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PIGMENTED LESIONS OF THEORAL MUCOSA

In the course of disease, the mucosal tissues can assume a variety of discolorations. and such color changes can be attributed to the deposition of either endogenous or exogenous pigments. The endogenous pigmentation of the oral mucous membraneis most often explained by the presence of hemoglobin , hemosiderin , and melanin .
Hemoglobin imparts a red or blue appearance to the mucosa . In contrast, hemosiderin appears brown and is deposited as a consequence of blood extravasation, which may occur as aconsequence of trauma or a defect in hemostatic mechanisms .Melanin is the pigment derivative of tyrosine and is synthesized in melanocytes, . An increase in melanin pigment occurs when melanocytes over synthesize or over populate.
The specific coloration, tint, location, multiplicity, size, and configuration of the pigmented lesion(s) are of diagnostic importance .
Exogenous pigments are usually traumatically deposited directly into the submucosa .However, some may be ingested ,absorbed, and distributed hematogenously, to be precipitated in connective tissues, particularly in areas subject to chronic inflammation, such as the gingiva. exogenous pigment may be generated by chromogenic bacteria that colonize the keratinized surface of the tongue (hairy tongue).

▼BLUE/PURPLE VASCULAR LESIONS

Hemangioma
Vascular lesions presenting as proliferations of vascular channels are tumor like hamartomas when they arise in childhood ; The hemangiomas of childhood are found on the skin, in the scalp, and within the connective tissue of mucous membranes. Approximately 85% of childhood-onset hemangiomas spontaneously regress after puberty. the lesion may harbor vessels close to the overlying epithelium and appear reddish blue or, if a little deeper in the connective tissue, a deep blue Whereas most hemangiomas are raised and nodular, some may be flat, macular, and diffuse, particularly on the facial skin, where they are referred to as port-wine stains. Hemangioma in the oral mucosa, may continue in macular fashion or become tumefactive Angiomatous lesions occurring within muscle (so-called intramuscular hemangiomas) may fail to show any surface discoloration. Thus, the clinical appearance of benign vascular hamartomas can be quite variable, ranging from a flat reddish blue macule to a nodular blue tumefaction. Most oral hemangiomas are located on the tongue frequently extend deeply between the intrinsic muscles of the tongue. The lip mucosa is another common site for hemangiomas in children; these tumors are usually localized, blue, and raised Most patent vascular lesions will blanch under pressure; indeed, placing a microscope glass slide over the pigmented area and adding pressure will often demonstrate this feature.. Microscopically, a hemangioma may comprise numerous large dilated vascular channels lined by endothelial cells without a muscular coat; such lesions are referred to as cavernous hemangiomas. Patients who require treatment can undergo conventional surgery,laser surgery, or cryosurgery. Larger lesions that extend into muscles are more difficult to eradicate surgically, and sclerosing agents such as 1% sodium tetradecyl sulfate may be administered by intralesional injection. These agents result in postoperative pain, and the patient must be managed with amoderate-level analgesic Cutaneous port-wine stains can be treated by subcutaneous tattooing or by argon laser

Varix
Pathologic dilatations of veins or venules are varices or varicosities, and the chief site of such involvement in the oral tissues is the ventral tongue. Lingual varicosities appear as tortuous blue, red, and purple elevations that course over the ventrolateral surface of the tongue, with extension anteriorly . they represent a degenerative change in the adventitia of the venous wall and are of no clinical consequence. They are painless and are not subject to rupture and hemorrhage. These lesions also tend to occur in the lower lip, appearing as a focal raised pigmentation. They may be blue, red, or purple, and the surface mucosa is often lobulated or nodular. Whereas some can be blanched, others are not, due to the formation of intravascular thrombi. The varix resembles the hemangioma both clinically and histologically, yet it is distinguished by two features:
(1) the patient’s age at its onset and
(2) its etiology.
varix arises in older individuals and, once formed does not regress. the varix represents a venous dilatation that may evolve from trauma such as lip or cheek biting. The traumatic event probably damages and weakens the vascular wall and culminates in dilation.
MicroscopicallyThey may be represented by a single dilated vascular channel lined by endothelial cells lacking a muscular coat, or they may comprise numerous tortuous channels
The lesion can be excised or removed by other surgical methods, including electrosurgery and cryosurgery ntralesional 1% sodium tetradecyl sulfate injection is effective as well, yet it is usually more painful than simple excision.

