Soft Tissue Tumors – Types, Causes, Symptoms, Treatment

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 4 min read
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Article Summary

Soft Tissue Tumors /Soft tissue sarcomas are cancerous (malignant) tumors that originate in the soft tissues of your body. This illustration shows a soft tissue sarcoma of the thigh muscle just above the knee. Soft tissue sarcoma is a rare type of cancer that begins in the tissues that connect, support, and surround other body structures WHO classification of Soft Tissue Tumors The World Health Organization...

Key Takeaways

  • This article explains WHO classification of Soft Tissue Tumors in simple medical language.
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Definition

Soft Tissue Tumors /Soft tissue sarcomas are cancerous () tumors that originate in the soft tissues of your body. This illustration shows a soft tissue of the thigh muscle just above the knee. Soft tissue sarcoma is a rare type of cancer that begins in the tissues that connect, support, and surround other body structures

WHO classification of Soft Tissue Tumors

The World Health Organization (WHO) classification of soft tissue tumors is the most widely used pathologic classification system for such disorders. The current revision, part of the 5th edition of the WHO series, was published in 2020 and is reflected in the article below 1.

Classification

Adipocytic tumors

  • lipoma
  • lipomatosis
  • lipomatosis of nerve
  • lipoblastoma and lipoblastomatosis
  • angiolipoma
  • myolipoma of soft tissue
  • chondroid lipoma
  • spindle cell/pleomorphic lipoma
  • hibernoma
  • spindle cell/pleomorphic lipomatous
  • atypical lipomatous tumor/well-differentiated liposarcoma
  • dedifferentiated liposarcoma
  • myxoid liposarcoma
  • pleomorphic liposarcoma
  • myxoid pleomorphic liposarcoma

Fibroblastic/myofibroblastic tumors

  • nodular fasciitis
  • proliferative fasciitis and proliferative myositis
  • myositis ossificans and fibro-osseous pseudotumor of digits
  • ischemic fasciitis
  • elastofibroma
  • fibrous hamartoma of infancy
  • fibromatosis colli
  • juvenile hyaline fibromatosis
  • inclusion body fibromatosis
  • fibroma of the sheath
  • desmoplastic fibroblastoma
  • myofibroblastoma
  • calcifying aponeurotic fibroma
  • EWSR-SMAD3-positive fibroblastic tumor (emerging)
  • angiomyofibroblastoma
  • cellular angiofibroma
  • angiofibroma of soft tissue
  • acral fibromyxoma
  • nuchal-type fibroma
  • Gardner fibroma
  • calcifying fibrous tumor
  • palmar/plantar fibromatosis
  • desmoid-type fibromatosis
  • lipofibromatosis
  • giant cell fibroblastoma
  • dermatofibrosarcoma protuberans
  • solitary fibrous tumor
  • inflammatory myofibroblastic tumor
  • low-grade myofibroblastic sarcoma
  • superficial CD34-positive fibroblastic tumor
  • my inflammatory fibroblastic sarcoma
  • infantile fibrosarcoma
  • adult fibrosarcoma
  • myxofibrosarcoma
  • low-grade fibromyxoid sarcoma
  • sclerosing epithelioid fibrosarcoma

So-called fibrohistiocytic tumors

  • tenosynovial giant cell tumor
  • deep fibrous histiocytoma
  • plexiform fibrohistiocytic tumor
  • giant cell tumor of soft tissue

Vascular tumors

  • hemangiomas
    • synovial hemangioma
    • intramuscular hemangioma
    • arteriovenous malformation/hemangioma
    • venous hemangioma
  • anastomosing hemangioma
  • epithelioid hemangioma
  • lymphangioma and lymphangiomatosis
  • tufted angioma and Kaposiform hemangioendothelioma
  • retiform hemangioendothelioma
  • papillary intralymphatic angioendothelioma
  • composite hemangioendothelioma
  • Kaposi sarcoma
  • pseudomyogenic hemangioendothelioma
  • epithelioid hemangioendothelioma
  • angiosarcoma

