Gastric malignant lymphoma

Introduction to gastric malignant lymphoma Gastric Malignant Lymphoma is the most common type of gastric non-cancerous malignancy, accounting for 3% to 5% of gastric malignancies. It occurs in the gastric lymphatic reticular tissue and is a type of lymph node-exclusive non-Hodgkin's lymphoma with primary and secondary features. The latter refers to other parts of the body or to systemic lymphoma and is the most common type. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: abdominal pain, abdominal distension, intestinal obstruction

Cause of gastric malignant lymphoma

Causes:

Virus infection (35%):

The etiology of gastric malignant lymphoma is still unclear. Some scholars believe that it may be related to the infection of certain viruses; patients with malignant lymphoma are found to have low cellular immune function, so it is speculated that cellular immune function may occur under the infection of certain viruses. The disorder and disorder lead to the onset of disease. In addition, gastric lymphoma originates from the submucosal or mucosal lamina propria lymphoid tissue, where the tissue is not exposed to the gastric cavity and is not directly in contact with carcinogens in food, so the cause of the disease and gastric cancer Different, and thus more likely to be associated with systemic factors causing abnormal growth of lymphoid tissue in the stomach.

Helicobacter pylori infection (30%):

In recent years, the relationship between gastric malignant lymphoma and Helicobacter pylori (Hp) infection has been widely concerned. Parsonnet et al found that HP infection rate in gastric malignant lymphoma, including mucosa-associated lymphoid tissue (MALT) patients. 85%, while the control group was only 55%, suggesting that Hp infection is associated with the occurrence of gastric lymphoma. Clinical microbiological and histopathological studies have shown that the acquisition of gastric mucosal MALT is the result of immune response after Hp infection, Hp The chronic infection state stimulates the accumulation of lymphocytes in the mucosa, and a series of autoimmune reactions triggered by it activate immune cells and their active factors such as IL-2, which cause the proliferation of lymphoid follicles in the gastric mucosa, which is the occurrence of gastric lymphoma. The foundation is laid, the occurrence of MALT is related to Hp infection, and the treatment of eradication of Hp can cause MALT to subside, which has caused people's attention. Bayerdorffer E et al reported that 33 patients with Hp gastritis with primary low-grade MALT lymphoma After radical treatment of Hp, it was found that more than 80% of patients had complete tumor disappearance after eradication of Hp infection, while advanced tumors were highly malignant. The tumors do not respond to the cure of Hp infection, suggesting that the development of primary low-grade MALT lymphoma may be associated with chronic Hp infection, but the long-term efficacy of simple Hp eradication for gastric MALT lymphoma remains to be followed up for a long time. The relationship between low or low gastric acidity and gastric lymphoma remains uncertain.

Pathogenesis:

Gastric malignant lymphoma can occur in various parts of the stomach, more common in the corpus and antrum, small curved side and posterior wall. The lesions are usually large, sometimes polycentric, and often limited to the mucosa or submucosa. Gradually spread to the duodenum or esophagus on both sides, or gradually penetrate the full layer of the stomach wall and invade the adjacent surrounding organs, often with gastric lymph node metastasis, due to reactive hyperplasia can have obvious regional lymph nodes Swollen.

1. General morphological characteristics:

The naked eye is not easy to distinguish from gastric cancer. Friedma divides the general morphology of primary gastric lymphoma into the following types:

(1) ulcer type: the most common, this type is sometimes difficult to distinguish from ulcerative gastric cancer, lymphoma can be multiple ulcers, but gastric cancer is usually a single ulcer, lymphoma caused by ulcers is shallow, diameter several centimeters to ten centimeters The bottom of the ulcer is not flat, and it may be covered with gray-yellow necrotic material. The edge is convex and hard, and the surrounding folds are thickened and thickened, and are radial.

(2) Invasive type: similar to gastric hard cancer, the stomach wall shows gastric localization or diffuse infiltration hypertrophy, wrinkles become coarse and bulging, the stomach area is enlarged and granular, and the mucosa and submucosa are extremely thickened, becoming grayish white and muscular layer. Often infiltrated and even destroyed, the subserosal layer is often involved.

(3) Nodular type: There are many scattered small nodules in the gastric mucosa, the diameter is half a centimeter to several centimeters, and the mucosal surface usually has superficial or deep ulcers, and the gastric mucosal folds between the nodules often thicken. The nodules are located in the mucosa and submucosa, often extending to the serosal surface, grayish white, unclear, thick, and even large folds.

