Assessment of Oral Mucosal Changes

Leucoplakia Interventions for Treating Oral Leukoplakia

• Leucoplakia is defined as a mainly light-coloured patch with a potential risk of cancer when other known diseases or conditions (e.g. other changes that possibly increase the risk of cancer) have been excluded (WHO 2021).
• Found in 1-4% of the population, usually in persons over 60 years old.
• Most cases are caused by tobacco use, some are idiopathic.
• Clinically, leucoplakia is a well-defined patch or area that cannot be scraped off and is usually evenly light-coloured on the surface (homogenous; picture F1).
• Non-homogenous forms (nodular, verrucous, proliferative verrucous leucoplakia or erythroleucoplakia) are rare.
• The mean risk of a malignant change is 4% in homogenous leucoplakia, but considerably higher in non-homogenous leucoplakia.
• Proliferative verrucous leucoplakia (PVL) is a rare multi-focal form of leucoplakia that expands over the years and eventually turns into carcinoma in more than half of the cases. The diagnosis of PVL requires correlation of clinical and histopathological features both retrospectively and prospectively. In the initial phases, no dysplasia is usually found, but instead the histopathological diagnosis may be epithelial hyperplasia, hyperkeratosis, and/or lichenoid reaction.
• Statistically the most dangerous area is the floor of the mouth and the underside of the tongue.
• Diagnosis is based on the clinical picture and histology.
• Treatment often involves surgical excision, particularly if a biopsy shows dysplasia or if the change is located in a risk area. Cessation of smoking is important. Clinical follow-up is to be arranged at intervals of no more than 3-12 months. It has been noted that the removal or non-removal of a leucoplakia does not correlate with the prognosis of the lesion. Careful follow-up is most important!

Erythroplakia

• Erythroplakia denotes a mainly reddish, in most cases well circumscribed, mucous membrane lesion that cannot be diagnosed as any other specific disease (picture F2).
• Erythroplakia is nearly always associated with dysplasia and 20-45% of the cases will develop into a cancer Cancers of the Head and Neck. Even in half of changes that clinically look like erythroplakia, a carcinoma is diagnosed already at the time of initial diagnosis.
• Erythroplakia must always be completely removed.

Oral lichen planus and lichenoid changes

• Oral lichen (ruber) planus is associated with an approximately 1% risk of undergoing malignant change. See separate article Oral Lichen Planus.

Discoid lupus erythematosus (DLE)

• The mouth lesions are roundish, poorly defined reddened areas encircled by a radial white rim, and may be associated with white spotting (picture F3). The most common sites are the buccal areas, palate and the lower lip.
• Diagnosis is based on the clinical picture and histological findings of a biopsy. If DLE is suspected a biopsy should be taken of a lesion, and half of the sample should be sent for IF examination (fresh tissue required).
• Oral DLE changes are considered to involve a potentially increased risk of malignancy, especially when located on the lips.
• See also Discoid Lupus Erythematosus.

Syndromes that increase the risk of oral cancer

• APECED Apeced (Autoimmune Polyendocrinopathy - Candidiasis - Ectodermal Dystrophy)
• Fanconi anaemia http://www.orpha.net/en/disease/detail/84
• Xeroderma pigmentosum http://www.orpha.net/en/disease/detail/910
• Dyskeratosis congenita http://www.orpha.net/en/disease/detail/1775
• Plummer-Vinson syndrome http://www.orpha.net/en/disease/detail/54028

Pigment changes of the oral mucosa

• Physiological pigmentation is usually symmetrical over the gums (picture F4).
• Inflammatory diseases, such as lichen planus Oral Lichen Planus, may cause pigmentation of the mucous membranes.
• Smoking-induced melanosis usually occurs in the labial gums.
• Amalgam tattoo is the most common pigmented change of the oral mucosa. It is caused by amalgam particles invading the mucous membranes. Amalgam tattoo is usually a greyish blue, dark spot on the gums, close to a dental filling (picture F5) or the site of a removed tooth, but it may be located anywhere on the oral mucosa.
• Some cases of pigmentation are drug-induced (e.g. antimalarials, cytostatic medication, zidovudine, imatinib).
• A widespread pigmentation may be attributable to a systemic illness, such as Addison's disease, Peutz-Jeghers syndrome, Albright's syndrome or neurofibromatosis. If the patient presents with diffuse pigmentation of the oral mucosa and the lips without a systemic illness, the possibility of Laugier-Hunziker syndrome should be considered.
• Melanotic macule refers to a local pigmented lesion. It may be idiopathic or caused by one of the aforementioned factors.
• Naevi and melanoma are rare but possible on the oral mucosa.
• If in doubt the diagnosis must be confirmed with a biopsy.