What is a soft-tissue mass?
A soft-tissue mass is a lump arising from tissues such as muscle, fat, fascia, tendon-related tissue or other structures outside bone. Many are benign, but the cause cannot always be established by touch alone.
When should a lump be assessed?
An enlarging, deep, fixed, painful, recurrent, persistent or unexplained lump should be assessed. These features do not prove that a mass is malignant, but they help determine whether investigation is appropriate.
- Increasing size
- A deep or fixed mass
- Persistent pain or swelling
- A recurrent mass
- An unexplained or persistent mass
Does a painless lump matter?
Yes, in some circumstances. A painless mass may still merit assessment depending on its size, depth, growth and clinical context; lack of pain does not establish that it is harmless.
Ultrasound versus MRI
Ultrasound may help assess selected superficial lesions. MRI is often useful for a deeper or indeterminate mass, but not every lump requires MRI; the choice depends on location, examination and the question that imaging needs to answer.
Imaging before biopsy
Appropriate imaging is commonly completed before biopsy so the mass can be defined and the safest diagnostic route planned. The sequence depends on the lesion and clinical context.
Why biopsy planning matters
If biopsy is needed, its route should be coordinated with the team that would provide definitive treatment. An unplanned excision or poorly placed biopsy can complicate later definitive surgery, so an unexplained mass should not be treated as a simple removal without assessment.
What does biopsy involve?
Selected cases may use an image-guided core biopsy or another planned technique. Pathology helps guide subsequent treatment, but not every soft-tissue lesion requires biopsy.
What happens after pathology?
A benign lesion may be observed or treated according to its diagnosis and symptoms. A malignant diagnosis requires appropriate staging and coordinated multidisciplinary planning before treatment is selected.
When faster assessment is appropriate
A rapidly enlarging mass, or one with other concerning features, deserves timely assessment. This does not mean that every soft-tissue lump is an emergency.
Is every soft-tissue lump cancer?
No. Many masses are benign, but a changing or unexplained mass should be assessed rather than assumed to be harmless.
Should a lump be removed before imaging?
Not routinely. Imaging and biopsy planning may be important before any excision, especially for a deep, enlarging or unexplained mass.
Does every soft-tissue mass need a biopsy?
No. The need for biopsy depends on the examination, imaging and diagnostic question.
Should a painless lump be checked?
It may need assessment if it is enlarging, deep, persistent, recurrent or otherwise unexplained.
Written and medically reviewed by: Dr. Yousef Abuodeh Consultant Orthopedic Surgeon