Symptoms of Fibrosarcoma

Fibrosarcoma is a rare malignant tumor that arises from fibroblast cells, which are the cells responsible for producing the fibrous tissue that connects muscle to bone.

This type of cancer is most commonly found in middle-aged adults, and primarily occurs in the long bones of the thigh, upper arm bone, or jaw, although tumors can arise nearly anywhere in the body.

Fibrosarcoma produces excess collagen in places that it shouldn’t throughout the body. Therefore symptoms are often nonspecific and can be felt anywhere in the body.

This article will review the symptoms of fibrosarcoma and when to see a doctor.

Woman in pain

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Frequent Symptoms

Because fibrosarcomas are usually located deep within soft tissue, they can go undetected for a long period of time. Symptoms often don’t present until the tumor begins to compress nearby tissue or organs. Fibrosarcomas can affect all organ systems in various ways.

Symptoms differ based on the age, type, and location of the tumor. Additionally, they may evolve based on the extent to which tumors invade local tissue or metastasize (spread to distant body sites). 

Fibrosarcoma symptoms may look different in adults and children. In both, a palpable, painless lump may be the first sign that appears, however childhood fibrosarcoma symptoms may include:

  • A painless or tender mass in an extremity (arm or leg) or the torso
  • Pain or soreness caused by a pinched nerve or compressed muscles
  • Limping or other difficulty using legs, feet, arms, or hands, especially in older children

Adult fibrosarcoma symptoms generally include:

  • Swelling in various parts of the body (may be with or without pain), especially the limbs
  • Cough
  • Dark stool
  • Vomiting blood
  • Irregular bleeding from the vagina
  • Pain in the abdomen

Rare Symptoms

Fibrosarcomas represent between 2% to 4% of primary bone tumors. They usually occur in deep tissues adjacent to bone, but on occasion, they develop in the medullary, or interior portion, of the bones.

The distal femur—the area of the thigh bone just above the knee—is the most common site of fibrosarcoma of the bone. This type of fibrosarcoma can cause osteolytic or bone-destroying lesions that result in pain, swelling, and numbness, along with tingling in the arms and legs.

Pain at the fibrosarcoma site without the presence of a lump is also common.

Who Is Most Affected by Fibrosarcoma?

Fibrosarcomas occur equally in men and women. There are few, if any, reported differences in the propagation of symptoms based on gender. Adult cases have been reported from the second to the seventh decades of life, although the majority of cases occur from ages 40 to 60.

The tissues affected in childhood fibrosarcoma can differ from those in adult cases. Therefore, the two carry different symptoms, but symptoms are consistent and similar in both when the same organs or bones are affected.

When to See a Healthcare Provider/Go to the Hospital

A unexplained lump or mass is usually the first sign of fibrosarcoma. New pain or swelling at the site where fibrosarcoma is suspected is the most common symptom that the cancer is growing.

If you experience worsening symptoms or new pain, seek immediate medical attention. 


Fibrosarcoma is a very rare type of cancer that causes excess collagen to be produced where it should not be. Symptoms of this cancer often don’t appear until the cancer is suppressing nearby organs or tissues. Symptoms may include a lump or mass in soft tissue or swelling through the body, especially in the arms and legs.

A Word From Verywell 

Dealing with symptoms of fibrosarcoma is not easy. Even more, coping with the possibility of having this type of cancer can be difficult and very stressful.

Getting ahead of your symptoms by figuring out the best and safest ways to relieve your pain and discussing how you feel with a trusted healthcare provider and loved ones may be helpful.

If you feel new or recurrent pain, contact your healthcare provider as soon as possible. They may be able to provide you with timely pain management and early treatment to help you feel better.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Augsburger D, Nelson PJ, Kalinski T, et al. Current diagnostics and treatment of fibrosarcoma—perspectives for future therapeutic targets and strategies. Oncotarget. 2017;8(61):104638-104653. doi:10.18632/oncotarget.20136

  2. Dana-Farber Cancer Institute. About childhood fibrosarcoma.

  3. Kalil RK. Fibrosarcoma of bone. In: Santini-Araujo E, Kalil RK, Bertoni F, Park YK, eds. Tumors and Tumor-Like Lesions of Bone. Springer; 2015:435-440.

By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.