(4) polyp type: less common, forming a localized mass under the gastric mucosa, which is polypoid or scorpion-like in the stomach cavity, and some are flat disc-shaped, the lesion texture is soft. The mucosa often has ulcer formation. .

(5) Mixed type: In one case specimen, there are two or three types of lesions present at the same time.

2. Histological characteristics:

(1) Highly differentiated lymphocyte type: mature lymphocyte proliferation, usually without the histological features of malignant cells.

(2) Low-differentiated lymphocyte type: Lymphocytes show varying degrees of immature, which is roughly equivalent to lymphosarcoma, which originally belonged to large cells or lymphoblasts.

(3) Mixed cell type: tumor hyperplasia containing lymphocytes and histiocytes instead of which cells, these tumors usually have nodular shape.

(4) Tissue cell type: Tumor proliferation of mature and differentiated cells in different stages of tissue cells.

(5) Undifferentiated type: Tumor proliferation of original reticulocytes which did not differentiate significantly by tissue cells or lymphocyte systems.

3. Histopathological classification:

(1) Histological classification: gastric malignant lymphoma is mainly divided into 3 types, namely lymphosarcoma, reticulocyte sarcoma and Hodgkin's disease, lymphosarcoma is the most common, and Honnors reports 74 cases of primary malignant stomach. Lymphoma, including 41 cases of lymphosarcoma, 29 cases of reticulocyte sarcoma, and 4 cases of Hodgkin's disease.

(2) Immunological classification (lukes and collins): According to the immunological characteristics of T cells and B cells, malignant lymphoma is divided into U cell type (non-B non-T cells, ie, unshaped cells), T cell type, B Cell type, M cell type (monocyte, tissue cell), this classification has certain application value, can clearly identify most non-Hodgkin's lymphoma B cell type, most low malignant non-Hodge Gold lymphoma is also a B-cell type; T-cell type is highly malignant and highly aggressive, and Hodgkin's disease is mostly of this type; U-cell type is more malignant and less sensitive to chemotherapy.

4. Clinical staging:

Determining the clinical stage of gastric malignant lymphoma is important for selecting treatment options and predicting the prognosis of patients. To accurately understand the extent of the lesion, the relationship between the tumor and surrounding tissues and organs must be examined by fiberopticoscopy, B-ultrasound, CT or MRI. In order to understand the tumor infiltration of the stomach, adjacent to the abdominal organs and lymph nodes, the Ann Ar-bor staging method or other improved methods are most commonly used.

In stage IIIE and IV lesions, it is often impossible to distinguish between primary gastric lymphoma and secondary gastric lymphoma because the percentage of gastric infringement in patients with acute non-Hodgkin's lymphoma is quite high.

Gastric malignant lymphoma prevention 1. Strictly prevent virus invasion: It can establish a line of defense in the body through vaccination (such as hepatitis vaccine, etc.), promote sleep, and go to the playground. It does not give any chance to invade the virus. 2, strengthen the body's immune system: eat three meals, take care of the nutrients related to immunity, prevent malnutrition; rational use of drugs, try to avoid antibiotics, corticosteroids and other drugs that damage the immune system. 3, pay attention to food hygiene: do not eat moldy food, eat less pickled, fried and high-fat foods, quit smoking (including second-hand smoke), can drink alcohol, but never excessive. 4, purification environment: room decoration and strive to be environmentally friendly, the correct use of mobile phones, computers, ionizing radiation control within the allowable range. 5. Avoid harmful chemical substances: If you do not use or use less hair dye, remove pesticides and other anti-pollution treatments for fruits and vegetables. 6, moderate sunbathing: sunbathing has a significant preventive effect on lymphoma, but can not be excessive exposure, and vice versa can lead to skin cancer. 7. High-risk groups: If you have genetic factors or are old and weak, you should eat some anti-malignant lymphoma foods and alkaline foods with high alkalinity as appropriate.

Gastric malignant lymphoma complications Complications abdominal pain, abdominal distension, intestinal obstruction

Gastrointestinal infiltration causes abdominal pain, bloating, intestinal obstruction, and bleeding. Causes erosion, ulceration, bleeding or perforation when the tumor invades the mucosa. Malignant lymphoma lacks fiber composition and is soft in texture. It is not easy to cause obstruction when the tumor is huge.

