The introduction of flexible endoscopes has made it possible to observe the interior of the stomach and colon, allowing for accurate diagnoses of both benign and malignant diseases. Advancements in pathological anatomy enable us to examine specimens under a microscope, helping to determine the histological nature of tissue samples or lesions and to distinguish between benign and malignant conditions. The assessment of potential malignancy is based on various factors, including the mobility, surface characteristics, and shape of the polyp, as well as the results obtained from staining and magnification techniques.