Carcinoid is a slowly growing potentially malignant tumor that is capable of releasing hormonally active elements. This phenomenon belongs to the category of neuroendocrine neoplasms. A tumor is formed from the cells of the diffuse system, which are present in all internal organs. The bronchopulmonary apparatus ranks second in terms of the number of these structures, yielding primacy to the digestive tract.
Carcinoid of the lung is a non-aggressive malignant tumor, which, in case of timely detection and the presence of a competent therapeutic regimen, has a favorable prognosis.
Mechanism of occurrence
Neuroendocrine cells, on the basis of which pathological neoplasms are formed, appear even in the period of intrauterine development in the neural crest area, after which they move to the lungs. The tumor contains neurosecretory granules that produce biogenic amines - histamine, norepinephrine, prostaglandins, adrenaline, serotonin - and hormones.
Lung carcinoid is a proximal type of cancer. In this type of pathology, the release of biologically activeelements are very low or completely absent, there is also no clear and detailed clinical picture of the disease.
Views
Based on the cellular structure, these cancers are classified into two categories.
Typical lung carcinoid is a highly differentiated neuroendocrine anomaly. The neoplasm is formed by the smallest cells with large nuclei and granules that produce a secret. These structures, in turn, also subdivide the disease into classes:
- trabecular - atypical cells demarcated by special fibrous layers;
- adnocarcinoma - a neoplasm is localized on the mucous membrane, its surface is covered with a prismatic layer of the epithelium, and its structure is predominantly glandular;
- undifferentiated - formed in the epithelial layer, spreads quite quickly and provokes the initiation of metastasis;
- mixed.
Atypical lung carcinoid occurs in only 10-30% of all cases. This tumor has an aggressive character, spreads rapidly, has increased hormonal activity, and metastasizes throughout the body. Such cancer resembles an infiltrate with a disorganized structure, which consists of large pleomorphic elements. In the lungs with this type of pathology, necrotic foci may appear.
Reasons
As you know, the reliable causes of various types of cancer still remain unidentified, and lung carcinoid in thisplan is no exception. But experts have found several predisposing conditions that may well provoke the onset of a tumor in the respiratory system. These should be attributed primarily to:
- genetic predisposition;
- severe stages of viral infections;
- chronic poisoning of the body with alcohol and tobacco.
Clinical picture
Lung carcinoid is equally diagnosed in both men and women. People aged 10 to 80 are susceptible to the disease. A malignant tumor is localized most often in the central zone of the organ, not far from the large bronchi, and a little less often in the parenchyma.
Severe symptoms usually begin with relapses of pneumonia. The victims have bouts of dry unproductive cough, sputum excretion is minimal, with clots or streaks of blood. Symptoms of the pathology are similar to bronchial obstruction and bronchial asthma, which is characterized by a feeling of suffocation. In parallel with carcinoid, the damaged lobe of the lung develops.
In every third patient, the defect is completely asymptomatic. Often, a neoplasm is discovered absolutely by chance during a preventive examination of the body.
Comorbidities
Simultaneously with cancer progresses ectopic syndrome, which is caused by increased production of hormones produced by tumor cells. The symptoms of this disease are:
- moon face;
- weight loss of legs and arms against the background of loss of muscle mass;
- acne;
- scarlet blush on the cheeks with a slight bluish tint;
- excessive amount of fat in the area of the chest, neck, abdomen and face;
- stretch marks in the buttocks, abdomen and thighs.
It is noteworthy that with this pathology, injuries on the skin heal very slowly. In the representatives of the weaker sex, facial hair appears according to the male type. The bones become too brittle. Over time, blood pressure readings increase.
In some cases, patients have functional disorders in the work of the digestive tract in the form of diarrhea and paroxysmal pain in the abdominal cavity. Hot flashes occur, carcinoid heart disease is born.
Distant metastases are most commonly found in liver tissues.
Diagnosis
When lung cancer is suspected, the patient is examined using instrumental and laboratory techniques. First of all, a clinical analysis of urine and blood is performed. Then the organs of the chest cavity are carefully examined.
Carcinoid of the lung is initially detected on an x-ray. To obtain more information, the patient is sent for computed tomography, which clearly demonstrates pathological changes in the tissues of the organ in several projections. In addition, the lymphatic and skeletal systems of the body are examined.
In case of detectionbronchoscopy is performed to take biological material for histology. A special smear is made from tissue samples, which is examined under a microscope - this is how the nature of the tumor is determined.
To diagnose the disease, it is also very important to detect the presence of hormones and biologically active elements produced by cancer cells. To do this, small doses of histamine-like drugs are introduced into the patient's body. If the patient has a reaction of a vegetative type - arrhythmia, hot flashes in the head and neck area, colic in the abdomen, a diagnosis of "functioning carcinoid" can be made.
Additionally, other diagnostic methods can be used:
- magnetic resonance imaging;
- scintigraphy;
- positron emission tomography.
Treatment of lung carcinoid
The main therapeutic measure used in relation to patients with this diagnosis is the surgical removal of damaged tissue. For this, an anatomical resection is performed - a segment or lobe of the lung is excised, and the parenchyma remains intact. In the case of surgical intervention, relapses of the pathology are extremely rare. Such treatment gives a positive result.
If the carcinoid has penetrated into the bronchus, the damaged area of the tree is resected and sutured with special threads. This is necessary to align the cartilage of the organ.
If cancer is found directly in the lung, lymph nodes are removed andfiber in the mediastinal area.
Together with surgery, the patient is recommended chemotherapy, radio wave exposure, the use of potent immune medications. With the help of drugs, the hormonal background of the patient is corrected.
Further prognosis for lung carcinoid
This disease is not considered dangerous. The five-year life expectancy for lung carcinoid of a typical form is about 90-100%. But with an atypical course of pathology, the situation is much worse. In this case, hardly 50-60% of patients can speak of a five-year survival rate. Only 30% reach the ten-year life expectancy threshold.
After surgery, even in the case when cancer cells remain along the resection line, the neoplasm rarely provokes relapses. One in four patients may well live up to 25 years.
Prognosis for atypical lung carcinoid, as already mentioned, is not so rosy. In the case of lymph node metastases, the five-year survival rate reaches only 20%. That is why, when an atypical lung carcinoid is detected, therapy that involves the preservation of the damaged organ is simply inappropriate.
