Melanotic Lesions of Head and Neck Region

7/31/2019 Melanotic Lesions of Head and Neck Region

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Emergency Medicine

Emergency Medicine

MELANOTIC LESIONS OF

HEAD AND NECK REGION

PRESENTED BY:

ASHISH VYAS

PGT,ORAL AND MAXILLOFACIAL SURGERY

RDC,GUWAHATI

GUIDED BY:DR A.K.ADHYAPOK

PRINCIPAL AND H.O.D

DEPARTMENT OF ORAL AND MAXILLOFACIAL

SURGERY

RDC,GUWAHATI



INTRODUCTION

Human oral and head and neck mucosa is not

uniformly coloured and several degrees of chromatic

variegation may be observed in physiological and

pathological conditions.

Melanin-associated lesions represent the most

common pigmentations and include benign entities

as well as mucosal melanoma, an extremelyaggressive neoplasm.



ORAL MUCOSAL MELANOCYTES• Melanocytes are dendritic cells located

mainly in the basal layer of the

epidermis and in some mucousmembranes.

• They are widely distributed and presentin large numbers in the oral mucosa.

• They are regularly interspersed betweenthe basal keratinocytes.

• Melanocytic dendrites reach a numberof keratinocytes in the close vicinity,and through these dendrites, melanin istransported and transmitted to theseepithelial cells.

• The main biochemical function of themature melanocyte is a process calledmelanogenesis through which the cellproduces and delivers melanin pigment.





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Emergency Medicine

• Melanotic

macules

of the oral cavity are relatively

common lesions, caused by an increased production

and deposition of melanin within the basal cell layer,

the lamina

propria

, or both.

• Melanotic

macules

are usually single, well

-circumscribed blue or brown

-

to

-

black lesions

homogeneously colored, and less than 1 cm in

diameter.

• These

melanotic

macules

are idiopathic and may be

conceptualized as the rare mucosal corollary to the

much more common skin freckle (

ephelis

), althoughthe

melanotic

macule

does not darken in response

to sun exposure as does the skin freckle.



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Emergency Medicine

• They are most

commonly seen on

the lower lip

vermilion or on the

attached

gingiva

,

but they can occur

on any oral site.



Emergency Medicine Emergency Medicine

DIFFERENTIAL DIAGNOSIS

• The most important lesion todistinguish from a melanotic

macule is an early melanoma.

• Although most oral melanomas

will be black or blue and willmore characteristically have

varying shades of brown to black

within them, early melanomas

may appear as homogeneous as

melanotic macules.

• The most common lesion that

may appear similar to a

melanotic macule is an amalgam

tattoo.




TREATMENT

• Single lesions should undergo excisional biopsy torule out melanoma.

• The early identification of a small melanoma woulddramatically improve the prognosis in a case with an

otherwise poor prognosis.• When multiple lesions are present, it is often prudent

to biopsy one or two lesions.

• Choose the largest, darkest, most raised (if any are

raised), and most irregularly bordered ones toundergo biopsy.

• If the biopsy confirms more than one melanoticmacule, a screening work‐up for Peutz ‐ Jeghers

syndrome and Addison disease is required.




SMOKER‟S MELANOSIS

• Smokers' melanosis is a focal increase inmelanin pigmentation in the oral mucosa found

in cigarette, pipe, and cigar smokers who

smoke frequently.

• The melanosis is either a diffuse patch of

brownish discolored mucosa or numbers of small melanotic macules.

• The lesion is not dysplastic or premalignant,

but its presence indicates a continual and

frequent smoking habit that places the patient

at an increased risk for oral carcinoma.

• Most lesions are seen on the labial mucosa

and floor of the mouth, but the tongue, gingiva,

and buccal mucosa may also be involved.




TREATMENT

• Only lesions suggestive of melanomaby virtue of induration, thickening,ulceration, or darkening in color requirebiopsy.

• Because these lesions are notthemselves dangerous, no specifictreatment is required.

• However, smoking reduction or cessation is strongly advised, which, inturn, will often result in a lightening of the pigmentation and in some caseselimination of it.







MELANOYTIC NEVI

• Nevi, also called moles, are benign collections of nevus cells that are derived either from melanocytesor from the same neural crest precursors asmelanocytes.

