An elongated and multinodular neurofibroma, formed when the tumor involves either multiple trunks of a plexus or multiple fascicles of a large nerve, such as the sciatic. Some plexiform neurofibromas resemble a bag of worms, others produce a massive ropy enlargement of the nerve. (Adapted from WHO.). The disease is EFO_0000658 (plexiform neurofibroma). Also known as: Elephantiasis Neuromatoses, Elephantiasis Neuromatosis, Neurofibroma, Plexiform, Neurofibromas, Plexiform, Neuroma, Plexiform, Neuromas, Plexiform, Pachydermatocele, Pachydermatoceles.