(Amoebic Liver Abscess)
. 2-10 %
.Less common in women and rare in children.
.Develop any time during intestinal infection.
.Generally appears when the intestinal symptoms
.In the majority of cases, the hepatic complication
appears after about 1-3 months of the disappearance
of the dysentery attack.
Genesis of Hepatic Lesions-----
. The trophozoites are carried as emboli by the radicles of
the portal vein from the base of an amoebic ulcer in the
large intestine (caecum and the ascending colon).
.Capillary system of the liver acts as an filter and hold these
.Trophozoites multiply in large no. and their cytolytic
.Local accumulation –obstruction to the circulation—
thrombosis of the portal venules – anaemic nerosis of the
surrounding liver cells.
.Primary lesion – focal
necrosis of the liver cells
(starting point of liver
continues in concentric
.First necrotic material
consists of a solid slough --
--- centre liquefies by
cytolytic action -----
.Big sized abscess is formed
by coalescence of these
.Generally confined to the
postero-superior surface of
the right lobe.
.To the naked eye, the
appearance of the abscess
area is reddish brown in
colour with a semifluid or
.The wall of the abscess cavity is
ragged and shaggy in
appearance and is formed by
the necrotic liver tissues
which gradually merge into
the healthy zones with an
intervening zone of
Three zones can be
1.)A central zone of cytolysed
granular material with no
2.)An intermediate zone consisting
of degenerated liver cells, a few
cells,red blood cells and an
occasional trophozoites seen.
3.)Aperipheral zone consisting of
congested capillaries with
varying degrees of necrosis of
liver cells. The amoeba can be
seen multiplying in this area
and invading the adjoining
healthy liver tissue.
Pus of Liver Abscess---
.Pus is a mixture of sloughed liver tissue and blood.
.It is chocolate brown in colour and thick in
consistency (ANCHOVY –SAUCE PUS).
.Microscopically– reveals degenerated liver cells ,a few
red blood cells and occasional leucocytes.
Clinical features of Amoebic Liver Abscess
.Onset is insidious.
.Pain and tenderness in the right hypochondrium .
.Pain is sometimes reffered to the right acromial region.
.Dry cough may often be associated.
.Occasionally the pain is reffered to the lower abdomen or
the right iliac region.
.Fever- A slight rise of temp. in the evening which later
becomes quotidian and takes on a hectic character.
.The patient becomes emaciated.
. The lower border of the liver is palpable below the
coastal margin and is tender. Liver dullness may
.The movement of the right side of chest during
respiration is diminished.
.Occasionally, there may be a bulging of the parieties,
indicating the pointing of the abscess.
.The left lobe of liver may undergo a compensatory
hypertrophy in a very big abscess.
Lung signs- these are due to the collapse of the
right lung base caused by the growing liver abscess.
Apical impulse- this may be displace upwards and
laterally by a large abscess.
Intestinal symptoms are absent. On abdominal
palpation, areas of thickening of the bowel with
tenderness may be present.
LABORATORY DIAGNOSIS OF AMOEBIASIS
Diagnosis of Intestinal Amoebiasis
A.)Symptomatic Group—cases of Acute
1.)Examination of stool----
.Dark brown offensive semi-fluid stool.
.Acid in reaction
.Admixed with blood,mucus and much faecal matter.
.It does not adhere to the container.
.The cellular exudate is scanty and consists of only the nuclear masses
(―pyknotic bodies‖) of a few pus cells, macrophages and epithelial cells.
.The red blood cells are clumped and are reddish –yellow or yellowish-
green in colour.
.Presence of Charcot- Leyden crystals.
C.)Demonstration of E.histolytica (by examining
an unstained preparation microscopically)—
.Fresh stool unmixed with any antiseptic or urine s/b examined.
.In acute cases ,the amoebic trophozoites can easily be recognised by their
characteristic movement and the presence of red blood cells.
.Iodine stained preparations is used to demonstrate cysts
and dead trophozoites.
.The trophozoite of E.histolytica stains yellow to light brown.
.Nucleus is clearly visible with a central karyosome.
.The cytoplasm of cystic stage shows smooth and hyaline
. Nuclear chromatin and karyosome appear bright yellow,
glycogen mass stain golden brown and chromatid bars are
.Trichome stain is used to demonstrate intracellular features
of both trophozoite and cysts.
