Nerve Sheath Tumour

A nerve sheath tumour is a growth that arises from the cells that wrap around and support peripheral nerves — the nerves outside the brain and spinal cord that carry signals to and from the limbs, face, and body. These tumours can develop anywhere a peripheral nerve runs, and they tend to grow slowly over weeks to months. In dogs, they occur most often in older animals, and certain larger breeds may be more commonly affected. Owners often first notice a lump under the skin, typically on a leg, or they may observe that their dog is favouring a limb, showing discomfort when moving, or experiencing weakness or altered sensation in a specific area. Because the tumour involves a nerve, signs can include lameness that does not improve with rest, muscle wasting in the affected limb, or changes in how the paw is placed or held. In some cases, a tumour affecting a nerve in the chest or abdomen may cause signs that are less easy to localise. This page explores the signals that may suggest a nerve sheath tumour, what is happening at the level of the nerve and surrounding tissue, how these growths are investigated through imaging and sampling, and the range of approaches that exist for managing them. The goal is to help you understand the nature of the condition and the framework within which decisions are made.