use the pointed tip of the rod is non deflecting in comparison with the beveled syringe needle tip typically employed the localization device may be advanced easily through the tissues secured by engagement into the surrounding area disengaged at will and subsequently removed as often as desired the device may be repositioned as often as is required to become localized at a specific target lesion or mass in its engaged position the device has firm bidirectional security and cannot accidently slip forward or backward in the tissue surgically the cannula shaft is easy for the surgeon to follow easily palpable and can be approached from any direction there is no need for additional wire thickening or wire reinforcement to avoid accidental breakage or inadvertent loss into the tissues once inserted at a localized site the tissues may slide freely around the cannula and the patient may move freely without fear of changing the positioning of the rod tip relative to the target site finally in the event that the target lesion is found to contain fluid matter it is possible to remove the rod completely and utilize the cannula as a double port end hole and open slot aspiration device the simplest embodiment of the present invention is illustrated by fig1 5 which provide cross sectional views of the present invention as individual elements and as an assembled unit fig1 shows a canula 10 having a substantially cylindrical tubular wall 12 a.