A benign tumor formed by more or less abnormal nerve fibers. There are two types of neuroma. Amputation neuroma develops when a nerve has been severed, when its end is far from the root, or when the resection is due to the amputation of a limb. The plexiform neuroma is caused by a dense proliferation of nerve fibers; it is superficial and leads to a palpable swelling under the skin, which can be felt as a small knot.
