Oral Cancer page 2-DoctorSpiller.com

Leukoplakia

leukoplakiaPersons who smoke heavily or use smokeless tobacco such as snuff and chewing tobacco tend to get whitish patches called leukoplakia on the oral mucosa (the wet tissue lining the mouth) .  The lefthand image above shows a fairly typical patch on the side of a man’s tongue.  The image to the right shows a similar patch on the floor of the mouth. These patches can happen anywhere in the oral cavity such as on the cheek mucosa, the roof of the mouth, or the back of the throat.  The common denominator seems to be HEAVY use of cigarettes or prolonged contact of snuff or chewing tobacco with cheek tissue.  Leukoplakia is not itself a form of cancer, but is considered pre-cancerous and should be biopsied (a procedure in which a tiny piece of tissue is sent out for microscopic examination) since about 20% are found to be pre-malignant .  It is white, firm tissue and cannot be scraped off.  It generally goes away when the stimulation of the tobacco stops, but with continued heavy tobacco use it can transform into squamous cell cancer.

In order to picture what a cancer developing in these lesions would look like, imagine irregular red blotches developing inside the white leukoplakic plaque, and a large red border developing around the entire lesion!

erythroplakiaErythroplakia (see image above) is the term applied to red blotches which appear within areas of white leukoplakia.  Erythroplakia is considered to be more dangerous than leukoplakia alone.  Click on the image to the left or the one to the immediate right to see these images enlarged, and other scary images of leukoplakia.   Neither leukoplakia nor erythroplakia are contagious conditions.

The number one cancer of the head and neck is cancer of the larynx–the voice box–which is more susceptible to particulate carcinogens such as cigarette smoke and various forms of pollution than other tissues.  The majority of patients who get cancer of the larynx are men between 60 and 70 years old who have a history of heavy smoking and generally heavy drinking.  Women in the same category are also prone to squamous cell carcinoma.

Snuff Pouch

Snuff_pouch_3Snuff pouches are a form of hyperkeratosis (leukoplakia) that develops on the mucosal surfaces in the oral cavity where the patient keeps snuff.  These areas are generally located in the vestibule, which is the fold where the lips or cheeks curve as they approach the teeth.  These lesions take the form of verrucous (wart-like), linear folds which develop a white thickening of the mucosa over a period of years.  The longer the snuff habit remains active, the thicker and whiter the leukoplakia, and the more likely the lesion is to transform into an aggressive form of squamous cell carcinoma (cancer) known as verrucous carcinoma.  In most cases, cessation of the habit prior to the development of the cancer results in the disappearance of the lesion and a return to normal mucosa.  The lesion pictured here is is a very early lesion with a very thin coating of leukoplakia, and should regress with cessation of the snuff habit.

Cancer of the lip

CarcinomaLipCancers on the lips are a special case.  They generally strike the lower lip and are more likely to happen after long, repeated episodes of exposure to the sun.  Cancer of the lip is also squamous cell carcinoma and has the same clinical course as intraoral cancers.  Going to the beach several times a summer is generally not a significant risk factor for cancer on the lip.  Most people who get this form of cancer tend to be outdoor workers who labor all day in the sun for years on end.  Perhaps because more people work indoors today than ever before, the incidence of cancer of the lip is decreasing.

What about the other 10% that are not squamous cell carcinoma?

The probability of developing any type of cancer increases with age!  Chronic illness is another factor that increases the likelihood of developing these forms of cancer.  There are, unfortunately, numerous types of cancer that can originate in various oral structures including bone, lymph nodes, salivary glands etc.  These are not necessarily associated with known risk factors the way squamous cell cancer is associated with smoking, drinking and promiscuous oral sexual activity. There is some evidence that non squamous cell cancers of the oral cavity are related to precipitating factors such as exposure to the Epstein Barr virus (the virus responsible for mononucleosis which in some persons seems able to remain dormant in the body for a lifetime) as well as the human papillomavirus (HPV), and radiation treatments to the head and neck for cancer or acne (not diagnostic x-rays).  Radiation was once a treatment modality for facial acne (back in the early 20th century) but is no longer used because of the obvious danger from large amounts of radiation. It is still used in the treatment of carcinomas and Sarcomas (two different classifications of malignancy) but is carefully aimed and metered to avoid side effects.