Angiosarcoma

Malignant vascular neoplasms, distinct from Kaposi’s sarcoma,are not related to human immunodeficiency virus (HIV) and can arise anywhere in the body. appear red, blue, or purple. They are rapidly proliferative and therefore present as nodular tumors. They have a poor prognosis and are treated by radical excision.

Kaposi’s Sarcoma

Kaposi’s sarcoma (KS) was rarely encountered in the oral cavity prior to 1983. The classic form generally appeared in two distinct clinical settings
(1) elderly men (in the oral mucosa and on the skin of the lower extremities)
(2) children in equatorial Africa (in lymph nodes).
KS is an indolent tumor with slowly progressive growth. Although classified as a malignancy, classic Kaposi’s sarcoma does not show a great tendency for metastasis and probably has never caused the death of a patient. The oral tumors are red, blue, and purple, and the hard palate is the favored site; the skin tumors tend to localize in the dorsal aspect of the feet and great toe. After 1983, oral KS became much more prevalent Indeed, the mere presence of KS lesions in HIV seropositive subjects constitutes a diagnostic sign for acquired immunodeficiency syndrome (AIDS). The cutaneous lesions begin as red macules and enlarge to become blue, purple, and ultimately brown nodular tumefactions. The oral lesions continue to show a predilection for the posterior hard palate, and they also begin as flat red macules of variable size these lesions increase in size to become nodular growths, and some will involve the entire palate, protruding below the plane of occlusion. The facial gingiva is the second most-favored oral site; The early plaque or macular stage lesions are painless and do not require treatment. Nodular lesions may become unsightly and interfere with mastication; in this situation, therapy may be desirable. Surgical excision is not usually attended by severe hemorrhage, but electrocautery is recommended, either as a primary form of surgery or as a coagulative hemostatic adjunct to conventional excision. Intralesional injection of 1% sodium tetradecyl sulfate will result in necrosis of the tumefactions; however it is painful, and the patient should be prescribed a moderate-strength analgesic Intralesional 1% vinblastine sulfate is also beneficial;

Hereditary Hemorrhagic Telangiectasia

is a genetically transmitted disease inherited as an autosomal dominant trait Characterized by multiple round or oval purple papules measuring less than 0.5 cm in diameterThe lesions represent multiple microaneurysms, owing to aweakening defect in the adventitial coat of venules. There may be more than 100 such purple papules on the vermilion and mucosal surfaces of the lips as well as on the tongue and buccal mucosa.The facial skin and neck are also involved. The lesions may be seen during infancy but are usually more prominent in adults There is no treatment for the disease. If the patient would like to have the telangiectatic areas removed for cosmetic reasons, the papules can be cauterized by electrocautery in a staged series of procedures using local anesthesia

▼BROWN MELANOTIC LESIONS

Ephelis and Oral Melanotic Macule
Ephelis represents an increase in melanin pigment synthesis by basal-layer melanocytes, without an increase in the number of melanocytes. Ephelides can be encountered on the vermilion border of the lips,with the lower lip being the favored site since it tends to receive more solar exposure than the upper lipLip ephelides are asymptomatic and occur equally in men and women. They are rarely seen in children The intraora lephelis are oval or irregular in outline,are brown or even black, and tend to occur on the gingiva, palate, and buccal mucosa. Once they reach a certain size, they do not tend to enlarge further

