Neuroendocrine tumors of the gastrointestinal tract

Gastrointestinal carcinoid tumors are formed of a certain type neuroendocrine cells. These cells are scattered throughout the thoracic and abdominal regions, but most are found in the gastrointestinal tract. Neuroendocrine cells produce hormones, which help control the digestive juices and muscles that help move food through the stomach and intestines. The carcinoid a tumor is most commonly found in the gastrointestinal tract and bronchi and may also produce hormones to release into the body.

Carcinoid Gastrointestinal tract tumors are rare and most grow very slowly. They occur in 0.03-0.08% of patients. The tumor usually occurs in the thin ones gut, rectum and the appendix. Sometimes more than one tumor forms.

They differ ripe hormone-producing carcinoid cells and immature or non-educational and not containing serotonin. Metastases are often larger than the tumor itself.

Bronchial tumors are usually solitary and develop in the main bronchi.

Clinical picture

Often carcinoid tumors do not have a pronounced clinic and are discovered incidentally during surgery for ileus or at autopsy after the patient's death. Sometimes  diagnosisit is placed during appendectomy with a preliminary diagnosis of appendicitis.

 

The most characteristic symptoms when affecting the gastrointestinal tract are:

On the duodenum:

Signs and symptoms of gastrointestinal carcinoid tumors in the duodenum (the first part of the small intestine) may include the following:

• Stomach ache;
• Constipation;
• Diarrhea;
• Change in stool color;
• Nausea;
• Vomiting;
• Jaundice (yellowing of the skin and sclera);
• Acids in the stomach.

Jejunum and ileum

The signs and symptoms of carcinoid tumors in the jejunum (the middle part of the small intestine) and the ileum (the last part of the small intestine that connects to the large intestine) may include the following:

• Stomach ache;
• Weight loss for no known reason;
• Easy fatigue;
• Feeling of swelling;
• Diarrhea;
• Nausea;
• Vomiting.

On a large intestine

The signs and symptoms of carcinoid tumors in the fat one bowel may include the following:

• Stomach ache;
• Weight loss for no known reason.

 

On the rectum

Signs and symptoms of carcinoid tumors in the rectum may include blood in the stool, rectal pain, constipation.

 

From the side of the skin – flush syndrome, prolonged cyanosis, telangiectasias, pelogroid dermatosis;
From the side of lungs – asthma;
On heart – right-sided endocardial fibrosis, tricuspid insufficiency and pulmonary stenosis.
Flush syndrome occurs with increased secretion of serotonin. Warming of the head, redness of the face, headache is observed. Dizziness and hypotension may occur. In some cases, hyperplasia and inflammation of the gums is observed. Carcinoid syndrome can occur under the influence of mental excitement, consumption of alcohol, cheese, eggs and injection of adrenaline and pentagastrin.

 

Carcinoid tumors are often combined with the syndrome of Zollinger–Ellison and peptic ulcer disease – increased serotonin and histamine cause ischemia of the gastric mucosa, hypersecretion and hyperchlorhydria.

 

Diagnosis

The diagnosis is made by measurement 5-hydroxyindoleacetic acid (5-HIOC) in 24-hour urine.

An increase in glycine, iron, copper and zinc in the urine is characteristic. False positive high values of 5-HIOK they can be found in the urine when eating foods rich in tryptophan - bananas, walnuts, prunes, blueberries, figs, potatoes, gooseberries. Slight increase in urinary flow 5-HIOK is observed in small intestinal bacterial overgrowth, disease of Whipple and gluten enteropathy.

The small size of primary tumors makes them difficult to detect on X-ray examination of the gastrointestinal tract. Selective angiography, upper and lower fibroendoscopy with targeted biopsy are used.

In case of suspicion of metastasis in the liver - ultrasound, CAT, laparoscopy with biopsy.

Treatments

The diet should be rich in nicotinic acid. All factors that can cause quinine manifestations of carcinoid syndrome - alcohol, physical exertion and foods rich in tryptophan - should be avoided.

Pathogenetic treatment includes medications that suppress the formation, release, action of serotonin, inhibitors of quinine production and of histamine, somatostatin as an inhibitor of the secretion of hormones suppressing intestinal secretion and motility, corticosteroids.