The clinical and anatomical concept of “soft tissue” as defined by the WHO from 1969 includes all non-skeletal tissue of non-epithelial nature: smooth and striated muscles, synovial tissue, tendons and ligaments, muscle fat , subcutaneous fat or hypodermis, connective tissues (fibrous), nerve cells and vascular tissue. Neoplasms in them are soft tissue tumors. Among them are any tumors of the above tissues and tumors of an unclear lesion of embryogenesis.
Causes of Soft Tumors
Their reasons are not fully understood today. Some provoking factors for the development of a soft tissue tumor are known. It could be:
- dysfunctional heredity (for example, tuberous sclerosis causes sarcoma);
- chemical carcinogens of any origin;
- gene disturbances are not excluded;
- the presence in the body of herpes viruses and HIV;
- ionizing radiation, reduced immunity;
- soft tissue injuries (they lead to oncology in more than half of cases);
- the presence of scar tissue;
- bone pathologies may precede tumors;
- some diseases, such as Recklinghausen disease.
Often benign tumors can become malignant. According to statistics, malignant soft tissue tumors in general oncopathology occupy about 1%. There are no sexual and age-related degradations, but most often these tumors occur after 25 years. And after 80 years, this figure already exceeds 8%. Favorite localization - lower limbs, neck, stomach, etc.
Classification
The systematization of soft tissue tumors is very complex, taking into account a variety of indicators. In the article, it is presented by the simplest divisions. Types of soft tissue tumors can be divided into mesenchymal ( internal organ tumors - sarcomas, leiomyomas) and PNS tumors. The type depends on the etiology of the onset of neoplasm.
In practice, WHO applies the classification - soft tissue tumors are divided by type of tissue:
- from fibrous tissue;
- fatty;
- muscle
- vascular;
- synovial and serous membranes, cells of the peripheral nervous system (PNS);
- cartilage tissue.
All tumors are combined into 4 large divisions: benign, malignant, or borderline, locally aggressive and rarely metastatic. Benign soft tissue tumors do not have cellular atypism, do not give metastases and rarely recur. Malignant have completely opposite properties, leading to the death of the patient. Borderline tumors (locally aggressive) recur without metastases; rarely metastatic manifest themselves on this side in less than 2% of cases.
According to metastases, tumors are quantified:
- 1 point - 0-9 metastases;
- 2 points - 10-19;
- 3 points - more than 20 metastases.
Benign soft tissue tumors
Types of tumors:
- Lipoma - based on adipose tissue, localized in areas of the body with the presence of lipid tissue. It is palpated as a painless swelling of a soft-elastic consistency, it can grow for several years.
- Angiolipoma - formed on blood vessels, more often diagnosed in children. Localized in the back of the muscles. If not a concern, only observation is recommended.
- Hemangioma is a very common vascular tumor. More common in children. If there are no manifestations, treatment is not necessary.
- Fibroma and fibromatosis - consists of fibrous tissue. Bright representatives are fibromas and fibroblastomas. Fibromas contain cells of mature connective fibrous tissue; fibroblastomas are based on collagen fibers. They form the so-called. fibromatosis, among which the most common tumor of soft tissues of the neck, such as fibromatosis of the neck, is most common. This tumor occurs in newborns on the sternocleidomastoid muscle in the form of a dense grain up to 20 mm in size. Fibromatosis is very aggressive and can grow into neighboring muscles. Therefore, mandatory removal is required.
- Neurofibroma and neurofibromatosis - is formed from cells of the nervous tissue in the nerve membrane or around it. The pathology is hereditary, with growth it can squeeze the spinal cord, then neurological symptoms appear. Prone to degeneration.
- Pigmentary nodular synovitis is a tumor from the synovial tissue (lining the inner surface of the joints). Often goes beyond the joint and leads to degeneration of surrounding tissues, which requires surgical treatment. Frequent localization is the knee and hip joint. It develops after 40 years.
Benign tumors of muscle tissue
The following tumors have a benign character:
- Leiomyoma is a tumor of smooth muscles. It has no age restrictions and is multiple in nature. Tends to degenerate.
- Rhabdomyoma is a tumor of striated muscles in the legs, back, and neck. By structure in the form of a nodule or infiltrate.