• Nevi on skin are very common; nearly every person

has at least one.• Nevi on the oral mucosa are very uncommon, withless than 1% of individuals possessing a truemucosal nevus.

• About 1% of newborns have a nevus.

• The number of individuals with nevi increases andthe number of nevi on each individual increases to apeak at puberty.

• Although nevi can occur on any skin surface, greater numbers appear on sun‐exposed surfaces.




MELANOCYTIC NEVI

• Melanocytic naevi constitute benign neoplasms of • cutaneous melanocytes, which frequently harbour oncogenic BRAF or, less commonly, NRAS or HRAS mutations .

• Probably, oncogenic mutations drive the initial

hyperproliferation that results in the formation of thenaevus, while a subsequent growth-arrest responsewith the features of oncogene-induced cellular senescence accounts for the cessation of further growth .

• Different from normal melanocytes which areregularly interspersed as single cells among basalkeratinocytes, forming the so-called “epidermal-melanin unit”, nevomelanocytes tend to cluster incompact so-called theques




TYPES OF NEVI

JUNCTIONAL COMPOUND DERMAL




JUNCTIONAL NEVUS

• Junctional nevi are flat or onlyslightly elevated.

• Nevus cells (nests) at the DEJ.

• Most are hairless and small,varying in size from 1 to 10 mm .

• They are only rarely seen as acongenital nevus.

• Most arise at about age 2 yearsand evolve into compound nevi inthe teen years.

• Junctional nevi on the palms,soles, and genital areas remain junctional and never seem toconvert to a compound nevus.

• Transformation into a melanoma

is very rare.




COMPOUND NEVUS

•Compound nevi tend to beelevated with a uniformlyround or oval shape.

• Many are natural skin color,others are somewhat darker.

•Light brown, dome-shapedpapule

• Nevus cells at the DEJ anddermis

• Hair is often present arising

around a compound nevus.• With increasing age, nevibecome more elevated andmay develop a wartyappearance.

• Melanoma transformation isalso rare.




DERMAL NEVUS

• Nests of nevus cells in the dermiswith no component at the DEJ.

• Dermal nevi may also be of naturalskin color or darker.

• All are elevated nodules and become

firm as fibrous tissue replacesdegenerated nevus cells.

• Most are described as domeshaped, but others may be warty.

• The warty surface is regular and

symmetric throughout the lesion.• Some dermal nevi will also develop a

stalk and produce a pedunculatedlesion resembling a skin tag,particularly in the groin, axilla, and

neck.




TREATMENT

• Any skin nevus with signs suggestive of a melanoma requires excision down toand including the subcutaneous level.

• All mucosal nevi require excision downto and including the submucosal level.

• Excision of such nevi eradicates thelesion and may lead to diagnosis of an

early melanoma.• Static nevi without features suggestive

of a melanoma do not require excision

and may be followed.




BLUE NEVUS

• The blue nevus, a blue dermal nevus, isusually small (less than 5 mm) and appearsas a regular, round elevated nodule. Itappears blue because the melanin pigment,which is naturally brown, is located deepwithin the dermis.

• The brown pigment and the thickness of

skin absorb the longer wavelengths of light(eg, reds, oranges, yellows) and reflect themore penetrating, shorter wavelengths, suchas blue (ie, the Tyndall effect).

• The blue nevus will appear in childhood onthe dorsum of hands, extremities, and scalp.

• It has a low potential for malignanttransformation.

• However, a larger, rare variant, called thecellular blue nevus, has a higher melanomatransformation rate. It is frequently larger than 1 cm and most often located on the

buttocks.




HALO NEVUS

• AKA Sutton‟s nevus, perinevoidvitilgo, & leukodermaacquisitum centrifugum

• A pigmented nevus withsurrounding depigmented zone

• Nevus is usually compound or

intradermal• May be single or multiple• Usually on the trunk• Mostly develop in teenagers

• The nevus architecture is

obscured by a denselymphocytic infiltrate

• Lymphocytes infiltrate amongthe dermal nevus cells, whicheventually degenerate and

disappear.




SPITZ NEVUS

•A variant of the compound nevus.

• A smooth-surfaced, raised, round,slightly scaly, firm papule withdistinctive pink, brownish red, or purplish red color.

