Q: Dear Dr. Repici, which are the most useful instrumental tests for diagnosis of a tumor? Thank you for your attention. Best regards.
A: For the diagnosis of colorectal cancer, colonoscopy is the most common and main instrumental test performed. This noninvasive exam consists of a delicate through examination of the anus with a flexible tube, called a colonoscope, through which it is possible to examine the entire colon and rectum. In cases where the presence of a polyp or other abnormal tissue is identified, it is possible to make a withdrawal of a fragment or the entire lesion and send it to the laboratory for histological examination under a microscope. Sigmoidoscopy is performed in a similar manner but only allows the exploration of the lower part of the colon and rectum. During this examination if polyps or abnormal tissue are identified, it is also possible to remove them or send tissue samples to the laboratory to detect the presence of any tumor cells. As we said, the Rx barium enema is a radiological examination of the entire colon-rectum, which may not highlight the smaller diameter polyps and does not allow tissue samples to be performed or polyps that are eventually identified to be removed. In special cases selected by the medical practitioner, a virtual colonoscopy using images captured by a CT scan (computed tomography) may be performed to obtain information about the internal structures of the colon. A computer processes the images to get detailed representations that allow us to ensure the presence of polyps or other abnormal tissue on the inner wall of the colon.