Pericytic (perivascular) tumors

  • glomus tumors
  • myopericytoma, including myofibroma
  • angioleiomyoma

Smooth muscle tumors

  • of deep soft tissue
  • EBV-associated smooth muscle tumor
  • inflammatory leiomyosarcoma
  • leiomyosarcoma

Skeletal-muscle tumors

  • rhabdomyoma
  • embryonal rhabdomyosarcoma
  • alveolar rhabdomyosarcoma
  • pleomorphic rhabdomyosarcoma
  • spindle cell/sclerosing rhabdomyosarcoma
  • ectomesenchymoma

Gastrointestinal stromal tumors

  • gastrointestinal stromal tumors

Chondro-osseous tumors

  • soft-tissue chondroma
  • extraskeletal osteosarcoma

Peripheral nerve sheath tumors

  • schwannoma (including variants)
  • neurofibroma (including variants)
  • perineurioma
  • granular cell tumor
  • dermal nerve sheath myxoma
  • solitary circumscribed neuroma
  • ectopic meningioma and meningothelial hamartoma
  • benign triton tumor/neuromuscular choristoma
  • hybrid nerve sheath tumors
  • malignant peripheral nerve sheath tumor
  • malignant melanotic nerve sheath tumor

Tumors of uncertain differentiation

  • intramuscular myxoma
  • juxta-articular myxoma
  • deep (“aggressive”) angiomyxoma
  • atypical fibroxanthoma
  • angiomatoid fibrous histiocytoma
  • ossifying fibromyxoid tumor
  • myoepithelioma/myoepithelial /mixed tumor
  • pleomorphic hyalinizing angiectatic tumor of soft parts
  • haemosiderotic fibrolipomatous tumor
  • phosphaturic mesenchymal tumor
  • NTRK-rearranged soft tissue neoplasms
  • synovial sarcoma
  • epithelioid sarcoma
  • alveolar soft part sarcoma
  • clear cell sarcoma of soft tissue
  • extraskeletal myxoid chondrosarcoma
  • desmoplastic small round cell tumor
  • extrarenal rhabdoid tumor
  • PEComa
  • intimal sarcoma
  • undifferentiated sarcoma

Changes from the prior version

New entities and variants

Newly introduced entities include the following

  • adipocytic tumors
    • atypical spindle cell/pleomorphic lipomatous tumor
    • myxoid pleomorphic liposarcoma
  • fibroblastic and myofibroblastic tumors
    • angiofibroma of soft tissue
    • superficial CD34-positive fibroblastic tumor
    • EWSR-SMAD3-positive fibroblastic tumor
  • vascular tumors
    • epithelioid hemangioendothelioma features two newly recognized subtypes
    • anastomosing hemangioma
    • tufted angioma and Kaposiform hemangioendothelioma are classified together
  • pericytic (perivascular) tumors
    • myopericytoma, including myofibroma – new subtype: cellular myofibroma/myopericytoma
  • smooth muscle tumors
    • EBV-associated smooth muscle tumor
    • inflammatory leiomyosarcoma
  • skeletal muscle tumors
    • spindle cell/sclerosing rhabdomyosarcoma – three subtypes
  • tumors of uncertain differentiation
    • NTRK-rearranged soft tissue neoplasms

Other changes

  • melanotic schwannoma – now renamed to malignant melanotic nerve sheath tumor
  • dedifferentiated liposarcoma – the adverse prognostic impact of myogenic and rhabdomyoblastic differentiation as well of a high grade on the FNCLCC (French Federation of Cancer Centers Sarcoma Group) grading system
  • solitary fibrous tumor – extrapleural’ has been removed

References

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Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
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Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
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Avoid these mistakes

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Get urgent help if

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Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

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Care roadmap for: Soft Tissue Tumors – Types, Causes, Symptoms, Treatment

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
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  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

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