In general, the symptoms of benign tumors are very scarce, manifestations can occur only with tumor growth with compression of the nerve trunk or vessel.
Soft tissue malignancies
Almost all of them belong to sarcomas, which occupy 1% of all oncologies. The most common occurrence age is 20-50 years. Sarcoma develops from cells of connective tissue, which is still under development and is immature. It can be cartilage, muscle, fat, vascular tissue, etc. In other words, sarcoma can occur almost everywhere and does not have a strict attachment to one organ. On a section, the sarcoma resembles a pinkish-white fish meat. She is more aggressive than cancer, and is inherent in:
- infiltrating growth in adjacent tissues;
- after removal in half of patients, it recurs;
- gives metastases early (to the lungs most often), only with abdominal sarcoma - to the liver;
- has explosive growth, in terms of mortality is in 2nd place.
Types of sarcomas of soft tissues and their manifestations
Liposarcoma - occurs wherever there is tissue with a large amount of fat, most often on the thigh. It has no clear boundaries, it is easily palpated. Growth is slow, rarely gives metastases.
Rhabdomyosarcoma, or PMC, is a tumor that affects striated muscle tissue. More often affects men after 40 years. A tumor in the form of a dense fixed node is located in the middle of the muscles, does not cause pain, is palpated. Favorite localization is the neck, head, pelvis and legs.
Leiomyosarcoma is a tumor that affects smooth muscle tissue. Occurs rarely, usually in the uterus. It is considered a dumb tumor and manifests itself only in the later stages. Detected by chance in other studies.
Hemangiosarcoma is a tumor of blood vessels. It is localized deep in the muscles, soft in structure, painless. These include Kaposi’s sarcoma, hemangiopericytoma, and hemangioendothelioma. The most famous Kaposi's sarcoma (formed from immature vascular cells when exposed to the herpes simplex virus type 8; characteristic of AIDS).
Lymphangiosarcoma - formed from lymph vessels.
Fibrosarcoma - arises from connective tissue, often localized in the muscles of the legs and trunk. On palpation is relatively mobile, has the appearance of a tubercle of round or oval shape. It can grow to large sizes. It occurs more often in women.
Synovial sarcoma - can be diagnosed at any age. Painful on palpation, due to poor absorption of the membrane in the joint, pus or blood easily accumulates. If there is a cyst inside the tumor, it is elastic when palpated. If it has calcium salts, it is solid.
Nerve tissue sarcomas - neurogenic sarcomas, neuromas, sympathoblastomas, etc. Since we are talking about nerve tissue, in half of the patients tumor formation is accompanied by pain and neurological symptoms. Tumor growth is slow, a favorite place for appearance is the lower leg and thigh. This tumor is rare, occurs in middle-aged men. The tumor is usually coarse, in a capsule; sometimes it can consist of several nodes located along the nerve trunk. Palpation, it is defined as a “soft-elastic consistency”, but with clear boundaries, it may contain calcareous inclusions and then it becomes hard. Pain and other symptoms are rare. In close proximity to the skin, it can grow into it, with a bone - it can grow there. Metastases are rare, mainly to the lungs. Relapses are common. Summarizing the above, it should be recalled: for the most part, tumors have an elastic or solid consistency. If softening areas are found, they talk about the decay of the tumor.
Borderline tumors
In their behavior, they resemble benign formations, but suddenly, for unclear reasons, they begin to metastasize:
- Swelling dermatofibrosarcoma is a tumor in the form of a large node over the skin. It grows very slowly. With its removal, half of the patients gives relapses, metastases do not happen.
- Atypical fibroxanthoma - may occur with an excess of ultraviolet radiation in elderly patients. It is localized in open areas of the body. In appearance it resembles a clearly bounded knot, which can be covered with ulcers. May metastasize.
Clinical picture
Malignant soft tissue tumors in the initial stages grow imperceptibly, without manifesting themselves. In 70% of patients, they are detected in other studies by accident and become the only symptom. If the formation is adjacent to a large nerve trunk, formed from the membranes of the sensory nerve or grows into the bone, a symptom of pain is characteristic. More often the tumor has limited mobility in the transverse displacement, it looks like a single node. It does not grow into the nerve trunks, but shifts them to the side. When it grows into a bone, it becomes motionless.
