Diagnostic des sarcomes

Diagnosing sarcomas: the importance of specialized management

Although the vast majority of tumors are not sarcomas, you should still see a doctor to obtain a precise diagnosis. Never allow symptoms to continue or worsen without medical advice.

Sarcomas: when to seek consultation

It is important to see a doctor quickly, preferably a sarcoma specialist, if certain symptoms arise or develop.

  • A deep, unexplained mass or a superficial lesion measuring more than 5 cm in diameter in the torso, arms or legs.
  • Any abdominal mass measuring more than 5 cm.


Sarcomas: possible diagnostic errors

Today we are increasingly aware that the variety and rarity of sarcoma cases may lead to problems in evaluating them, for the patient and even for the doctor. Since sarcomas can be mistaken for a benign tumor, a hematoma, an abscess or simply a lump of fat, it may sometimes be diagnosed at a late stage. When there is an evaluation error, a physician may also decide on inappropriate surgery, which may complicate the treatment of the tumor.


Sarcomas: expertise is necessary

If a sarcoma is suspected, your physician will refer you to an expert sarcoma center, which will provide multi-disciplinary, specialized care.

The biopsy must be carried out using a special technique, taking great care to avoid contamination of the surrounding areas by the cancerous cells if the tumor is indeed malignant. As a first line of treatment, the biopsy is performed through the skin using a needle. This enables clean surgery to be performed, in a single block and with healthy tissue around the tumor unaffected.

  • The sample must be analyzed by an anatomopathologist belonging to the reference network for sarcoma pathology for soft tissue and visceral sarcoma (RRePS) cases, even if an initial diagnosis was made somewhere other than a reference center.
  • Treatment of the sarcoma must be decided upon by a specialized multi-disciplinary team (including the oncologist, surgeon and radiologist). If surgery is required, it must be performed by a surgeon trained in this type of tumor. 

Institut Curie is one of the national expert centers for analysis and management of sarcomas. See the complete list of French centers.


Sarcomas: clinical exam

The physician may:

  • Palpate the affected area of the body and assess the mass and its mobility
  • Check to see if there is weakness in a limb, decreased movement, numbness
  • Search for general signs, in particular malnutrition in the case of abdominal sarcoma
  • Search for possible ganglions (rare)


Sarcomas: imaging exams

If the slightest doubt exists, one or more imaging exams are prescribed by the physician, depending on the case:

  • CT scan for sarcoma in the chest or abdomen
  • MRI and radiography for sarcoma in the limbs
  • MRI for tumors of the chest and abdominal wall, the head or the neck
  • Ultrasound for small, superficial tumors
  • Scintigraphy for bone sarcoma

>>Biopsy is essential for suspected sarcomas

If the imaging reveals a suspicious mass, a biopsy is performed, either through the skin, controlled by ultrasound or scan, or via surgery. It distinguishes a benign tumor from a malignant one, and if malignant, the exam can determine whether or not it is a sarcoma.

In most cases, a percutaneous biopsy is needed. If the tumor is superficial and small (less than 5 cm), it can be removed directly and analyzed. The biopsy must be discussed at a specialized center before any surgery is performed. 


Sarcomas: assessing the grade and stage of the tumor

If the sample is found to be malignant, the biopsy can determine the grade. The size and depth of the tumor are also carefully measured.

  • The grade of the tumor is assessed according to complex criteria (degree of abnormality, speed of growth, whether or not there is necrosis), which ascertain its severity.
  • The stage of the cancer takes into account the grade of the tumor, its size, the degree of propagation to neighboring tissues, invasion by the surrounding lymph-node cells and whether or not there are metastases.

Advanced analysis of the sarcoma

In a cancer center with a molecular biology platform, it is also possible to analyze the tumor’s DNA; in many sarcoma cases, there is a chromosome or genetic anomaly. This analysis can confirm the type of sarcoma and, in some cases, point to the appropriate chemotherapy treatment.

The discovery of the genetic alterations responsible for Ewing sarcoma led to the development, in 1994, of a molecular test to diagnose this disease at Institut Curie.