Paraneoplastic syndrome is a clinical picture of a disease in which the patient has systemic manifestations of a malignant disease that occurs without metastases. This syndrome is caused by the action of certain substances synthesized by tumor formation.
Paraneoplastic syndromes are also called paraneoplasias, they represent a very heterogeneous group of diseases that develop in the body under the influence of oncological changes, but are not a consequence of the action of a specific malignant formation on certain organs and tissues. These disorders appear as a result of its conditional effect on metabolic processes and other body functions.
Paraneoplastic syndrome and pathological anatomy are closely related.
Criteria
The following criteria are distinguished:
- The parallel development and simultaneous existence of cancer and non-cancer.
- The disappearance of the symptoms of a benign disorder after applying radical surgical procedures to remove a malignant neoplasm, or effective radiation treatment and chemotherapy.
- The resumption of paraneoplastic syndrome with the appearance of tumor metastases, or with a relapse of this disease.
- The correlation of both processes.
The first scientific descriptions of the connection between non-cancer diseases and malignant neoplasms appeared more than a century ago, and the researchers who first described them are French physician-therapist Trousseau and dermatologist from Austria Gebra. However, the modern doctrine of such medical phenomena is one of the youngest in the field of oncological science and literature. There are still a lot of unresolved issues that concern not only the paraneoplasia mechanism, but also which diseases can be classified as paraneoplastic. Nevertheless, in modern medicine, the knowledge of practicing oncologists of the possibilities of combining various diseases that, one way or another, may be associated with the presence of a malignant tumor in the body, is very important.
These studies and practices are important not only for this reason. It is known that paraneoplastic syndromes tend to develop at any stage of the oncological process, but most often at later stages. These diseases can be disguised as benign lesions, which hide the earliest forms of cancer. Moreover, sometimes there are cases of manifestations of such syndromes, which are the very first signs of malignant tumors. From this follows their special diagnostic value. The term "paraneoplastic disease" in modern literature is considered not quite accurate, since such ailments do not accompany malignant neoplasms, but are caused by them.
There are no specific and clear data on how often paraneoplastic syndrome occurs in oncology, however, judging by the data of medical studies, this frequency can vary from 15 to 70% and higher with the progression of the tumor process. Nowadays, more than 70 types of malignant tumors are known to cancer medicine, and this list is growing every year, and information about paraneoplasias is becoming more and more.
In the endocrine system
Paraneoplasia of endocrine origin include diseases such as hypercorticism, often associated with oncological diseases developing in the human lungs, as well as tumor processes in the pancreas, organs of the abdominal cavity, and digestion. Mostly male patients suffer from these ailments. In such cases, the development of paraneoplastic disorders can be regarded as follows: the cells of some tumors have high hormone-producing activity, and an excess or, on the contrary, a deficiency of a certain hormone causes the development of endocrinological disorders. The mechanism of hypoglycemia, which in most cases accompanies oncological processes, has the same structure.
These syndromes in endocrinology are often observed with the development of cancer of the lungs and bronchi, some forms of which, for example, intercellular, have a high ability of hormone production of an ectopic nature.
Paraneoplastic ophthalmic syndromes are also found.
Circulatory system diseases
This kind of damage to the hematopoietic system is quite rare. These include some forms of anemia, in which malignant tumors, which are often accompanied by proliferation of lymphatic tissue, by the autoimmune mechanism provoke the death of a large number of red blood cells. One of the forms of paraneoplastic syndrome in oncology of this category is polycythemia, which is extremely rare. It can accompany tumor processes in the kidneys. This disease can also occur due to too high production of erythropoietin.
The most common phenomenon among paraneoplastic syndromes in pediatric oncology of the hematopoietic system is a violation of blood coagulation. For example, multiple thromboses of an immigrant nature. It is estimated that approximately 5-10% of all cases of venous thrombosis are similar paraneoplastic diseases. Especially in cases where they occur in a place of unusual localization, for example in the occipital veins or on the hands.
Paraneoplastic syndrome in neurology
These diseases are most often found in oncological lesions of the lungs, mainly in men, and manifest themselves in the form of neuromuscular disorders. These include, for example, peripheral neuritis. Somewhat less common are lesions of the central nervous system in the form of a certain degeneration of neurons, as well as white matter.
In addition to peripheral neuritis, paraneoplastic neurological syndromes are very rarely diagnosed during the life of patients, and their true nature is determined already during the autopsy.
Paraneoplastic diseases of the muscular system
These diseases, with the exception of neuromyopathy, are manifested in the form of myopathies, myositis and myasthenia gravis, which lead to muscle atrophy. Prostigmine ceases to increase muscle mass. In this case, muscle pain is practically absent, and tendon reflexes are also stopped. Paraneoplastic myopathy is much more common in practice than is commonly thought.
