Oral melanosis is a benign pigmented lesion arising in the oral cavity. Oral pigmentation is asymptomatic and does not usually cause any alteration to the texture or thickness of the affected area. The colour can be uniform or speckled and can appear solitary or as multiple lesions. Depending on the site, depth, and quantity of pigment, the appearance can vary considerably. Oral pigmentation is found in the following places: Oral pigmentation affects about 3% of the population and is most likely seen in those with dark skin; however people with light skin have, on average, 30 local pigmented areas and in some circumstances will present intra-orally. They are more often found in females than males and the typical age at presentation is 40 years although they can appear at any age. Diagnosis of oral pigmentation is by a complete history taken by the clinican followed by a thorough clinical examination. Management of such lesions is typically by close clinical monitoring, photographs and measuring tools. A biopsy may be indicated where the following features are present: large or new-pigmented lesions and those with a papular appearance or irregular colouration.
Oral pigmentation affects about 3% of the population[1] and is most likely seen in those with dark skin[2]; however people with light skin have, on average, 30 local pigmented areas and in some circumstances will present intra-orally. They are more often found in females than males[3] and the typical age at presentation is 40 years although they can appear at any age[4]
The autosomal dominant disorder Peutz-Jeghers Syndrome is characterized by ‘intestinal hamartomatous polyps in association with mucocutaneous melanocytic macules’. These macules often vary in shades of brown, size and are confluent, Although any oral site can be affected, in almost all cases pigmented macules appear on the buccal mucosae, lips and around the mouth. Pigmented macules on the face are less common. The extent of oral involvement and degree of pigmentation varies between each individual case.
An individual who has this syndrome has a relative risk fifteen times greater of developing cancer in comparison to the general population.
In older patients, the main consequence of the syndrome is cancer. The sites mainly affected include the pancreas, stomach, lungs, colon, small intestine, uterus, breasts and the ovaries and breasts. Additionally, Peutz-Jeghers Syndrome can be associated with other reproductive site cancers including sertoli cell tumours and adenoma malignum of the cervix.
In young patients, intussusception and obstruction of the small intestinal obstruction and are the main complications, these are caused by the small intestinal location of the polyps.
Systemically oral melanosis can also be associated with the following;
- Pregnancy
- Oral contraceptive intake
- Exposure to sunlight
- HIV [5]
- Antimalarial drug therapy [6]
Melanotic macules can be found on the buccal mucosa, lip, palate, alveolar ridge and gingiva.[7]
Oral Melanosis can also be classified as 2 categories, melanocytic or non-melanocytic. (Melanocytic being the genesis due to the increase in melanotic pigments and non-melanocytic origin being the genesis from non melanotic causes). The prevalence of melanocytic and non-melanocytic causes of oral melanosis was roughly 1:1.[7][8]
Oral pigmentation affects about 3% of the population[1] and is most likely seen in those with dark skin[2]
For Peutz Jeghers syndrome the frequency is approximately 1 case per 60,000-300,000 people in the USA. Equal occurrence in both sexes and all races. Average age of diagnosis being 23 years in men and 26 years in women.[9]
Smoker’s melanosis is present in all age groups, has no observed sex or race predilection.[7]
For hyperplastic or neoplastic processes, the mean age of oral melanotic macule (hyperplastic- increase in malanoticpigments without an increase in malanocytes) is 43.1 years with the mean size of the lesion was about 6.8mm. The female: male ratio is 2:1 and lower lip being the most common location. For oral melanoma (neoplastic) the mean age was 53.8 years with equal ratio of female:male and most common location being in the palate or gingiva.[9][10]
For oral Melanoma (neoplastic lesion) ,the mean age was 53.8 years with equal ratio of female:male and most common location being in the palate or gingiva.[9][10]
The occurrence of oral malanosis on the cheeks were (21%) ,alveolar mucosa (16.6%) , gingiva (11.8%). Amalgam tattoo being majority of the cases (46.3%) , malanotic macules (22.9%) and nevus (20.5%). [11]
Many different diseases can cause melanin pigmented lesions in the mouth through
Melanin is an endogenous pigment synthesized by melanocytes that are located in the basal layer of epithelium. Melanin is then transferred to keratinocytes in melanosomes. Nevus cells in the skin and oral mucosa also produce melanin. Oral melanosis can present as black, gray, blue or brown lesions depending on the site and amount of melanin deposition in tissues[12]
Increased melanin production without increase in melanocytes[13]
Increased production of melanin without increase in number of melanocytes[14]
Decrease in blood adrenocortical hormone level causes increased levels of adrenocorticotropic hormone secreted by anterior pituitary gland. As a result, melanocyte-stimulating hormone is induced which causes oral melanosis[13]
Increased melanin production to defend against damage from tobacco smoke[13]
Increased number of dendritic melanocytes [13]
Accumulation of nevus cells at the basal layer of the epithelium or in the connective tissue or both[13]
Increased number of malignant melanocytes[13]
There is a variety of different treatment options for Kaposi sarcoma. The appropriate therapy options may vary depending on the variation of disease and the patients immune status[15]. If the lesion is localised, usually found in classical Kaposi sarcoma, and not systemic treatments can be any from lasers, cryotherapy, non-intervention, chemotherapy and immune upregulation[16] . For generalized and systemic cases chemotherapeutic drugs are used[17]. HAART is also a recognised treatment if the patient is known to suffer from AIDS-related Kaposi sarcoma. For cases of iatrogenic Kaposi sarcoma any immunosuppressive medication should be stopped or reduced if able.
Smokers melanosis may resolve over several years following smoking cessation[18].
An initial biopsy of the lesion may be carried out first to determine correct diagnosis. Following this there is a number of different treatment options available. The combination used will be based on the individual patient and presenting melanoma. Surgical resection[19] is most commonly carried out. This involves cutting out the lesion and ensuring complete removal from the oral cavity. Chemotherapy and Radiotherapy are considered first line management[20] and they may be used in conjunction with surgery. Another option available is Immunotherapy. The aim of this is to target cells or molecules in the immune system in an effort to destroy tumours[21]. This can be done by suppressing or stimulating the patients immune system. After treatment has been carried out patients should be seen for regular follow ups[22] to manage any reoccurrence early and ensure complete healing following surgeries. If the melanoma has progressed extensively and metastasised, treatment, for example surgery, would be carried out in a palliative nature only[23].
The content is sourced from: https://handwiki.org/wiki/Biology:Oral_melanosis