|Year : 2013 | Volume
| Issue : 2 | Page : 121-125
Unusual extensive physiologic melanin pigmentation of the oral cavity: A clinical presentation
K Mallikarjuna, S Gupta, S Shukla, S Chaurasia
Department of Pedodontics and Preventive Dentistry, Hitkarini Dental College and Hospital, Hitkarini Hills, Dumna Road, Jabalpur - 482 005, Madhya Pradesh, India
|Date of Web Publication||26-Jul-2013|
Department of Pedodontics and Preventive Dentistry, Hitkarini Dental College and Hospital, Hitkarini Hills, Dumna Road, Jabalpur 482 005, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Pigmented lesions are commonly found in the oral cavity. Oral pigmentations may be physiological or pathological in nature. It may represent as a localized anomaly of limited significance or the presentation of potentially life threatening multisystem disease. Oral pigmentation has a multifactorial etiology. Most of the oral pigmentations are physiologic. Evaluation of a patient with pigmented lesions should include a full medical and dental history, extraoral and intraoral examinations. In this article, we report a case of extensive physiologic pigmentation of the oral cavity in a 12 year old female patient, posing a diagnostic challenge.
Keywords: Melanin, oral cavity, physiologic, pigmentation
|How to cite this article:|
Mallikarjuna K, Gupta S, Shukla S, Chaurasia S. Unusual extensive physiologic melanin pigmentation of the oral cavity: A clinical presentation. J Indian Soc Pedod Prev Dent 2013;31:121-5
|How to cite this URL:|
Mallikarjuna K, Gupta S, Shukla S, Chaurasia S. Unusual extensive physiologic melanin pigmentation of the oral cavity: A clinical presentation. J Indian Soc Pedod Prev Dent [serial online] 2013 [cited 2019 Apr 21];31:121-5. Available from: http://www.jisppd.com/text.asp?2013/31/2/121/115718
| Introduction|| |
The development of pigmented lesions in the oral region often gives rise to concern for both patients and doctors.  The term "pigmentations of the oral mucosa" may be applied to a wide range of entities caused by the accumulations of one or more pigments and featuring a change in color of the tissues.  Human mucosal epithelium is not uniformly colored and several degrees of chromatic variegations may be observed in physiologic and pathologic conditions. 
Oral pigmentations occur in all races. There were no significant differences in the oral pigmentation between males and females. The intensity and distribution of racial pigmentation of the oral mucosa is variable, not only between races, but also between different individuals of the same race and within different areas of the mouth. 
Oral hyper pigmentation may be focal or diffuse, acquired or familial and due to exogenous or endogenous in origin.  Exogenous pigmentation is commonly owing to foreign-body implantation in the oral mucosa. Endogenous pigments include melanin, melanoid, oxyhemoglobin, reduced hemoglobin and carotene; others are caused by bilirubin and iron.  Localized areas of increased melanin in the oral mucosa that are not associated with systemic diseases or syndromes have been variably termed ephelis, lentigo, melanoplakia, melanotic macule and focal physiologic melanosis. 
Melanin is produced by melanocytes in the basal layer of the epithelium and is transferred to adjacent keratinocytes via membrane bound organelles called melanosomes. Melanin is also synthesized by nevus cells, which are derived from the neural crest and are found in the skin and mucosa. Pigmented lesions caused by increased melanin deposition may be brown, blue, grey, or black, depending on the amount and location of melanin in the tissues. ,
Most of the oral pigmentations are physiologic and are probably genetically determined. Dummet suggested that the degree of pigmentation is partially related to mechanical, chemical, and physical stimulation. In darker skinned people, oral pigmentation increases, but there is no difference in the number of melanocytes between fair-skinned and dark skinned individuals. The variation is related to the difference in the activity of melanocytes. , The aim of this article is to present a case of unusual extensive physiologic melanin pigmentation of the oral cavity and its clinical presentation.
| Case Report|| |
A 12 year old dark complexioned female patient reported to the Department of Pedodontics and Preventive Dentistry in Hitkarini Dental College and Hospital with the chief complaint of pain in the lower right and left posterior teeth region since 1-2 months. The pain was mild and aggravates while chewing food. During intraoral examination, it was observed that the pain was due to over retained 75 and 85, which were grade II mobile. A treatment plan of extraction of over retained 75 and 85 was made to be done under local anesthesia.
On examination of the oral cavity the tongue was observed to be hyperpigmented, an accidental finding. There was diffused pigmentation on the dorsal surface of the tongue sparing the lateral borders of tip of the tongue [Figure 1]. On the ventral surface, the lateral borders of the tongue were pigmented, whereas the lingual mucosa on both sides of the lingual frenum appears to be normal [Figure 2]. On the buccal mucosa there was diffused pigmentation on the right and left posterior molar region [Figure 3]. Another brownish black diffused pigmented lesion was present on the palate extending from attached gingiva to the junction of hard and soft palate [Figure 4].
|Figure 1: Clinical view of the patient showing diffuse bluish black borders pigmentation on the dorsal surface of the tongue|
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|Figure 2: Clinical view of the patient showing pigmentation on lateral borders of ventral surface of tongue|
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|Figure 3: Clinical view of the patient showing bluish black pigmentation on right buccal mucosa|
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|Figure 4: Clinical view of the patient showing diffuse pigmentation extending from attached gingiva to the junction of hard palate and soft palate|
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The patient's history revealed that she was born with these pigmentations, with no change in color and size. There was no history of trauma to the area. Her past dental, medical and personnel history was non-contributory.
