Sarcoma | Cancer of the skeletal system and soft tissues



Sarcoma is cancer that starts in connective or supporting tissues such as bones, muscles, fat, cartilage, and blood vessels. Sarcoma is rarer than carcinoma.

A sarcoma is a malignant tumor that forms at the expense of connective tissue or the tissues that derive from it, such as cartilage tissue or bone tissue. It can also form at the expense of non-cartilage supporting tissues such as muscles or the peripheral nervous system.

Sarcomas are mostly metastasize via the bloodstream. We can distinguish two large groups: sarcomas of the skeletal system and sarcomas of soft tissues (english soft tissue). There are also carcinosarcomas, i.e. mixed tumors that contain both malignant epithelial cells (=carcinoma) and malignant mesenchymal cells (= sarcoma). This includes, for example, the malignant mesodermal mixed tumor of the uterus or ovary, also called Müllerian mixed tumor. In extremely dedifferentiated carcinomas, the histological picture is similar to that of a sarcoma. One speaks z. B. of sarcomatoid renal cell carcinoma. Molecularly, however, it can be proven that the tumor is epithelial, i.e. carcinoma.

A distinction is made between sarcomas of the bones and sarcomas of the soft tissues and viscera (Organ contained in a body cavity (brain, heart, stomach, liver, intestine, lung, spleen, kidney, uterus).

Examples of sarcomas skeletal system and soft tissues

According to the current WHO classification, sarcomas are divided into around 100 different entities . These differ according to their (partially) suspected cell origin , their molecular genetic changes, their morphology and their biology.

The exact classification of a sarcoma in the appropriate diagnostic group is of great importance for further treatment, since the individual entities have a different risk of recurrence and daughter tumors (metastases).

Sarcomas of the skeletal system

  • Osteosarcomas: which develop in most cases on the bones of the limbs, in particular the femur (near the hip or the knee) and the pelvis.
  • Ewing’s sarcomas: which can be located on all large bones, but especially the bones of the pelvis and the bones of the legs.
  • Chondrosarcomas: are tumors developing from cartilage tissue.
  • Chordoma: can occur anywhere within the spine or the base of the skull (i.e lower back and the base of the skull).
  • Adamantinoma: typically found in the diaphyses and metaphyses of long bones.

Sarcomas of soft tissues

Sarcomas of soft tissue forms in soft tissues of the body, including muscle, tendons, fat, blood vessels, lymph vessels, nerves, and tissue around joints.

According to the involvement of the blood vessels, soft tissue sarcomas can be classified according to the Schwarzbach classification, and according to the involvement of the nerves according to the Sweiti / Schwarzbach classification.

Soft tissue and visceral sarcomas are the most common sarcomas. The current classification of sarcomas gives them the name of the tissue they resemble.

  • Blood vessels: angiosarcomas
  • Blood vessels and soft tissues: hemangiopericytoma
  • Fibrous tissue (tendons and ligaments): fibrosarcomas
  • Fatty tissue: liposarcomas
  • Skeletal muscles: rhabdomyosarcomas
  • Walls of the digestive system: gastrointestinal stromal tumors (GIST). Skin or mucous membranes that line the gastrointestinal (GI) tract, from mouth to anus, including the stomach and intestines: Kaposi’s sarcoma
  • Smooth muscles: leiomyosarcomas
  • Dermis: dermatofibrosarcoma
  • Nerve sheath tumor of the lung or malignant peripheral nerve sheath tumors: neurogenic sarcoma
  • Cancer that’s most often found in soft tissue such as muscles and tendons: malignant fibrous histiocytoma


Sarcomas are quite rare, with only 15,000 new cases registered each year in the United States. Sarcomas thus account for about 1% of the 1.5 million new cancer diagnoses in that country each year. 

The gastrointestinal stromal tumor (GIST) is the most common form of sarcoma, with around 3000-3500 cases per year in the United States.

Sarcomas affect people of all ages. About 50% of bone sarcomas and 20% of soft tissue sarcomas are diagnosed in people under the age of 35. Some sarcomas, such as leiomyosarcoma, chondrosarcoma, and gastrointestinal stromal tumor (GIST), are more common in adults than in children. Most bone sarcomas, including Ewing’s sarcoma and osteosarcoma, are much more common in children and young adults.

