| Abstract|| |
A helminthoma is an inflammatory tumor of the bowel wall, which results when an intestinal worm or larva penetrates the wall of the gut, usually the cecum or colon. A helminthoma can occur in any country where infestation of the intestinal tract with worms is common. It has been seen most often in West and East Africa and parts of South America. In some parts of West Africa, this disease is well known to villagers, who describe it as having 'a turtle in the belly.' We report such a case with diagnostic dilemma.
Keywords: Chronic abscess bowel, eosinophilic granuloma bowel, helminthic pseudotumor, helminthoma, oesophagostomiasis
|How to cite this article:|
Tauro LF, Martis J, Hegde B R, John S K, Kumar P. A turtle in the belly: Helminthoma. Saudi J Gastroenterol 2007;13:33-6
| Introduction|| |
A helminthoma is an inflammatory tumor of the bowel wall, which results when an intestinal worm or larva penetrates the wall of the gut, usually the cecum or colon. This definition does not include intra- or retro-peritoneal inflammatory mass or abscess, which occurs when a worm (e.g., Ascaris ), penetrates completely through the bowel wall. It has been seen most often in West and East Africa and parts of South America., In some parts of West Africa, this disease is well known to villagers, who describe it as having 'a turtle in the belly.' Local heat is applied until it ruptures. We report such a case with diagnostic dilemma.
| Case Report|| |
A 20-year-old male patient was presented with right lower abdominal pain for one month. Patient gave no history of diarrhoea, malena, or loss of weight. He was treated conservatively elsewhere for suspected appendicular mass two weeks prior to admission in our hospital. Abdominal examination revealed a well-defined, non-tender, mass measuring 10´8 cm in the right lower quadrant. The mass was freely mobile in all directions like a 'turtle,' within the right iliac fossa and the right lumbar region.
Blood picture revealed leucocytosis with neutrophilia and eosinophilia (10%). ESR was 24 mm at 1 hour. Serum biochemistry was within normal limits. Microscopic examination of stools revealed ova of hookworm. Abdominal ultrasound identified a well-defined 9.2´5 cm encapsulated collection in the right iliac fossa. Barium enema studies demonstrated a well-defined intra-luminal filling defect in the cecum, with normal filling of appendicular lumen. There was no obstruction to the bowel lumen [Figure - 1]. Colonoscopy identified an intramural mass in the cecal wall with normal stretched mucosa over the underlying mass; rest of the colon was unremarkable. Mucosal biopsies were normal. Percutaneous needle aspiration yielded thick pus. Gram staining and acid-fast bacilli stains were negative and culture was sterile. Cytology of the aspirated pus was negative for malignant cells.
The patient was treated conservatively with broad-spectrum antibiotics and antihelminthics. However, the mass persisted on clinical and radiological examinations. Explorative laparotomy revealed an indentable, mobile mass arising from the cecum without any surrounding inflammatory changes. Appendix was normal and retrocecal in position [Figure - 2]. Multiple mesenteric lymph nodes were present. Local ileo-cecal resection with ileo-ascending colon end-to-end anastomosis was performed. Mesenteric lymph node was biopsied. Cut open specimen of the cecum revealed a well-encapsulated mass arising from the antero-lateral wall of the cecum, projecting into the cecal lumen. Mucosa overlying the mass was intact. Appendix was not inflamed and the lumen was patent [Figure - 3]. Cut surface of the mass showed uniloculated cyst filled with thick purulent material. Histopathology revealed attenuated lining of the cyst with partial denudation, lymphoidal infiltration of the wall. Few ill-defined granulomas were seen. Appendix showed no significant pathology. Lymph node showed sinus histiocytosis and reactive hyperplasia. Features were compatible with antibiotic attenuated chronic abscess of colonic wall/helminthoma [Figure - 4].
Patient made an uneventful post-operative recovery. At 12 months follow-up, patient remained asymptomatic.
| Discussion|| |
Diagnosis of helminthoma is very difficult. Unless the pathologist makes a careful search for the worm, the cause will go unrecognized. The intactness of the mucosa, with no evidence of ulceration and the intramural location of the mass would help to rule out carcinoma. Further, there may not be melena clinically in case of inflammatory pseudotumors. The more gradual onset of symptoms, absence of periumbilical pain, eosinophilia and visualization of normal appendix by radiological imaging should exclude appendicitis. Sonographic appearance in the right lower quadrant of a brightly echogenic finger-like projection extending into a cystic mass, with or without scattered internal echoes, should suggest the possibility of periappendiceal or diverticular abscess. Amoebiasis or amoeboma may be recognized if there are other areas of colitis, as well as local contraction around the full width of the bowel.
