An endoscopic exam involves using an instrument, inserted into natural openings or man-made openings, to examine internal passages or the inside of hollow organs or viscera. This can be effective in the nasopharynx, larynx, esophagus, stomach, large bowel, bladder and parts of the lungs. The common endoscopic procedures used in cancer diagnosis are listed in the table below.
Common Endoscopic Examinations
|colonoscopy||colon and rectum|
|ophthalmoscopy||interior of the eye|
|panendoscopy||urinary bladder and urethra|
|sigmoidoscopy||colon up to sigmoid flexure|
A bronchoscopy is the examination of the bronchi in the lungs. The scope can be inserted through the oral or nasal cavity. The pharynx, larynx, and trachea can be seen as the bronchoscope goes through to the bronchi. Using the flexible bronchoscope, the interior segmental and subsegmental bronchi can be visualized. The endoscopist looks for irregular bronchial folds, mucosal thickening, stenosis, friable tissue, and many other abnormalities such a tumor mass. Normally, biopsies bronchial washings are obtained during a bronchoscopic exam. A proctoscopy is often done using a rigid scope.
A sigmoidoscope is more flexible and can be used to observe the colon, up into the descending colon at greater than 30 cm. In the past, rigid sigmoidscopes were often used but they have been replaced with flexible sigmoidoscopes. Flexible scopes allow greater visualization of the sigmoid colon. A fiberoptic colonoscope is a flexible instrument that examines the colon to the cecum. Often, the physician will photograph and biopsy any abnormalities or suspicious areas seen during colonoscopy.
A cytoscope is used to examine the interior of the bladder. It is inserted through the urethra, so the urethra can also be examined. Abnormalities can be surgically removed or electrocauterized during the cystoscopic procedure.
The entire endoscopic procedure report must be read to obtain pertinent information. Endoscopic reports define certain observations, tumor location, pertinent findings, diagnosis, or the impressions of cancer. For example, colonoscopy reports should state the distance of the abnormality from the anal verge. Esophagoscopy reports should state the distance of the abnormality from the incisors to help determine the exact location of the tumor. Any biopsies or washings sent for microscopic examination should be noted. It is important to locate copies of the pathology and cytology reports to confirm the diagnosis of cancer.
Some endoscopic procedures can be accomplished through natural openings in the body. Others must be performed through incisions into the body. For example, thoracoscopy is used to examine the pleural cavity. The instrument is inserted through an intercostal space. Mediastinoscopy is performed through an incision in the neck and allows visualization of the area between the lungs. The mediastinal lymph nodes that are examined for potential involvement by metastatic cancer can determine the unresectability of a lung cancer.
Laparoscopy, performed through an incision in the abdodminal wall, allows the visualization of intra-abdominal structures. Laparoscopy is useful in gastrointestinal and gynecologic malignancies to diagnose both the primary organ and metastatic involvement. Needle biopsies of the liver are often done under the direct visualization of the laparoscope. Some surgeries can be completed as laparoscopic or lararoscope-aided procedures. A culdoscopy incision is made through posterior vaginal wall and allows visualization of the cul-de-sac.
The endoscopic retrograde cholangiopancreatogram (ERCP) allows direct visualization and contrast x-rays of the ampulla of Vater and the duodenal mucosal ERCP is helpful in diagnosing both pancreatic and bile duct cancers.