Embodiments of the invention are directed to a medical device and methods for collecting a tissue sample from a patient's body. The device may include a first tube defining a lumen and an aperture at a distal end of the first tube. A second tube extends within the lumen of the first tube and defines a lumen and slots, where at least some of the slots have sharp edges configured to shear tissue. The second tube is movable relative to the first tube such that the sharp edges cut a plurality of samples from tissue disposed within the aperture.