Extraoral examination revealed no significant findings. Lymph nodes were not palpable. The gingiva revealed usual morphologic pattern of physiologic melanosis. No other marked deformity or pigmented lesion was noted extraorally or intraorally. A thorough systemic examination of the patient was performed and was non-contributory.
By evaluating the patient`s history, systemic conditions and clinical findings, a diagnosis of physiologic melanin pigmentation of the oral cavity was made.
| Discussion|| |
Changes in color of the oral mucosal surfaces can be of paramount significance because they frequently represent diagnostic evidence of either local or systemic disease. The alterations however may not always be evident for the color of healthy oral mucosa varies considerably; furthermore, assessing pigmentation as a marker of disease requires clinical experience and thorough evaluation. , An algorithm based on the typical or predominant presentations of the various pigmented lesions of the oral cavity is presented in Graph 1 [Additional file 1] and it should not be taken as absolute indicator of diagnosis. The interpretation of the color can be subjective and is influenced by the amount and location of the pigment within the mucosa. 
Physiologic pigmentation of the oral mucosa is clinically manifested as multifocal or diffuse melanin pigmentation with variable prevalence in different ethnic groups. Melanin is normally found in the skin, produced by melanocytes, its functions include absorption of ultraviolet light and scavenging of some cytotoxic compounds. ,
Melanocytes were first identified in the oral epithelium by Becker in 1927; a few years later they were isolated from samples of gingival tissues by Laidlaw and Cahn. During early intrauterine life, the precursors of melanocytes migrate from the neural crest to the epidermis and the hair follicles, becoming differentiated into the dendritic cells.  Head and neck region are the first site of the body where melanocytes appear after approximately 10 weeks of gestation. 
Melanocytes are located in the basal epithelial layer of squamous mucous membranes and do not contact each other. They are regularly interspersed between the basal keratinocytes. Normal melanocytes of the oral mucosa have a small, round nucleus and a small amount of a clear cytoplasm, with slender dendrites extending between adjacent keratinocytes. ,
Physiologic melanin pigmentation is manifested not by an increased number of melanocytes, but rather by increased melanotic activity of these cells. It is characterized histologically by increased amounts of melanin in the basal layer, the upper portion of lamina propria, or both.  Oral physiologic melanin is not limited to any one race, although it is a common characteristic of the more heavily pigmented races. Physiologic pigmentation of the oral mucosa may occur in any location; although, the gingiva is the most commonly affected. In general, pigmentation of the tongue appears as asymmetric spots or plaques on the dorsal surface or lateral borders. ,
Increased melanin pigmentation of the oral mucosa is a clinical finding in a number of systemic disorders, including Peutz-Jeghers syndrome (associated with intestinal polyposis), Adissons disease (chronic adrenal cortical insufficiency), Albright syndrome (polyostotic fibrous dysplasia), Von Recklinghausen disease (neurofibromatosis), Hemochromatosis (resulting from faulty metabolism of iron) and Acanthosis Nigerians. Dark pigmentation can result from intoxification with a range of heavy metals such as mercury, silver and lead. Certain drugs such as anti-malarials (quinolines), antibiotics (minocycline) and chemotherapeutic agents (doxorubicin) may also produce black pigmentation of the oral mucosa. ,
Physiologic pigmentation develops during the first decade of life but may not come to the patient`s attention until later. The color ranges from light to dark brown. The attached gingiva is the most common intraoral site of such pigmentation, where it appears as a bilateral, well demarcated, ribbon like, dark brown band that usually spares the marginal gingiva. Physiologic pigmentation of the buccal mucosa, hard palate, lips and tongue may also be seen as brown patches with less well-defined borders. The physiologic pigmentation is asymptomatic and no treatment is required. 
Hyperfunction of melanocytes is also present in pigmented nevi and in melanoma. Primary oral melanoma is relatively rare. Its prognosis is very poor and early diagnosis is therefore of vital importance. Almost all oral melanomas are pigmented, appearing as a brownish to bluish-black, elevated mass. The tumour may arise in a previously existing, flat, pigmented zone, or as a rapidly enlarging growth that show ulceration and spontaneous haemorrhage. Because benign oral melanosis can transform into melanoma, it has been suggested that any intra oral melanin pigmentation be viewed with suspicion. However, patches of physiologic melanin pigmentation are usually present from childhood and are frequently multiple, whereas nevi are generally solitary and can be present from birth or develop later. ,
In the present case, patient's past, medical, drug and personal history was evaluated. On intraoral examination, an extensive dark brownish, diffuse, flat pigmented lesion was present on the dorsal and ventral surface of the tongue and also on the hard palate and patches on the left and right buccal mucosa with no change in colour and size since many years. Based on these findings, a diagnosis of physiologic melanin pigmentation of the oral cavity was made.
| Conclusion|| |
Diagnosis of pigmented lesions of the oral cavity is a challenging task. Most of the oral pigmentations are physiologic, but sometimes it can be a precursor of severe diseases. Therefore, evaluation of a patient presenting with pigmented lesion should include a full medical and dental history, extraoral and intraoral examinations and laboratory tests. Clinical tests such as diascopy, radiography and a biopsy can be used to confirm a clinical impression and reach a definitive diagnosis.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]