Knowledge collection for gastric cancer diagnosis

Gastric cancer must be differentiated from gastric ulcer, simple polyps in the stomach, benign tumors, sarcomas, and chronic inflammation in the stomach. Sometimes it also needs to be differentiated from hypertrophy of gastric folds, giant folds, gastric mucosal prolapse, pyloric muscle hypertrophy, and severe gastric fundus varices. Today we will talk about the knowledge about gastric cancer diagnosis:

1. Laboratory examination

Early suspicion of gastric cancer, low or absent free gastric acid, such as decreased hematocrit, hemoglobin, and red blood cells, occult blood in stool (+), low total hemoglobin, inverted white blood cells, etc., water and electrolyte disorders, acid-base imbalance and other laboratory abnormalities.

(II) X-ray manifestations

Double contrast of gas and barium can clearly show the contour of the stomach, peristalsis, mucosal morphology, emptying time, filling defects, niche shadows, etc. The accuracy of the examination is nearly 80%. Barium contrast is the first choice and main method for gastrointestinal tumor examination, and it is of great significance for the diagnosis of gastrointestinal tumors. For the elderly, children, those with severe spinal deformities, those with cardiovascular complications, and those who are afraid of gastroscopy, gastrointestinal barium meal X-ray examination should be the first choice besides gastroscopy. However, some lesions are difficult to detect by X-ray examination, such as early gastric cancer. Therefore, X-ray diagnosis must be closely combined with clinical practice, and suspicious lesions must be repeatedly examined and closely followed up. Negative X-ray examination cannot rule out the existence of lesions. Barium contrast has promoted the development of "gastrointestinal dynamics", which is the study of the motor function of the gastrointestinal tract, as well as a series of technical changes that occur in barium contrast. It is the key to give full play to the advantages of double contrast of gas and barium. , especially for the detection of early tumors, it has important diagnostic value.

(III) Fiber endoscopy

It is the most direct, accurate and effective method for diagnosing gastric cancer. At present, gastroscopy has become the most important tool for diagnosing upper gastrointestinal diseases. The three main endoscopes used in clinical practice are fiber endoscopes, electronic endoscopes and ultrasonic endoscopes. Endoscopic and ultrasonic endoscopic characteristics of gastric cancer For gastric cancer, the basic morphology of lesions is mainly observed under endoscopy: bulge, erosion, depression or ulcer; darkening or lightening of the surface color; rough and uneven mucosal surface; whether the lesion boundary is clear and the state of the surrounding mucosal folds. The lesions are distinguished by comparing with normal mucosa.

Gastroscopy is particularly suitable for: ① those who suspect benign or malignant tumors in the stomach; ② dynamic observation of gastric ulcerative lesions in a short period of time to distinguish between benign and malignant; ③ finding the primary lesion of clavicular lymph node metastasis. Gastroscopy can directly observe changes in the gastric mucosa, and biopsy the lesion tissue through the gastroscope. The size of the cancer should be estimated under the microscope. Those less than 1 cm are called small gastric cancers, and those less than 0.5 cm are called micro gastric cancers. This improves the early detection of gastric cancer. In addition, active treatment is given to gastric precancerous lesions such as gastric polyps, gastric ulcers, and chronic atrophic gastritis, especially those with moderate to severe metaplasia or atypical hyperplasia of the intestinal epithelium, after biopsy diagnosis, to ensure the purpose of early detection and early treatment of gastric cancer.

(IV) Exfoliative cytology examination

Some scholars advocate this examination when clinical and X-ray examinations reveal suspected gastric cancer.

(V) B-ultrasound

It can be used to understand whether there is metastasis to the surrounding solid organs.

1. Destruction of normal gastric wall structure: The cancer infiltrates and grows along the gastric wall, often invading all layers of the gastric wall, causing the gastric wall to thicken, with unclear layers and a rough, uneven mucosal surface. ① For example, in the case of protruding gastric cancer, the tumor protrudes from the gastric wall into the cavity, with an uneven surface and a cauliflower pattern, and the image resembles a "ring-like" change. ② In the case of ulcerative gastric cancer, the surface of the lesion area is dirty or bleeding, so the echo is strong, and the tumor often reaches the muscular layer to form a large and shallow disc-shaped ulcer, with a circle of embankment-like protrusions on the edge and a depression in the middle. The phenomenon of echo loss is common, which resembles a "crater" or "crater-like" image change. ③ Infiltrative type, because the infiltrative growth of the cancer involves all layers of the gastric wall, the gastric wall is locally or diffusely thickened with unclear boundaries.

