What Are Benign Soft Tissue Tumors? Types, Symptoms, Causes, and Treatment Explained
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What are benign soft tissue tumors?
Benign soft tissue tumors are noncancerous lumps under the skin that can develop anywhere there is soft tissue, such as in the muscles, tendons and fat. [1] Because they are not cancer, most of these tumors do not cause serious health problems, and small tumors that are not causing any issues may not need any treatment at all.
Key takeaways
Benign soft tissue tumors are noncancerous lumps under the skin. [1] They develop wherever soft tissue exists, including muscles, tendons, and fat, and they do not spread or become cancer.
There are dozens of types; lipomas, nerve sheath tumors, hemangiomas, and fibromas are common. Each type forms from a different kind of soft tissue, such as fat cells, nerve support tissue, blood cells, or fibrous connective tissue. [1]
Many people have no symptoms. Common symptoms include soft or squishy lumps under the skin, with pain occurring only if a large tumor presses on a nerve or organ.
Diagnosis involves a medical history, physical exam, imaging such as MRI, and sometimes a biopsy. [1] A pathologist examines tissue under a microscope to confirm the tumor is benign.
Benign soft tissue tumors are about 10 times more common than cancerous ones. [1] Most do not require treatment; surgery is used for tumors that cause pain or affect organ function, and radiation may prevent recurrence.
What the research says
Size, depth, and growth help flag the lumps that need more workup. A family-medicine clinical review advises further workup for any soft tissue mass that is deep to the fascia, 5 cm in diameter or larger, growing rapidly, or appearing suddenly without explanation. Imaging for concerning masses may include ultrasonography, radiography, and MRI with contrast, and an incisional biopsy can help establish a diagnosis. (Achar et al., Am Fam Physician, 2022) [2]
Advanced MRI techniques can help separate benign from malignant tumors, but they are not perfect. A meta-analysis of 18 studies covering 1,319 patients with musculoskeletal soft tissue tumors (623 malignant, 696 benign) found that the apparent diffusion coefficient from diffusion-weighted MRI had a pooled sensitivity of 0.80 (95% CI 0.77–0.82) and a pooled specificity of 0.63 (95% CI 0.60–0.67). (Wang et al., J Cancer, 2021) [5]
Computer-assisted image analysis is a promising tool for sorting benign from malignant tumors. A systematic review and meta-analysis of 21 studies involving 3,866 patients found that radiomics and deep learning models had a combined sensitivity of 0.84 (95% CI 0.76–0.89) and specificity of 0.88 (95% CI 0.69–0.96) for distinguishing benign from malignant soft tissue tumors. The authors called for more rigorous, multicenter prospective validation. (Dai et al., Acad Radiol, 2024) [6]
What Are Benign Soft Tissue Tumors?
Benign soft tissue tumors are noncancerous lumps under your skin. They develop anywhere you have soft tissue, such as your muscles, tendons, and fat. [1]
The word “benign” is the key to understanding these growths. A benign tumor is not cancer. [1] It does not invade other tissue the way cancer does, and it does not spread throughout the body. Most benign soft tissue tumors never cause significant health problems.
Depending on your situation, your healthcare provider may recommend surgery to remove the tumor and/or radiation therapy to keep the tumor from coming back, which is called recurring. [1]
What are soft tissue tumor types?
There are dozens of soft tissue tumor types. Some of the more common tumor types include: [1]
Tumor Type | What It Forms From | Notes |
Fat cells [1] | The most well-known type; angiolipomas are lipomas made of fat and blood vessels | |
Nerve sheath tumors | Soft tissue surrounding and supporting nerves [1] | Schwannomas and neurofibromas are common nerve sheath tumors |
Hemangiomas | Blood cells [1] | Formed from clusters of small blood vessels |
Fibromas | Fibrous connective tissue [1] | Desmoid tumors are a type of fibroma [1] |
Benign fibrous histiocytoma (BFH) | Fibrous mass [1] | May develop anywhere in the body [1] |
Symptoms of Benign Soft Tissue Tumors
You can have this condition without having symptoms at all. [1] Many benign soft tissue tumors are discovered by chance and never cause any discomfort.
When symptoms do occur, the most common ones include lumps or bumps under your skin that feel soft or squishy when you touch them. [1] These bumps are usually movable and painless in their early stages.
Pain can develop if a large tumor presses on a nerve or organ. [1] This pressure is one of the main ways a harmless lump begins to affect daily life.
Symptoms at a glance
Symptom | Details |
No symptoms | Many people have the condition without any symptoms |
Soft or squishy lumps | Lumps or bumps under the skin that feel soft to touch [1] |
Pain | Occurs if a large tumor presses on a nerve or organ [1] |
Functional effects | Large tumors may press on organs and affect their function [1] |
Quality-of-life impact | Tumors affecting nerves can be very painful [1] |
What Causes Benign Soft Tissue Tumors?
