胃平滑肌肉瘤

　　胃平滑肌肉瘤与胃肠道其他间质肿瘤类似胃平滑肌肉瘤主要起源于平滑肌组织，少部分可能为神经起源，部分由良性胃平滑肌瘤恶变而来。

　　半数的胃平滑肌肉瘤病例有肿瘤中心性溃疡，加之血循环丰富，故破溃后常易发生上消化道出血，以黑便多见。少数患者出血量大时可出现呕吐咖啡样物或解红色血便。肿瘤可直接侵犯胃周围组织，常累及大网膜及腹膜后，并经血行转移，多见于肝，其次为肺。淋巴转移不常见。

　　胃平滑肌肉瘤的临床表现与肿瘤生长部位、类型、病期及有无并发症等有关。早期无特异性症状，典型者表现如下：

　　1、腹痛

　　约50％以上的患者发生腹痛，常先于出血和肿块。多为隐痛或腹部不适感，偶呈剧痛。腹痛系由瘤体膨大、牵拉、压迫邻近组织所致。

　　2、腹部包块

　　半数左右出现腹部包块，小者如核桃。多有粘连，较固定，触之常有囊性感，触痛不明显。

　　3. Gastric hemorrhage

　　Gastric smooth muscle sarcoma with bleeding is also common, often intermittent, persistent small amount of bleeding. Black stools are the main manifestation, and hematemesis is rare. Extremely few cases present with massive bleeding or shock. The main cause of bleeding is that the tumor is compressed or insufficiently supplied, causing central necrosis and infarction, as well as ulceration on the surface of the tumor. It may be accompanied by anemia symptoms.

　　4. Other manifestations such as fever and weight loss.

　　The above are the symptoms and signs of gastric smooth muscle sarcoma. If there are the above suspected symptoms, it is necessary to actively go to the hospital for examination, and the doctor will guide the treatment according to the results. Early detection and early treatment of the disease are important.

　　Since the etiology of gastric smooth muscle sarcoma has not been clarified, there is no special preventive method. In addition to paying attention to dietary hygiene and avoiding or reducing the intake of possible carcinogens, it is recommended to eat more vegetables and fruits rich in vitamin C. For so-called precancerous lesions, close follow-up should be conducted to detect changes early and receive timely treatment.

　　Gastric smooth muscle sarcoma is a malignant tumor originating from gastric smooth muscle tissue. Among gastric non-epithelial malignant tumors, it ranks second after non-Hodgkin's lymphoma, and its clinical manifestations in X-ray barium meal and gastroscopy lack specificity, easily confused with gastric cancer, gastric smooth muscle tumor, and other primary gastric tumors. Preoperative diagnosis and differential diagnosis are relatively difficult. Then, what kind of laboratory tests do gastric smooth muscle sarcoma patients need? The following introduces the laboratory examination items of gastric smooth muscle sarcoma.

　　1. Routine blood tests and pathological examinations

　　1. Routine blood tests may show changes such as iron deficiency anemia.

　　2. Histopathological examination

　　For suspected cases, routine biopsy should be performed during gastroscopy to clarify the pathological diagnosis. The biopsy material should be taken deeply. Because the pathological changes of gastric smooth muscle sarcoma are mainly in the submucosa, only 25% of the common biopsy forceps can reach the submucosa. Therefore, relying solely on endoscopic biopsy is unreliable, but if tumor top ulcer biopsy or excisional biopsy is adopted, multiple sampling can help in histological diagnosis, with a positive rate of up to 53.8%. The diagnostic criteria are:

　　① The nuclear mitotic rate of the tumor cells is ≥4 per 25HPF.

　　② The tumor cells are dense, and the heterogeneity is obvious.

　　③ The diameter of the tumor is ≥6cm.

　　④ The tumor cells invade the surrounding tissues.

　　⑤ Necrosis and cystic change may occur.

　　The diagnosis of gastric smooth muscle sarcoma mainly relies on X-ray barium meal contrast and gastroscopy or CT and other examinations.

　　1. X-ray examination

　　The gross morphology of gastric smooth muscle sarcoma is mainly extragastric and intragastric-extragastric types, with corresponding characteristics in X-ray barium meal contrast.

　　(1) Intragastric type:

　　① Submucosal circular or semicircular filling defects can be seen, with smooth edges, and soft adjacent mucosa is a characteristic.

　　② The mucosal folds on the tumor surface are flattened and disappear, and the mucosal folds can reach near the tumor, and peristalsis reaches the edge of the tumor.

　　③ The base of the tumor is relatively wide.

　　④ Individual cases may show ulcers of different sizes.