A minorsalivary gland tumor tends to be a firm mass on one side of the palate (the roof of the mouth).  They do not occur in the midline.  If it is cancerous, it will remain enlarged and will not go away after two or three weeks.  About 50% of these large persistent masses will prove to be malignant (cancer).  On the other hand, be aware that small salivary glands in the palatal mucosa do sometimes become infected.  When this happens, they can become sore and slightly enlarged, but the problem is generally temporary and disappears without treatment within two weeks.

About 80% of all salivary gland tumors  begin in the parotid glands.  (A tumor is simply a mass. It is not necessarily cancerous.)  The patient notes a swelling on the side of the face below and in front of the ear.  This swelling does not get larger and smaller at different times of the day (as salivary gland infections do), but remains constant, or grows larger over time.  10%-15% of salivary gland tumors start in the submandibular glands  causing a swelling on one side of the neck just under the jawline.  These also remain enlarged over time.  The rest develop in the sublingual gland, causing a similar swelling under the chin, or in one of the many minor salivary glands.  Most tumors of the parotids are benign (noncancerous).  Masses in the minor salivary glands (the smallest of salivary glands) are more frequently malignant (cancerous), however because there are so many more parotid gland tumors, a greater number of cancers are found in the parotid glands than any of the other salivary glands.  (For a diagram of the major salivary glands, see my page on Dry Mouth.)

Malignant Melanoma

MelanomaOne of the most deadly forms of oral cancer is Malignant melanoma. Thankfully, it is very rare in the oral cavity.  It begins as small black spot, generally smaller than a millimeter, and develops irregular borders as it grows larger (see image on the right).  Melanoma can happen on any tissue in the mouth, particularly inside the lips, cheeks, undersurface of the tongue and on the hard palate.  It is likely to be tan, dark brown or black, sometimes mixed with red or gray.

Melanoma occurring anywhere other than the mouth is generally considered to be fairly treatable.  Unfortunately, due to the anatomy of the head and neck, oral melanoma is most often fatal.

AmalTatooFortunately, most dark spots on oral tissue are likely to be amalgam tattoos  discussed in more depth on the sores, lumps and bumps page.  Amalgam tattoos happen after dental appointments, remain stable, do not grow larger over time, and are relatively circumscribed (without diffuse, irregular borders).  They also tend to have a blue-gray color, unlike the dark brown or black seen in melanoma. They are most common on the gums, cheeks and floor of mouth immediately adjacent to teeth.  Amalgam tattoos attain and maintain their maximum size shortly after the introduction of the amalgam into the tissue, while melanomas will grow and change shape over the course of a week or two.

How dentists screen for oral cancer

Although screening by your dentist is the best method of reducing the pain, suffering and mortality related to oral cancers, it is not altogether reassuring to know that differentiating early malignant and premalignant lesions from benign growths is quite difficult, even for experienced dental practitioners.  Early stage oral cancers are asymptomatic and the clinical characteristics associated with malignancy such as pain, swelling, redness, enlargement, fixation (becoming bound down to underlying tissue) and deformation of the surrounding tissues generally do not develop until quite late in the clinical course of the disease.

Visual Exam

Until recently, there were only two courses a dentist could take when he saw a suspicious early lesion.  (“Lesions” are abnormal growths, erosions or sores.)  The first, and most frequent course was waiting several weeks to see if the lesion progressed or regressed.  If It went away, all was well, and the crisis was averted.  If it got bigger, or if the lesion had been present for several weeks and was already of significant size on initial examination, then the dentist proceeded to the second course which is a sectional (knife) biopsy in which the patient is anesthetized and a piece of the lesion is surgically removed and sent to a laboratory in formalin for microscopic analysis.  The microscopic examination of the tissue sample provides a definitive diagnosis upon which to base a treatment plan.