Main variants and their fabric of origin

OriginType of sarcoma
Adipose tissueLiposarcoma is a malignant form of lipoma, is a neoplasm of adipose tissue , it can appear in any part of the body. Unlike its benign form, liposarcoma appears deeper, to the touch it appears to be hard and elastic. They occur most frequently in the abdomen (retroperitoneally), but can also develop in the neck , subendocardium or subpericardium, and also in other parts of the body.
Smooth muscle tissueLeiomyosarcoma is a malignant tumor of smooth muscle tissue. It should not be confused with leiomyoma, which is a benign tumor originating from the same type of tissue.
Striated muscle tissueRhabdomyosarcoma is a tumor malignant, specifically a sarcoma arising from striated muscle cells.
Vascular endotheliumHemangiosarcomaHemangiosarcoma and Kaposi’s sarcoma (this is caused by a virus belonging to the family of herpesviruses , HHV-8, also called KSHV ( “virus Kaposi’s sarcoma”). Such cancer is common in immunosuppressed , especially in people with of AIDS ; and if small it disappears after adequate antiretroviral therapy.
BoneOsteosarcoma is a cancer of the bone primary malignant.
CartilageChondrosarcoma is a rare tumor malignant of bone that originates from cartilage tissue
Own connective tissueFibrosarcoma is a form of cancer that originates from the connective tissue fibroblasts. It mainly affects the skin, tendons, muscle groups and the periosteum . It is also found in veterinary medicine and mainly affects dogs and cats.
NerveMalignant neoplasm of the nerve sheathsEwing’s sarcoma
Interstitial cells of CajalGastrointestinal stromal tumor are the tumors mesenchymal (ie derived from connective tissue ) more frequent in gastrointestinal tract and represent around 1-3% of all cancers in this part of the body.

The majority of paratesticular neoplasms are represented by tumors of mesenchymal origin and about 30% of them are malignant.

Very rare variants of Sarcoma

Leiomyosarcoma (LMS) of the spermatic cord

Leiomyosarcoma (SML) of the spermatic cord is a rare neoplasm originating from the stromal cells of the smooth muscle of the adnexa of the testis.

The behavior of leiomyosarcoma (SML) is related to the anatomical site from which it originates, unfortunately there are few data on these tumors when they occur in the paratesticular region. Metastases are usually seen to the lymph nodes, lungs, or liver; however they are rare neoplasms. The majority of tumors at this site are low-grade, although high-grade lesions behave aggressively.

Epithelioid sarcoma

The epithelioid sarcoma is a malignant tumor of soft tissue,  also said connective (sometimes also involves the tendons). Epithelioid sarcoma is also called “young adult cancer”, because it usually affects people aged 15 to 35 years.

Ewing’s sarcoma

The Ewing’s sarcoma is a cancer that affects residual cells of the embryonic nature body, destined to become cells of the nervous tissue or skeletal tissue, but which are in an immature state when they get sick. It can develop in both bone and soft tissue. It is usually a highly malignant neoplasm, however sensitive to both chemotherapy and radiotherapy.

Synovial sarcoma

The synovial sarcoma is a malignant tumor that affects the mesenchymal cells that differentiate into cells of the synovial membrane. Although the synovial membrane is often found inside the joints, this type of tumor can develop outside the joints.


Angiosarcoma affects the endothelium cells of blood vessels. Endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels, and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells form the barrier between vessels and tissue and control the flow of substances and fluid into and out of a tissue.


Primary malignant tumor that arises from the peripheral nerves. half of the cases originate in patients with Neurofibromatosis type I : for these reasons, a sudden increase in volume of a neurofibroma must always be carefully evaluated in a patient with neurofibromatosis.


Osteosarcoma (bone cancer) is a malignant tumor of the bone cells, which is subdivided into different subtypes. Many patients first complain of pain that may be worse at night, may be intermittent and of varying intensity and may have been occurring for some time. Teenagers who are active in sports often complain of pain in the lower femur, or immediately below the knee. If the tumor is large, it can present as overt localised swelling. Sometimes a sudden fracture is the first symptom, because the affected bone is not as strong as normal bone and may fracture abnormally with minor trauma. In cases of more deep-seated tumors that are not as close to the skin, such as those originating in the pelvis, localised swelling may not be apparent.


The Rhabdomyosarcoma is part of so-called soft tissue sarcomas, tumors that develop in the muscles, fat or connective tissue. In particular, at the basis of rhabdomyosarcoma there is the tumor transformation of rhabdomyoblasts, cells that normally give rise to voluntary skeletal muscles, or those subject to our will.

It is a highly aggressive form of cancer that develops from mesenchymal cells that have failed to fully differentiate into myocytes of skeletal muscle. Cells of the tumor are identified as rhabdomyoblasts.

There are four subtypes – embryonal rhabdomyosarcoma, alveolar rhabdomyosarcoma, pleomorphic rhabdomyosarcoma, and spindle cell/sclerosing rhabdomyosarcoma. Embryonal, and alveolar are the main groups, and these types are the most common soft tissue sarcomas of childhood and adolescence. The pleomorphic type is usually found in adults.


