GASTRIC TUMOURS . BY PROF. MOHAMED A. EL GHARBAWI e-mail: email@example.com
Benign tumours:Rare Adenoma: In the antrum Sessile or pedunculated Malignant change is rare. Treatment: Excision Small : endoscopic Big: by surgery (2)Fibroma, lipoma and leiomyoma: Grow to outside Mucosa may be stretched over the tumourand may ulcerate.
Carcinoma of the stomach Incidence: Most countries (20/100.000) > In Japan (100/100,000) Age: Above 50 Commonest between 70-80ys. In Japan, Iran, South Africa it occurs at younger age. Sex: Male/Female = 2 : 1 Etiology: No definite etiological factor
Precancerous lesions 1- Adenomatous polyps. 2- Pernicious anemia: Incidence of carcinoma is 3 times > normal individuals. 3- Chronic gastritis: atrophic gastritis, gastritis following gastric operations 4- Chronic gastric ulcer. 5- Achlorhydria, especially when associated with protein malnutrition, viral infection and hypogammaglobulinemia. 6- Alcoholism. 7- Blood group A is more in cancer stomach patients.
Pathology Macroscopic types 60% occur in the pyloric antrum 25% in the body 10% in fundus 5% diffuse in stomach Recently there is an increase in the incidence of carcinoma affecting the upper third of the stomach and cardia. Gastric cancer is classified into two types: Earlygastric cancer:Mucosa or submucosa is infiltrated. Diagnosed in screeningprograms by endoscopy. Early gastric cancer may be protruding, superficial, or excavating (penetrating).
B. Advanced gastric cancer: Common and diagnosed clinically. It may take the form of: 1) A fungating cauliflower-like mass. 2) An ulcer with raised indurated edges and usually surrounded by smaller ulcers. 3) Colloid carcinoma. All layers of the stomach are infiltrated by areolar tissue containing transparent gelatinous substance.
4) The diffusely infiltrating variety Linitis plastica in which the wall of the stomach is markedly thickened and indurated and the lumen is markedly reduced this may occur only in the antrum or may affect the stomach diffusely. The mucous membrane is intact and the lesion may be missed by endoscopy.
LINITIS PLASTICADIFFUSE ADENOCARCINOMACANCER STOMACHPATHOLOGICALSPECIMEN
Unfortunately, All cases fall into the category of late cancer due to absence of Screening programs and the cases are diagnosed when become clinically evident at late stage.
Microscopically • Stomach cancer is adenocarcinoma in • 95% with various grades of differentiation • The less the differentiation the worse the prognosis. • Both colloid carcinoma and Linitis plastica carry a bad prognosis. • In linitis plastica, it is difficult to find malignant cells under the microscope. • Rarely, stomach cancer is squmaous cell carcinoma • as a spread of oesophageal cancer to the cardia
HISTOPATHOLOGYOF ADENOCARCINOMA(UP)DIFFUSE ADENOCARCINOMALINITIS PLASTICA(DOWN)COLLOIDALSIGNET RING ADENOCARCINOMA
N.B: Lauren's classification: Lauren classified cancer stomach into 2 groups Group I (80%): (Intestinal gastric cancer): cancer in this group developed from gastric epithelium which has undergone intestinal metaplasia and the cells resemble the cells of small intestine ( have brush borders). The growth appearance of this group includes Fungating or polypoidal mass (40%), more in body &fundus or Malignant ulcer type (40%), more in pylorus
LAUREN’S CLASSIFICATIONVERSUSWHO CLASSIFICAION&INTESTINAL TYPEHISTOPATHOLOY
2) Group II (20%): diffusegastric carcinoma or infiltrative type. Usually in pylorus.
Spread Direct spread is infiltration of the wall of the stomach in depth, in circumference, and in length. The last is important because the spread occurs for some length beyond the edge of the tumour, a point to remember when planning a radical operation. After the gastric wall has been transgressed carcinoma will infiltrate any neighbouring structure as the liver, spleen, pancreas or colon.
2. Lymphatic spread occurs both by permeation and by embolization. It first occurs to perigastric lymph nodes then to more centrally placed groups. Good knowledge of the lymphatic drainage of the stomach is important in planning radical surgery. 3. Blood spread occurs mainly to the liver and very rarely beyond it to bones.
4. Transcoelomic spread occurs to the ovaries in youngfemales (ovaries are not yet atrophic). These ovarian secondaries are known as Krukenberg's tumours. Metastases to the Douglas Pouch lead to what is known as Blumer's shelf.
Clinical features Usually diagnosed at a late stage because of the vague and mild symptoms, patients present late, Also, late diagnosis by the clinician. A high index of suspicion is needed for its detection at an earlier stage. Most of cases are discovered late due to absence of a massive screeningprogram. Patients with carcinoma of the stomach may fall into one or more of 5 groups:
Dyspepsia group. A person above 40 years who begins to complain of dyspepsia should be fully investigated for the possibility of stomach cancer. The patient has anorexia and vague sense of discomfort after meals. Epigastric pain may occur and in late cases and may be severe. Nausea and early satiety is common. A particular dislike to meat is often described but is only rarely seen.