• Typically, firm,rosy papule on the

face, especially on the cheek.• 3 – 10 mm in diameter.• Female predominance.• Epidermal irregular acanthosis,

pseudoepitheliomatous

hyperplasia, and thinning of theepidermis• Nevus cells are pleomorphic, but

mostly spindle-shaped (fusiform),or polygonal (epithelioid) cells




SPITZ NEVUS

• The Spitz nevus has clinical and histologicfeatures mimicking those of a melanoma.

• The nevi present as red or reddish‐brown,smooth‐surfaced nodules, usually between 0.5and 1.5 cm.

• Clinically, Spitz nevi may suggest a melanomabecause they emerge suddenly, unlike other nevi that develop slowly as macular lesionsand evolve into nodular dermal nevi.

• They may also be suggestive of a melanomabecause of their vascular nature, which maylead to bleeding following minor trauma.




TREATMENT

•Spitz nevi usually require excision to rule outmelanoma and other diseases on the differential list.

• Excision is accomplished with 1‐ to 2‐mm marginsand includes the entire subcutaneous level.

• If the pathologist identifies the lesion as a Spitz

nevus, no further excision or treatment is required.• The Spitz nevus does not recur, not even in thecase of incomplete excision.

• Therefore, in equivocal cases in which thehistopathologic distinction between melanoma and a

Spitz nevus is uncertain, follow‐up is recommended. Any evidence of clinical recurrence is interpreted as

evidence of melanoma.




NEVUS OF OTA

• The nevus of Ota is a unique nevus that

represents a melanocytic disorder following the distribution of one or moredivisions of the trigeminal nerve .

• About 48% are congenital or appear within a few weeks of birth, and 36% ariseat puberty, thereby creating a bimodal

incidence peak.• The nevus will appear as a diffuse

brownish discoloration or a cluster of small, blue‐black, well‐demarcated spots.

• The skin over the maxillary division of thetrigeminal nerve seems to be involved

more frequently than the other divisions,and corresponding nevi simultaneouslyappear on the oral mucosa, nasalmucosa, and sometimes on theconjunctiva of the ipsilateral eye.




NEVUS OF OTA

• Neither the cutaneous component nor theoral mucosa membrane component of thenevus of Ota is associated withmelanoma.

• The nevus of Ota is thought to representa developmental anomaly of excessmelanocytes residual from neural crestcells that migrated along a trigeminalnerve distribution.

• In those arising during puberty, it may bea hamartomatous proliferation of theseresidual cells stimulated by hormonalincreases.




TREATMENT

• The nevus of Ota is merely a matter of cosmetic concern; rarely does it undergotransformation to melanoma, nor does thenevus usually progress throughout life.

• However, patients with ocular involvement

have a high incidence of secondaryopen‐angle glaucoma due to melanocytescollecting at the angle, causing obstruction of drainage.

• They also have a higher incidence of retinal,iridic, and cerebral melanomas.

• Therefore, patients with cutaneous lesionssuggestive of nevus of Ota should undergo anophthalmologic evaluation.




NEVUS OF ITO

• The nevus of Ito is similar to the nevus of

Ota; however, it mostly occurs in thedeltoid region.

• It may be seen on the upper chest, back,or supraclavicular area as well.

• Like the nevus of Ota, this nevus formsalong peripheral nerve fibers.

• Clinically, it will present as a bluishhyperpigmentation, which on fine sensorytesting may be associated with a localparesthesia.

• On occasion, the nevus has beenassociated with reduced sweating

presumably because of its associationwith small sympathetic fibers, whichinnervate facial sweat glands.




DYSPLASTIC NEVUS

• The dysplastic nevus is a clinicallyand histologically atypical nevusrepresenting the single mostimportant precursor to a cutaneousmelanoma.

• More than the congenital nevus, itis the primary pigmented lesion thattransforms into a melanoma.

• Dysplastic nevi appear either

sporadically or in aautosomal‐dominant inheritedcondition called dysplastic nevussyndrome (DNS).




DYSPLASTIC NEVUS

• Clinically, the dysplastic nevus differs from theordinary nevus. It is usually larger, and manyare greater than 1 cm, whereas the commonnevus rarely exceeds 0.6 cm.

• Its borders are irregular, with the color fading

gradually into the surrounding skin, in contrastto the well‐demarcated and regular borders of the ordinary nevus .

