Omental cyst

Introduction to omental cyst Omental cyst is a rare disease, accounting for only about 5% of omental disease, and its incidence is much lower than that of mesenteric cyst. The ratio of the two is about 1:5. The omental cyst is located on the two layers of the omentum. Between the membranes, it is divided into true cysts and pseudocysts. The former is mostly due to abnormal development of congenital ectopic lymphoid tissue or lymphatic obstruction. The wall of the capsule is thin, and the wall is covered with a single layer of endothelial cells, which can be single room or Multi-room, the contents are mostly pale yellow serum and chyle-like liquid, accompanied by bleeding, infection cases, the fluid in the sac is bloody, grass green, orange-red or brown, the capsule wall is hypertrophied, edematous, and the intima disappears; It can be caused by inflammation, injury and parasites. Its wall is thick, composed of inflammatory cells and fibrous connective tissue. It is not lined with endothelial cells, mostly single room, containing turbid inflammatory exudate or blood. basic knowledge The proportion of illness: 0.03% Susceptible people: no special people Mode of infection: non-infectious Complications: intestinal obstruction, intestinal torsion, retinitis, abdominal pain

Omental cyst etiology

(1) Causes of the disease

The cause may be related to the following factors:

1. A certain segment of the lymphatic vessel is blocked and enlarged to form a cyst.

2. Variation of embryonic cells: Cysts can be developed by the proliferation of residual or ectopic embryonic tissues.

3. Injury hemorrhage: Degenerated from hematoma, which may be foreign body or surgical injury.

4. Inflammatory reaction: Pseudocysts occur mostly after inflammation, which may be the result of fat necrosis, or may be caused by other causes.

(two) pathogenesis

Omental cysts are divided into two types: true cysts and pseudocysts. True cysts are rare. Due to abnormal development of congenital ectopic lymphoid tissue or lymphatic obstruction, the cystic wall is thin and the wall is covered with a single layer of endothelial cells. Single or multi-room, the contents are mostly light yellow serum and chyle-like liquid. The pseudocyst is secondary to traumatic hematoma of the omentum, inflammation, fat necrosis or foreign body reaction. The wall of the capsule is thick, only fibrous tissue. Unlined endothelial cells, mostly single rooms, contain turbid inflammatory exudate or blood.

Omental cyst prevention

If the disease is caused by the original disease (such as the formation of hematoma due to injurious bleeding), the primary disease is treated to prevent the occurrence of omental cyst.

Omental cyst complications Complications, intestinal obstruction, volvulus, retinitis, abdominal pain

The disease can be complicated by intestinal obstruction or intestinal torsion, and can be complicated by retinal inflammation, clinically severe abdominal pain.

Omental cyst symptoms Common symptoms Mobile dullness weight loss abdominal pain Calcified peritonitis Peritoneal irritation Abdominal swelling Abdominal mass Nausea Ascites

Small cysts generally have no clinical symptoms, and are often found by chance during open surgery. Large cysts can have symptoms, characterized by abdominal fullness and abdominal pain. Patients often occasionally find a mass in the abdomen at night and abdomen on the back. When there is a feeling of pressure, and intestinal obstruction or bowel torsion, severe abdominal pain can occur. Abdominal examination: the abdomen can be swollen and swollen. The mass is mostly located in the upper abdomen, soft, sac sexy, relatively active, no tenderness or deep In sexual tenderness, occurs in the greater omentum, small cysts, the boundaries are clear and easy to reach, a wide range of activities, and giant cysts or complications, palpation is unclear, easily misdiagnosed as tuberculous peritonitis, ascites, etc. When the giant omental cyst is in the supine position, the abdominal abdomen is voiced, and only two flank or waist are drum sounds. In the deep, the bowel sounds are heard, and the whole abdomen has a sense of vibration, but there is no moving dullness.

The clinical manifestations of this disease vary depending on the size of the cyst and the presence or absence of complications, which are grouped into 4 types:

1. Abdominal block type: The abdomen clearly touches the cystic mass with no tenderness and great mobility, which may be accompanied by abdominal pain or falling pain.

2. False ascites type: only seen in giant omental cysts, the abdomen gradually increases, the whole abdomen bulges, can not clearly touch the mass, the liquid wave tremor is obvious, but there is no mobile dullness.

