Amebiasis presenting as acute appendicitis

A case of fulminant amoebic colitis during systemic chemotherapy for gastric cancer

Amoebiasis is a parasitic infection caused by the protozoan, Entamoeba histolytica. At times, amoebiasis is activated under immunosuppressive conditions such as chemotherapy. We report a case of fulminant amoebic colitis resulting from an asymptomatic Entamoeba histolytica infection, which was activated by chemotherapy for gastric cancer. The patient developed diarrhea and fever after three courses of chemotherapy for gastric cancer and was diagnosed with acute enteritis. A colonoscopy and biopsy were performed because of the bloody stool. Histopathological findings revealed amoebic invasion of the rectum. Therefore, the patient was diagnosed with amoebic colitis and was treated with metronidazole. Emergency surgery was performed because intestinal perforation was suspected after which his general condition improved and was discharged. Subsequently, gastric cancer surgery was performed and the patient was discharged without postoperative complications. Hence, amoebic colitis should be listed as a differential diagnosis, and a colonoscopic biopsy should be performed when colitis occurs during chemotherapy for cancer.

Fulminant Necrotising Amoebic Colitis of Whole of Large Bowel: A Rare Complication of a Common Infectious Disease

Background

Fulminant necrotising amoebic colitis (FulNAC) is an uncommon and grave complication of a very common infectious disease widely prevalent in tropical countries. In most of the cases reported, only a segment of large bowel was gangrenous. The involvement of the whole of the large bowel, as in our case, is very rare and has very high mortality ranging from 55% to 100%. Case Summary. A 50-year-old gentleman presented with an acute abdomen with a history of crampy abdominal pain and passage of blood mixed with mucous and loose stools. After resuscitation and investigations, the patient was taken up for laparotomy and the findings showed that the caecum was sloughed off and the entire large bowel had multiple perforations. Subtotal colectomy with ileostomy was performed. Histopathological examination showed evidence of pancolitis with multiple colonies of amoebic trophozoites. Discussion. Entamoeba histolytica is a protozoon that affects the large intestine and liver in humans. There can be various presentations of amoebiasis: asymptomatic infection (90%), symptomatic noninvasive infection (6–8%), acute amoebic colitis (dysentery), or fulminant colitis with perforation. FulNAC is an uncommon complication, difficult to diagnose and treat, and associated with a high mortality rate, ranging from 55% to 100%.

Conclusion

It is important to consider the possibility of fulminant necrotising amoebic colitis (FulNAC) as an uncommon and fatal complication of amoebiasis, especially in tropical countries, where amoebiasis is prevalent. Early diagnosis and antiamoebic treatment, along with urgent aggressive surgical resection of the involved segment and exteriorization of the proximal and distal bowel ends, are shown to reduce mortality.

Amebic acute appendicitis: systematic review of 174 cases

BACKGROUND

This study aimed to determine the clinical and demographic features of acute amebic appendicitis by reviewing the reported cases.

METHODS

The PubMed and MEDLINE databases were searched to identify articles related to amebic appendicitis using key words. The search included all articles published between 1935 and 2012 without restricting language, journal, or country.

RESULTS

A total of 174 cases of amebic appendicitis reported in 42 articles were analyzed. The mean age of the patients was 23.5 years (range 2 months-83 years). The majority of patients were male (74.0 %), and the majority of cases were reported from countries with high/moderate risk for amebiasis (76.5 %). A history of traveling to a high/moderate-risk country was cited in 64.0 % of the overall cases. The interval between travel and onset of clinical symptoms ranged from months to years. History of or coexisting dysenteric diarrhea was present in only 7.0 and 14.0 % of overall cases, respectively. A preoperative diagnosis of amebiasis was cited for only five cases (3.0 %). Complicated appendicitis was present in 30.7 % of cases, some of which required colon resection. Severe postoperative intraabdominal complications (e.g., liver abscess, abdominal sepsis, gastrointestinal fistula, hemorrhage) occurred in 19.4 % of surgery-treated patients. The overall mortality rate was 3.2 %.

CONCLUSION

Appendectomy specimens should be routinely sent for histopathologic examination. In the case of suspected amebic acute appendicitis, extra precautions-early appendectomy, metronidazole for antibiotic prophylaxis, wet-preparation examination, obtaining a timely pathology result, increasing the awareness of uncommon complications of appendectomy-can hasten appropriate therapeutic intervention and improve outcome.

Acute Amoebic Appendicitis: Case Reports and Review of Parasitic Appendicitis

Amoebic appendicitis is very rare, occurring in about 0.5% to 2% of acute appendicitis, and usually not reported in children. We report a case of confirmed acute amoebic appendicitis complicating amoebic colitis in a 7-year-old Pakistani boy living in southern Jeddah, Saudi Arabia, and briefly review the literature on parasitic appendicitis.

Unusual histopathological findings in appendectomy specimens: A retrospective analysis and literature review

AIM: To document unusual findings in appendectomy specimens.

METHODS: The clinicopathological data of 5262 patients who underwent appendectomies for presumed acute appendicitis from January 2006 to October 2010 were reviewed retrospectively. Appendectomies performed as incidental procedures during some other operation were excluded. We focused on 54 patients who had unusual findings in their appendectomy specimens. We conducted a literature review via the PubMed and Google Scholar databases of English language studies published between 2000 and 2010 on unusual findings in appendectomy specimens.

RESULTS: Unusual findings were determined in 54 (1%) cases by histopathology. Thirty were male and 24 were female with ages ranging from 15 to 84 years (median, 32.2 ± 15.1 years). Final pathology revealed 37 cases of enterobiasis, five cases of carcinoids, four mucinous cystadenomas, two eosinophilic infiltrations, two mucoceles, two tuberculosis, one goblet-cell carcinoid, and one neurogenic hyperplasia. While 52 patients underwent a standard appendectomy, two patients who were diagnosed with tuberculous appendicitis underwent a right hemicolectomy. All tumors were located at the distal part of the appendix with a mean diameter of 6.8 mm (range, 4-10 mm). All patients with tumors were alive and disease-free during a mean follow-up of 17.8 mo. A review of 1366 cases reported in the English literature is also discussed.

CONCLUSION: Although unusual pathological findings are seldom seen during an appendectomy, all appendectomy specimens should be sent for routine histopathological examination.