A medical instrument usable with an ultrasound-endoscope for performing a needle biopsy on a patient's internal body tissues usable at a surgical site not visible to the unaided eye or viewed endoscopically, comprises an elongate tubular member with a hollow needle element connected at its distal end, a sheath member housing said tubular member and needle element, an actuator subassembly with a shifter member operatively connected to elongate tubular member's proximal end, and a distal camming subassembly, said subassembly enabling a rotating motion of said needle member while handle actuator is moved in the forward direction. Upon inserting an ultrasound-endoscope into a patient and locating a mass, the fine needle with sharply pointed spoon shaped distal end is inserted into the mass aided by endoscopic and ultrasonographic guidance. Once in the mass, a camming action is initiated, causing rotation of the fine needle within the mass, resulting in a scooped out core biopsy. This instrument enables the performance of a fine needle aspiration requiring only one or two needle introductions, with a resultant core biopsy substantial enough for diagnostic purposes.
