Page 217 - Medicine and Surgery

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Chapter 5: Disorders of the liver 213

Aetiology/pathophysiology Hepatic adenomas are oestrogen dependent tumours
In man hydatid disease is caused by one of two tape- generally only seen in women. They are strongly asso-
worms Echinococcus granulosus and Echinococcus mul- ciated with the oral contraceptive pill. Usually asymp-
tilocularis. Echin. granulosus infections occur following tomatic, they may rupture causing intraabdominal
ingestion of food contaminated with infected dog faeces. bleeding and pain. Removal is advised because of dif-
Echin.multilocularisiscarriedbyfoxesandsmallrodents. ficulty differentiating them from a well-differentiated
Sheep and cattle perpetuate the life cycle. In humans the hepatoma.
embryos hatch in the duodenum and enter the liver via Focalnodularhyperplasiaisalsoseenmorecommonly
the portal system. Once in the liver the embryos form a in women and oestrogen plays a role.
hydatid cyst and may be disseminated to the lung, kidney Solitary simple liver cysts are rare but multiple liver
or brain. cysts may be seen in patients with inherited polycystic
kidney disease.
Clinical features
The disease may be symptomless but chronic right up- Primary hepatocellular carcinoma
perquadrant pain with enlargement of the liver is the
common presentation. The cyst may rupture into the Definition
biliary tree or peritoneal cavity and may cause an acute Also called hepatoma, this is a tumour of the liver
anaphylactic reaction. parenchyma.

Investigations Incidence/prevalence
Eosinophilia is common and serological tests are avail- Relatively uncommon in the Western world (2–3%), but
able. Small, calcified cysts may be seen on plain abdom- by far the most common primary tumour of the liver
inal X-ray. Ultrasound or CT scanning can demonstrate worldwide.
cysts.
Age
Management Usually in middle-aged and elderly.
Mebendazole or albendazole is commenced prior to any
intervention. Percutaneous ultrasound guided fine nee- Sex
dle aspiration with injection of scolicidal agents and re- M > F (3–4:1)
aspiration may be used. Large symptomatic cysts may be
surgically excised intact taking great care to avoid con- Geography
tamination of the peritoneal cavity. High incidence (40% of all cancers) in countries where
predisposing factors such as hepatitis B are common, e.g.
in Africa and the Far East.
Tumours of the liver
Benign tumours of the liver Aetiology
Tumours arise in a chronically damaged liver especially
Benign tumours of the liver must be differentiated from in cirrhosis independent of the cause. Hepatitis B virus
malignant tumours such as metastases or primary hepa- carrier states and chronic active hepatitis predisposes to
tocellular tumour and cysts or abscesses. There are four primary hepatocellular carcinoma, especially when hep-
main types: atitisBinfectionoccursinearlylife.Hepatotoxinssuchas
Cavernous haemangiomas are the most common be- mycotoxinspresentinfood,increasetheincidenceofpri-

nign tumours of the liver. Usually asymptomatic, they mary cancer. Aflatoxin, produced by Aspergillus flavus,
rarely become large and produce pain, enlarged liver is frequently found in stored nuts and grains in tropical
or haemorrhage. They may be detected at ultrasound countries. Other risk factors include drugs such as oral
or at laparotomy. Biopsy may cause haemorrhage. contraceptives following long-term use and androgens.