Infective Liver Lesions

Question 1

Name 3 risk factors for pyogenic liver abscess

Answer 1

• male >50
• immunocompromised
• underlying cause : infective endocarditis, intra-abdo sepsis etc

Question 2

Microbiology pyogenic abscess? (3)

Answer 2

40% monomicrobial (systemic arterial spread), 40% poly (portal spread), 20% culture negative

• mostly gram negative: mostly E. coli!, enterococcus, klebsiella, strep faecalis, proteus vulgaris (GIT origin or portal spread)
• gram +: staph and strep (ass with endocarditis, in dwelling catheter, IV drug)
• anaerobes (bacteroides fragilis),a typical (mycobacterium, fungi in immunocompromised or receiving chemo)

Question 3

Symptoms pyogenic liver abscess? (4)

Answer 3

• very sick! May present in septic shock
• RUQ pain without jaundice
• swinging temperature
• cough and dyspnoea (diaphragm irritation)

Question 4

Clinical features pyogenic liver abscess? (5)

Answer 4

• very sick! May present in septic shock
• hypotension , tachycardia, swinging temperature
• RUQ tender without jaundice
• peritonitis, pleural/pericardial effusion if rupture
• parapneumonic effusion common
• signs of etiology

Question 5

Ultrasound features pyogenic liver abscess? (4)

Answer 5

Round/oval hypo-echoic lesion
Septa or debris
Well defined borders!
Internal echoes

Question 6

Ultrasound features pyogenic liver abscess? (4)

Answer 6

Well defined round
Hypo-dense
Rim enhancement in arterial phase!
May have air fluid level in abscess

Question 7

How should a pyogenic abscess be drained?

Answer 7

Try percutaneous (contraindicated if coagulopathy, close to major vessel, ascites, surgical cause) then laparoscopic then open
NB to send for MCS

Question 8

Microbiology amoebic abscess?

Answer 8

Entamoeba histolytica

Question 9

Most common site amoebic liver abscess?

Answer 9

Anterior right superior lobe

Question 10

Characteristics of amoebic liver abscess? (3)

Answer 10

Necrotic centre
Anchovy like pus
Pus odourless unless secondarily infected

Question 11

Clinical presentation and history amoebic liver abscess? (3)

Answer 11

• not as sick as pyogenic but still symptomatic, unless secondarily infected with bacteria. Similar presentation to pyogenic
• travel history!
• hepatomegaly

Question 12

How confirm diagnosis pyogenic liver abscess?

Answer 12

Blood cultures may reveal in 50%
Mostly imaging and pus culture

Question 13

How confirm diagnosis amoebic liver abscess?

Answer 13

Ameobic serology: fluorescent antibody test positive

Question 14

CT features amoebic liver abscess? (4)

Answer 14

Well rounded
Thick rim enhancement! Halo sign.
Ragged peripheral edge (oedema)
Central septa with or without fluid levels

Question 15

Treatment amoebic liver abscess? (4)

Answer 15

Medical treatment mainstay (all other abscesses = drain)
- metronidazole 750mg tds po for 10 days (adverse effect = lead taste)

Surgical drainage only if
- failure medical treatment
- abscess on left lobe liver (high risk rupture into pericardium)
- large >5cm

Question 16

Treatment pyogenic abscess?

Answer 16

Drain! No role for medical therapy except adjuvant antibiotics

Question 17

Most common infective liver abscess?

Answer 17

Pyogenic

Question 18

Microbiology hydatid cyst?

Answer 18

Echinococcus granulassi = tapeworm
Found in sheep raising areas, carried by dogs

Question 19

Features of hydatid liver cyst?

Answer 19

3 layers
Outer: 2-4mm, compressed liver tissue with a fibrous capsule
Middle: 2mm, a nuclear hyaline ectocyst
Inner: germinal endings derived from the parasite

The cyst contains a mother cyst and may also contain daughter cysts

Question 20

Symptoms hydatid liver cyst?

Answer 20

Mostly asymptomatic! Hydatid = Healthy.
May have some dull RUQ pain
If rupture though, anaphylactic shock! DONT DRAIN

Question 21

Ultrasound findings hydatid liver cyst? (4)

Answer 21

• well defined
• budding sign on membrane
• freely floating hyper-echoed sand (scolices)
• wall calcifications

Question 22

How confirm diagnosis hydatid liver cyst?

Answer 22

ELISA serology for echinococcal antibodies

Question 23

CT features hydatid cyst? (5)

Answer 23

• well defined
• hypodense
• ring like calcification of peri-cyst
  -daughter cysts with mother cyst peripherally
  -rosette appearance

Question 24

Treatment hydatid liver cysts? (4)

Answer 24

Medical always first!
- albendazole 3 weeks before surgical treatment with 1 “rest” week because it causes bone marrow suppression

Surgical options to drain:
- open drainage
- laparoscopic aspiration and instillation (of H2O2 or alcohol) with re-aspiration (best)
- PAIR procedure (percutaneous aspiration, instillation, re-aspiration)