A solitary neurofibroma (also known as a 'Solitary nerve sheath tumor,' and 'Sporadic neurofibroma') may be 2 to 20mm in diameter, is soft, flaccid, and pinkish-white, and frequently this soft small tumor can be invaginated, as if through a ring in the skin by pressure with the finger, a maneuver called 'button-holing.':619