The difficulty with this protocol is that there is a high incidence of oral abnormalities which can be candidates for biopsy.  It is claimed that between 5 and 15% of all new patients present with abnormal lesions in their mouths, however these include such lesions as aphthous, fibromas and many of the other obviously benign conditions explained on the Sores, Lumps and Bumps page.  No knowledgeable dentist would consider these to be candidates for biopsy.  Even so, quite a few truly suspicious lesions do walk through our doors with only about 5% turning out to be cancer.  Given these odds, it is impractical to immediately subject all these lesions to a potentially painful procedure like a surgical biopsy.  Thus, using the older protocol, virtually everyone presenting with an early lesion was sent home to wait the obligatory two to three weeks to see if it progressed or not.  While not a dangerous course of action, it still left any potential malignancy to progress for the entire waiting period plus whatever time it took to examine the biopsy tissue.  It was not especially reassuring for either the dentist or the patient to know that if there was a cancerous lesion, it had to wait at least a month to be removed!

Brush biopsy

Oralcdx

A better screening method has recently become available.  It is called the Brush Biopsy (Oral CDx).  This consists of placing a small, sterile, hard bristled brush over the lesion and twirling it around until part of surface of the lesion is abraded away.  The procedure rakes up cellular material from the entire thickness of the surface of the lesion onto the brush.  Although this procedure may irritate the area, (it should produce pinpoint bleeding areas) it does not generally require local anesthesia.  The cellular material scraped up on the brush is smeared onto a glass slide, fixed with a chemical that comes with the kit, and dried.  The glass slide is then placed into a plastic container and sent to a lab for computer scanning and further manual examination of suspicious cells.  The makers of this biopsy kit claim 100% accuracy in identification of abnormal cellular components provided that the clinician was aggressive enough in obtaining a full thickness sample.  The brush biopsy does NOT establish a definitive diagnosis.  It does indicate the need for a surgical biopsy to establish the diagnosis.

It should be noted that not all experts on oral cancer believe that cytological examination alone is suitable as a screening device for oral squamous cell carcinoma.  The brush biopsy is not suitable for melanoma ( pigmented lesions) or lesions on the dry parts of the lips.  It is generally reserved for use on lesions that show eroded or overgrown mucosal surfaces.  Its principle use is for pre-cancerous lesions that will develop into squamous cell carcinoma.  It is not useful for deeper lesions such salivary gland tumors.

Using fluorescent screening devices

Abnormal cells reflect and absorb light differently than healthy cells. When excited by violet light, healthy cells fluoresce blue-green while abnormal cells appear dark. this is especially apparent when viewed through a filtering lense or glasses. This technique has both advantages and disadvantages.

Advantages

Abnormal cells stand out making it possible to see them before the lesion (the abnormal area) becomes visually apparent. It is sometimes possible to see the full extent of the lesion, even when only a small central area is visually apparent. Another advantage is that the fluorescent exam does not cause pain or other complications.

Disadvantages

Not all abnormal lesions appear dark against a bright background of normal tissue, and in some cases the visual exam in ordinary light is more diagnostic than the fluorescent exam. Secondly, many non-cancerous lesions will show up as dark areas. Lesions such as geographic tongue or trauma (for instance biting the cheek or tongue) will not fluoresce and may be mistaken for cancerous lesions by less experienced clinicians. Finally, a biopsy is often indicated when a suspected lesion is found, and false positives can lead to additional expense and trauma to the patient.

If you have come here to look for images of lumps, bumps, sores or discolorations that you noticed in the mirror this morning, this is one of four pages with images you may find useful.  Read this page,Then proceed to three other pages on which you will find more images of both normal and abnormal oral structures and lesions 

Normal oral anatomy
Lumps, bumps and sores and discolorations
Oral manifestations of AIDS 

Kaposi’s Sarcoma==>> 

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