An endoscopy tool for measuring a size of a polyp observed on an internal wall of a body cavity being scanned by an endoscope is provided. The tool is inserted within the body cavity via a service/working channel of the endoscope. The tool has at least a scaled catheter portion having markings for determining a distance of the polyp from a tip of the endoscope； and an operating portion having an elongate member connected to a biopsy tool. The scaled catheter portion has a proximal and a distal end. The elongate member has a distal end and a proximal end coupled with the distal end of the scaled portion. The biopsy tool is connected to the distal end of the elongate member. The determined distance is used for measuring the size of the polyp by an image processing module coupled with the endoscope.
