
Findings:
· A low attenuated mass lesion involving most of the left lobe of the liver ( red
arrow with liquefied center showing multiple internal septations and shaggy outline.
· In more caudal cuts, there are features of acute appendicitis seen in the form of enhancing thickened appendix with retained intraluminal fluid ( yellow arrow).
Diagnosis :
Pyogenic liver abscess due to acute appenditis.
Teaching points:
· Two types of liver abscesses:
pyogenic and amebic .
. Amoebic liver abscess is usually solitary, subcapsularly located. The route of infection is via
intestinal amoebiasis, treated by conservative treatment.
· Pyogenic liver abscess is usually multiple, multiloculated, formed of multiple small abscesses coalescing together forming a large cavity with shaggy outline, may contain air and in such cases it is a pathognomonic feature, must be drained and treated with antibiotics
· The route of infection is via 5 sources :
- through hepatic artery from any systemic septic focus like osteomyelitis or
sinusitis
- through portal vein such as appendicitis or diverticulitis
- through CBD in ascending cholangitis
- Direct spread from contiguous infection like cholecystitis or peptic ulcer
- In cases of penetrating trauma.
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* CT features of acute appendicitis
: appendix is more than 7 mm in diameter, thickened enhanced wall, appendicolith
( intraluminal stone), periappndiceal inflammatory changes ( fat stranding) , or fluid collection and extraluminal air ( signs of perforation