I would like to classify surgical amoebiasis as follows:

I Intestinal presentation or Colonic presentation

1. Massive, lower Gl bleed
2. Perforation
3. Rectal amoeboma
4. Caecal amoeboma

II Appendix

1. Amoebic appendicitis
2. Colitis of the caecum presenting as "appendix"

III Peritoneum

1. Primary amoebic peritonitis without perforation of the amoebic ulcer
2. Amoebic peritonitis secondary to perforation of amoebic ulcer
3. Amoebic peritonitis following ruptured inferior surface liver abscess
4. Amoebic peritonitis following inferior surface liver abscess without frank rupture.

IV Ruptured Liver Abscess

1. Pericardial amoebiasis
2. Pulmonary amoebiasis
3. Pleural amoebiasis
4. Rupture elsewhere in the abdomen

V Brain—Amoebic abscess of the brain

Vl Bone—Amoebic Osteomyelitis

Vll Perianal—Cutaneous Amoebiasis

Ia) Massive Lower Gl Bleed

There are many occasions, when amoebic colitis behaves as ulcerative colitis. Some of the complications like massive Gl bleed which are very well described in ulcerative colitis, rarely can occur in patients of amoebic colitis. Figs. 1, 2 & 3 show that in fulminating amoebic colitis, the colon may not show typical undermined ulcers. Instead the whole colon may be diffusely ulcerated and may bleed profusely. With the result, 1-2 litres of blood may need to be transfused to the patient.

Although surgical intervention and resection of the bleeding colon is one of the options in the management of a massive bleed from "any inflammatory bowel disease" if the sigmoidoscopic biopsy of the ulcer demonstrates E. histolytica, as far as possible, surgery should not be done. This is because the surgeon will not be able to repair the friable colon.

b) Perforation

Perforation of an amoebic ulcer occurs in fulminating cases of amoebic colitis. Unlike duodenal ulcer perforation, but like typhoid and tuberculous ulcer perforation, amoebic perforations are silent and painless. Since the patient does not complain of pain, it can be easily missed. The diagnosis is made when a typical picture of amoebic peritonitis (described below) develops in a patient having amoebic dysentery. Such patients are usually malnourished, often alcoholic or have poor immunologic profile.

No surgery should be attempted. Often the perforations are multiple. The colon is friable so that the surgeon will not be able to handle it on the table without braking it into pieces.

The treatment should be strictly conservative. The associated amoebic liver abscess/multiple abscesses should not be missed, and if detected drained.

c) Rectal Amoeboma

This entity is diagnosed when the patient complains of bleeding per rectum. There is a mass felt per rectum whose biopsy report turns out to be nonmalignant, but shows features of amoebiasis. Amoeboma is a misnomer because as shown in Fig. 4, the mass is due to intestinal pseudo-polyps and not due to amoebic granuloma. Such polyps are extremely common in ulcerative colitis. But in amoebic colitis, these occur more often in rectum and caecum, which are the main sites of amoebic infection. With a single course of antiamoebic drugs, as soon as the amoebic inflammation and the mucosal oedema subsides, this rectal lump disappears like magic. It should never be operated upon.

None of the surgeons has carefully seen the histopathological report which has never mentioned the presence of a granuloma but has always shown features of amoebic colitis.

d) Caecal Amoeboma

Just like rectal Amoeboma, the caecal Amoeboma does not exist. Not a single case of amoebic granuloma of the colon has ever been reported in which E histolytica was demonstrated histopathologically. This entity does not exist but has been manipulated by surgeons because of poor follow up in the postmortem room. In Bombay city alone, to my knowledge, half a dozen patients of caecal Amoeboma have been operated in private hospitals and nursing homes and have died. No autopsy was done.

However, at the J.J. Hospital, while working in the autopsy room for one year, I could study this entity clearly (Fig. 5). In short, the caecal amoeboma is a local lump produced by severe amoebic typhlitis around which, a localized peritonitis occurs and the adjoining omentum and intestines get matted. The situation can be compared to an appendicular lump. With anti-amoebic drugs and antibiotics the lump dissolves as fast as the appendicular lump does with antibiotics. The rest of the management is same as an appendicular lump. If the patient is operated upon, he will definitely die because the Surgeon will not be able to handle the friable colon.

In the past, radiologists played a big role in misguiding the clinicians by reporting "filling defect in the caecum". In the modern days, the diagnosis should be based on sigmoidoscopy and the histopathology of the mucosal biopsy. Rarely, such an inflammatory lump can occur over any part of the colon in a patient of fulminating amoebic colitis.

II Appendix

a) Fig. 6 shows a picture of amoebic appendicitis seen at the autopsy and confirmed histopathologically. But then, this patient died of fulminating amoebic colitis and the whole of colon, appendix, and the terminal part of the small intestine were also affected by the disease.

Therefore, although this is a true entity, the surgeon is not likely to see this patient with "appendix" presentation because the patient will have severe diarrhoea and dysentery with pain in the RIF due to amoebic typhlitis.

b) Very often a wrong diagnosis of 'cold' pathological appendix is made because some patients who complain of recurrent pain in RIF shows non-visualisation of the appendix on a barium meal examination. The latter finding is misguiding and has no significance. Most of these patients have irritable colon. In some of them, there may be a few amoebic ulcers in the caecum. Many surgeons know this fact and therefore after removal of "cold" appendix, the surgeons prescribe anti-amoebic and colonic sedative drugs to all such patients.

III Peritoneum

Amoebic peritonitis can be

1. localised as described above under caecal amoeboma or
2. generalised (Fig. 7).

