Introduction

Finding a new lump or swelling under your skin can be unsettling. You may wonder: Is it harmless? Could it be cancer? Do I need surgery?

The vast majority of soft tissue lumps are benign (non‑cancerous). However, some can be complex, locally aggressive, or – in rare cases – malignant (a sarcoma). Accurate diagnosis is essential to avoid unnecessary surgery on one hand and dangerous delays on the other.

In this blog, I explain how we assess soft tissue lesions, which ones need treatment, and when a lump should be referred to a specialist sarcoma centre.

What Are Soft Tissue Lesions?

Soft tissue includes muscles, fat, blood vessels, nerves, tendons, and the deep skin layers. A lesion is simply an abnormal growth within this tissue.

Common Benign Lesions

• Lipoma – a soft, rubbery lump made of fat cells. Usually painless and slow‑growing.
• Sebaceous cyst – a small, dome‑shaped lump filled with keratin (often from a blocked hair follicle).
• Fibroma – a firm, benign growth of fibrous tissue.
• Neurofibroma – a benign nerve sheath tumour (sometimes associated with neurofibromatosis).

These lesions are typically asymptomatic, but they can become painful if they press on nerves, grow large, or become infected.

Complex Benign Lesions

Some benign tumours behave more aggressively, even though they do not spread to other parts of the body:

• Desmoid fibromatosis – a locally invasive tumour that can recur after excision. It may require medical therapy (NSAIDs, hormonal treatment) or wide local excision.
• Intramuscular lipoma – a lipoma deep within a muscle, which can be harder to remove completely.
• Pigmented villonodular synovitis (PVNS) – a rare, benign but destructive joint lesion.

These need expert imaging (MRI) and often discussion in a multidisciplinary team (MDT).

Malignant Lesions (Sarcoma)

Sarcomas are rare (less than 1% of adult cancers) but serious. They can arise in any soft tissue. Warning features include:

• Deep, fixed lump that is growing rapidly
• Size larger than 5 cm (about the size of a golf ball)
• Pain, especially at night
• Recurrence after previous excision

If a sarcoma is suspected, immediate referral to a specialist sarcoma centre is essential for definitive treatment.

How We Diagnose Soft Tissue Lesions

I offer a rapid, clear diagnostic pathway for any worrying lump.

Step 1: Clinical Examination

I will feel the lump, check its size, depth, mobility, and tenderness. I will also ask how long you have had it and whether it is changing.

Step 2: Imaging

• Ultrasound – quick, painless, and tells us if the lump is solid, cystic, or vascular.
• MRI – the gold standard for deep or suspicious lesions. It shows the exact anatomy, relationship to muscles and nerves, and any aggressive features.
• Step 3: Core Needle Biopsy

If the lump is deep, larger than 5 cm, or has suspicious MRI features, I arrange an image‑guided core needle biopsy. A small sample of tissue is taken and sent for histopathology and, if needed, molecular studies.

Biopsy results are usually available within 5‑7 days.

Management Plan – Tailored to Your Lesion

Once we have a diagnosis, we follow a clear, evidence‑based plan:

• Small, benign, asymptomatic → Clinical surveillance (regular checks) or discharge.
• Symptomatic or enlarging benign → Surgical excision under local anaesthetic (for superficial lumps) or day‑case general anaesthetic (for deeper lesions).
• Complex benign (e.g., desmoid) → Discuss all options: surveillance, medical therapy (NSAIDs, hormone treatment), or wide local excision.
• Malignant or high‑grade sarcoma → Immediate referral to a specialist sarcoma multidisciplinary team for definitive oncological surgery, radiotherapy, or chemotherapy.

I work closely with London’s sarcoma networks to ensure a seamless handover. You will never be left wondering what comes next.

What Happens During Excision of a Benign Lump?

Most superficial lipomas and sebaceous cysts can be removed in a minor procedure room under local anaesthetic. You remain awake, but the area is completely numb. The procedure takes 15‑30 minutes, and you go home the same day.

Larger or deeper lesions are removed in a day‑case operating theatre under general anaesthetic. We use fine, cosmetic incisions to minimise scarring. Recurrence after complete excision is very low (less than 2‑5% for most benign tumours).

When Do We Refer to a Sarcoma Centre?

If a core biopsy shows a sarcoma or any high‑grade malignant tumour, I will refer you immediately to one of London’s specialist sarcoma centres (e.g., Royal National Orthopaedic Hospital or University College London Hospital). There, you will have access to:

• Sarcoma specialist surgeons
• Oncology (chemotherapy, radiotherapy)
• Specialist radiology and pathology
• Reconstruction and rehabilitation services

This ensures you receive the highest level of care for rare and complex malignancies.

Final Thoughts – Don’t Ignore a Changing Lump

Most lumps are nothing to worry about. But if you notice a lump that is growing, painful, deep, or larger than 5 cm, please get it checked.

As a consultant colorectal and general surgeon, I offer a fast, compassionate, and thorough soft tissue lesion service. Whether it is a simple lipoma that needs removal or a concerning lump that requires specialist referral, I will guide you every step of the way.

Book a Consultation

If you have a soft tissue lump and would like a professional opinion, please contact my team.

Call: 0 7716 638840
Book an e‑consultation or face‑to‑face appointment via our website.