　　(2) Extragastric type:

　　When the mass grows larger towards the cavity, the gastric contour shows extrinsic indentation deformation and displacement, as well as intracavity filling defect or indentation shadow formation.

　　If there is a large extragastric mass coexisting with an indentation shadow, this type should be considered, as gastric cancer rarely has extragastric masses.

　　(3) Gastric wall type:

　　The tumor grows inward and outward simultaneously, and the mass inside and outside are connected to form a dumbbell shape.

　　(4) Smooth muscle sarcoma of the gastric fundus:

　　A semi-arc soft tissue mass is seen in the gastric bubble, and even if the lesion is close to the cardia, it rarely involves the lower end of the esophagus.

　　Barium contrast and imaging characteristics are as follows:

　　There is a circular filling defect with a regular edge in the stomach, and a typical umbilical-like ulcer shadow may appear in the middle of the filling defect. If the tumor is an extragastric type, then the phenomenon of stomach compression and displacement can be seen, and it is necessary to pay attention to whether there is flattening of the gastric mucosa, which is helpful for diagnosis.

　　① Soft tissue mass shadow or filling defect in the stomach:

　　Gastric double-contrast barium examination can show circular or elliptical soft tissue masses with a relatively smooth contour, which may be lobulated. The larger the mass, the more obvious the lobulation. After appropriate pressure with barium, a filling defect can be displayed. If the tumor is located on the lesser curvature or greater curvature of the gastric body, it appears as a semi-arc filling defect on the section line, with irregular contour and rough edges.

　　② Changes in gastric mucosa and the formation of shadow:

　　The mucosa on the surface of the tumor is easily damaged, and the necrosis, liquefaction, and shedding of the tumor lead to ulceration. During barium meal X-ray examination, barium can enter the necrotic cavity, forming an irregular depression shadow or 'bull's eye sign'.

　　③ Organ displacement:

　　When the extracavitary type tumor is large, it can deform the gastric cavity, displace surrounding organs, and artificial pneumoperitoneum gastric wall contrast can clearly show the soft tissue mass growing outward locally, as well as the size, contour, and extent of the mass.

　　(2) CT and MRI examination: CT examination helps determine the location, extent of the lesion, and the degree of invasion of adjacent tissues or organs.

　　CT and MRI images are difficult to differentiate from smooth muscle tumors, and the following characteristics are common:

　　① Soft tissue masses are usually large and limited to one side of the gastric wall. The tumor surface is smooth or lobulated, and the mass grows inward or outward, or both inward and outward, with a dumbbell shape in the typical case.

　　② Occasionally, calcification can be seen in the unenhanced images.

　　③ Necrosis and ulceration form, with low-density areas seen in the soft tissue mass. If it communicates with the gastric cavity, gas and contrast agent shadows can be seen inside, showing specificity.

　　④ Enhancement scanning shows significant enhancement in most cases.

　　⑤ The boundary between the tumor and the surrounding normal gastric wall is clear.

　　⑥ The chance of liver metastasis is high, and lymph node metastasis is rare. In some cases, the liver metastasis focus shows a 'target heart sign', where a slightly higher density shadow can be seen in the center of the low-density focus.

　　2. Gastroscopy

　　The characteristics of submucosal masses are visible:

　　The mucosa on the surface of the tumor is semi-transparent, and umbilical-like ulcers may appear in the center. If the tumor is large, the bridge folds around the mass are not as prominent as in benign smooth muscle tumors, the mass boundary is unclear, and coarse folds or even rigid gastric wall may appear.

　　An intracavitary or intracavitary and extracavitary type of mass is visible, which is large and soft, protruding into the gastric cavity. It is spherical, nodular, or lobulated, with a smooth surface and may have ulcers or bleeding. A 'bridge fold' can be found in masses with a diameter over 5cm, limited to part of the tumor margin.

　　During endoscopic biopsy, since the tumor is often located in the submucosa, it is necessary to try to take deep挖掘-type forceps from the deep mucosa to obtain a higher positive diagnostic rate. However, in elderly patients, one should be vigilant about the occurrence of severe bleeding after deep biopsy.

　　3. Selective Angiography

　　Smooth muscle tumors are rich in blood supply. Selective abdominal aortic angiography can detect tumor vessels, tumor staining, and supplying arteries. During the hemorrhagic period, contrast agents can be seen to leak into the ulcer surface and the gastric cavity. This provides a reference for the surgical method. As it is an invasive examination, it is rarely used in clinical practice.

