Echinococcal cyst

Echinococcus cyst is a parasitic disease caused by the larval stage of Ehinocococcus granulesus with damage to the liver, lungs and other organs with a fine capillary network. Man is an intermediate master of the band helminth, they can also be: horses, camels, pigs, cows. The final hosts are: dogs, wolves, cats, foxes and other predators. In the intestines of the final hosts matures mature maturing parasite: a worm 4-7 cm long, which is attached to the wall of the intestine with the help of a scolex: four muscular suckers and proboscis with forty hooks. Three segments with different phases of development are attached to the head: the young proglottid, the hermaphrodite proglottid, the mature proglottid. Mature proglottid as it ripens, is rejected and with intestinal masses and seeds the environment with 400-800 eggs. Inside each egg there is a six-cob embryo - oncosphere.

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How does the echinococcal cyst develop?

The infection of a person comes from stroking the animal's fur: dogs, cats, cows, horses - or by biting grass infested with eggs. Therefore, the disease is more typical for areas with developed cattle breeding or extensive forest land, but can be noted in any zone, since eggs can spread and with dust. They are very viable: at 0 ° live 116 days, and at a plus temperature of up to 6-8 months.

Even boiling is kept for up to 20 minutes. This is despite the fact that one dog can allocate up to 20 thousand parasites. Multiply this figure by 800, and you will become clear the dissemination of the environment. Therefore, endemic zones can be formed.

Eggs of the parasite, getting from the environment into the stomach, penetrate into the portal venous network and get stuck in the capillaries of the liver, the smaller ones settle in the capillaries of the lungs. These are the two most common localizations. But if the patient, due to pulmonary hypertension, has open arteriovenous shunts in his lungs, eggs can enter the large circle of blood circulation with the defeat of any organ and tissue, more often of the kidneys, spleen, brain. Develop slowly, only 5-6 months after infection is formed larva.

In the liver from the oncosphere, an echinococcal cyst is formed - the larvocyst from 1 to 50 cm, but there are cases of larvocysts up to 10 liters. It is filled with a turbid liquid, the daughter bubbles float inside, they can have grand bubbles - hydatid sand. In the lungs, smaller volumes of bubbles do not contain hydatid sand, so they are called "acephalokists". A dense fibrous capsule forms around the bay.

The parasite causes a very complex pathogenesis of the disease, but it is not necessary to the full extent for clinicians. It is necessary to remember the main points: the echinococcal cyst is allergenic, forms polyallergy, eosinophilia and a complex of specific antibodies that allow immunoreactions to reveal the disease in the initial stages. Echinococcal cyst causes atrophic compression of tissues with complete or partial dysfunction, which can be identified by 4 laboratory tests. A rupture, opening it with the ingress of contents onto the peritoneum, causes a profound, immediate anaphylactic shock, which practically can not be suppressed. Immunity is not formed. Possible re-infection. But the developed echinococcal cyst serves as a monopolist. Other blisters with it develop extremely rarely, in contrast to alveococcosis. The clinic is polymorphic. There are 3 stages in the flow;

1. Latent (asymptomatic) - from the moment of oncosphere penetration to the appearance of the first symptoms. There are no complaints. Echinococcal cyst is detected accidentally during operations on the abdominal cavity. Less often, and in a later period, when the echinococcal cyst reaches 3-5 mm, it can be detected with ultrasound or computed tomography.
2. Symptomatic, when there are symptoms of impaired function of the organ of localization due to compression of the organ parenchyma itself and surrounding tissues. Common symptoms: weight loss, weakness, urticaria, zosinophyllia of the blood. Local manifestations are very poorly expressed. When localized in the liver: pain, a feeling of heaviness in the right hypochondrium, with external location palpable tumor-like elastic formation, a symptom of the trembling hydatids is revealed (above the tumor-shaped formation they set the palm with the fingers apart, with a strong tapping on the third finger shows a characteristic trembling). If the echinococcal cyst is located in the lung: chest pain; persistent dry cough, hemoptysis.
3. Occurrence of complications: the echinococcal cyst is inflamed, calcification, a breakthrough into the abdominal or pleural cavity. This is accompanied by pain syndrome, anaphylactic shock, the formation of festering fistula, ascites, jaundice, liver failure, respiratory failure, lung atelectasis, etc.

