Hydatid disease or echinococcosis is an endemic disease in cattle grazing and developing areas, particularly Australia, New-Zealand, Middle East, India, Africa, South America, and Turkey. It is a parasitic infection caused by the cestode Echinoccocus granulosus. Dogs are definitive hosts, and adult worms are found in their small intestine. Humans, the accidental intermediate hosts, get infected either by contact with the definitive host or by consuming vegetables and water contaminated with the hydatid ova. In humans, the hydatid disease commonly involves the liver (75%) and the lungs (15%). Despite the abdomen bearing the brunt of this disease entity, it is an extreme rarity to encounter its multivariate presentation in two pure vegetarian, non-sheep rearing, and economically sound individuals, from an urban area. We report two such cases who presented to us in the Emergency Department, within a short span of each other (one week), along with the relevant literature review.
Keywords: Echinococossis, Echinoccocus granulosus, Idiopathic presentation
|How to cite this article:
Aggarwal G, Tirkey S, Jain DK, Lubana P, Moses S. Varied presentations of idiopathic abdominal echinococossis: Two cases with literature review. Ann Trop Med Public Health 2010;3:14-8
|How to cite this URL:
Aggarwal G, Tirkey S, Jain DK, Lubana P, Moses S. Varied presentations of idiopathic abdominal echinococossis: Two cases with literature review. Ann Trop Med Public Health [serial online] 2010 [cited 2020 Aug 14];3:14-8. Available from: http://www.atmph.org/text.asp?2010/3/1/14/76178
Hydatid disease or echinococcosis is an endemic disease in cattle grazing and developing areas, particularly in Australia, New-Zealand, Middle East, India, Africa, South America, and Turkey. It is a parasitic infection caused by the cestode tapeworm Echinoccocus granulosus. Dogs are definitive hosts, and adult worms are found in their small intestine. Humans get infected either by contact with the definitive host or by consuming vegetables and water contaminated with the hydatid ova. In humans, the hydatid disease commonly involves the liver (75%) and the lungs (15%). The remaining (10-15%) of the cases include the other regions of the body. 
Despite the abdomen bearing the brunt of this disease entity, it is an extreme rarity to encounter its multivariate presentation in two pure vegetarian, non-sheep rearing, and economically sound individuals, from an urban area. We report two such cases who presented to us in the Emergency Department within a short span of each other (one week).
|Materials and Methods|
Two male patients, one an elderly male of 75 years and a relatively younger 32-year-old, presented to the Emergency Department of our hospital, within a gap of one week.
A 75-year-old, pure vegetarian, urban male, a driver by occupation, presented with shortness of breath on exertion, orthopnoea, progressively increasing abdominal distention, associated with difficulty in passage of motion-flatus, and numerous episodes of non-bilious projectile vomiting. He had a past history of two laparotomies (scars of which were visible over his abdomen), 20 years ago, at a private hospital [Figure 1]. On physical examination, he was an extremely lean and thin man with a large protruding abdomen. His abdomen was distended, but non-tender, with the following vital signs – pulse of 100 / minute, blood pressure – 90 / 60 mmHg, respiratory rate of 24 / minute, and temperature of 37.4 degrees centigrade. He had decreased breath sounds in both lower lung fields. The rest of the physical examination was unremarkable. His routine laboratory investigations were normal. An ultrasound examination reported features of intestinal obstruction due to a large multicystic lesion. The CT (Computed Tomography) scan revealed multiple, well-defined, cystic lesions in both liver lobes, the largest being 17 x16 x 15 cm, with an anteroinferior extension. A few cysts showed septae and daughter cysts and were abutting into the peritoneal surface of the anterior abdominal wall. These cysts were producing a massive pressure effect on the surrounding structures, displacing the bowel loops to the left corner of the abdomen, but not invading them. Incidentally, a 3 x 2 cm haemangioma was also reported in segment III of the liver [Figure 2].
|Figure 1 :Patient, with scars of prior two laparotomies over the anterior abdominal wall.
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|Figure 2 :CT scan showing large liver hydatid cysts with a hemangioma, in segment 3.
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The patient was taken up for an emergent laparotomy, explaining the due risks related to age, anesthesia, triple surgery, complications and recurrence.
