EVERYTHING YOU NEED TO KNOW ABOUT SOFT TISSUE SARCOMA

The symptoms of soft tissue sarcoma can vary based on the location of the tumor. It occurs broadlt either in the extremities (arms and legs) or the retroperitoneum (the area behind the abdominal cavity), and thus the symptoms differ due to the anatomical differences and the impact on nearby structures. 

1. Visible Lump or Mass:
   The most common symptom is a noticeable lump or swelling in the affected limb. This mass may be painless at first but can become painful as it grows or compresses surrounding tissues.
2. Pain:
   Pain may develop if the tumor presses on nearby nerves, muscles, or bones. The pain may be persistent or worsen with activity.
3. Limited Mobility:
   As the tumor grows, it can affect the range of motion in the affected limb, making it harder to move the arm or leg normally.
4. Swelling:
   In addition to the lump, swelling can occur, especially if the tumor obstructs blood flow or lymphatic drainage in the affected area.
5. Skin Changes:
   In some cases, the skin over the tumor may become red or warm, particularly if there is inflammation due to the growing mass.
6. No Immediate Symptoms:
   Often, the tumor may not cause pain or symptoms in its early stages. It may be discovered incidentally when a lump is noticed, or after it begins to affect movement.

1. Abdominal Mass or Swelling:
   A retroperitoneal soft tissue sarcoma may cause a visible or palpable mass in the abdomen, though it is less likely to be as easily detected as a lump in the limbs due to the deep location.
2. Pain:
   Pain or discomfort in the abdominal or lower back region is a common symptom. This may result from the tumor pressing on nearby organs, muscles, or nerves. The pain can vary from mild to severe.
3. Digestive Symptoms:
   As the tumor grows, it may put pressure on surrounding organs like the intestines, kidneys, or bladder. This can cause symptoms like nausea, vomiting, loss of appetite, bloating, or constipation.
4. Unexplained Weight Loss:
   A person with a retroperitoneal sarcoma may experience unexplained weight loss, which can occur if the tumor interferes with digestion or if it is an aggressive form of cancer.
5. Back Pain:
   Back pain, particularly in the lower back, can be a symptom if the tumor is located near the spine or affecting nearby nerves.
6. Urinary Symptoms:
   If the tumor presses on the kidneys, ureters, or bladder, it may cause urinary problems, such as frequent urination, difficulty urinating, or blood in the urine.
7. Silent or Subtle Symptoms:
   Retroperitoneal sarcomas are often difficult to detect early because they are located deep within the body. Symptoms may not become noticeable until the tumor has grown quite large, making early diagnosis challenging.

The workup for retroperitoneal soft tissue sarcoma follows a similar process to that of extremity sarcomas, but it requires additional considerations due to the deep and often asymptomatic nature of the tumor in the retroperitoneal space. Here's a comprehensive step-by-step outline of the diagnostic workup:

• History: The physician will begin by taking a detailed medical history, including the patient's symptoms (e.g., abdominal pain, weight loss, digestive issues) and any previous exposure to radiation, genetic conditions, or family history of cancer.
• Physical Examination: The doctor will assess for any palpable mass in the abdomen or flank. Since retroperitoneal tumors are deep, they may not always be detectable on physical exam, especially in early stages. The exam will also include checking for signs of metastasis (e.g., enlarged lymph nodes).

Imaging is essential for determining the tumor's size, location, and involvement with surrounding structures. Given the retroperitoneum’s deep location, these studies are particularly important.

• Abdominal Ultrasound: 
  • This can be used to identify the presence of a mass in the abdomen or retroperitoneal space. While it may help guide further imaging or biopsy, it is generally less definitive for soft tissue tumors.
• CT Scan (Computed Tomography): 
  • CT of the Abdomen and Pelvis: This is the primary imaging modality used to evaluate retroperitoneal masses. CT provides detailed images of the mass’s size, location, and any involvement of adjacent structures like the kidneys, adrenal glands, bowel, and major blood vessels (e.g., the aorta or vena cava). It also helps identify any potential metastasis to the lungs or other organs.
  • Contrast-enhanced CT may be used to assess the tumor's vascularity and to distinguish it from other types of tumors (e.g., lymphomas, metastatic tumors).
• MRI (Magnetic Resonance Imaging): 
  • MRI is highly useful for assessing the extent of soft tissue involvement, especially in relation to adjacent structures like nerves, muscles, and blood vessels. It is particularly beneficial when the tumor is near critical structures and when surgical planning is required.
  • MRI provides superior contrast resolution for soft tissues, making it helpful in characterizing the tumor’s borders and identifying whether there is invasion of neighboring organs or blood vessels.
• PET Scan (Positron Emission Tomography): 
  • A PET scan may be used to assess metabolic activity and evaluate for distant metastasis, particularly if the CT or MRI findings are unclear or if the sarcoma is suspected to be aggressive.
  • PET can help identify areas of high metabolic activity, which may indicate active disease or metastasis, especially in the lungs, liver, or bones.

