5

Liver

Pyogenic Abscess

Spread via:

• Biliary system (obstruction)

Most common

For example: cholangiocarcinoma, CBD stone

• Hematogenous spread

For example: appendicitis, diverticulitis

Single abscess or multiple abscesses

More common in the right hepatic lobe

Bacteria

• Monomicrobial 40%, polymicrobial 40%, culture negative 20%

• Gram-negative organisms most common

• Escherichia coli found in two-thirds of abscesses

• Opportunistic organisms in AIDS patients

Fungal and mycobacterial

• Blood cultures positive, ∼50% of cases

Presenting signs and symptoms

• Fever (most common), right upper quadrant abdominal pain/tenderness, jaundice

Treatment

• Antibiotics and drainage

• Manage etiology of the pyogenic abscess

Amebic Abscess

Caused by Entamoeba histolytica

Most common abscess worldwide—infects up to 10% of worldwide population

Amebic cysts are ingested, passing through stomach and small bowel unharmed → trophozoite in colon → spreads into liver via portal venous system from colon

Presenting signs and symptoms

• History of recent travel to endemic areas

• Right upper quadrant pain, fever, jaundice, diarrhea

• Labs

Serologic testing

Leukocytosis

Normal bilirubin

Treatment

• Metronidazole

RADIOLOGY

General Liver Abscess (Fig. 5.1)

Multilocular, rim enhancing mass with focal areas of fluid attenuation representing blood or pus

FIGURE 5.1 A,B

A. Heart

B. Vertebra

C. Kidney

D. Spleen

E. Descending aorta

FIGURE 5.1 A

FIGURE 5.1 B

Pyogenic Abscess

Chest x-ray

• Nonspecific findings—elevated right hemidiaphragm, right-sided pleural effusion, and atelectasis can be seen

Ultrasound

• Multiloculated fluid collection within the liver, sometimes with posterior acoustic enhancement

CT findings

• Multilocular fluid collection ± air–fluid levels with areas of peripheral enhancement

Amebic Abscess

Ultrasound

• Typically, a round hypoechoic, homogeneous lesion with posterior acoustic enhancement

CT findings

• Round, rim-enhancing hypodense lesions with a peripheral zone of edema

• May contain central septations

Hemangioma

Most common benign tumor of the liver

More common in females (3:1)

If greater than 5 cm then considered a giant hemangioma

Mostly asymptomatic. Normal LFTs and tumor markers

If symptomatic: Kasabach–Merritt syndrome (presents with bruising, purpura, thrombocytopenia with consumptive coagulopathy, microangiopathic hemolytic anemia)