The chondrosarcoma is a primary malignant tumor that arises from cells of cartilage. It is a rare tumor malignant of bone that originates from cartilage tissue . The most common symptom of the condition is pain. Primary chondrosarcomas arise from a small group of cartilage cells; the secondary develop slowly from a previous benign tumor of cartilage. The tumor can in some cases metastasize to the lungs. An extremely rare form of chondrosarcoma can emerge as a primary tumor in soft tissue, without bone involvement.
Middle-aged and older people are the most frequently affected population. The neoplasmit is twice as common in males than females. Treatment includes surgical removal of the tumor.

Symptoms, Diagnosis, Therapy of Sarcoma


Symptoms vary greatly depending on the location and type of sarcoma. “For a soft tissue sarcoma, the presence of a lump / mass with a deep localization and an evolutionary criterion (which moves and which grows) must alert and push the patient to consult”, adds our interlocutor. He may also have pain, transit disorders (in case of intra-abdominal location), fractures (bone sarcoma), bone pain, deterioration of the general condition, breathing difficulties, etc.

The pathology can manifest itself with the presence of a swelling similar to a bruise that is initially attributed to a trauma or a bruise; in the case of tumor masses that develop in depth, the discovery occurs after the patient complains of pain, feels a sense of compression or discovers blood loss.


The diagnosis is made by means of ultrasound , which can follow magnetic resonance imaging and biopsy with needle aspiration of the eventual mass tissues detected.

Despite the rarity of the disease, it is estimated that there are more than fifty types of sarcomas, which require different therapeutic treatments. It is therefore advisable to seek a second and even a third opinion from other pathological anatomy experts to ensure that the diagnosis emerged in the first biopsy is correct.

Subsequently, the patient is often suggested to undergo a CT scan with contrast fluid to the chest and abdomen and a positron emission tomography to check for the presence of any distant metastases or secondary tumor sites, also in order to achieve a precise TNM staging system (TNM) is a globally recognised standard for classifying the extent of spread of cancer. It is a classification system of the anatomical extent of tumor cancers. It has gained wide international acceptance for many solid tumor cancers, but is not applicable to leukaemia and tumors of the central nervous system.


The treatment of sarcoma varies according to the histological subtype identified by the biopsy . In any case, the pathology requires a multidisciplinary approach which consists in the involvement of a team made up of oncologists, oncological surgeons, pathological anatomy experts, radiotherapy experts . This type of assistance is available at the regional cancer centers or at the IRCSS centers, which by virtue of the greater case history also have greater knowledge and experience.

The surgical approach is very important in the treatment of most sarcomas. Limb-conserving surgery can save amputation in at least 90% of cancer cases. Additional treatments, including chemotherapy and radiotherapy, can be given before and or after surgery.

Chemotherapy significantly improves the prognosis for patients, especially those with bone sarcomas. The treatment can be a long and tiring process, which due to the side effects of chemotherapy can even last about a year. However, this is necessary to cure the disease.

  • The treatment of choice for liposarcoma is surgical resection. Chemotherapy is not used outside the experimental setting. Adjuvant radiotherapy can also be used after surgical excision.
  • Rhabdomyosarcoma is treated with surgery, radiation therapy, and / or chemotherapy. Most patients with rhabdomyosarcoma can have a survival rate of 50-85%.
  • Osteosarcoma (bone cancer) is often treated with surgical resection in combination with neoadjuvant chemotherapy. Radiation therapy is a second alternative although it often does not bring great results.

For advanced soft tissue sarcomas, the efficacy of the monoclonal antibody olaratumab has been talked about since September 2017 and now the usefulness of a new molecule called larotrectinab seems to emerge.

Treatment of sarcomas and complex tumors

Surgery is the cornerstone of the curative treatment of sarcomas, when it is possible and the disease is not metastatic. It can be combined with radiotherapy and / or chemotherapy.

The therapeutic choice is made in a concerted manner, between specialists from different disciplines (surgery, radiotherapy, oncology, imaging, anatomopathology) and always takes into account the uniqueness of each patient.


As with all rare pathologies, the initial management of a sarcoma in an expert center reduces the risk of recurrence and improves the survival rate. Indeed, the shortcomings of an unsuitable initial surgery are never completely remedied by a more aggressive secondary treatment.

Reference center for the treatment of sarcomas, supports the surgical treatment of all visceral and soft tissue sarcomas, whatever their location, whether they are primary or in a situation of recurrence.

The care is based on a personalized care plan, established in a concerted manner between specialists from the different disciplines, taking into account the uniqueness of each patient and favoring the preservation of bodily integrity.

Isolated limb perfusion

49% of soft tissue sarcomas develop from a limb. Gustave Roussy is one of the only centers in the world to practice isolated limb perfusion, an alternative to amputation.

