Let’s move on to a discussion of liver abscesses. We’ll focus on amebic and pyogenic liver abscesses.
Let’s begin with amebic abscesses. This is a picture of a pathology after the drainage of pus from a liver.
You’ll notice that the pus is in central region of this picture. Amebic abscesses are classically associated
with some recent travel to indigenous regions usually in the subtropics such as Mexico or India.
Organism involved is a protozoan Entamoeba histolytica. Demonstrating symptoms are usually between
8 and 12 weeks after the exposure. It’s suspected to be a fecal-oral contamination. This is an important
slide describing a portal circulation explaining how the Entamoeba histolytica which has oral feces
transmission can end up in the liver. Once a protozoan enters the colon, it follows the green arrow.
The green arrow shows where the colon drains into the superior mesenteric venous system that then
has a confluence onto the portal system. As you know, the liver’s blood supply is 75% contributed
by the portal vein. This is how Entamoeba histolytica obtains access to the liver and sets up shop
causing an abscess. I have a question for you. What are some potential complications of amebic abscesses?
I’ll give you a second to think about this. The answer is the biggest fear is rupture. Rupture or extension
of the abscess into the abdomen, pleural space, or extension to the pericardium particularly from the left lobe
of the liver can cause significant problems. If the rupture occurs in the abdomen, it can cause peritonitis
creating a surgical abdomen. If the rupture happens into the pleural space, patients may complain of
difficulty breathing. It can lead to an empyema or an abscess collection in the lung. Lastly, because of
the proximity of the left lobe of the liver to the pericardium, this can cause pericarditis and an abscess in the heart.