Epithelioid sarcoma
Epithelioid sarcoma
Also known as:ES, distal-type epithelioid sarcoma, proximal-type epithelioid sarcoma, INI1/SMARCB1-deficient soft tissue sarcoma, China Second Rare Disease Catalog item 24
Epithelioid sarcoma is a rare aggressive soft tissue sarcoma, often affecting teenagers and young adults, that may begin as a painless nodule or non-healing sore on the hand, forearm, foot, knee, or lower leg.
Start Here
A quick guide to the next step: which department to start with, what to prepare, and what to ask.
A painless but enlarging nodule, firm mass, or non-healing ulcer on the hand, foot, forearm, or lower leg should be evaluated by an orthopedic oncology or sarcoma team.
Epithelioid sarcoma can grow slowly but has risks of local recurrence, lymph node spread, and distant metastasis. It is often mistaken for infection, granuloma, cyst, or a chronic wound, so pathology is crucial.
Localized disease centers on complete surgery at a sarcoma center, often with radiation assessment. Unresectable or metastatic disease may use chemotherapy, targeted therapy such as tazemetostat, clinical trials, or palliative care.
It is usually not inherited. Many tumors show INI1/SMARCB1 loss at the tumor level, which helps pathology and treatment decisions.
It can look like a chronic wound, wart, infection, rheumatoid nodule, or granuloma and may grow slowly without pain. Incision and drainage or wound care without biopsy delays diagnosis.
This page helps patients and families organize care leads. It does not replace a clinician’s diagnosis or treatment plan. For testing, medication, referrals, emergency care, and support applications, follow qualified clinicians, medical institutions, support organizations, and official sources.
Diagnosis Path
Organized around the practical patient journey: identify clues, avoid common delays, then prepare for care.
When to Suspect It
- A small firm subcutaneous nodule on the finger, palm, forearm, foot, knee, or lower leg keeps enlarging.
- A skin sore does not heal or repeatedly breaks down despite antibiotics or wound care.
- The mass is painless or mildly painful, imaging suggests deep soft tissue involvement, or nearby lymph nodes enlarge.
- Pathology suggests epithelioid or sarcomatoid tumor, INI1 loss, or uncertain diagnosis.
Common Wrong Turns
- Treating it as infection, cyst, wart, foreign-body granuloma, or rheumatoid nodule for too long.
- Incision, drainage, or small excision without proper pathology and margin review.
- After diagnosis, not completing chest and lymph node staging or not referring to a sarcoma center.
- Focusing only on the primary lesion while missing recurrence, lymph node, or lung spread risk.
Departments to Start With
- Sarcoma center
- Orthopedic oncology
- Medical oncology
- Pathology
Before the Visit
- Record when the mass or sore began, growth speed, pain, ulceration, infection treatment, and surgeries.
- Bring MRI, CT, ultrasound, chest imaging, lymph node tests, and original images.
- Bring biopsy or surgery pathology, immunohistochemistry, INI1/SMARCB1, margins, and molecular tests.
- Summarize function impact, prior radiation or chemotherapy, medicines, and family cancer history.
Tests to Ask About
- Core needle or incisional biopsy planned by the sarcoma team.
- MRI of the primary site, chest CT, lymph node ultrasound or biopsy, or PET/CT for staging.
- Pathology immunohistochemistry, including INI1/SMARCB1 expression when appropriate.
- For unresectable or metastatic disease, whether tazemetostat, chemotherapy, radiation, or clinical trials fit.
Questions for the Doctor
- Has a sarcoma pathologist confirmed the diagnosis, and is INI1 lost?
- Is disease localized, lymph node-positive, or metastatic?
- Can surgery preserve function and achieve clear margins, and is radiation needed?
- If it recurs or spreads, what targeted therapy, chemotherapy, or trial options exist?
- Which sites should be monitored and how often?
Basic Information
Medical Notes
More complete medical explanations are kept here for discussion with clinicians.
Symptoms
Epithelioid sarcoma often affects adolescents and young adults. Distal-type disease commonly appears on the hands, forearms, feet, knees, or lower legs as a slowly enlarging firm nodule, subcutaneous lump, or non-healing sore that may be painless.
Some patients have multiple nodules, ulceration, pain, or enlarged nearby lymph nodes. Proximal-type disease may occur in the trunk, perineum, or deep soft tissue and can be more aggressive.
Diagnosis
Diagnosis depends on imaging and pathology. MRI helps define local extent; chest CT and lymph node evaluation are used for staging. Biopsy should ideally be planned by the sarcoma team to avoid compromising later surgery.
Pathology needs immunohistochemistry and careful differential diagnosis, often including INI1/SMARCB1 loss. It can be confused with infectious granulomas, rheumatoid nodules, squamous cell carcinoma, melanoma, and other soft tissue sarcomas.
Treatment
Localized disease is treated with complete surgical removal and negative margins when possible, while preserving limb function. Radiation may be used before or after surgery depending on size, location, margins, and recurrence risk.
Metastatic, recurrent, or unresectable disease may be treated with chemotherapy, targeted therapy, radiation, and clinical trials. NCI drug information lists tazemetostat for selected patients with locally advanced or metastatic epithelioid sarcoma that cannot be removed by surgery.
Long-term Care
Follow-up includes examination of the primary site, local MRI or ultrasound when needed, chest imaging, and lymph node assessment. New lumps, sores, pain, cough, weight loss, or lymph node changes should be reported.
Fertility and Family
Epithelioid sarcoma is usually not inherited. Because many patients are young, fertility preservation should be discussed before chemotherapy, radiation, or targeted therapy when relevant.
When to Seek Urgent Care
Seek urgent care for heavy bleeding from an ulcerated tumor, infection with fever, marked limb swelling or pain, shortness of breath, chest pain, serious infection during treatment, or severe medicine reactions.
Prognosis
Outcome depends on location, size, margins, recurrence, and spread. Early sarcoma-center care, complete staging, and long-term follow-up are important.