Carcinoid (Carcinoid Syndrome)

Carcinoid (carcinoid syndrome)

A rare, potentially malignant, hormonally active tumor of chromaffin cell origin. The predominant localization of this tumor is in the appendix, less often in the ileum, colon (especially rectum), and even more rarely in the stomach, gall bladder, pancreas; extremely rarely occurs in the bronchi, ovary and other organs.

Etiology
The origin of many symptoms of the disease is due to the hormonal activity of the tumor. A significant release of serotonin, lysyl-bradykinin and bradykinin, histamine, and prostaglandins by tumor cells has been proven.

Symptoms, course
The clinical picture consists of local symptoms caused by the tumor itself and the so-called carcinoid syndrome caused by its hormonal activity. Local pain is detected; Often there are signs reminiscent of acute or chronic appendicitis (with the most common localization of the tumor in the appendix) or symptoms of intestinal obstruction, intestinal bleeding (if localized in the small or large intestine), pain during defecation and discharge of scarlet blood with feces (with rectal carcinoid ), weight loss, anemia.

Carcinoid syndrome includes peculiar vasomotor reactions, attacks of bronchospasm, hyperperistalsis of the gastrointestinal tract, characteristic skin changes, lesions of the heart and pulmonary artery. It is not observed in a pronounced form in all patients, but more often in cases of tumor metastases, especially multiple ones, to the liver and other organs.

The most characteristic manifestation of carcinoid syndrome is sudden short-term redness of the skin of the face and upper half of the body, accompanied by general weakness, a feeling of heat, tachycardia, hypotension, sometimes lacrimation, runny nose, bronchospasm, nausea and vomiting, diarrhea and cramping abdominal pain. The attacks last from a few seconds to 10 minutes, and can be repeated many times during the day.

Over time, skin hyperemia can become permanent and is usually combined with cyanosis, hyperkeratosis and hyperpigmentation of the skin of the pellagroid type occur. Often, patients are diagnosed with insufficiency of the tricuspid heart valve and stenosis of the mouth of the pulmonary trunk (less often other heart defects), circulatory failure.

Laboratory testing in the vast majority of cases shows increased levels of 5-hydroxytryptamine in the blood (up to 0.1-0.3 mcg/ml) and in the urine, the final product of its transformation, 5-hydroxyindoleacetic acid (over 100 mg/day).

X-ray examination of the tumor is difficult to detect due to its small size and eccentric growth. The peculiarity of the tumor is slow growth and relatively rare metastasis, as a result of which the average life expectancy of patients is 4-8 years or more. Most often, metastases are found in regional lymph nodes and the liver.

Death can occur from multiple metastases and cachexia, heart failure, and intestinal obstruction. Treatment is surgical (radical removal of the tumor and metastases). Symptomatic treatment of hot flashes consists of prescribing alpha-adrenergic receptor blockers (phentolamine); glucocorticoids, phenothiazine neuroleptics, and H2-histamine receptor blockers (ranitidine) are less effective.