Intraoperatively, there was a large cystic lesion extending from the right half of the liver to occupy nearly the entire pelvis. Numerous daughter seedlings were also present throughout the abdomen involving nearly all intraperitoneal organs. The right liver lobe was completely engulfed by the humongous cystic lesion and could not be delineated separately from the cyst. On deroofing, numerous intact daughter cysts were evacuated, over a black muslin cloth, ensuring complete asepsis and avoiding spillage. In addition, three other large cysts were found, lying posterior to the right liver lobe, over the left lobe and occupying the gastrohepatic area, respectively. These were subsequently deroofed, taking utmost care to avoid rupture and spillage of the daughter cysts [Figure 3]. The peritoneal implants were also thoroughly evacuated. The entire procedure took nearly four hours and yielded 8 kgs of intact daughter cysts [Figure 4]. The postoperative period was uneventful and the patient was discharged on the 14 th post-operative day, with advice to attend regular follow-ups.
|Figure 3 :Deroofed hydatid cysts.
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|Figure 4 :8 kilograms of daughter hydatid cysts obtained after deroofing as well as intraperitoneally.
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A 32-year-old businessman, also a pure vegetarian, presented with an inability to pass flatus associated with off-and-on constipation and progressively increasing abdominal distention. He had gradually started developing a lump in the left lower abdominal quadrant, which had increased over five years to about 13 cm x 8 cm in size. On physical examination, he was an averagely built man, with a protruding left lower abdomen. His vital signs at presentation were – a pulse of 100 / minute, blood pressure of 90 / 60 mmHg, respiratory rate of 24 / minute, and temperature of 37 degrees centigrade. On per abdominal examination, he had an intraperitoneal cystic lump of about 13 x 8 cm in the left iliac fossa, extending into the hypogastric region and was freely mobile in almost all directions. The rest of his physical examination was unremarkable. His routine laboratory investigations were normal. Ultrasonography revealed a well-defined, thick-walled lesion of size 11 cm x 7 cm, with multiple cysts of varying sizes seen inside with echogenic shadows, suggestive of a Hydatid Cyst. The CT (Computed Tomography) scan, [Figure 5], revealed a large, uniformly thick-walled, oval-shaped cystic lesion in the lower abdomen and upper pelvic cavity region, measuring 14 x 7 x 11 cm, with multiple enhancing daughter cysts and a camalote appearance of the inner membranes, causing a significant displacement of the bowel loops, suggestive of a large hydatid cyst in the supra- and retrovesical regions The patient was prepared for laparotomy and partial pericystectomy followed by sterilization of the cyst cavity with an injection of a scolicidal agent, and eradication of the daughter scolices via mechanical removal, was performed. The postoperative period was uneventful and the patient was discharged on the ninth postoperative day.
|Figure 5 :CT scan coronal section showing the dimension of the cyst.
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The earliest mention of Hydatid disease dates back to Hippocrates, who used the term “Liver filled with water” for it. Famous Arab Physician Al-Rhazes wrote about the disease more than a thousand years ago.  It is a zoonotic illness caused by cysts of Echinococcus granulosus, whose primary host is the dog. Human disease occurs when tapeworm ova are ingested by humans, either by consuming unwashed and uncooked vegetables or as a result of close contact with a working or a pet dog.  Hydatid disease, also known as echinococcosis or hydatidosis, is caused by infection with the larva of the tapeworm of genus Echinococcus.
E. granulosus cysts following primary infection may inhabit any anatomic site. The two most common organs involved are the liver (65%) and the lungs (25%). Other less common sites affected by cysts include the muscles (5%), bones (3%), kidneys (2%), spleen (1%), heart (1%), pancreas (1%), and central nervous system (1%). 
Of the four known species of Echinococcus, three are of medical importance in humans. These are Echinococcus granulosus, causing cystic echinococcosis (CE); Echinococcus multilocularis, causing alveolar echinococcosis (AE); and Echinococcus vogeli.