Nevocellular Nevus and Blue Nevus

nevi are due to benign proliferations of melanocytes. There are two major types, based on histology,
1-junctional nevi. arise from basal-layer melanocytes early in life maintain their localization to the basal layer.In general, they are flat and brown and have a regular round or oval outline
2- compound nevi. With time, the melanocytes form clusters at the epitheliomesenchymal junction and begin to proliferate down into the connective tissue although they do not invade vessels or lymphatics. Such nevi assume a domeshaped appearance and are referred to as compound nevi.
The blue nevus isThe second type of nevus, not derived from basal-layer melanocytes, the melanocytic cells reside deep in the connective tissue and because the overlying vessels dampen the brown coloration of melanin, yielding a blue tint. In the oral mucosa, both nevocellular and blue nevi tend to be brown and may be macular or nodular .
They may be seen at any age and are found most frequently on the palate and gingiva but may also be encountered in the buccal mucosa and on the lips. Biopsy is necessary for diagnostic confirmation Simple excision is the treatment of choice

Malignant Melanoma

On the facial skin, the malar region is a common site for melanoma because this area of the face is subject to significant solar exposure. is most common among white populations that live in sunbelt regions. Melanomas may appear macular or nodular, and the coloration can be quite varied, ranging from brown to black to blue, with zones of depigmentation An important difference is that unlike common nevi that exhibit smooth outlines, melanomas show jagged irregular margins. These lesions are more common among elderly. patients and show a male predilection. The term “lentigo maligna melanoma” or “Hutchinson’s freckle” has been applied to these facial skin lesions that exhibit atypical melanocytic hyperplasia or melanoma in situ.

These lesions have a good prognosis if they are detected and treated before the appearance of nodular lesions, which indicates invasion into the deeper connective tissue Mucosal melanomas are extremely rare. Their prevalence appears to be higher among Japanese people Melanomas arising in the oral mucosa tend to occur on the anterior labial gingiva and the anterior aspect of
the hard palate. In the early stages, oral melanomas are macular brown and black plaques with an irregular outline. They may be focal or diffuse and mosaic, Any pigmented oral lesion with an irregular margin or with a history of growth should be suspect, and a biopsy of it should be performed without delay. Microscopically, oral mucosal melanomas may exhibit a radial or a vertical pattern of growth The radial or superficial spreading pattern is seen in
macular lesions;. Once vertical growth into the connective tissue progresses, the lesions can become clinically tumefactive. The vertical growth phase connotes a poor prognosis because of the likelihood of lymphatic and hematogenous metastasis, Excision with wide margins is the treatment of choice Computed tomography and magnetic resonance imaging studies should be undertaken to explore regional metastases to the submandibular and cervical lymph nodes. A variety of chemo- and immunotherapeutic strategies can be used once metastases have been identified

Drug-Induced Melanosis

A variety of drugs can induce oral mucosal pigmentation These pigmentations can be large yet localized the lesions are flat and without any evidence of nodularity or swelling. The chief drugs implicated are the quinoline, hydroxyquinoline, and amodiaquine antimalarials The pigment is not confined to oral mucosa and is also encountered in the nail bed and on the skin.
Last, oral contraceptives and pregnancy are occasionally associated with hyperpigmentation of the facial skin, particularly in the periorbital and perioral regions This condition is referred to as melasma or chloasma. The cause is unknown, and the pigment may remain for quite some time after withdrawal of the incriminated drug.
Microscopically, basilar melanosis without melanocytic proliferation

Physiologic Pigmentation

other causes of hyperpigmentation are , racial pigmentation, representing basilar melanosis, evolves in childhood and usually does not arise de novo in the adult.