3. Concealed type: mostly small cysts, accidentally found for abdominal surgery.

4. Acute abdomen type: cysts complicated by torsion, internal bleeding, ulceration or secondary infection, can cause acute abdominal pain, and peritoneal irritation, cysts rapidly increase after cystic hemorrhage, easy to infection, because most cysts are multi-atrial Infection is not easy to control, patients with high fever or long-term low fever, intermittent abdominal pain, lack of energy, poor appetite, weight loss, anemia and other symptoms of consumption of poisoning, clinically similar to tuberculous peritonitis, very easy to misdiagnosis, cyst rupture manifested in external force After the abdomen or various reasons lead to increased intra-abdominal pressure, sudden severe abdominal pain, abdominal distension, accompanied by obvious anemia, obvious blood or even inflammatory peritonitis, often like acute abdomen admitted hospitalization, cyst torsion occurs in the greater omentum free In the middle, small cysts, a wide range of activities, due to gravity-related cyst torsion, clinical manifestations of persistent abdominal pain with paroxysmal aggravation, with nausea, vomiting, physical examination found abdominal mass, confirmed by the operation of the omental cyst torsion.

Omental cyst examination

Laboratory inspection

In acute abdomen, most patients may have an increase in the number of peripheral white blood cells.

Film degree exam

1. Abdominal X-ray film

It can be seen that the abdomen has a soft tissue shadow filled with liquid, and the dermoid cyst can sometimes have calcification, bone and/or teeth and other structures.

2. Barium meal check

There may be signs of small bowel displacement or compression, the small intestine is moved to the posterior superior abdomen and the sides of the spine, the stomach is displaced upwards, the distance between the anterior abdominal wall and the small intestine is significantly widened, and the transverse colon is displaced upwards in the barium enema examination, and the descending colon is displaced to the posterior lateral side. .

3.B-ultrasound

As the preferred method of examination, if it can show the anterior abdominal wall, the boundary is clear, and the cystic mass is easily pushed by the probe to all sides, and the boundary between the liver, spleen, pancreas, kidney and ovary is clear, then the diagnosis of the disease is made. It is of great value. Because the examination is simple, rapid and painless, it is especially useful for the diagnosis of omental cysts with concurrent torsion or internal hemorrhage.

4. Celiac angiography

The presence of a large omental artery and its branches extending and surrounding the cyst provides direct and powerful evidence for the diagnosis of this disease.

5. Laparoscopy

The lumps can be viewed directly.

Diagnosis and differentiation of omental cyst

diagnosis

X-ray examination of gastrointestinal barium can be found in the small intestine displacement and compression signs, difficult to identify with mesenteric masses, skin-like cysts can be seen calcification or teeth, bones and other structures, ultrasound helps to determine whether the cyst is single or multi-room, but need Different from mesenteric cysts, posterior peritoneal cysts and ovarian cysts, B-ultra-visible cysts move up and down with the breathing, and the small intestine moves to the retroperitoneal wall. Intravenous pyelography can be used to identify the retroperitoneal cyst. The exact location is best for CT scan, but CT It is also difficult to determine the source of the cyst, and it is also feasible to perform laparoscopic angiography, which can show that the omental artery and its branches extend and surround the cyst, and often require surgical exploration for final diagnosis.

Differential diagnosis

The disease lacks characteristic symptoms and signs, so the clinical diagnosis is difficult. The correct diagnosis rate of preoperative diagnosis is only 13% to 57%. It should be clinically associated with tuberculous peritonitis, mesenteric lymphadenitis, mesenteric cyst, and echinococcosis cyst. Identification.

Tuberculous peritonitis

The disease is mainly childhood and young adult diseases, more common in women, clinically subacute and chronic and other manifestations, most have low fever, infirmity, weight loss, anemia, night sweats, diarrhea and other symptoms of poisoning, common ascites The mobile voiced sound is positive, often with mild tenderness and muscle tension, showing a typical "dough-like" touch, and the tuberculin test has diagnostic value.

2. Non-specific mesenteric lymphadenitis

The disease occurs in preschool and school-age children, and there are many boys. The children often have a history of recent upper respiratory tract infections. The typical symptoms are umbilical cord, right lower abdomen and right abdominal cramps. Children with pain and pain feel good. The white blood cell count is increased.

3. Echinococcus granulosus cyst

The disease is most commonly seen in pastoral residents, more males, clinical manifestations have no differential significance, but by sedimentation test, complement binding test Casoni test can be identified.

4. Mesenteric cyst

Mesenteric cysts and omental cysts are difficult to distinguish clinically. Selective superior mesenteric artery angiography is important. Mesenteric cysts can push the mesenteric vessels up or apart.

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