Pulsating lump in neck, movable and soft. ultrasound of carotid clear. what is this?

Could be direct : Or indirect pulsation. Should be evaluated for blood flow by ultrasound.

Hard to say: A movable pulsating lump could be a lymph node that is lying on the carotid and you are feeling a transmitted pulse. Try ultrasound over the mass to see if it is fluid or solid.If it is solid it possibly should be removed to make sure it isn't a tumor.