Diagnosing soft tissue sarcoma

The clinician first assesses the lump or affected area and reviews how it has changed. MRI, CT or ultrasound may define its depth, relationship to nearby structures and the safest route for tissue sampling. Imaging can raise or lower concern, but the tissue findings identify whether the mass is a sarcoma and which type it is.

A core needle biopsy removes small cylinders of tissue, often with imaging guidance. An incisional biopsy may be considered when a needle sample cannot be taken safely or does not answer the diagnostic question. The pathologist examines cell appearance and may use immunohistochemistry or molecular tests to distinguish among sarcoma subtypes and other conditions.

The biopsy route is chosen with future surgery in mind because the sampled area may need to be removed with the tumour. This is why biopsy is ideally coordinated by the specialist team that would provide treatment. A second pathology opinion may be requested when the appearances are unusual or the classification remains uncertain.

Avoid having an unexplained deep or enlarging lump removed before specialist imaging and biopsy planning. Bring earlier scans, procedure notes and pathology material if you are referred from another centre. Tell the team about blood-thinning medicines, allergies and implanted devices before imaging or biopsy.

After tissue confirms the diagnosis, further scans may check the original area and other parts of the body. Ask whether the pathology names a specific subtype and grade, whether more tissue testing is pending, and when the multidisciplinary team will review the results. Those details shape decisions about tumour removal surgery, radiotherapy and chemotherapy.

Book an assessment for a lump that is enlarging, lies deep in the body, returns after removal, or causes persistent pain or altered movement. Soft tissue sarcoma can present as a lump that is not painful, but many lumps have non-cancerous causes; the examination and imaging determine what needs further investigation.

Seek urgent help if swelling suddenly affects breathing or swallowing, if a limb becomes cold or markedly weak, or if severe pain develops with rapid swelling. These features can reflect pressure on important structures and warrant prompt care regardless of the eventual diagnosis.

Useful questions include: Who planned the biopsy route? Has a sarcoma pathologist reviewed the sample? What subtype and grade were found? Ask whether the sample was sufficient, which scans are still needed, and whether the case will be discussed by a team that includes radiology, pathology, surgery, medical oncology and radiation oncology.