A medical device includes an elongate single-wire memory-metal body with a complete length that includes a proximal stylet length, an intermediate self-coiling stylet length, and a distal stylet length that is generally straight and non-self-coiling. The moment of force of the self-coiling stylet length is less than the moment of force of the medical endoscopy needle that is resistant to the stylet's self-coiling force. The device may further include being incorporated into an endoscopy needle system where the single-wire stylet body is disposed through a lumen of a medical endoscopy needle.