A generalised peritonitis can present as

1. acute painful surgical abdomen or
2. picture of gradual distension and dull ache of the abdomen without board-like rigidity.

(A) Acute painful surgical abdomen due to amoebic peritonitis invariably occurs following a rupture of a liver abscess usually located on the inferior surface and more often in the left lobe (Fig. 8).

After the introduction of new antiamoebic drugs, the incidence of this entity has gone down.

Years back, a ruptured liver abscess was considered as one of the three common causes of acute abdomen (others being perforated duodenal ulcer and appendix). I have known many surgical postgraduates writing a thesis on this subject.

In most of the cases described by them, the diagnosis of the ruptured liver abscess was made only at the operation table. Clinically, it was hardly ever suspected. Operation is easy to perform because in more than 90% patients of amoebic liver abscess, the colon is healthy and can be handled easily. In 50% of these cases, the caecum may show a few amoebic ulcers only.

Following are my suggestions to suspect "ruptured liver abscess" in any case of acute abdomen in our country before the surgery is performed. In case, this diagnosis is suspected, I.V. metronidazole drip can be started immediately and continued during the surgery.

Following are the points, which are in favour of "ruptured liver abscess" in a case presenting with acute abdomen.

1. History of alcoholism or bloody diarrhoea or dysentery a few weeks earlier.
2. Unlike silent perforated duodenal ulcer or appendix, when the patients are healthy before the present crisis, on eliciting the history, it will be found that the patient had fever during the last few days.
3. History of pain in the left or right shoulder will be in favour of a second amoebic liver abscess present elsewhere.
4. Presence of intercostal and pointtenderness over the liver.
5. Enlargement of the liver upwards elicited by percussion.
6. Since a routine X-ray chest is always done in a patient of acute surgical abdomen, presence of

1. an elevated dome of the diaphragm,
2. a non-elevated but a fuzzy, irregular right dome of the diaphragm, should favour the diagnosis of amoebic liver abscess where the second abscess on the inferior surface has ruptured.

1. When the blood tests are done, leucocytosis will not help to differentiate it from then severe anaemia of 8-9 gms, especially in a male patient together with leucocytosis will favour a diagnosis of ruptured amoebic liver abscess.
2. Blood sample should be sent for urgent analysis of serum-alkaline-phosphatase. Elevated levels of this enzyme should make one very suspicious of ruptured amoebic liver abscess. Slightly raised levels of serum bilirubin will also be in favour of liver abscess.
3. Most of the surgeons will always do a P.R. examination in a case of acute surgical abdomen. Proctoscopy should also be done in such patients. If during this examination, an ulcer is seen or even a severe congestion is noticed, a rectal swab should be done immediately and examined under the microscope by the bedside. Presence of E. histolytica will strongly favour the diagnosis of amoebic liver abscess.

As discussed above, the patients of amoebic abscess having a few colonic ulcers often do not have symptoms of "accompanying" diarrhoea or dysentery.

(B) Second type of amoebic peritonitis is the one where there is no onset of severe, acute, sudden abdominal pain. The onset is gradual and the clinical picture is like the one observed in the past in cases of typhoid peritonitis. The patient develops gradual abdominal distension. There is a generalised ache all over the abdomen. On examination, there is a tympanitic note all over the abdomen. Sometime, shifting fluid dullness can be elicited in the loin. The liver dullness may or may not be obliterated. On auscultation the bowel sounds are not heard.

Board like rigidity is conspicuously absent. But the whole abdomen is tender to touch.

This type of peritonitis often occurs in a patient of fulminating amoebic dysentery, but can also occur as a leak from a liver abscess. In the former, although there can be perforation of a single or multiple amoebic ulcers. Amoebic infection can also spread from the mucosa to the peritoneum without actual perforation.

The management of this type of peritonitis is strictly conservative. The prognosis is already gloomy, but the temptation to open the abdomen should be resisted. Surgery will invariably lead to fatal results.

IV) Ruptured Liver Abscess

The liver abscess can rupture into pericardium (Fig. 9) or into the lung or the pleura. Although this is all surgical amoebiasis, the patients do not land up with a general surgeon. With aspiration of the pericardial or pleural cavities, repeated liver aspirations and antiamoebic drugs, most of the patients recover. Unlike in past; in modern days very rarely will the patient need surgery for pericardial or pleural amoebiasis.

V) Brain—Amoebic Abscess

After the introduction of new antiamoebic drugs, this entity has disappeared and is not likely to be seen. The management should be like that of tuberculoma. After CT or MRI studies, medical treatment should be started and blood test of I.H.A. should be regularly followed to see the progress. Rarely ever surgery will be required. Over diagnosis of this condition can occur.

VI) Bone—Amoebic Osteomyelitis

I have described two cases of amoebic Osteomyelitis of the ribs as iatrogenic complication of surgical drainage of amoebic liver abscess.

VII) Perianal—Cutaneous Amoebiases

A lot of Perianal Surgical conditions of the skin—some mimicking condylomata can occur due to amoebiasis. Majority respond to medical treatment and surgery is not required.

ACKNOWLEDGEMENT

I am grateful to Dr. Rananaware, pathologist of Bombay Hospital, who was my Pathology teacher in the autopsy room during my one year of sabbatical leave at J.J. Hospital. Also thanks to Mr. Tulpule and Dr. Gadgil who were helpful to me.

FOR FURTHER READING:

1. Amoebic Liver Abscess—Kapoor O.P., S.S. Publishers, Bombay, 1979.