Metastatic amoebic abscess of the brainSD Deodhar1, Vatsala D Trivedi1, AP Desai2, Anuradha Murthy2
1 Department of Surgery, Seth G.S. Medical College and K.E.M. Hospital, Parel, Bombay-400012, India
2 Department of Pathology, Seth G.S. Medical College and K.E.M. Hospital, Parel, Bombay-400012, India
A case-of Amoebic abscess of brain is presented and relevant Literature reviewed.
Amoebic abscess of the liver is commonly known to burst into the peritoneal cavity and other abdominal viscera, or into the pleura and the lung. Involvement of distant organs is rare. Metastatic brain abscess is even more rare. We had recently under our care, a case of amoebic abscess of the brain, associated with amoebic abscess of the liver and the lung. The rarity of this case prompted us to report this cases.
R.H.,a 40 year old male was admitted to the King Edward VII Memorial Hospital, Bombay on 8th February, 1978 at 11.15 A. M, in a. moribund condition. History was not available. Attempts at resuscitation were made. However the patient expired within half an hour of admission.
Autopsy revealed the following:
The body was of a 40 year old male, fairly built and poorly nourished; the external examition did not reveal any abnormalities.
On internal examination, the peritoneal- cavity contained 300 cc of yellowish grey coloured pus coming from the liver.
The liver was grossly enlarged and weighed 2.5 Kgs. An abscess, 7 cm. in diameter, was present on the superior surface of the right lobe of the liver. The walls of the abscess were shaggy and the cavity contained necrotic yellowish grey coloured material. (See [Figure 1] on page 102A). Several other abscesses of different sizes were also present in the liver. The biliary system. was normal.
The liver abscess had burst into the right pleural cavity which contained 150 ccs of purulent material. The right lung was collapsed and showed an abscess in the lower lobe. (See [Figure 2] on page 102A).
The meninges were normal. The brain was congested and oedematous. There were 2 abscesses, each 1 cm. in diameter, one in the left temporal lobe and one in the left basal ganglia, (See [Figure 3] on page 102A).
The pus from the liver abscess did not reveal any vegetative forms of Entamoeba histolytica.
The colon did not show any evidence of amoebic colitis.
The histapathology report was as follows:
Microscopic examination of the sections taken from the liver, lung, brain and spleen showed characteristic changes of amoebic abscess. There was extensive amorphous necrosis with infiltration by mononuclear cells. Vegetative forms of Entamoeba histolytica were seen in large number in the liver and the lung. The brain and the spleen showed a few E. histolytica. These were 3-4 times larger thaon mononuelca, cells and showed nuclei with central karyosomes. The cytoplasm showed ingested red blood cells. They were stained with haematoxylin and eosin stain and also with naphthol green B stain. There forms were surrounded by a clear halo. (See [Figure 4] and [Figure 5] on page 102B) .
Amoebic brain abscess is a rare and a fatal complication of amoebiasis.  In 1838, Morehead` first observed the association of brain abscesss with tropical liver abscess. In 1904, Kartulis  was able to demonstrate for the first time vegetative forms of Entamoeba. histolytica in a brain abscess. Later on, Legrand  described a case in 1912 and Armitage  collected about. 4 cases from literature in 1919. Craig  in 1944 in his 40 years study said that he never saw amoebic brain abscess except as a museum specimen. Reddy and Thangavelu  in 1948 in. an analysis of 2461. cases of dysentery treated in. Madras General Hospital recorded 1011 cases of amoebic dysentery of which 44 cases came up for autopsy, but they could not demonstrate a single amoebic brain abscess.
In a recent review of 104 autopsies of metastatic brain abscess by Gates et al  in 1950 not a single amoebic brain abscess was found. Orbison et al  in 1951, were able to collect 83 reports of the condition of which diagnosis was authenticated by demonstration of vegetative forms of amoebae in 22 lesions. To this they added 5 more cases, in 3 of which amoebae were found. Since then at least 4 more cases are reported by Koshy  (1950) , de-la-Maza and Guzmane  (1953), Kirk  (1956), Lanshoek  (1958). In 3 of these, amoebae were found in brain lesions. In Kirk's  case at Singapore there were 3 large abscesses in the left cerebral hemisphere and one in the cerebellum containing E nta moeba Histolytica. Of these 92 cases only 10 were unassociated with liver or lung abscess and only 5 of these proved by finding Entamoeba, histolytica in brain abscess, the first two by Kartulis  third byPutney and Baker  fourth by Stein and Kazan  5th by Halpert and Ashley. In a series of 135 autopsies where death was attributed to amoebiasis, Odunjo  . from Lagos found 4 brain abscesses in the cerebral hemispheres. The largest brain abscess was 8 cm. in diameter. E ntamoeba Histolytica could be demonstrated only in one case. In our case also we were able to demonstrate Entamoeba histolytica by routine as well as special NGB (Naphthol Green B) stain. 
Involvement of the brain is a rare complication and usually preceded by similar involvement of the liver or lung or both. The exact route by which Entamoeba histolytica reaches the brain is not very clear, particularly in those cases where there is no involvement of the lung or liver. The possible explanation could be
(a) The amoebae pass through the lung alveolar filter.
(b) Healed liver and lung lesions with a metastatic brain abscess which has become fatal.
(c) Through the prevertebral veins of Batson  as suggested by Stein and Kazan  Collis  in 1944 in an extensive review of all theories on the pathogenesis of metastatic brain abscess from thoracic disease came to the conclusion that the method of spread is retrograde passage of infected material from the thoracic wall to the prevertebral plexus of veins and then to the cerebrum. He also demonstrated how reversal of flow in the spinal system of veins is facilitated by the patient lying flat on his back. In 1940 Batson  demonstrated that coughing and sneezing, with consequent intra-abdominal pressure changes squeeze the blood from the intra-abdominal veins to the prevertebral veins.
According to Armitage  (1919) (as quoted by Collard and Kendal  ) the process originates from small areas of free amoebic meningitis and the infection reaches the depth of neural tissue and forms a metastatic brain abscess.
Diagnosis of amoebic brain abscess is very difficult as the symptoms resemble those of brain tumour, and abscess is invariably fatal. In the case presented by Powell and Neame  initially the condition simulated hemiparesis due to cerebral thrombosis. There was no evidence of hepatic or pulmonary involvement. The diagnosis of amoebic brain abscess was considered only when the patient developed symptoms of amoebic dysentery.
Whereas emetine and chloroquine are known to be concentrated in liver and are therefore effective in. amoebic liver abscess, 3 there is no evidence that they reach amoebicidal concentration in the brain, where it has been shown that concentration of both is low. At present it is doubtful whether we have any drug which has much effect on this condition.
Thanks are due to the Dean, K.E.M. Hospital and Seth G. S. Medical College. Parel, Bombay for his permission for reporting this case.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]