A characteristic paraneoplastic syndrome in the muscle system is also myasthenia gravis, which affects mainly the pelvic muscles, as well as the human body. Polymyositis can be observed, which, as a rule, is accompanied by a variety of damage to the skin.
Consider the paraneoplastic syndrome in rheumatology.
Joint lesions
Such disorders in the human body are manifested much more often than others in the form of hypertrophic osteoarthropathy, when a predominant lesion of the fingers occurs. This paraneoplastic syndrome is characterized by a strong thickening of the fingers, and it is observed in people suffering from cancer of a bronchogenic nature, as well as pleural tumors. This violation in most cases can be accompanied by gynecomastia.
Lymphatic system lesions
Such violations in the lymph node system are detected, as a rule, during histological examination of biopsy or autopsy materials. They manifest themselves in the form of the development of tuberculoid structures that do not have signs of caseous necrosis in the lymph nodes with any kind of cancer of the internal organs. This histological structure may be characteristic of a disease such as sarcoidosis, which is also called Beunier-Beck-Schaumann disease. Often paraneoplastic syndrome occurs with lung cancer. Such violations in the lymphatic system of the body were previously considered random combinations of two unrelated diseases - oncology and sarcoidosis. Abnormalities in the functioning of the lymph nodes were detected, as a rule, when conducting studies to detect the presence of metastatic formations in cancer of the lungs, cervix, etc. Today, such disorders are considered to be a paraneoplastic disease.
With skin lesions
Skin paraneoplastic syndromes are very diverse, since the skin is the organ where their manifestations are localized most often. One of the most common and studied diseases of this nature is considered to be acanthosis nigricans - a specific chronic dermatosis, the clinical picture of which is characterized by the presence of papillomatous thickenings, as well as skin tightness with hyperpigmentation and hyperkeratosis, localized mainly in the area of the axillary hollows and on the back of the head. The lion's share of patients with this disease is diagnosed with oncology of the pancreas or stomach, sometimes lungs. In women, these ailments can be a sign of ovarian and breast cancer.
It is very important to note that the bulk of patients with acanthosis nigricans have a clinical picture of the development of some tumor processes, but initially such patients turn to dermatologists. Thus, the diagnosis by a specialist of a typical chronic dermatosis in an adult dictates the urgent need for a thorough examination for cancer. If the results of such diagnostics have yielded negative results, such patients should be on a follow-up at a cancer institution for a long period of time.
The next most frequent occurrence is paraneoplastic syndrome, which manifests itself in the form of a skin disease such as dermatomyositis. In patients who have been diagnosed with this disease, which belongs to the group of collagenoses, tumor processes are detected 6-8 times more often than in other people. Oncological diseases that can cause this disease are sarcoma and cancer of various internal organs, lymphoma, leukemia.
With other skin diseases known to medicine, described in science as paraneoplastic, the frequency of their combination with oncological formations is significantly lower than in cases with dermatomyositis and acanthosis nigricans.
Unclassifiable forms
Similar violations are very diverse. They, as a rule, do not appear in the form of lesions of the internal organs of a person. Symptoms of paraneoplastic syndrome in this case may be:
- a variety of fevers of unusual origin, especially in patients with metastases;
- weight loss in the presence of negative nitrogen balance, which is due to the decay products of malignant tumors;
- pain in cases where there is no direct connection between the tumor and the surrounding nerve endings;
- some mental disorders, etc.
Pathogenesis
This aspect, as well as the mechanism of the distant effect of malignancy, has not been studied well enough to draw conclusions. It is believed that such symptoms, if we consider their connection with oncological ailments, are secondary diseases, and in order for them to begin to develop, it is necessary to change the internal background of the body. When these prerequisites arise, it appears that a wide variety of factors are involved, for example, cachexia, hormone-producing tumor tissue, autoimmunization of the body, trophic disorders, and many others.
Nevertheless, there are special genetically determined complexes of symptoms, one of the manifestations of which is an oncological neoplasm. A variety of nosological forms that are known by the names of the authors who described them can serve as an example here. For example, Peitz-Turen-Jägers syndrome, which manifests itself in the form of hyperpigmentation of the skin of the fingers, as well as around the natural openings on the body, as well as generalized intestinal polyposis.