2. Abnormal stomach morphology and changes in gastric motility: Due to the above reasons, the tumor invades the stomach wall, causing irregular thickening of the stomach wall, resulting in narrowing and deformation of the stomach cavity. In addition, due to the growth of the tumor, the stomach wall becomes stiff, and the peristalsis decreases or disappears, resulting in slow gastric emptying and gastric fluid retention. 3. Metastasis of gastric cancer: Gastric cancer metastasis is divided into direct spread, hematogenous, lymphatic metastasis and implantation. Direct spread is mainly due to tumor invasion of the serosal layer, often affecting adjacent organs. In addition, there are certain rules for the spread of gastric cancer, such as the spread of cardia cancer to the lower esophagus or direct invasion of adjacent organs such as the liver, greater omentum, transverse colon, pancreas and abdominal wall; pyloric cancer generally spreads to the duodenum. The images of these invaded tissues show that the original clear boundaries between the stomach and surrounding organs are destroyed, forming unclear boundaries or causing the affected organs to change into a "pseudo-kidney shape". If gastric cancer metastasizes along the lymphatic vessels, round or quasi-round enlarged lymph nodes are often seen around the porta hepatis or abdominal aorta, which are low echoes, nodules or masses. Therefore, enlarged lymph nodes around the stomach and abdominal aorta and typical signs of liver metastasis are important evidences for ultrasound to indicate gastric malignant tumors, and are also helpful for determining the tumor stage. They are an indispensable supplement to gastroscopy and X-ray barium meal examinations.

(VI) CT examination

Understand the invasion of gastric tumors, the relationship with surrounding organs, and whether resection is possible. CT signs of gastric cancer: Early gastric cancer is difficult to display with conventional CT. It mainly relies on double contrast radiography of gas-barium and fiber endoscopy. Dynamic CT can show the multi-layer structure of the gastric wall and the destruction of the mucosal layer to diagnose early gastric cancer. The manifestations of advanced gastric cancer are: 1. Thickening of the gastric wall, but thickening of the gastric wall is not a unique manifestation of gastric cancer, and it needs to be differentially diagnosed with gastric lymphoma, chronic hypertrophic gastritis, etc. 2. The mass in the gastric cavity has an irregular shape and a rough surface, which may be accompanied by ulcers of varying depths. 3. When the tumor infiltrates outward, it manifests as a thinning of the fat layer around the stomach, and involves adjacent organs such as the liver and pancreas. 4. Enlarged lymph nodes in the greater and lesser curvature of the stomach, and beside the abdominal aorta

Differentiation of gastric cancer from other malignant tumors:

(1) Primary gastric malignant lymphoma: Primary gastric malignant lymphoma accounts for 0.5% to 8% of gastric malignant tumors. It is more common in young and middle-aged people and is prone to occur in the gastric antrum. The clinical manifestations are similar to gastric cancer. About 30% to 50% of Hodgkin's disease patients have persistent or intermittent fever. The detection rate of lesions in X-ray barium meal examination can reach 93% to 100%, but only 10% can be diagnosed as gastric malignant lymphoma. X-ray signs are diffuse irregular thickening of gastric mucosal folds, multiple ulcers with irregular patterns, large folds formed in the mucosa at the edge of the ulcer, single or multiple round filling defects, and "cobblestone-like" changes. When huge gastric mucosal folds, single or multiple polypoid nodules, and surface ulcers or erosions are seen during gastroscopy, gastric lymphoma should be considered first.

(2) Gastric Leiomyosarcoma: Gastric Leiomyosarcoma accounts for 0.25% to 3% of gastric malignant tumors and 20% of gastric sarcomas. It is more common in the elderly and is prone to occur in the gastric fundus and body. The tumor is often >10 cm and is spherical or hemispherical. Large ulcers may occur due to ischemia. According to the location, it can be divided into: ① Intragastric type (submucosal type), the tumor protrudes into the gastric cavity; ② Extragastric type (subserosal type), the tumor grows outside the stomach; ③ Gastric wall type (dumbbell type), the tumor grows both inside and outside the stomach.

The above is the knowledge about gastric cancer diagnosis that we have prepared for you. I hope it can be helpful to you. If you have any questions, you can also consult our online consulting experts of Feihua Health Network. We are always here to answer your questions. Feihua Health Network has always been by your side to care about your health problems. Feihua Health Network wishes you good health!

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