　　4. B-ultrasound Examination

　　For gastric smooth muscle tumors with larger volume, B-ultrasound and CT examination can be helpful for diagnosis. Most smooth muscle tumors show different degrees of internal high and low echo areas in B-ultrasound, with uneven echo, irregular shape, and unclear edges. Sometimes liquefaction, necrosis, and cystic changes can be seen, but the final diagnosis still requires pathological tissue examination.

　　5. Endoscopic Ultrasound Examination

　　Due to the high frequency of endoscopic ultrasound, it directly contacts the inner wall of the digestive tract, resulting in less attenuation and high resolution. It has extremely high diagnostic value in distinguishing submucosal tumors from extramural compression. With the help of contrast agents, it can clearly show the five-layer structure of the gastric mucosa, and can clearly define the submucosal lesions, extramural compression, and the depth of tumor infiltration, etc. It has great diagnostic value for interstitial and mixed types and provides help for clinical physicians to choose treatment plans. Smooth muscle tumors occur in the muscular layer, and the cross-sectional image often shows hyperechoic images in the muscular layer, with uneven or even echo, and irregular edges. It is necessary to judge comprehensively according to the size of the mass and the echo. For a mass with a diameter of 4.0 cm and uneven echo, the possibility of smooth muscle tumor is very high. Endoscopic ultrasound examination has important reference value for tumor size, growth pattern, infiltration depth, and whether there is lymph node metastasis, etc., and provides clues for improving the positive rate of biopsy, determining the surgical method, and judging the prognosis.

　　6. Laparotomy

　　Gastroscopy deep pathological tissue examination is the key to the diagnosis of this disease. In some cases, there are clear abdominal masses that require laparotomy to make the final diagnosis.

　　The above are the laboratory tests that gastric smooth muscle tumor patients need to undergo, and these tests are very helpful in understanding the disease. The surgical treatment for this disease is effective.

　　The type of food for patients with gastric smooth muscle tumors can be chosen according to the patient's dietary preferences and habits, but it is important to consume as much nutrient-rich and easily digestible high-protein, high-vitamin diet as possible. For example, fish, eggs, fresh vegetables, and fruits (it is best to drink juice) and so on. Attention should be paid to iron supplementation because after gastrectomy, the stomach acid that acts on iron (converts trivalent iron to divalent iron) is lost, causing malabsorption. Some iron preparations can be taken orally under the guidance of a doctor, and iron pots should be used in daily life. Eating more iron-rich foods such as animal liver, spinach, and soy products is also beneficial. Drinking some yogurt is also beneficial.

　　Gastric smooth muscle tumors are not sensitive to chemotherapy or radiotherapy. After diagnosis, surgical treatment should be performed, and the type of operation is determined according to the size, location, and whether there is metastasis of the tumor. The tumor resection rate is relatively high, and some reports indicate that the resection rate can reach as high as 95%. Gastric smooth muscle tumors should be resected according to the extent of the lesion. Smaller sarcomas can be locally extensively resected at a distance of more than 3cm from the tumor margin. Larger sarcomas should undergo partial or total gastrectomy and lymphadenectomy around the stomach. Because the tumor of gastric smooth muscle tumors sometimes grows very fast, but rarely invades adjacent organs, so it is best to strive for surgical resection, which can often achieve satisfactory results. If there is a solitary metastatic tumor in the liver and the patient's general condition is good enough to tolerate surgery, partial gastrectomy and local resection of the liver metastatic tumor can be performed, which can also achieve satisfactory palliative efficacy. The following surgical methods are often used:

　　1.楔形胃切除

　　Applicable to those with tumors less than 5cm or suspected of being malignant from benign肌瘤. The margin is determined to be above 2-3cm, suture the margin, and do not change the anatomical and physiological structure of the digestive tract.

　　2. Partial Gastrectomy

　　Applicable to those with tumors larger than 5cm and less than 10cm, or tumors close to the esophagus or pylorus, the margin should be more than 5cm from the tumor.

　　3. Total Gastrectomy

　　Applicable to those with tumors invading most of the stomach, resect the entire stomach and omentum.

　　4. En-bloc Resection

　　Applicable to those with invasion outside the stomach. Resect the stomach wall and all grossly visible tumors outside the stomach, as well as a certain range of tissue around them, and then reconstruct the digestive tract according to the situation, trying to be consistent with the anatomical and physiological structure of the digestive tract.

　　5. Recurrent Tumors

　　Even if surgery is difficult, it is still possible to try surgical resection, and it should be as much as possible to resect the tumor and the involved organs.

　　Feihua Health Network reminds you:Chemotherapy and radiotherapy are not sensitive to gastric smooth muscle tumors, and the 5-year survival rate after resection is 35-50%.