The duration of each stage can not be ascertained, it usually occurs asymptomatically up to 5 years, imperceptibly 3-5 years. In most cases, it appears only when complications develop.

True relapses are extremely rare, after a long time after a radical operation. False relapses, caused by the violation of radicality, the abandonment of wall sections, seeding with daughter bladders are noted in a year after the operation in 11.8% of cases.

How is the echinococcus cyst recognized?

Echinococcal cyst is diagnosed on the basis of epidemiological history, clinical picture, complex clinical examination data: X-ray, ultrasound, functional and laboratory, magnetic resonance, etc. X-ray methods are most effective at calcification of the bladder, since in this case a ring of calcification, characteristic only for echinococcus. In the lungs, the echinococcal cyst is identified by a fibrous calcification ring, its shape varies at different phases of respiration - Nemenov's symptom; Between the membrane of the bladder and the fibrous capsule, a strip of gas - a symptom of Velo-Petenil - is often traced. If the echinococcal cyst of the lung is ruptured radiologically the Garcia-Sogers symptom is formed - characteristic shadows appear that look like a "floating lily" or "floating ice floe", which are caused by the shadow of the wall of the bladder and the shadow of the shell.

Due to possible seeding, the echinococcal cyst should not be punctured. But if the puncture is mistakenly done, an urgent laboratory test is carried out (the presence of chitin, schex scapula) and immediately performed; urgent surgical intervention. With punctate, you can also carry out the reaction of Katsoni: 0.1 ml of saline is injected intradermally into one forearm; in another - 0.1 ml sterile punctate bubble - there is a reaction in the form of hyperemia, itching, swelling. Its reliability is up to 50%, therefore, it is practically not used;

Two specific reactions are mainly used;

1. Immunological reaction of Fishman's latex agglutination. Its reliability is 96.3%. It is safe for the patient; can be used for relapses. They are mainly used for mass studies in endemic foci.
2. Simultaneously with latex agglutination, serological enzyme-immunological reactions with specific antigens are carried out. This reaction reveals the invasion already on the 7-21th day after infection. With its help, the echinococcal cyst and alveococcosis are differentiated.

Alveococcosis is a multi-chamber echinococcus caused by a helminth: Ehinokokkus alveolaris. Its structure and invasion are similar to hydatidic echinococcus. It is localized mainly in the liver. The ultimate host: fox, fox, wolf, dog, cat. Man is an intermediate host.

Infection occurs: when peeling skins, shaking them in a room, contacting with contaminated animals, eating strawberry seeds. Basically observed in taiga areas, more often in hunters, eggs are very tenacious, even at minus 40 degrees survive throughout the year.

In the development of the disease, the same 3 stages are noted as in hydatidid echinococcus. The clinic is also expressed in the development of hepatic insufficiency: weakness, weight loss, jaundice; but, unlike cirrhosis, there is never ascites. The liver is initially enlarged and very dense - according to Lyubimov - "iron liver" - later it becomes bumpy to the touch.

Complications differ from hydatidosis echinococcosis: it germinates in neighboring organs, gives metastases to the lungs, brain. The parasitic tumor is prone to decay in the center with sequestration, there may be a breakthrough into the abdominal and pleural cavities, the hepatic ducts and bronchi.

Diagnosis at the early stages of development is rarely done - 15% of cases, mainly with mass surveys of the population. It is more often detected in the late period when examining the liver to determine the cause of the development of liver failure; On the survey radiographs small calcareous calcifications are "calcareous sprays." More reliable data are obtained with computed tomography and laparoscopy.