Intraluminal cecal hydatid cyst presented as chronic intestinal obstruction.

A 70-year-old male presenting with abdominal pain was clinically diagnosed to have chronic intestinal obstruction due to lesion in ileo-cecal junction based on barium meal follow through. He underwent right hemicolectomy and the lesion was ascertained to be an intraluminal hydatid cyst in the caecum. Intraluminal cecal hydatid cysts can mimic malignancy on radiological investigations. It should be considered as a differential diagnosis in patients presenting with intestinal obstruction in endemic regions for hydatid disease.

Hydatid disease is a major cause of human morbidity and mortality in endemic areas of the world such as India, Australia, Middle East, Africa, South America, and Turkey.[1] Liver and lung are the most common organs involved, but hydatid cysts may reside in any blood fed organ. The spleen, ovaries, brain, bones, and heart are the other sites known to be involved.[2]

Intraluminal intestinal hydatidosis is rare and typically goes un-diagnosed as most patients pass cysts in the stool (hydatidiarrhea) and remain asymptomatic.[3] We present an uncommon lesion of intraluminal hydatid cyst in the cecum, which presented as chronic intestinal obstruction.

THE CASE

A 70-year-old male from Khandesh area of Maharashtra, India, presented with complaints of diffuse chronic abdominal pain with intermittent nausea and vomiting for a year. He also complained of altered bowel habits. Barium meal follow through was performed, which revealed an intraluminal space-occupying lesion in the distal ileum causing partial obstruction [Figure 1]. Computed tomogram (CT) scan could not be performed due to cost constraints. A clinical diagnosis of chronic intestinal obstruction due to malignant lesion in the ileo-cecal region was made. Hematological, renal and liver function test results were within the normal range. An exploratory laparotomy revealed a solid, palpable cystic lesion of 6-8 cm in the caecum near ileo-cecal junction. The mesenteric lymph nodes were not enlarged and the liver was normal. A right hemicolectomy followed by ileo-colic anastomosis was performed and the specimen was sent for histopathology.

Figure 1

Barium meal follow through showing intraluminal space-occupying lesion in distal ileum causing partial obstruction

An approximately, 30 cm length of intestine, consisting terminal ileum, cecum, appendix and ascending colon was received for histopathology. The appendix was grossly enlarged up to 10 cm in length with a cecal mass measuring 7 cm × 6 cm [Figure 2]. The cecal mass on cut section showed unilocular cyst involving the wall of cecum and appendix had luminal width of 2.5 cm [Figure 3]. The cyst wall was gelatinous and multiple small cysts were seen in it. Histopathological study of the ulcerated cecal mucosa [Figure 4a and b] and submucosa showed a cyst lined by laminated hyaline membrane. Cyst contained multiple protoscolices and degenerated eosinophilic protoplasmic material [Figure 4c and d]. Thus, a diagnosis of intraluminal cecal unilocular hydatid cyst was made. The patient made a fast recovery after surgery and was discharged home on the sixth post-operative day. He was prescribed a month's course of albendazole and followed-up for about a year without any abdominal complaints.

Figure 2

Appendix was grossly enlarged (10 cm long) with cecal mass measuring 7 cm × 6 cm

Figure 3

The cecal mass in cross section showing unilocular cyst involving the wall of caecum. The cyst wall was gelatinous and had multiple daughter cysts within it. The appendix was grossly dilated (luminal width 2.5 cm)

Figure 4

(a, b) Histological sections showing ulcerated cecal mucosa (H and E, ×100) and submucosa showing cyst lined by laminated hyaline membrane. (c, d) The cyst contained multiple protoscolices and degenerate eosinophilic protoplasmic material (H and E, ×400)

CONCLUSIONS

Hydatid cyst disease is a zoonotic disease caused by the larval stage of Echinococcus granulosus (dog tapeworm), E. multilocularis, or E. vogeli.[4] This disease occurs when humans ingest the hexacanth embryos of the dog tape worm. Infestation by hydatid disease in humans most commonly occurs in the liver (55-70%) followed by the lung (18-35%).[5] Hydatid cysts also occur in extrahepatic locations such as lung, brain, heart, pancreas, mesentery, and uterus.[2] However, intraluminal intestinal hydatid cysts are rare and asymptomatic and patients present with the passage of hydatid membranes in stool.[3] Hydatid cysts developing in mesosigmoid or in retroperitoneum may cause mechanical obstruction of bowel.[67] In our case, the cyst was intraluminal, involving the cecum and therefore was obstructing the ileo-cecal junction, which led to chronic intestinal obstruction.

Ultrasonography is the first line of screening for abdominal hydatidosis. It is particularly useful for detection of cystic membrane, septa, and to look for hydatid sand (the scoleces, daughter cysts, hooks, and calcareous corpuscles of Echinococcus tapeworms in the fluid within a primary or daughter hydatid cyst). CT scan best demonstrates cyst wall calcification and cyst infection.[8] A CT scan could not be performed due to cost constraints in this case and diagnosis of a malignant intestinal lesion was made based upon the patient's age, symptoms and narrowing of intestine on Barium meal study. Immunoelectrophoresis, enzyme-linked immunosorbent assay, latex agglutination and indirect hemagglutination tests are also being carried out for the diagnosis, screening, and the post-operative follow-up for recurrence.[9]

The treatment of choice for localized hydatid cysts in liver or lungs is principally surgical while the therapy for inoperable cases remains medical.[10] Albendazole or praziquantel remain the mainstays of medical therapy. In our case, as the clinical diagnosis was malignant lesion of intestine, the pre-operative medical therapy for hydatidosis was not given; however, albendazole was given for a month post-operatively. Hydatid cysts can be removed surgically after sterilizing them with formalin or alcohol. Pre- and post-operative 1 month courses of albendazole or 2 weeks of praziquantel should be considered in order to sterilize the cyst, decrease the chance of anaphylaxis, decrease the tension in the cyst wall and to reduce the recurrence rate post-operatively.[11] Intra-operatively, the use of hypertonic saline or 0.5% silver nitrate solutions before opening the cavities tends to kill the daughter cysts and therefore prevent further spread or anaphylactic reaction. In our case as the lesion was thought to be malignant, the cyst was excised unopened and in-toto along with the loop of intestine. To our knowledge, this is the first case of intraluminal intestinal hydatid disease, which was instigating chronic intestinal obstruction. Intraluminal intestinal hydatid cyst can mimic a malignant lesion clinically and radiologically. Early and accurate diagnosis helps in management of the patient, thereby reducing morbidity and mortality. Intraluminal intestinal hydatid cysts should be considered as a differential diagnosis in cases of intestinal obstruction, especially in endemic regions.