04 “look at the right side of the liver what allows differentiation between anterior and posterior liver?”

Looks like the Right hepatic vein there (pop onto screen and points out on image in overlay)

17:12-17:21 “yes, exactly the right hepatic vein comes out, now how to separate between superior and inferior?”

I see the Right Portal vein coming over here (pop onto screen and point out on image in overlay)

18:03- 18:29 “exactly, this segment here, that segment there, all relative to the veins… six inferior”

Okay, now would be a really good time for a diagram of this anatomy, conveniently we have one available under the media player. Scroll all the way down in the app and you’ll find it

18:29- 18:34 “so the reason this all matters, is the pretext staging system”
19:30- 20:04 – to classify in a more anatomic fashion... free segments minus 4 is your pretext stage.

We’ve included a table on the PRETEXT system to review. Pretext 1 has 3 contiguous sections free of disease, Pretext 2 has 2 continuous sections free of disease, Pretext 3 has 1 free section, and pretext 4 has diffuse tumor burden in all 4 sections of the liver.

additionally, this staging system is the framework for the treatment algorithm.

45:53- 46:04 “for a pretex 1 and 2 tumor… offer resection at diagnosis”
46:44-46:55 “patient’s with bigger tumors that did not get resected…get set into different risk categories… high risk”

Pretext 3 and 4 is the big game changer, this change in practice is what improved survival rates for patients with hepatoblastoma from less than 30% in the 70s and 80s to between 80-90% today.

47:08-47:31 “guidelines for Pretext 3… send to a center for transplant, or advanced liver resections. guidelines for pretext 4…. Some need to be transplanted”

So if you have Pretext 3 or 4 disease there are specific indications for liver transplant, mainly if they have unresectable disease where its either not safe to resect, or resection would leave the patient without adequate liver remnant. But the most important part of these guidelines is to refer patients to transplant centers for evaluation. The earlier, the better.

37:39-38:00 “you refer these patients to liver transplant centers much earlier send to transplant center that can do aggressive resection.

And if you would like more details on these survival benefits related to liver transplant, yes, it is also in the link below!

After classifying the PRETEXT stages, you’re not quite done. There is an ongoing trial to better delineate treatment algorithms for all stages of Hepatoblastoma. CHIC is responsible for another multinational, ongoing trial called PHITT or The Pediatric International Tumor Trial identifies high and low risk features for each of these PRETEXT stages.

00:58:08- 58:20 “PHIT study, we contribute to it, the treatment has evolved…”

This is the Schema that is used for this study

00:38:30-38:34 “this is the schema for hepatoblastoma and we will break this down a little bit more”

Looking at schema in background then back to camera wide eyed

giggles in background. No worries …details of this study among others can be found in the link below...

00:58:39 on screen with Todd

Management of these malignant liver tumors continues through improved treatment, multidisciplinary teams, international collaborative efforts and research. Thank you for joining us for this update on Pediatric Hepatoblastoma.

Please remember to check the link below for access to the entire lecture. Follow us on social media, like and subscribe to our u- tube channel, like and if you are listening on a podcast let us know what you think or suggest ideas you may like to hear about in the future leave us comment. Until then-

This is Todd, Ellen, and I am Rod… and remember, knowledge should be free!

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