The skin over a soft tissue tumor in the later stages becomes crimson-cyanotic, edematous, grows into the surrounding tissue. The surface may ulcerate. The saphenous veins expand as a subcutaneous mesh. There is local hyperthermia. In addition, the disease is no longer limited to the local clinic, the general symptoms of intoxication in the form of cachexia, fever, weakness of the whole organism are added.
Blood vessel metastasis is hematogenous, in 80% of cases it occurs in the lungs. Among benign soft tissue tumors of unclear histogenesis, one can name a myxoma, which is characterized by an irregular shape, contains a jelly-like substance and is most often localized in the heart chamber. Therefore, it is also called a cavity tumor. In 80% of patients, it occurs in the left atrium. Such tumors are invasive, that is, they quickly grow into neighboring tissues. It usually requires removal and plastic surgery if necessary.
Diagnostics
Diagnosis of soft tissue tumors is quite complicated due to the scarcity of clinical manifestations. If sarcoma is suspected, the examination should begin with a biopsy. This is an important point in the study, since in the future a biopsy will give complete information about the nature of the pathology.
X-rays are appropriate and informative only with dense tumors. It can show the dependence of the tumor on neighboring bones of the skeleton.
If there is a localization of the formation on the legs, abdominal cavity - arterial angiography becomes important. It makes it possible to accurately determine the location of the tumor, reveals a network of neovascular located randomly. Angiography is also needed to select the type of operation.
MRI and CT will show the prevalence of pathology, which determines the course of treatment. Ultrasound of a soft tissue tumor is used as a primary diagnostic tool or to confirm a preliminary diagnosis. Ultrasound of soft tissues is widely used and indispensable for conducting diffdiagnosis.
Tumor treatment
Treatment of a soft tissue tumor is based on 3 main methods - this is a radical operation, radio and chemotherapy as a complement. Then this treatment will be combined and more effective. But the main operation remains.
Modern methods for removing benign tumors
Today, 3 methods are used to remove benign soft tissue tumors:
- by means of a scalpel;
- CO2 laser
- radio wave method.
The scalpel is used only for highly differentiated tumors that have a better prognosis in terms of recovery.
CO2 laser - when removing soft tissue tumors of a benign nature, it makes it possible to remove them qualitatively and modernly. Laser treatment has many advantages over other methods and gives much better aesthetic results. In addition, it has an accurate directivity in which neighboring surrounding tissues are not damaged. The method is bloodless, the rehabilitation period is shortened, there are no complications. It is possible to remove hard to reach tumors.
With the radio wave method (on the Surgitron apparatus), soft tissue incision is performed by exposure to high-frequency waves. This method does not give pain. Surgitron can remove fibroids and any other benign tumors on the chest, arms, neck.
The main treatment for all malignant tumors is surgical. Surgical removal of soft tissue tumors is carried out by 2 methods: wide excision or amputation of the limb. Excision is used for medium and small sizes of tumors that have retained mobility and are located at a shallow depth. In addition, there should not be their germination in blood vessels, bone and nerves. Relapse after excision is not less than 30%, they double the risk of death of the patient.
Indications for amputation:
- there is no possibility of wide excision;
- excision is possible, but the saved limb will not work due to impaired innervation and blood circulation;
- other operations have failed;
- prior palliative amputations led to unbearable pain, stench due to tissue disintegration.
Limb amputation is performed above the level of the tumor.
Radiation therapy as a method of monotherapy for sarcoma does not give any results. Therefore, it is used as a supplement before and after surgery. Before surgery, it affects the formation in such a way that it decreases in size and is easier to operate. It can also help to make an inoperable tumor operable (70% of cases give a positive effect with this approach). Its use after surgery reduces the possibility of relapse. The same can be said about chemotherapy - using the combined method is most effective.
The prognosis for 5-year survival in sarcomas has a very low percentage due to their increased aggressiveness. Much depends on the stage, type of tumor, age of the patient and the general status of the body.
Synovial sarcoma has the worst prognosis, the survival rate for this disease is not more than 35%. The remaining tumors with early diagnosis, the success of the operation and an adequate recovery period are more likely to survive for 5 years.