2. Insidious group (Anorexia, Asthenia, Anemia). Restlessness, easy fatigue and unexplained weight loss. Patient is found to be anemic. Anemia in the elderly should always raise the possibility of malignancy̦ the stomach being one of the commonest to cause it. Unfortunately, these symptoms may pass unnoticed, and the disease is discovered late.
3. Mass group. An epigastric mass. About 30% of patients presenting with mass will be found to have inoperable carcinoma on exploration. 4. Obstructive group. Carcinoma at one end of the stomach causes obstructive symptoms and will and will present earlierthan the more common variety occurring in the antrum or body. At the cardia it will lead to dysphagia while at the pylorus it causes vomiting (see pyloric stenosis).
5. Metastatic group. A hard irregular liver due to secondaries, jaundice, malignant ascites, or an enlarged left supraclavicular lymph node "Troisier's sign", all of which are signs of inoperability. Hematemesis and melena are uncommon while perforation is still rare. A patient known to have a gastric peptic ulcer who becomes refractory to treatment should be viewed with suspicion.
Investigations Blood picture. may reveal micro or macrocytic anaemia. 2. Barium meal. 75% accuracy. It is the most accurate for pyloric growths. It is important to obtain a mucosal relief pattern before filling the stomach with barium. Small growth may overlockedif this is omitted. A barium study with views taken in the Trendlenburg's position to detect growths in the fundus and cardia.
If the lesion is of the cauliflower like variety, it will appear as a persistent irregular filling defect. If it is a malignant ulcer it will appear as an ulcer niche outside the ulcer bearing area. If the lesion is linitis plastica there will be marked narrowing of the lumen of the stomach but the flow of barium is not interrupted .
BARIUM MEALIN CANCER STOMACH(UP)CAULIFLOWERFUNGATIN(DOWN)DIFFUSELINITIS PLASTICA
3. Endoscopy It directly view the tumor and multiple biopsies should be taken. Endoscopy can detect tumours at an earlier stage than can radiology. 4. An abdominal US is essential for the detection of liver metastases. Its role in assessing lymph node involvement is less important. ENDOSONOGRAPY FOR EVALUATION OF LOCAL SPREAD
GASTROSCOPYFORCANCER STOMACH(UP)ULCER TYPE(DOWN)DIFFUSELINITIS PLASTICA TYPE
5. CT scan is more accurate for the detection of • lymph node involvement than a US and may • be helpful in pre-operative staging of the • disease • 6. Estimation of CEA antigen has a better value • for prognosis rather than diagnosis.
Treatment Early cases. The aim of treatment is cure. A radical operation has to be performed. This entails removal of the tumour with an adequate safety margin above it of at least 5 cm and 1.5 cm of the duodenum below it, together with both omenta.
All the draining lymph nodes must be removed ligation and division of the vessels around which they are located, the left gastric, the right gastric, and the twoepiploics.
According to the site of the neoplasm, the extent of resection will be determined: For tumours of the lower third of the stomach, a lower radical partial gastrectomy is performed with anastomosis of the remaining upper stomach to the jejunum. This anastomosis is called ( Billroth II or Polia) gastrectomy. (b) For tumours of the middle third of the stomach a total radical gastrectomy is performed and the oesophagus is anastomosed to a Roux-en-Y loop of jejunum .
(c) Tumours of the upper third are treated by oesophagogastrectomy through a thoraco - abdominal incision to guarantee an upper safety margin. The upper oesophagus is anastomosed to a Roux-en-Y loop of jejunum.
Patients with incurable or irresectable lesions may have some benefit from various palliative procedures: Palliative gastrectomy. If it can be performed, gastrectomy offers the best chance of palliation. 2. Forirremovable tumours in the pyloric region an anterior gastrojejunostomy is performed ( Devine gastric exclusion)
3. For irresectable lesions in the upper stomach, an oesophagojejuostomy can be performed. 4. Radiotherapy and chemotherapy. These are used in the inoperable, non resectable, incompletely resected or recurrent cases.
The prognosis Prognosis is very bad. The 5 years survival rate is very low and the only hope of cure depends upon early diagnosis and treatment. Carcinoma arising on the top of a pre-existing peptic ulcer carries the best prognosis as the associated chronic inflammation obstructs the lymphatic retards the spread.
Sarcomas of the Stomach (3%): Sarcoma of the stomach is a rare tumour and it may be in the form of a Liomyosarcoma, lymphosarcoma or Hodgkin's sarcoma. Sometimes resection gives better results than for carcinoma; more-over irradiation may be of value.