Nerve tissue tumours
The peripheral nervous system (PNS) includes the parts of the nervous system outside the brain and spinal cord. Soft tissue sarcomas can develop anywhere in the PNS.
Malignant peripheral nerve sheath tumours (MPNSTs)
MPNSTs start in Schwann cells. These cells make up the sheath, or protective covering, around nerves. MPNSTs include neurofibrosarcomas, malignant schwannomas and neurogenic sarcomas. These tumours are most common in adults between 30 and 50 years of age. They are known to develop in people with neurofibromatosis, which is a genetic disorder of the nervous system that affects the development of nerve cell tissues.
MPNSTs can start anywhere on the body. But they tend to develop on the major nerves of the body’s trunk, especially at the back of the abdomen (called the retroperitoneum), and in the extremities, especially the lower limbs.
These tumours are usually high grade, which means that they grow quickly and are likely to spread to other parts of the body. As the tumour grows and presses on the nerve, it may cause pain or dysfunction, depending on the location.
Malignant granular cell tumours
Malignant granular cell tumours are thought to develop in nerve tissue. These rare tumours usually form as a mass just under the skin (subcutaneous). They can develop anywhere in the body. They commonly develop in the mouth, pancreas and bile duct (the tube that caries bile from the liver to the small intestine).
These tumours can occur in many places at the same time, but most are single tumours. They rarely spread, or metastasize, to other parts of the body.