The present embodiments provide apparatus for facilitating endoscopic resection of tissue. The apparatus comprises proximal and distal barrels. The proximal barrel is adapted to be coupled to an endoscope. A cutting member is disposed within a lumen of the distal barrel and configured to resect a segment of tissue. In one embodiment, a central longitudinal axis of the proximal barrel is radially offset from a central longitudinal axis of the distal barrel, thereby allowing the cutting member to be centered relative to the working lumen of the endoscope. Additionally, the cutting member may comprise at least one viewing window that permits endoscopic visualization of tissue distal to the distal barrel when the cutting member is disposed within the distal barrel.