E granulosus is the most common of the three. Echinococcus granulosus is a small, 5-mm tapeworm, responsible for unilocular hydatid cyst disease. The life cycle involves only two hosts, one definitive and the other intermediate. Humans act as an accidental intermediate host. The life cycle has three developmental stages, (a) the adult tapeworm in the definitive host, (b) eggs in the environment, and (c) the metacestode in the intermediate host. Metacestodes are ingested by the definitive host. The metacestodes mature into the tapeworm in the definitive host, and in turn, release eggs into the environment. The intermediate host ingests the eggs, which hatch into metacestodes, which infest the liver, lungs, muscles, and other organs of the intermediate host. Most of the people acquire the disease during their childhood, but do not present with the clinical signs and symptoms until late adulthood.  The natural progression of an untreated cyst may include calcification and death of the cyst, however, more frequently the cyst gradually enlarges. 
The hydatid cysts may resemble a multiloculated mass filling the entire peritoneal cavity. Such a condition is referred to as peritoneal hydatidoses.  Secondary hydatid disease of the peritoneum is usually the result of a traumatic or surgical rupture of a hepatic, splenic, or mesenteric cyst, with abdominal and pelvic dissemination. 
The close association of people with sheep and dogs and unavailability of clean potable water supply makes a region endemic to the disease.
A majority of the cases of hydatid disease come from rural areas or from people who have settled in urban centers after spending a vast majority of their life in villages. People usually acquire the disease during their childhood, but do not present with the clinical signs and symptoms until late adulthood. 
The type of the imaging modality used depends on the site and size of the hydatid cyst. Ultrasonogarphy (USG) is the first line of screening for abdominal hydatidosis and it is especially useful in the detection of cystic membrane, septa, and hydatid sand. It also forms the mainstay in the follow-up period, for the detection of any complication or recurrence per se.
A CT scan best demonstrates cyst wall calcification and cyst infection. CT scan imaging is also a modality of choice in peritoneal seedling.  The CT scan shows well-defined, solitary or multiple cysts that may be thin-walled or thick-walled. A hydatid cyst typically demonstrates a high attenuation value at unenhanced CT, even without calcification [Figure 1]. Multivesicular cysts can depict a typical honeycomb pattern.  The septa represent the walls of the daughter cysts housed within the mother cyst. A “wheel spoke” pattern can be observed when the daughter cysts are separated by the hydatid matrix. 
There are different types of serological tests that can be carried out for the diagnosis, screening, and follow-up of patients with hydatid disease. These include immunoelectrophoresis, enzyme-linked immunosorbent assay (ELISA), latex agglutination, and indirect hemagglutination (IHA) test.  The arc 5 immunoelectrophoresis test is confirmatory, as it detects antibodies against immunodominant as well as the specific antigen (antigen 5) of the cestode. A polymerase chain reaction (PCR), using recombinant DNA antigen, is of value to identify the particular species of Echinococcus. 
The diagnosis of HD can thus be established with the help of radiological and serological findings. The diagnosis is also easier when the lesion has multiple locations involving different organs or when the daughter cysts’ germinal membranes undergo detachment and calcification is concomitantly present.
Surgery is the mainstay of treatment for hydatid cysts of the liver. Laparotomy is the most common surgical approach.  Liver resection and pericystectomy are procedures that resect the closed cysts with a wide safety margin; however, they are considered as too radical procedures for hydatid cyst removal. Conservative procedures such as cystectomy and omentoplasty for hydatid disease should be the standard surgical procedures, because of their safety, simplicity, and effectiveness in fulfilling the surgical treatment criteria of multiple hydatid disease. Peritoneal hydatidosis has also been successfully removed surgically with similar conservative procedures. 
In cases suspected of having peritoneal spillage, antihelminthic drugs should be administered. In addition, small asymptomatic cysts, some daughter cysts, peritoneal secondary cysts, and splenic cysts could also be effectively treated with a prolonged therapy of Albendazole.  Preoperative Albendazole therapy helps to sterlize the gut, minimize anaphylaxis, and to reduce intra-cystic tension. It thus effectively lowers the recurrence rate postoperatively. 
Hydatid disease can thus affect any organ in the body, even in the absence of predisposing factors for the same, and hence, a high index of suspicion is a must in any abdominal neoplasm, with a preoperative diagnosis being possible radiologically, only if one is aware of the same. As the saying goes “what the mind knows is what the eyes see”.
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Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]