Medical researchers do not know all the reasons people develop benign soft tissue tumors. [1] The cause can differ from person to person and from tumor type to tumor type.
What researchers do know is that the origins fall into two broad categories:
In other words, some people are born with a genetic tendency toward these growths, while others develop them because of genetic changes that happen over the course of life. Lifestyle factors are not listed as known causes.
How Are Benign Soft Tissue Tumors Diagnosed?
Your healthcare provider will start by taking a thorough medical history. They may ask how long you have had the lump or bump and if it is growing. They may also ask about any recent injury that may explain why you have a lump. [1]
Next, they will perform a physical examination of the lump, checking its size, texture, and how it moves under the skin.
They may do imaging tests too. Providers may be able to diagnose some benign soft tissue tumors with magnetic resonance imaging (MRI). However, providers occasionally do biopsies to diagnose benign soft tissue tumors. A biopsy involves taking a sample of tumor tissue. Medical pathologists examine tissue samples under a microscope to determine if the tumor is benign or cancerous. [1]
Diagnostic steps at a glance
Step | What Happens |
Medical history | Provider asks how long the lump has been present, whether it is growing, and about any recent injuries [1] |
Physical examination | The lump is examined by touch and sight |
Imaging tests | MRI may be able to diagnose some benign soft tissue tumors [1] |
Biopsy | A tissue sample is taken when needed [1] |
Microscope examination | Medical pathologists confirm whether the tumor is benign or cancerous [1] |
Should I be worried?
A benign soft tissue tumor is not cancer. In fact, benign soft tissue tumors are about 10 times more common than malignant or cancerous soft tissue tumors. [1]
In general, you could have cause for concern if a bump that is a soft tissue tumor affects your quality of life. For example, soft tissue tumors that affect your nerves can be very painful. Some benign soft tissue tumors may grow large enough to press on your organs and affect their function. [1] If you develop a soft tissue tumor, ask your healthcare provider what you can expect.
How Are Benign Soft Tissue Tumors Treated?
A small soft tissue tumor that is not causing issues may not require treatment at all. [1] Watchful waiting is a perfectly reasonable approach when the lump is small, painless, and stable.
Providers typically do surgery to remove benign soft tissue tumors that cause issues like pain or that affect organ function. [1] Surgery is the standard treatment when a benign tumor stops being a neutral bystander.
Depending on the situation, your provider may also recommend radiation therapy to keep the tumor from coming back after it is removed.
Outlook and Prognosis
In general, benign soft tissue tumors do not cause significant health issues. [1] Most people live with these growths without any meaningful disruption to their health.
However, large tumors that press on nerves and organs may cause issues. In that case, providers may recommend surgery to remove the tumor. [1] Once removed or managed, the outlook is generally very good.
Can Benign Soft Tissue Tumors Be Prevented?
Unfortunately, you cannot prevent most benign soft tissue tumors. [1] Because the causes are rooted in genetics and gene mutations, there is no proven lifestyle step that stops these growths from forming.
What you can do is be aware of changes in your body that may be signs of a soft tissue tumor. While most soft tissue tumors are benign (noncancerous), some are cancerous. Talk to a healthcare provider if you have a lump or bump that does not go away. [1]
Living With a Benign Soft Tissue Tumor
How to take care of yourself
The best thing you can do is be aware of changes in your body. Talk to a healthcare provider if you notice new lumps or bumps that appear to grow. [1] Monitoring the lump over time is the most practical self-care step.
Questions to ask your healthcare provider
You may want to ask the following questions at your appointment:
What kind of benign soft tissue tumor do I have?
Why did I develop this tumor?
Could this tumor become cancerous?
What are the treatments?
Can the tumor come back after treatment?
Conclusion
Benign soft tissue tumors are noncancerous lumps that develop anywhere soft tissue exists, from muscles and tendons to fat under the skin. They come in dozens of types, including lipomas, nerve sheath tumors, hemangiomas, and fibromas, and they are roughly ten times more common than cancerous soft tissue tumors.
Many people never experience symptoms, but larger tumors can press on nerves or organs and cause pain. Diagnosis relies on a medical history, physical exam, imaging such as MRI, and occasionally a biopsy. Small, problem-free tumors often need no treatment, while problematic ones are typically removed with surgery, sometimes with radiation therapy to prevent recurrence.
If you notice a new lump or bump that does not go away or appears to grow, the best next step is a conversation with a healthcare provider. Knowing that a lump is not cancer can provide real peace of mind.
Turn confusing medical topics into clear visuals. If you explain health content to others, Rinnit's ready-made infographic templates can help you illustrate conditions like benign soft tissue tumors quickly, without design experience.
Frequently Asked Questions
What are benign soft tissue tumors?
Benign soft tissue tumors are noncancerous lumps under the skin. They develop anywhere you have soft tissue, such as your muscles, tendons, and fat, and they are not cancer. [1]
Are benign soft tissue tumors cancer?
