Stepper motors are small in scale, are they not? And, synchronous motors are also AC motors in steady state.
Synchronous motors are motors where the rotation of the magnetic field is synchronous with the rotation of the motor. For all induction motors, the induced field is a result of a varying magnetic field across the element in question. This implies that the speed of the rotor must be different than the speed of the magnetic field. Thus, no induction motor is a synchronous motor, almost by definition.