Main classification
Despite the fact that a single and clear classification of these syndromes does not exist, some researchers in the field of medicine have nevertheless systematized their main manifestations. These include:
- Exchange-endocrine diseases (hypercalcemia, carcinoid syndrome, hypertrophic osteoarthropathy, hyperuremia, cryofibrinogenemia, Itsenko-Cushing's syndrome, Acantosis nigricans, increased excretion of ADH, carcinoid syndrome, etc.).
- Endothelial diseases (thromboendocarditis and migratory thrombosis, as well as phlebitis). Allergic and autoimmune disorders of a secondary nature (systemic lupus erythematosus, Hashimoto's autoimmune thyroiditis, dermatomyositis, nephrotic syndrome, rheumatoid arthritis, hemorrhagic vasculitis, thrombocytopenic purpura, scleroderma, anaphylactic shock, urticaria, etc.)
- Lesions of the central nervous system, as well as neuromuscular diseases (dementia, psychosis, Eaton-Lambert syndrome and others).
- Other (celiac disease, effusion pericarditis , etc.).
Some diseases of a rheumatological nature may be associated with an increased risk of developing cancer pathologies. However, paraneoplastic processes often manifest themselves in the form of rheumatological diseases. Thus, in diagnosing the health status of such patients, specialists should adhere to the principles of increased alertness in connection with the possible oncological nature of these disorders.
Diagnostics
In order to qualitatively and adequately diagnose the nature of the origin of one or another paraneoplastic disease, there is a certain list of specific laboratory tests of the patient’s blood, which will help establish the cause of the occurrence of such disorders and rank them among a number caused by oncological changes in the human body.
These studies are special diagnostic tumor markers:
- for the mammary gland: CA-15-3, M20, M22, CEA, MUCI;
- for the uterus, as well as the cervix: M22, M20, CEA;
- testicles in men: CEA, hCG, AFP;
- ovaries in women: CA 125, AFP, CA 724, hCG, M22, CEA, M20;
- for the bladder: H / F, CYFRA 21-1;
- for the prostate gland: prostatic phosphatase, PSA total., PSA free .;
- for the thyroid gland: calcitonin, thyroglobulin, CEA;
- for lungs and bronchi: NSE, NEA, CYFRA 21-1, M22, CA 72-4, M20;
- for the stomach and esophagus: CA 72-4, CA 19-9, CEA;
- for the liver: AFP, CA 19-9, CEA.
There is a popular diagnostic method - immunoblot. Antibodies for paraneoplastic syndromes (antineuronal) are immunoglobulins, they are active against neurons of tumor tissue and protein antigens in the cytoplasm. This group includes antibodies Yo-1 (PCA1), Hu (ANNA-1), CV2, Ri (ANNA-2), Ma2, amphiphysin.
In neurology and oncology, analysis is often used, it is indispensable in the diagnosis of paraneoplastic neurological diseases, it helps to establish the presence of paraneoplastic encephalomyelitis, sensory neuropathy, progressive cerebellar degeneration, paraneoplastic myoclonia and ataxia, muscle stiffness syndrome. The biomaterial is blood serum, which is taken from a vein. Normally, the result should be negative.
With paraneoplastic syndrome, PDF is increased. Also, thromboembolic complications often lead to the death of cancer patients. The presence of chronic thrombohemorrhagic syndrome in the laboratory is diagnosed on the basis of an increased concentration of fibrinogen (2–2.5 times higher than normal), PDF (4–4.5 times higher than standard indicators), and increased platelet aggregation ability is also noted.
For the correct diagnosis of paraneoplastic and oncological processes in the human body, it is necessary to initially exclude the presence of autoimmune failures, which can occur with pathologies of the nervous system.
Autoimmune markers include:
- CRP (qual.), RF (qual.);
- CRP (count);
- AT to single-spirited. DNA
- ASLO;
- anti-ena
- LE cells
- Anti-MCV (Citrulline);
- AT to native DNA and others.
How else are paraneoplastic syndromes determined in the clinic of internal diseases?
Additional diagnostic criteria
Symptoms of a confirmed nature:
- Classical neurological syndromes with the presence of oncological education, which was diagnosed no later than 5 years after the development of this symptomatology.
- Non-classical syndromes that can disappear, or their severity is significantly reduced after anti-oncological therapy, however, in this case it should be revealed that the neurological deficit is not prone to independent remission.
- Nonclassical syndromes with malignant tumor processes and with the detection of antibodies to neurons.
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Medications are used in combination with chemotherapy. The following drugs are relevant today:
- a group of corticosteroids (Prednisolone);
- immunosuppressive agents such as "Cyclophosphamide", "Azathioprine";
- Piridostigmine-type neuromuscular stimulants;
- anticonvulsants such as "carbamazepine".
We examined the main types of paraneoplastic syndromes.