Symptoms of gastric malignant lymphoma Common symptoms Lymphatic outflow lymph nodes Congestive stomach upturn or stirring sensation of acute abdomen upper gastrointestinal bleeding abdominal pain weight loss peptic ulcer cachexia liver splenomegaly

Symptom

(1) Abdominal pain: The most common symptom of gastric malignant lymphoma is abdominal pain. The data show that the incidence of abdominal pain is above 90%, the nature of pain is variable, ranging from mild discomfort to severe abdominal pain, and even patients with acute abdomen. Most of them are dull pain and pain, and eating can be aggravated. The initial impression is generally ulcer disease, but the antacid can not be relieved. The abdominal pain may be caused by the peripheral nerve of the malignant lymphoma or the swelling of the lymph nodes.

(2) Weight loss: about 60%, caused by a large amount of nutrients consumed by tumor tissue and decreased intake of stomach anorexia, and severe cases may be cachexia.

(3) vomiting: related to tumor-induced incomplete pyloric obstruction, lesions in the antrum and pyloric area are more likely to occur.

(4) anemia: more common than gastric cancer, sometimes accompanied by hematemesis or melena.

2. Signs

Upper abdominal tenderness and abdominal mass are the most common signs. Hepatosplenomegaly can occur in patients with metastases, and a small number of patients may have no signs.

The rate of misdiagnosis at the time of clinical diagnosis is extremely high. The literature reports that it is more than 80%. There are two main reasons for this: one is that the incidence of this disease is low, which makes the clinician lack sufficient vigilance; the other is the specific signs in clinical manifestation and auxiliary examination. not much.

Examination of gastric malignant lymphoma

Histopathological examination and immunohistochemical examination are the main basis for the diagnosis of this disease.

General form

It is divided into ulcer type, multiple nodular type, polyp type and mixed type, which is difficult to distinguish from gastric cancer. Late cases show a huge brain-like change, similar to hypertrophic gastritis.

2. Type of histology

Most primary gastric lymphomas are non-Hodgkin's lymphoma, B-cell, T-cell lymphoma is rare, and Hodgkin's disease is rare.

3. Degree of differentiation

Primary gastrointestinal B-cell lymphoma is most common with mucosa-associated tissue (MALT) lymphoma, which is divided into two subtypes, low malignancy and high malignancy.

(1) B-cell low-grade MALT lymphoma: It is characterized by: 1 The tumor is mainly composed of central cell-like cells (CLL), the tumor cells are medium to small, the nucleus is slightly irregular, the chromatin is mature, and the nucleolus is not obvious. Much like small nucleated cells, 2 tumor cells invade and destroy coated epithelial cells and glandular epithelial cells, forming mucosal epithelial damage, 3 common lymphoid follicular structures or reactive lymphoid follicles, tumor cells infiltrating the lamina propria, submucosa and Muscle layer, and often involving mesenteric lymph nodes, 4 immunohistochemistry showed: CD21, CD35, CD20, bcl-2 is often positive, CD5, CD10 is negative, low-grade malignant MALT lymphoma must first be differentiated from benign lymphoid tissue proliferation In addition to mature lymphocytes, benign lymphoid tissue is often mixed with other inflammatory cells; lymphoid follicles with germinal centers often appear; often fibrous connective tissue hyperplasia: many cases have typical chronic gastric ulcer lesions; local lymph nodes without lymphoma Altered, immunohistochemistry showed polyclonal lymphocyte components.

(2) B-cell high-grade MALT lymphoma: there are obvious high-grade malignant foci in low-grade MALT lymphoma, which is characterized by enlarged tumor cells, irregular nuclear increase and transformed lymphocytes with nucleoli Cells (central mother cells), mitotic figures are more common, or Reed-Stemberg-like cells are visible.

Gastric malignant lymphoma is rare because of its history and symptoms. Therefore, the diagnosis is quite difficult. Once the diagnosis is clear, the lesions are often large. The time from onset to diagnosis is usually clear in patients with primary gastric lymphoma. Long, there are reports in the literature about 50% of patients more than 6 months, about 25% more than 12 months, although the diagnosis is more difficult, as long as through careful examination and analysis, it is possible to make a correct diagnosis in time, the current gastric lymphoma The main methods of diagnosis are:

1. X-ray tincture examination

It is the main method for diagnosing gastric lymphoma. Although X-ray examination often does not provide a clear diagnosis of malignant lymphoma, more than 80% of gastric lesions can be diagnosed as malignant lesions for further examination.

