Solitary Fibrous Tumor: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Solitary Fibrous Tumor?
A surgeon, often one who specializes in removing tumors, usually does the operation. Radiologists, pathologists, and oncologists may also be involved, and care is often coordinated by a team at a center experienced with rare tumors. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
A solitary fibrous tumor is a rare growth that starts in connective tissue, the tissue that supports organs. Most are not cancer and usually do not spread, though some can behave aggressively. They can appear almost anywhere but are often found in the lining of the lungs and chest or in soft tissue under the skin.
Symptoms
Many solitary fibrous tumors cause no symptoms and are found only when a scan is done for another reason. When symptoms happen, they depend on the tumor's location and size. A chest tumor may cause shortness of breath, a cough, or chest pain, while one under the skin may feel like a painless lump that slowly grows. Some tumors release hormones, causing low blood sugar, joint pain, or other unusual symptoms.
Causes and who gets it
Doctors do not know exactly what causes these tumors. Most have a change in a gene called NAB2-STAT6. They are rare and can occur in adults of any age, in both men and women.
How doctors diagnose it
Diagnosis usually starts with imaging, such as a CT scan or MRI. If a growth is found, a doctor may take a tissue sample in a biopsy. A pathologist can look for the gene change common in these tumors, which helps tell them apart from other growths.
Treatment
Surgery is the main treatment. The goal is to remove the entire tumor with a border of healthy tissue. If surgery is not possible, doctors may recommend radiation therapy or medicines. Regular follow-up scans are important after treatment.
When to see a doctor
See a doctor if you notice a growing lump, or have ongoing chest pain, a cough, or shortness of breath. Also seek care for unexplained low blood sugar symptoms such as sweating, confusion, or weakness.
How a direct primary care or concierge doctor fits in
A direct primary care or concierge doctor can be a helpful first stop. They can examine a lump, order imaging, refer you to the right specialists quickly, and help coordinate follow-up care.
Common questions
Is a solitary fibrous tumor cancer?
Most solitary fibrous tumors are not cancer and do not spread. However, some can grow quickly or come back after treatment, so doctors sometimes call them borderline. Every tumor is studied carefully to see how likely it is to behave aggressively.
Can a solitary fibrous tumor come back after surgery?
Yes, some tumors can return, sometimes many years later. That is why doctors recommend long-term follow-up with regular scans. The chance of returning depends on the specific tumor.
Why does a solitary fibrous tumor sometimes cause low blood sugar?
Some of these tumors make a hormone-like substance that drives blood sugar down, causing sweating, confusion, or weakness. Treating the tumor usually addresses this problem.
How common are solitary fibrous tumors?
They are rare, with only a small number of new cases each year. Because they are so uncommon, many general doctors may see only a few cases in a career, and care is often guided by specialists experienced with rare tumors.
Sources
- MedlinePlus - Soft Tissue Sarcoma
- National Cancer Institute - Soft Tissue Sarcoma-Patient Version - NCI
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