This technique involves temporarily isolating the affected limb from the bloodstream by means of a tourniquet. Chemotherapy can then be administered at doses greater than those delivered into the systemic circulation. This approach preserves the limb in more than 80% of cases, ensures a short recovery time and makes it possible to reduce the size of the tumor before possible surgery.


Radiation therapy is now extremely precise: it allows healthy tissue to be better spared by targeting the regions to be irradiated.

Any patient undergoing radiotherapy is offered a weekly consultation with a doctor. This follow-up appointment makes it possible to discuss with the patient, assess the toxicity and possibly adapt the treatment.

New functional imaging techniques make it possible to predict the tumor response to radiotherapy and to assess this response after radiotherapy and, therefore, to better personalize the treatment.

Learn more about Radiotherapy


Chemotherapy uses different molecules, used alone or in combination. New molecules, called targeted therapies, are also being used in clinical trials in some countries. By targeting the specifics of each tumor, they aim to improve the effectiveness of treatment while reducing their toxicity.

Learn more about Chemotherapy

Living with and after illness

Being diagnosed with cancer is a difficult time. The medical team is there to help and guide patients and their loved ones throughout this ordeal. In the case of sarcoma, the difficulties associated with possible mutilating treatments may in particular require specific support.

After the shock associated with the announcement of the disease, it is important for the patient to gradually become involved in its management. Staying on top and avoiding low morale contributes to the effectiveness of treatments.

During illness

After the shock associated with the announcement of the disease, it is important for the patient to gradually become involved in its management.

Staying on top and avoiding low morale contributes to the effectiveness of treatments. To this end, the support of relatives is important, as well as that of the nursing staff who can hear the concerns and answer the questions expressed.

Several devices outside the family and the healthcare team can also help the patient to accept the disease and to cope: he can, for example, find support from listening and information structures. It may also be beneficial to talk to a psychologist or psycho-oncologist. These specialists are generally available within the oncology departments themselves. Otherwise, do not hesitate to seek advice from the medical team.

The impact of treatments

In the case of sarcomas, mutilating treatments require appropriate care and support, both medically and psychologically.

While it is less common since studies have shown that removal of the tumor followed by radiation therapy achieves the same results, complete or partial limb amputation can sometimes be the only treatment option. It can lead to the placement of a prosthesis, made to measure, which requires patience and training. Today, prostheses reduce the risk of infection and can adjust as a child grows.

After an amputation, supportive care aims to guarantee the patient the best possible quality of life. The use of an occupational therapist, a psychomotor therapist and / or a physiotherapist can thus be beneficial. It is about learning how to live, move around and work after treatment for their sarcoma. If he will not quite get back to his “life before,” he can find, with the help of professionals, effective strategies to continue a life full of activities.

Psychologically, doctors compare the trauma of a mutilating treatment to that of a traffic accident. This breach of self-integrity can be difficult to come to terms with. In addition, the patient must adapt to the disability in a particularly difficult context. In addition to the disability, you must also learn to tame your new body even though the fear of the disease and its consequences is very present and the fear of a recurrence persists for a few years afterwards.

Sarcoma specialists are listening to these questions related to the psychological and social impacts of the disease. Depending on the patient’s request, the oncologist can refer him to psychological follow-up.

What follow-up after illness?

There is no regulatory recommendation for the follow-up of patients treated for soft tissue sarcoma and viscera.

The follow-up schedule, which usually lasts ten years, involves monitoring the risk of local recurrence and spread to other parts of the body, especially the lungs.

The frequency of appointments, which depends on the tumor aggressiveness assessed at the time of diagnosis, gradually becomes less frequent over time. For example, for aggressive and intermediate sarcomas, monitoring is often done every three months for two years, then twice a year until the fifth year, then once a year. For less aggressive sarcomas, appointments take place every six months for the first five years, then once a year.

List of all Cancers

The word “cancer” is a generic term for a large group of diseases that can affect any part of the body. We also speak of malignant tumors or neoplasms. One of the hallmarks of cancer is the rapid multiplication of abnormal growing cells, which can invade nearby parts of the body and then migrate to other organs. This is called metastasis, which is the main cause of death from cancer. Types of cancer (in alphabetical order of the area concerned):

Types of Cancer | List all of Cancers | Adult, Children, Head and neck, Digestive and Types of Blood Cancer

Information: Cleverly Smart is not a substitute for a doctor. Always consult a doctor to treat your health condition.

Sources: PinterPandai, Institut Curie, Johns Hopkins Medicine, WebMDCancer CenterSeattle Cancer Care Alliance

Photo credit: M. Sand, D. Sand, C. Thrandorf, V. Paech, P. Altmeyer, F. G. Bechara via Wikimedia Commons (CC BY 2.0)

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