Gastric malignant lymphoma is often non-specific under X-ray barium examination, often involving most of the stomach, and is diffuse and invasive, mostly accompanied by ulceration, as seen in the X-ray. Regular round filling defects, like cobblestone-like changes, have a more positive diagnostic value. In addition, if you see the following signs, you should consider gastric lymphoma: multiple malignant ulcers; located in the posterior wall of the stomach, the small curved side is large Shallow ulcer; filling defect or sputum around the appearance of very large mucosal folds; thickening of the stomach wall, stiffness, but peristalsis can still pass; the mass is larger, the shape of the stomach is not obvious, and does not cause obstruction; the tumor spreads over the pylorus Two fingers.

2. Fiber endoscopy

In order to confirm the diagnosis of lymphoma before surgery, fiberoptic endoscopy is more and more widely used. The general type of gastric lymphoma observed by endoscopy is often similar to that of gastric cancer, so it is difficult to make a diagnosis from the general manifestations of these tumors. It is necessary to rely on biopsy. If it is a submucosal lesion, it is difficult to obtain positive tissue specimens from the tumor below the mucosa. Therefore, the positive rate of biopsy is often not as high as that of gastric cancer. Gastric microscopic lymphoma may have mucosal fold hypertrophy and edema. Multiple superficial ulcers must be differentiated from hypertrophic gastritis and depressed early gastric cancer. Sometimes some ulcerated malignant lymphomas can be temporarily healed and are difficult to distinguish from gastric ulcers, such as malignant lymphomas with ulcerative lesions. The diagnosis can be confirmed by cell brushing under direct vision or by directly clamping the tumor tissue for biopsy.

3. Endoscopic ultrasonography

Ultrasound endoscopy can clearly show the layers of the stomach wall, so that the infiltration of gastric lymphoma can be seen. The technique can detect the upper gastrointestinal malignant tumor with a sensitivity rate of 83% and a positive rate of 87%. Lymph node metastasis.

4. Grayscale ultrasound and CT examination

It can be seen that the stomach wall is nodular thickening, which can determine the location, extent and response to the treatment. It is a gastric lymphoma of the abdominal mass. Ultrasonography can help diagnose.

Diagnosis and differentiation of gastric malignant lymphoma

diagnosis

Dawson (1961) criteria for the diagnosis of gastric malignant lymphoma:

1. No superficial lymphadenopathy.

2. The total number and classification of white blood cells are normal.

3. There is no mediastinal lymphadenopathy in the chest radiograph.

4. In addition to the involvement of the stomach and regional lymph nodes, no mesenteric lymph nodes or other tissues are violated.

5. The tumor does not involve the liver and spleen.

According to this, the diagnosis must be made after the operation, so those who have abdominal pain with fever, significantly reduced weight; upper abdominal pain can not be effective according to the treatment of peptic ulcer; upper gastrointestinal bleeding for a long time, accompanied by frequent vomiting Those who should think about the possibility of this disease, if necessary, consider exploratory laparotomy.

Differential diagnosis

The clinical symptoms of gastric lymphoma are often similar to gastric cancer or gastric ulcer, and attention should be paid to differential diagnosis.

Gastric cancer

In addition to pathology, clinical identification of gastric lymphoma and gastric cancer does have certain difficulties, but the main features of gastric lymphoma are: 1 average age of onset is lighter than gastric cancer; 2 longer course and overall condition; 3 obstruction, anemia and The cachexia is less common; 4 the tumor texture is softer and the cut surface is reddish; 5 the tumor surface mucosa is intact or not completely destroyed.

2. Pseudolymphoma

In addition, histological attention should be paid to the difference between benign pseudolymphoma. The clinical symptoms and X-ray findings of the two are very similar. In histology, a mixed infection infiltration appears in the lymphatic reticular mass, mature. Lymphocytes and various other infected cells appear in the follicular tissue at the same time, and are intertwined with the ubiquitous scar tissue. It is important to look for a true germinal center carefully, which can often be distinguished from lymphocyte sarcoma.

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