An instrument for precisely cutting tissue to controlled dimensions (length, width, depth, and shape) is provided for the removal of tissue specimens from remote sites in the body of a patient, such as from the gastrointestinal tract, urinary tract, or vascular structures, or any tissue surface or soft tissue of the body. The instrument has a housing and a substantially flexible shaft extending from the housing to a distal end. The distal end of the instrument has an open cavity into which tissue is receivable. Suction can be communicated along the shaft to the distal end for distribution across the cavity utilizing a manifold having a grated tissue engaging surface with opening(s) for applying the suction, thereby pulling tissue adjacent to the distal end into the cavity against the tissue engaging surface of the manifold. One or more hollow needles are extendable from the housing through the shaft into the cavity to enable infusion of fluid, such as saline or a hemostatic agent, into the tissue. A blade in the distal end is extendable through the cavity over the manifold and across the opening to cut the tissue held by suction and stabilized by the needles in the cavity. The shape and depth of the tissue removed by the cuts is in accordance with the contour of the tissue engaging surface and the size and shape of the cavity at the distal end. The tissue so removed by the instrument may be for therapeutic intervention and/or represent a tissue specimen for biopsy suitable of diagnostic evaluation. The tissue edges in the patient's body left after cutting with this instrument readily avail themselves to apposition for enhanced healing.