2.)Examination of blood --- shows moderate
.In early cases, it is always negative.
.It becomes positive only in invasive amoebiasis.
.Test used are---IHA, Latex agglutination test, ELISA.
B.)ASYMPTOMATIC GROUP- Cyst- passers or cyst –
1.)Examination of stool---
i)A natural stool for cysts.
ii) A smear prepared by concentration method(for cysts).
iii)A purged stool obtained after a saline cathartic (motile
trophozoite and cysts),
iv)The material collected by the use of sigmoidoscope
(trophozoite) when there are visible lesions in the sigmoido-
.Three consecutive stool sample s/b examined for detection of
cyst as excretion of cyst in stool is often intermittent.
b.)Cultural examination– stool negative microscopically,
when cultured ,have on various occasions shown the
presence of parasites. Robinson’s culture media and NIH
polyxenic culture media are now available for culture of
the stool for isolation of amoeba. Culture is not a routine
c.)Animal inoculation—Not used now a days.
2.)Blood picture- not characteristic.
3.)Serological Test—These cases are seronegative.
.Recently ,DNA probes and Radioimmunoassay have
been used to detect E.histolytica in stool.It is rapid
and specific method.
DIAGNOSIS OF HEPATIC AMOEBIASIS
1.)Diagnostic Aspiration –
.The aspirated pus may be examined for the
demonstration of trophic forms of E. histolytica.
.Trophic forms may be demonstrated in specimens of
liver biopsy taken from cases of miliary amoebic
3.)Examination of stool—
.Cysts of E.histolytica are present in less than 15%
cases of Amoebic liver abscess.
4.)Examination of Blood—
.Leucocytosis, varying from 15,000- 30,000 /mm3 of blood.
.DLC shows neutrophil granulocytes to be 70-75%.
.LFT show raised ALP and S.G.O.T level.
(It is now possible to get pure and specific antigen from the
trophozoites of E.histolytica grown in an axenic medium).
.Used for detection of specific antibody and mainly useful in diagnosis
of extra- intestinal amoebiasis.
.LAT, IHA,GD,IFA,ELISA may be used.
.LAT is fairly and frequently used.
. Serological tests are virtually always positive in hepatic abscess,but
only about 85% positive in cases of dysentery.
.RIA and CCIE have also been used in cases of amoebiasis.
6.) Intradermal Test—
.In an infected individual injection of 0.1 ml of an
antigen prepared from cultures of E. histolytica
produces at the site of injection an erythema which
manifest after 3 hrs. ,reaching a max. (9-10 cm in
dia.) after 20-24 hrs. and disappearing in another
.Right dome of diaphragm situated at a higher level.
.Sometimes there may be tenting of the diaphragm
because of basal pleurisy.
8.)Radio-isotope tracing of liver—
.Hepatic photoscan has been introduced to locate the
space occupying lesion in the liver.
.I 131 labelled Rose Bengal as the tracer agent,
observed an area of focal filling defect in amoebic
abscess of liver.
9.)USG of upper abdomen, CT scan of liver or
MRI scan also used for detection of amoebic liver
Diagnosis of Pulmonary Amoebiasis
.Demonstration of trophozoite of E.histolytica in the
sputum and by other immunological tests.
.The expectorated pus when examined fresh , may
demonstrate the motile forms (trophozoites) of
a.)In the intestinal wall, liver and other metastatic
lesions-----Emetine and Dehydroemetine(administered
b.)In the liver and lungs only--- Chloroquine.(1gm for 2
days followed by 5 gm daily for 3 weeks).
a.)Direct acting luminal or contact amoebicides.
ii.)Dichloracetamide group, diloxanide(entamide).
b.)Indirect- acting luminal amoebicides- Tetracycline.
3.) Both luminal and tissue amoebicides---
. Metronidazole(750 mg TDS for 5-10 days) and
related compounds like Tinidazole (2gms OD for 3
days)and Nitroimidazole are administered orally
i.)Boiled drinking water
ii.)Protection of all food and drink from contamination by
flies, cockroaches and rats.
iii.)Avoidance of use of raw vegetables and fruits.
iv.)Personal cleanliness and elementary hygienic
conditions are to be observed while taking meals.
i.)Effective sanitary disposal of faeces.
ii.)Protection of water supplies from faecal pollution.
iii.)Avoidance of use of human excrement as fertiliser.
iv.)Detection and isolation of carrier.