What kind of tumor is this and where does it occur?
The tumor develops from the interstitial cells of Cajal - a kind of pacemaker of the intestinal wall. In most cases, a mutation occurs in the cells, due to which the receptor constantly sends a signal to divide. The formation grows in the thickness of the wall, protruding into the lumen of the organ or outward into the abdominal cavity. The mucous membrane above it remains intact for a long time, and only when it is ulcerated does bleeding appear. The tumor metastasizes mainly to the liver and peritoneum, and rarely affects the lymph nodes, which distinguishes it from stomach cancer.
- The stomach is the most common location
- Small intestine
- Colon and rectum
- Esophagus and omentum - rarely
- Growth into the lumen of the organ or outward
- Metastasis to the liver and peritoneum
Symptoms
Small tumors up to a few centimeters usually do not manifest themselves in any way and remain an accidental discovery. Complaints appear as they grow. The most common scenario is chronic blood loss from the ulcerated surface: the person gradually becomes pale, tired, his hemoglobin drops, and the stool may darken. Large formations cause a feeling of heaviness and fullness, nausea, and early satiety. If located in the small intestine, obstruction is possible. Acute situations - massive bleeding or tumor rupture - require emergency care.
- Weakness, pallor, shortness of breath with anemia
- Black stools or bloody vomit
- Heaviness and discomfort in the upper abdomen
- Rapid satiety, nausea
- Palpable formation
- Weight loss
- Attacks of pain due to intestinal obstruction
How to make a diagnosis
During gastroscopy, the doctor sees a bulging wall with smooth, unchanged mucosa - a conventional pincer biopsy here is often uninformative because it takes only the superficial layer. Endoscopic ultrasound allows a more accurate assessment of the tumor: it shows from which layer the tumor grows, its size and structure, and makes it possible to take the material with a thin needle. Prevalence is assessed using contrast-enhanced computed tomography. The final diagnosis is made by morphologists using immunohistochemical research, supplemented by molecular analysis of mutations.
- Gastroscopy with examination of submucosal formation
- Endoscopic ultrasound with fine needle biopsy
- MSCT of the abdominal cavity with contrast
- MRI for rectal tumors
- Complete blood count and iron to evaluate anemia
- Immunohistochemical study
- Molecular genetic analysis of mutations
Risk assessment and surveillance
Tumors of this type are not simply divided into benign and malignant - the risk of progression is assessed. It depends on three main parameters: the size of the formation, its location and the mitotic index, that is, the rate of cell division. Small, low activity stomach tumors are considered low risk and some are simply monitored with endoscopic ultrasound. Small intestinal tumors of equal size behave more aggressively. It is the risk assessment that determines whether long-term drug therapy will be required after surgery.
- Tumor size
- Localization in the stomach or small intestine
- Mitotic index according to morphologist
- Capsular integrity, tumor rupture
- Type of mutation identified
- Surveillance plan for low-risk lesions
Treatment
The main method for a localized tumor is surgical removal within healthy tissue. Lymph nodes are usually not removed because they are rarely affected. It is important not to damage the capsule: rupture worsens the prognosis due to seeding of the peritoneum. A breakthrough in the treatment of this tumor was provided by targeted therapy with tyrosine kinase inhibitors: the drugs block the very signal for division. They are prescribed after surgery for high-risk cases, as well as for inoperable or metastatic tumors, sometimes before surgery to reduce the formation. The regimen is determined by the oncologist taking into account the mutation.
- Surgical removal of the tumor while preserving the capsule
- Laparoscopic operations with suitable sizes
- Targeted therapy with tyrosine kinase inhibitors
- Therapy before surgery to shrink the tumor
- Long-term treatment after surgery at high risk
- Observation with CT according to the oncologist’s schedule
- Conventional chemotherapy and radiation therapy are ineffective
