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ஐﻬ What Is a Soft Tissue Sarcoma?
Soft tissue sarcomas are malignant (cancerous) tumors that can develop from fat, muscle, nerve, fibrous tissues surrounding joints, blood vessel, or deep skin tissues. They can develop in any part of the body. Around 55% to 60% of them develop in the arms or legs. The rest begin in the trunk (15% to 20%), head and neck area (8% to 10%), internal organs, or the retroperitoneum (15%) (the back of the abdominal cavity). Sarcoma is the term used for cancers of these tissues.
The term soft tissue is used to distinguish these sarcomas from bone sarcomas. Bone sarcomas (osteosarcomas) are discussed in a different American Cancer Society document.
There are many types of soft tissue tumors, and not all of them are cancerous. When a tumor is not cancerous, it is called benign. When the term sarcoma appears in the name of a disease, it means the tumor is malignant. There are about 50 different types (not all are listed below) of soft tissue sarcomas.
ஐﻬ Tumors of Fat Tissue
Lipomas are benign tumors of fat tissue. They are the most common benign soft tissue tumor. Most are found under the skin, but they can develop anywhere in the body.
Lipoblastomas are benign fat tumors that occur in infants and young children.
Hibernomas, like lipomas, are also benign fat tissue tumors. They are much less common than lipomas.
Liposarcomas are malignant tumors of fat tissue. They can develop anywhere in the body, but they most often develop in the thigh, behind the knee, and inside the back of the abdomen. They occur mostly in adults between 50 and 65 years old. Some liposarcomas grow very slowly, whereas others can grow quickly. Your doctor can tell you which kind you have.
ஐﻬ Tumors of Muscle Tissue
The human body has 2 types of muscle: smooth and skeletal.
* Smooth muscle is found in our internal organs such as stomach, intestines, blood vessels, or uterus (womb) and causes them to contract. These muscles are involuntary -- that is, we don't control their movement.
* Skeletal muscle is sometimes called striated (because stripes can be seen inside the cells under the microscope). This is the muscle that allows us to move our arms and legs and other body parts when we want them to move -- that is, voluntary movement.
ஐﻬ Smooth muscle sarcomas
Leiomyomas are benign tumors of smooth muscle (or involuntary muscle). Leiomyomas can arise almost anywhere in the body in either men or women because they can start in tissues as widespread, for example, as blood vessels or intestine. The most common of these is the fibroid tumor that develops in many women. It is really a leiomyoma of the uterus.
Leiomyosarcomas are malignant tumors of involuntary muscle tissue. They can grow almost anywhere in the body but are most often found in the retroperitoneum and the internal organs and blood vessels where leiomyomas also arise. Less often, they develop in the deep soft tissues of the legs or arms. They tend to occur in adults, particularly the elderly.
ஐﻬ Skeletal muscle sarcomas
Rhabdomyomas are benign tumors of skeletal muscle (the muscle that is attached to bone and helps us to move). They are rare.
Rhabdomyosarcomas are malignant tumors of skeletal muscle. These tumors commonly grow in the arms or legs, but they can also begin in the head and neck area and in reproductive and urinary organs such as the vagina or bladder. Children are affected much more often than adults. For more information, see the American Cancer Society document, "Rhabdomyosarcoma."
ஐﻬ Tumors of Peripheral Nerve Tissue
Nerves run throughout the body. The brain and spinal cord are also considered central nerve tissue. The tumors discussed here are tumors of the nerves that run throughout the body, but not the brain or spinal cord.
Neurofibromas, schwannomas (neurilemoma), and neuromas are all benign tumors of nerves. These tumors can occur almost anywhere in the body. An inherited condition called neurofibromatosis or von Recklinghausen disease causes people to develop many neurofibromas throughout their body. Some of these, if they formed from very large nerves such as those in the upper arms or neck, can become malignant.
Malignant schwannomas, neurofibrosarcomas, or neurogenic sarcomas are malignant tumors of the cells that surround a nerve. A new name for these is malignant peripheral nerve sheath tumors.
ஐﻬ Tumors of Joint Tissue
All of our joints are surrounded by tough tissue called synovium, which produces the fluid that lubricates the joint surfaces so that they move smoothly. Tumors of joints start in the synovium.
Nodular tenosynovitis is a benign tumor of joint tissue. It is most common in the hands and is more common in women than in men.
Synovial sarcoma is a malignant tumor of the tissue around joints. The most common locations are the knee and ankle. Other sites are the shoulder and hip. It tends to occur mostly in children and young adults, but can also occur in older people.
ஐﻬ Tumors of Blood Vessels and Lymph Vessels
Hemangiomas are benign tumors of blood vessels. They are rather common, are often present at birth, and can affect the skin or internal organs. They sometimes disappear without treatment.
Glomus tumors are benign perivascular (around blood vessels) tumors. They usually are found under the skin of the fingers.
Hemangiopericytoma is a tumor of perivascular tissue. It most often develops in the legs, pelvis, and retroperitoneum (the back of the abdominal cavity). It is most common in adults. These can be either benign or malignant. They donít often spread to distant sites, but tend to come back where they started, even after surgery.