Café au Lait Pigmentation

In neurofibromatosis, an autosomal dominant inherited disease, both nodular and diffuse pendulous neurofibromas occur on the skin and (rarely) in the oral cavity.A concomitant finding is the presence of “café au lait pigmentation these lesions have the color of coffee with cream and vary from small ephelis-like macules to broad diffuse lesions. Microscopically, café au lait spots represent basilar melanosis without melanocyte proliferation

Smoker’s Melanosis

Diffuse macular melanosis of the buccal mucosa, lateral tongue, palate, and floor of the mouth is occasionally seen among cigarette smokers Thus, it is probable that in certain individuals, melanozgenesis is stimulated by tobacco smoke products. The lesions are brown, flat, and irregular; some are even geographic or maplike in configuration

Pigmented Lichen Planus

erosive lichen planus can be associated with diffuse melanosis. usually in the buccal mucosa and vestibule

Endocrinopathic Pigmentation

Bronzing of the skin and patchy melanosis of the oral mucosa are signs of Addison’s disease and pituitary-based Cushing’s syndrome. the cause of hyperpigmentation is oversecretion of ACTH, a hormone with melanocyte-stimulating properties. In both cases, the skin may appear tanned, and the gingiva, palate, and buccal mucosa may be blotchy Endocrinopathic disease should be suspected whenever oral melanotic pigmentation is accompanied by cutaneous bronzing. Serum steroid and ACTH determinations will aid the diagnosis, and the pigment will disappear once appropriate therapy for the endocrine problem is initiated.

HIV Oral Melanosis

HIV-seropositive patients with opportunistic infections may have adrenocortical involvement by a variety of parasites which manifests signs and symptoms of Addison’s disease. HIV-seropositive patients presenting with diffuse multifocal macular brown pigmentations of the buccal mucosa

Peutz-Jeghers Syndrome

Multiple focal melanotic brown macules are concentrated about the lips while the remaining facial skin is less strikingly involved. Similar lesions may occur on the anterior tongue, buccal mucosa, and mucosal surface of the lips. Ephelides are also seen on the fingers and hands.

▼BROWN HEME-ASSOCIATED LESIONS

Ecchymosis
erythrocyte extravasation into the submucosa will appear as a bright red macule or as a swelling if a hematoma forms. The lesion will assume a brown coloration within a few days, after the hemoglobin is degraded to hemosiderin patients taking anticoagulant drugs may present with oral ecchymosis, . Coagulopathic ecchymosis of the skin and oral mucosa may also be encounteredin hereditary coagulopathic disorders and in chronic liver failure.

Petechia

Capillary hemorrhages will appear red initially and turn brown in a few days once the extravasated red cells have lysed and have been degraded to hemosiderin. Petechiae secondary to platelet deficiencies or aggregation disorders are usually not limited to the oral mucosa but occur concomitantly on skin By 2 weeks, the lesions should have disappeared

Hemochromatosis

The deposition of hemosiderin pigment in multiple organs and tissues secondary to a variety of diseases and conditions, including chronic anemia, porphyria cirrhosis, postcaval shunt for portal hypertension, and excess intake of iron. The oral mucosal lesions of hemochromatosis are brown to gray diffuse macules that tend to occur in the palate and gingiva.

▼GRAY/BLACK PIGMENTATIONS

Amalgam Tattoo
The lesions are macular and bluish gray or even black and are usually seen in the buccal mucosa, gingiva, or palate Such lesions are the consequence of traumatically introduces the metal flecks. into the adjacent mucosaAmalgam fragments can also be deposited in oral tissue during multiple tooth extractions. they are identifiable on radiographs of the area. Since amalgam tattoos are innocuous, their removal is not required,

Graphite Tattoo

Graphite tattoos tend to occur on the palate and represent traumatic implantation from a lead pencil

Hairy Tongue

Hairy tongue is a relatively common condition of unknown etiology The papillae are elongated, sometimes markedly so, and have the appearance of hairs.The hyperplastic papillae then become pigmented by the colonization of chromogenic bacteria, which can impart a variety of colors ranging from green to brown to black.Various foods, particularly coffee and tea, probably contribute to the diffuse coloration. Treatment consists of having the patient brush the tongue and avoid tea and coffee for a few weeks. Since the cause is undetermined, the condition can recur.

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