Commonest parasites to penetrate the bowel wall and cause helminthoma are the nematodes; the most important are the strongyli, Oesophagostomum apiostomum , and Oesphagostomum stephanostomum (var. thomasi ). Helminthoma can also be caused by Ancylostoma duodenale (hookworm) or the rare Oesophagostomum brumpti and bifurium . Anisakis may occasionally cause ileal or cecal nodules. Oesophagostoma are common parasites of the colons of farm animals and wildlife.,, Ashby BS et al . reported a case of eosinophil granuloma of the gastro-intestinal tract caused by the herring parasite, Eustoma rotundatum .
The worms may penetrate the intestinal mucosa and provoke an inflammatory reaction in the muscular layer of the bowel. This can develop into an abscess. Inflammatory adhesions may lead to bowel obstruction. The abscess may perforate into the bowel lumen, causing diarrhea or into the peritoneal cavity causing peritonitis or may adhere to the abdominal wall.,,, After the acute phase has subsided, the abscess may undergo resolution with absorption or calcification of the worm. Or the abscess may enter a chronic stage and become a further diagnostic problem. Microscopically, in the very early stage, one or more granulomas may be recognized. Usually there is edema with inflammation involving the submucosa, muscularis, and pericolonic adipose tissue. Intact surgical specimens are rarely obtained and finding the worm may be difficult because of severe inflammatory reaction. In the majority of patients, the worm will have degenerated and is no longer identifiable. The pathognomonic lesion of helminthoma is 2-4 cm in diameter and has a central zone of eosinophilic necrotic tissue, often with a zone of degenerating nuclei. There may be palisaded epithelioid cells surrounding the worm. Beyond the central necrosis are a mixture of eosinophils, lymphocytes, and plasma cells. Granulation and scar tissue form the outer perimeter.,
Patients usually have vague, non-specific complaints for short duration. Children may suffer intermittent attacks of colic for 2 or 3 weeks, simulating intussusception. There may be anorexia, nausea and vomiting and low-grade fever and the right lower abdominal pain. On clinical examination, there may be abdominal guarding and tenderness and often an easily palpable, smooth, tender mass. In acute cases in childhood, perforation of the cecum anteriorly with an abscess extending to the abdominal wall may be the presenting finding.,,
The white blood cell count is elevated, with moderate eosinophilia. For radiological diagnosis, essential finding is a mass in the wall of the bowel commonly localized in or adjacent to the wall of the cecum or ascending colon, best demonstrated by a barium enema with air contrast or by ultrasonography or computed tomography. It seldom encircles the lumen, but the intramural mass causes eccentric narrowing, mimicking extrinsic pressure. The edges of the mass are usually sharply defined and biconvex. Very rarely, barium may fill a small perforation following the route of the worm. The intervening bowel wall and mucosa will be normal, with visualization of a normal appendix. The calcified remnant of a worm in a helminthoma may be identified radiologically.
In our case, a 20 year-old-male patient was presented with freely mobile mass in the right lower quadrant of the abdomen. There was eosinophilia and stool microscopy revealed ova of hookworm. Barium enema studies demonstrated a well-defined intraluminal-filling defect in the cecum, with normal filling of appendicular lumen. There was no obstruction to the bowel lumen. Colonoscopic biopsies were normal. The mucosa was intact with no evidence of ulceration and the mass was located intramural. These features have ruled out carcinoma. Histopathology of the specimen revealed few ill-defined granulomas. To diagnose helminthoma, pathologist must search for worm/granulomas. Since helminthoma cases are rare in our sub-continent, the pathologist may not have searched for granulomas and a dead worm or worm might have degenerated and was no longer identifiable. Considering all these features, helminthoma is the more suitable diagnosis in this case.
In this case probably an acute helminthic abscess might have entered a chronic stage and became a diagnostic problem.
To conclude, we had a diagnostic dilemma in this case. Histological diagnosis in this case was antibioma. But, the commonest sites of antibioma are breast, thigh, and ischeorectal fossa. Literature review did not reveal any case of bowel antibiomas. The clinical, laboratory, radiological and pathological features of this case fit that of chronic helminthoma. Hence the surgeon and the pathologist must be aware of this entity. Diagnosis of helminthoma is very difficult. Unless the pathologist makes a careful search for the worm/granuloma, the cause will go unrecognized.
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Leo Francis Tauro
Deparment of General Surgery, Fr. Muller Medical College Hospital, Kankanady Post, Mangalore
Source of Support: None, Conflict of Interest: None
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]