Hemangioendothelioma is a blood vessel tumor that is less aggressive than hemangiosarcoma but still considered a low-grade cancer. It usually invades nearby tissues and sometimes can spread to distant parts of the body (metastasize). It may develop in soft tissues or in internal organs, such as the liver or lungs.
Angiosarcomas are malignant tumors that can develop either from blood vessels (hemangiosarcomas) or from lymph vessels (lymphangiosarcomas). These tumors can sometimes develop in a part of the body that has been exposed to radiation. Angiosarcomas are sometimes seen in the breast after radiation therapy for breast cancer or in the arm on the same side as a breast that has been irradiated or removed by mastectomy.
Kaposi sarcoma is a cancer formed by cells similar to those lining blood or lymph vessels. In the past, Kaposiís sarcoma was an uncommon cancer mostly seen in older people with no apparent immune system problems. It is most common in people with human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome (AIDS), but it can also develop in organ transplant patients who are taking medication to suppress their immune system. It is probably related to infection with a virus called human herpesvirus-8 (HHV-8). For more information, see the American Cancer Society documents, "Kaposi Sarcoma" and "HIV/AIDS."
Lymphangiomas are benign lymph vessel tumors that are usually present at birth. Lymph is a type of fluid that circulates in every tissue of the body, ending up in the venous system. It contains waste products from tissues and immune system cells. Lymphangiosarcomas are the malignant lymph vessel form of angiosarcomas.
ஐﻬ Tumors of Fibrous Tissue
Fibrous tissue forms tendons and ligaments and covers bones as well as other organs in the body.
Fibromas, elastofibromas, superficial fibromatosis, and fibrous histiocytomas are all benign tumors.
Fibrosarcoma is cancer of fibrous tissue. It usually affects the legs, arms, or trunk. It is most common between the ages of 20 and 60, but can occur at any age, even in infancy.
Fibromatosis is the name given to fibrous tissue tumor with features in between fibrosarcoma and benign tumors such as fibromas and superficial fibromatosis. They tend to grow slowly but, often, steadily. At one time they were called desmoid tumors, when they were closely attached to skeletal muscles. Now they are called musculoaponeurotic fibromatosis. They do not metastasize, but they can invade nearby tissues and are sometimes fatal. Some doctors consider these to be a type of low-grade fibrosarcoma; others believe they are a unique type of fibrous tissue tumors. Certain hormones, particularly estrogen, increase the growth of some desmoid tumors. Antiestrogen drugs are sometimes useful in treating desmoids that cannot be completely removed by surgery.
Dermatofibrosarcoma protuberans (DFSP) is a slow-growing cancer of the fibrous tissue beneath the skin, usually in the trunk or limbs. It invades nearby tissues but rarely metastasizes.
Malignant fibrous histiocytoma (MFH) is most often found in the arms or legs. Less often, it can develop inside the back of the abdomen. This sarcoma is most common in older adults. Although it mostly tends to grow locally, it can spread to distant sites.
ஐﻬ Tumors of Uncertain Tissue Type
Through microscopic examination and other laboratory tests, doctors can usually find similarities between most sarcomas and certain types of normal soft tissues. However, some sarcomas have not been linked to a specific type of normal soft tissue.
Myxoma is a benign tumor that usually is located in muscles but does not develop from muscle cells. The cells of a myxoma produce mucus-like material, a feature that distinguishes this tumor. It almost always occurs in adults.
Granular cell tumors are usually benign tumors of adults that occur often in the tongue but can be found almost anywhere in the body.
Malignant mesenchymoma is a rare type of sarcoma that contains some areas showing features of fibrosarcoma and other areas with features of at least two other types of sarcoma.
Alveolar soft-part sarcoma is a rare cancer that mostly affects young adults. The legs are the most common location of these tumors.
Epithelioid sarcoma most often develops in tissues under the skin of the hands, forearms, feet, or lower legs. Adolescents and young adults are often affected.
Clear cell sarcoma is a rare cancer that often develops in tendons of the arms or legs. Under the microscope, it shares some features with malignant melanoma, a type of cancer that develops from pigment-producing skin cells. How cancers with these features develop in parts of the body other than the skin is not known.
Desmoplastic small cell tumor is a rare sarcoma of adolescents and young adults, found most often in the abdomen. Its name means that it is formed by small, round cancer cells surrounded by scar-like tissue.
ஐﻬ Other Types of Sarcoma
There are other types of tumors called soft tissue sarcomas, however, these are all quite rare.
ஐﻬ Tumor-like Conditions of Soft Tissue
Some conditions of soft tissues are caused by inflammation or injury and can form a mass that looks like a soft tissue tumor. Unlike a true tumor, they do not come from a single abnormal cell, they have limited capacity to grow or spread to nearby tissues, and never spread through the bloodstream or lymph system. Examples include nodular fasciitis and myositis ossificans, which involve tissues under the skin and muscle tissues, respectively.