A biopsy is essential for confirming the diagnosis and identifying the specific type of soft tissue sarcoma.

• Needle Biopsy (Core Needle or Fine Needle Aspiration - FNA): 
  • In most cases, a core needle biopsy is performed, typically under imaging guidance (CT or ultrasound) to obtain a tissue sample. It’s minimally invasive and allows for a larger sample compared to FNA, which improves the accuracy of diagnosis.
  • FNA may be performed if the mass is easily accessible but is less preferred due to the smaller sample size.
• Open Biopsy (Incisional or Excisional): 
  • If the tumor is not easily accessible for a needle biopsy or if more tissue is needed for diagnosis, an incisional biopsy (removal of a portion of the tumor) may be performed.
  • Care must be taken during biopsy to avoid seeding the tumor along the needle tract.

After biopsy, the tissue sample is sent to a pathologist for evaluation:

• Histopathologic Examination: Microscopic evaluation is used to assess the tissue for sarcoma cells.
• Immunohistochemistry: Specific markers (proteins) are tested to determine the subtype of sarcoma. This can include markers for muscle, fat, fibrous tissue, or vascular origin, depending on the suspected type.
• Genetic Testing: In certain cases, genetic or molecular tests may be performed to identify specific mutations or chromosomal translocations characteristic of certain sarcomas (e.g., synovial sarcoma, liposarcoma).

Once the diagnosis is confirmed, staging is done to assess the size, extent, and whether the cancer has spread to other parts of the body.

• CT Scan of the Chest: This is done to check for lung metastasis, as the lungs are a common site of soft tissue sarcoma spread.
• Bone Scan: If there is concern about bone involvement, a bone scan may be done to assess for any skeletal metastasis.
• MRI of the Retroperitoneum: To assess the depth of the tumor and its relationship to nearby structures (e.g., large blood vessels, kidneys, intestines).
• PET Scan: For a more comprehensive assessment of distant metastasis or to evaluate areas of high metabolic activity indicative of spreading disease.

Retroperitoneal soft tissue sarcomas require careful management due to their deep location and potential involvement of critical structures. A multidisciplinary tumor board typically includes surgeons, oncologists, radiologists, pathologists, and other specialists to discuss the case and develop a comprehensive treatment plan.

• This team will consider the tumor's location, size, grade, and the patient's overall health to decide on the best approach for treatment, including surgery, chemotherapy, radiation, or a combination.

Neoadjuvant therapy is used to shrink the tumor before surgery, helping make the tumor more resectable and improving the chances of successful surgery and long-term survival.

1. Chemotherapy:
   Chemotherapy is commonly used for high-grade sarcomas to reduce the tumor size prior to surgery. This treatment helps to control micrometastatic disease and make surgical removal easier.
2. Radiation Therapy:
   External beam radiation is used to shrink the tumor and reduce the risk of recurrence, particularly for tumors located near vital structures or where achieving clear surgical margins is difficult. This is especially common for sarcomas in the extremities or retroperitoneal region.
3. Targeted Therapy and Immunotherapy:
   In certain cases, targeted therapies or immunotherapy may be used before surgery for specific subtypes of sarcoma, based on genetic or molecular features, to shrink the tumor or enhance the body’s immune response against cancer cells.

Adjuvant therapy is given after surgery to eliminate any remaining cancer cells, reduce the risk of recurrence, and improve overall survival, especially in high-risk sarcoma cases.

1. Chemotherapy:
   Adjuvant chemotherapy is used to treat any microscopic disease that may remain after surgery, particularly for high-grade sarcomas. This helps to prevent local recurrence and metastasis by targeting cancer cells that were not removed during surgery.
2. Radiation Therapy:
   After surgery, radiation therapy may be employed to treat the tumor bed, especially if clear surgical margins were not achieved or if the tumor was located in a challenging area. This helps to reduce the likelihood of the sarcoma returning in the same area.
3. Targeted Therapy and Immunotherapy:
   For certain sarcoma subtypes, adjuvant targeted therapy or immunotherapy may be recommended to target specific cancer pathways or enhance the body’s immune system in fighting residual cancer cells.