The diagnosis of subglottic laryngeal cancer can be difficult and overwhelming. Due to the fact that these tumors originate below the vocal cords, they may be more difficult to visualize than cancers of the vocal cords and supraglottic cancers. Further testing will be necessary to obtain a diagnosis and determine the best course of treatment.
Endoscopy, imaging, and biopsy are generally standard diagnostic approaches. Patients can expect their doctor to have a discussion with them about the risks, benefits, and alternatives to each of the following.
Endoscopy
An endoscope is a device that allows doctors to examine inside the body. It is made up of a thin flexible or rigid tube with a camera and light attached on the end. The lenses inside the endoscope provide magnification, allowing doctors to detect even small changes in the lining of the throat.
“Endoscopy” is simply the process of using an endoscope to visualize a particular part of the body. Doctors have specific types of endoscopic tools such as laryngoscopes, hypopharyngoscopes, bronchoscopes, and esophagoscopes—each designed to evaluate a different portion of the upper aerodigestive tract or throat. A flexible endoscope can be used in the clinic to visualize a subglottic mass, as this area is not easy to see otherwise. Vocal cord mobility will also be assessed with the flexible scope, which is an important component of the physical exam and will help determine tumor stage.
Sometimes direct laryngoscopy in the operating room is necessary to fully assess the size and position of the tumor. Laryngoscopy is a way to look far inside and around the throat and larynx, or voice box and is performed while the patient is asleep.
Biopsy
A biopsy is the removal of a small piece of tissue to examine under a microscope to see if it is cancerous. A biopsy of a suspicious growth in the larynx is usually needed prior to treatment. Subglottic laryngeal tumors require a direct laryngoscopy with biopsy, which is performed under general anesthesia in the operating room. In some cases, a fine needle aspiration (FNA) biopsy of any suspicious lymph nodes in the neck may also be helpful.
Imaging
Imaging scans, also known as radiologic studies, provide the doctor with an inside view of the body. Imaging of the head and neck will be required to determine the size, the invasiveness and the extent, and is a vital step prior to treatment of any tumor in the larynx. The most common imaging tests used are CT or MRI scans. A more advanced imaging study called a PET/CT may also be performed to evaluate if the cancer has spread to other sites in the body, as well as to determine if lymph nodes in the neck are likely to harbor cancer cells.