No. A benign soft tissue tumor is not cancer. Benign soft tissue tumors are about 10 times more common than malignant or cancerous soft tissue tumors. [1]
Where do benign soft tissue tumors develop?
Benign soft tissue tumors can develop anywhere you have soft tissue. [1] Common locations include areas with muscles, tendons, and fat under the skin.
What are the most common types?
There are dozens of types. The more common ones include lipomas (fat cell tumors), nerve sheath tumors (such as schwannomas and neurofibromas), hemangiomas (blood vessel tumors), fibromas (fibrous connective tissue tumors, including desmoid tumors), and benign fibrous histiocytoma (fibrous masses that may develop anywhere in the body). [1]
What is a lipoma?
A lipoma is a benign tumor that forms from fat cells. A related variant, the angiolipoma, is a lipoma made of fat and blood vessels. [1]
Do benign soft tissue tumors cause symptoms?
You can have this condition without having symptoms. Common symptoms include lumps or bumps under the skin that feel soft or squishy when you touch them, and pain if a large tumor presses on a nerve or organ. [1]
Can a benign tumor cause pain?
Yes, in some cases. Pain occurs when a large tumor presses on a nerve or organ. Soft tissue tumors that affect nerves can be very painful. [1]
What causes benign soft tissue tumors?
Medical researchers do not know all the reasons people develop these tumors. Some people inherit conditions that cause soft tissue tumors, while other tumors happen when genes mutate or change during a person's lifetime. [1]
How is a benign soft tissue tumor diagnosed?
A provider takes a thorough medical history, performs a physical examination, and may order imaging tests. Some tumors can be diagnosed with MRI. Occasionally, a biopsy is done, in which a sample of tumor tissue is examined under a microscope by a medical pathologist to confirm whether the tumor is benign or cancerous. [1]
What is a biopsy?
A biopsy involves taking a sample of tumor tissue. Medical pathologists examine the tissue sample under a microscope to determine if the tumor is benign or cancerous. [1]
Do I need treatment for a benign soft tissue tumor?
Not always. A small soft tissue tumor that is not causing issues may not require treatment. Providers typically do surgery to remove tumors that cause issues like pain or that affect organ function. [1]
How are benign soft tissue tumors treated?
The main treatment is surgery to remove tumors that cause pain or affect organ function. Radiation therapy may also be used to keep the tumor from coming back after removal.
Can a benign soft tissue tumor come back?
Tumors can recur. Radiation therapy is one method used to keep the tumor from coming back after treatment. Ask your provider whether your specific tumor type tends to recur.
What is the outlook for someone with this condition?
In general, benign soft tissue tumors do not cause significant health issues. [1] When large tumors press on nerves or organs, surgery may be recommended, and the overall outlook remains good.
Can I prevent benign soft tissue tumors?
Unfortunately, you cannot prevent most benign soft tissue tumors. The best approach is to be aware of changes in your body and to talk to a healthcare provider if you have a lump or bump that does not go away. [1]
When should I see a doctor about a lump?
Talk to a healthcare provider if you have a lump or bump that does not go away, and especially if you notice new lumps or bumps that appear to grow. [1] While most soft tissue tumors are benign, some are cancerous, so an evaluation is always worth it.
Related Reading
References
Cleveland Clinic. Benign Soft Tissue Tumors. Cleveland Clinic Health Library. Last updated March 29, 2023. Accessed October 15, 2026. https://my.clevelandclinic.org/health/diseases/16778-benign-soft-tissue-tumors
Achar S, Yamanaka J, Oberstar J. Soft tissue masses: evaluation and treatment. Am Fam Physician. 2022;105(6):602-612. PMID 35704829. https://pubmed.ncbi.nlm.nih.gov/35704829/
Church DJ, Krumme J, Kotwal S. Evaluating soft-tissue lumps and bumps. Mo Med. 2017;114(4):289-294. PMID: 30228613. https://pubmed.ncbi.nlm.nih.gov/30228613/
Nishio J. Updates on the cytogenetics and molecular cytogenetics of benign and intermediate soft tissue tumors. Oncol Lett. 2013;5(1):12-18. PMID: 23255885. https://doi.org/10.3892/ol.2012.1002
Wang Q, Xiao X, Liang Y, et al. Diagnostic performance of diffusion MRI for differentiating benign and malignant nonfatty musculoskeletal soft tissue tumors: a systematic review and meta-analysis. J Cancer. 2021;12(24):7399-7412. PMID: 35003360. https://doi.org/10.7150/jca.62131
Dai X, Zhao B, Zang J, et al. Diagnostic performance of radiomics and deep learning to identify benign and malignant soft tissue tumors: a systematic review and meta-analysis. Acad Radiol. 2024;31(10):3956-3967. PMID: 38614826. https://doi.org/10.1016/j.acra.2024.03.033
Medical disclaimer
The information provided in this article is for educational purposes only and is not intended as medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking care because of content you have read here. See a healthcare provider about any lump that does not go away, keeps growing, or causes pain.
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