Diagnosing Oromandibular Cancer
Getting to a diagnosis begins with a history and physical examination. If the symptoms haven’t been present for very long, or if the history and physical examination make the doctor less suspicious that your lesion is cancer, your doctor might try some medications and rehabilitation before jumping to a diagnosis of cancer.
At some point, if your doctor is not certain of a diagnosis, and if symptoms aren’t getting better (and definitely if symptoms are getting worse), your doctor should raise the possibility of starting a cancer work-up. Like most cancers in the head and neck, this will include some combination of biopsy and imaging tests, which is the term that doctors use to refer to X-rays, MRIs, CT scans, etc.
If you came to a specialist after having something small removed from your mouth and found it was cancer only afterwards, your doctor might skip some of the tests and jump to close follow-up or additional treatment. Be sure to bring all the reports and images from any prior treatment with you to your appointment with your head and neck cancer specialist.
Imaging refers to radiologic studies, or scans, that create pictures of the structures inside your head and neck. In general, for small tumours that are easily evaluated on physical examination (especially those in the front of the mouth), imaging might not be necessary. For larger tumours, or tumours in locations in the mouth that are difficult to examine, your doctor will probably order some sort of imaging to get more information about the tumour location and possible spread to regional lymph nodes.
An important reason to get a scan for oral cavity tumours is to see if there is any evidence of spread into the jawbones. Spread into the jawbones will influence what treatment your doctor recommends for you.
For oral cancers, if imaging is required, your doctor will most likely start with a computed tomography (CT) scan with contrast. Other tests might include magnetic resonance imaging (MRI) and/or a positron emission tomography (PET) scan.
Other tests might include jaw X-rays (Panorex), Dentascans or Cone Beam CT scans. These can help determine the extent of tumour invasion into the jawbones from the cancer.
A biopsy is the removal of a small piece of tissue to examine under a microscope to see if it is cancerous. At some point, you will need a biopsy of the suspicious lesion in your mouth (or a mass in your neck).
Fortunately, almost all tumours in the mouth can be biopsied in the office with a little numbing medicine (either a spray or a tiny injection or both). Just keep your mouth open and stay still. It will only take a few seconds to do the biopsy. After a piece of the lesion is removed, you will probably apply pressure with a bit of gauze to stop any tiny amount of bleeding that will result from the biopsy. The bleeding usually stops after a few minutes, or your doctor might dab it with a chemical to stop the bleeding.
In some cases, your doctor might take you to the operating room to perform a surgical biopsy.
The most common ways to do a biopsy inside the mouth include:
- Incisional oral biopsy: This is a biopsy in which your doctor will take a piece of the suspicious lesion without removing it all. He or she must be sure to get deep enough to make a good diagnosis.
- Punch biopsy:This is just another way to perform an incisional biopsy. Your doctor will use a tool called a punch forceps, which makes a quick snip to remove a piece of the suspicious area in your mouth.
- Excisional oral biopsy: In this technique, the whole area of concern is removed. Typically, if the diagnosis is unknown, it is better to do an incisional biopsy to find out what the diagnosis is, and then determine how much normal tissue needs to be removed around the lesion.
- Brush biopsy: This is often used by dentists, and they basically rub a few cells off the surface of a suspicious lesion. This is not ideal for diagnosing oral cancer because it doesn’t get into deeper layers of tissue. However, it can give some information and lead to a diagnosis of cancer.
The biopsy report is extremely important. Sometimes a doctor or dentist who cares and wants to help you will remove something that looks abnormal and send it off to a pathologist; unfortunately, the pathology report may be missing some important information, such as the grade of tumour, how deep it goes, whether it is endophytic, exophytic or ulcerated and whether there is a rim of normal tissue around the cancer. All these factors need to be evaluated either after a biopsy or after a more definitive removal of the cancer. Ask your doctor about the CAP Protocols, which is a standard way for pathology doctors to report results of their analysis.
If there is also a lump in the neck, your doctor might decide to biopsy that as well. There are a few different ways to do a biopsy of the neck:
- Fine needle aspiration biopsy: The most common and easiest way to biopsy is fine needle aspiration biopsy (FNAB), in which a tiny needle is placed into the tumour and some cells are drawn out through a syringe. The pathology doctor, known as a cytologist or cytopathologist, will then immediately look at the cells under the microscope and let your doctor know if there were enough cells to make a diagnosis. Several “passes” might be done to increase the likelihood that there are enough cells to make a diagnosis. The final diagnosis may take a few days to come back, so be patient.
DIFFERENT TYPES OF FINE NEEDLE ASPIRATION BIOPSIES
|“By Feel” FNAB||Ultrasound Guided FNAB||CT-Guided FNAB|
|When Your Doctor Might Use This Technique||If the lump can be easily felt by your doctor||If your doctor thinks it will be difficult to get the needle directly into the lump with certainty||If your doctor doesn’t think he or she will be able to get into the tumour by feel or with ultrasound guidance|
|What to Expect||Your doctor will feel the lump and place a tiny needle directly into it to extract some cells.||Your doctor will use a gentle probe on your face or neck, identify the tumour with the ultrasound and then watch the needle go directly into the tumour on the ultrasound machine.||You will be placed into a CT scanner, and a few low-dose CT scans will be performed—first to localise the tumour and then to make sure the needle that is placed is within the tumour. There is new technology known as fluoroscopic CT scanning in which the radiologist can quickly take a few scans without leaving the room in order to quickly insert the needle into the right place.|
Core Biopsy: Core biopsy is an alternative to fine needle aspiration. A core biopsy is done in the same way as an FNA biopsy, but it uses a larger needle and removes a core of tissue from the tumour rather than just a few cells. The likelihood of false positives and false negatives is much lower with a core needle biopsy than with a fine needle biopsy.
Open neck biopsy: An open biopsy involves making an incision over the tumour and removing a piece or all the tumour to make a diagnosis. An open biopsy of a neck mass is performed through an incision over the lump, and either a piece (incisional open neck biopsy) or the entire lump (excisional open neck biopsy) is removed to make a diagnosis. Except in a few special circumstances (such as if the tumour is likely a lymphoma or if other methods of diagnosis have not worked), this method should not be used to find the diagnosis of a neck mass.
Sentinel lymph node biopsy (SLNB): A sentinel lymph node biopsy is a new type of lymph node biopsy being used for some cancers of the head and neck. They are mainly used in skin cancers, such as melanomas and Merkel cell cancers, but some doctors are using them in oral cancers as well.
Cancer cells spread from a tumour to regional lymph nodes by traveling through a channel of lymph and making a stop in the first lymph node along the way—the sentinel node. In SNLB, special techniques are used to figure out where that first lymph node is located. Then, that lymph node is removed and analysed.
If there is cancer in that lymph node, then the rest of the lymph nodes in the region are removed. If there is no cancer in that lymph node, then your doctor will closely watch the area but save you from undergoing additional treatment that might not be necessary.
For oral cancer, the advantages and disadvantages of SLNB are not very clear and are still being studied.