Abstract: A probe or sheath for use on a probe for detecting and removing radioactively tagged tissue, e.g., a sentinel lymph node, within the body of a living being. The probe or sheath and probe is arranged to be inserted through a small percutaneous portal into the patient's body and is movable to various positions adjacent the tagged tissue to detect the presence of radiation therefrom so that it can be positioned immediately adjacent that tissue to ensnare or trap that tissue. The probe or sheath and probe can then be removed from the being's body, carrying the tagged tissue with it. The probe may be constructed to make use of a scintillation crystal, a collimator, adjustable or fixed, and a backshielding lightpipe. A blunt dissecting device is provided as part of the sheath or as part of the probe itself to aid in separating the tagged tissue from adjacent tissue without injury to the adjacent tissue. The probe may be a fully integrated, self-powered unit.