• It is variegated in color, usually a mixture of

brown, black, and red, whereas common neviare uniform in color .

• Common nevi have a site preference for sun‐exposed areas, while dysplastic nevi tendto occur at unusual sites such as the scalp,

buttocks, and breast.




DYSPLASTIC NEVUS

• Dysplastic nevi associated with dysplasticnevus syndrome have an exceedingly highmelanoma potential.

• Dysplastic nevi are found concomitantly on theskin of 90% of melanoma patients who have a

family history of melanoma.• Dysplastic nevi of either the sporadic type or

the familial DNS are not congenital but appear in midchildhood as a common mole.

• They begin to take on the clinical features of dysplastic nevi in the early teens, and newnevi continue to appear even past the age of 40 years.




TREATMENT

• The general approach is to excise two to four of themost suspicious nevi to establish a histopathologicdiagnosis.

• The excision uses 2‐ to 5‐mm margins to andinclusive of the subcutaneous level.

• If the diagnosis confirms dysplastic nevi, thegeneral rule is to excise all new nevi that arisethereafter and all of those in the scalp because of the difficulty of monitoring scalp lesions.

• Prophylactic excision of all remaining nevi is neither

practical nor indicated if there are more than 10.• Such lesions should be followed with serialexaminations and compared to baselinephotographs.







MNTI

• Melanotic neuroectodermal tumor of infancy (MNTI) is arelatively uncommon osteolytic-pigmented neoplasm thatprimarily affects the jaws of newborn infants.

• The MNTI, which originates from neural crest cells,represents an overgrowth of these cells rather than their usual involution.

• Normally, neural crest cells originate from a mantlearound the developing spinal cord and project out to theperiphery along sympathetic nerves.

• In other parts of the body, they populate the primordia of sympathetic ganglia and the adrenal medulla to become

neurosecretory cells of these respective structures.• In the maxilla and most peripheral sympathetic neuralpathways, they involute.

• Those that develop into the MNTI are the rare failures of involution, which instead proliferate into a tumor.




MNTI

• Although melanotic neuroectodermal tumor

of infancy (MNTI) is classified as a benignlesion, it is often clinically worrisomebecause of its rapid onset and alarming localgrowth rate.

• Often, sucking and feeding are impairedsecondary to the swelling.

• The patient is usually asymptomatic.• The typical melanotic

neuroectodermal tumor of infancy(MNTI) begins as a nonulcerated,lightly pigmented, blue or black

lesion on the anterior aspect of themaxilla and rapidly expands to forma swelling or a tumescence that iscosmetically obvious to the parentsof the infant.




MNTI

• The intraoral lesion appears as a sessile,lobulated mass, often reaching 2-4 cm indiameter by the time of diagnosis.

• Bone destruction and displacement of teethoften occur because of the intraosseous

location in the maxilla.• No thrill or pulse can be elicited from the

MNTI.

• Although the lesion expands rapidly, the

overlying mucosa remains intact.• More than 90% of MNTI occur in the head and

neck region, with most on the anterior part of the maxillary ridge. Other common sitesinclude the skull, the mandible, the epididymis,and the brain.




DIAGNOSTIC WORK UP

• The most important diagnostic step is aconfirmatory incisional biopsy.

• However, an occlusal radiograph that showsthe central incisor displaced to the peripheryof a mass that itself shows destruction of the

anterior maxilla is pathognomonic.• About 10% to 15% of MNTI will elaborate

vanillylmandelic acid (VMA or 3‐methoxy‐4‐hydroxy mandelic acid), which is

a soluble metabolic breakdown product of norepinephrine.

• It is indicative of the neuroectodermal cellorigin of this tumor.




TREATMENT

• The MNTI should be treated by a peripheral

• excision with 2‐ to 5‐mm margins .

• Although the destructive nature of this tumor and itsgrowth rate are significant, total maxillectomies andmaxillary resections with margins greater than 5 mm

are unnecessary.• Early excision is of great value. Limiting thedestruction that the tumor causes in the anterior maxilla will lessen the deformity and preservedeveloping teeth.

• The excision should include the overlying mucosa.The resultant wound may be packed with a tie‐over pressure dressing for 5 to 7 days to reduce oozing.

• The wound itself heals rapidly by granulation tissueand secondary epithelialization.







MELANOMA

• Melanoma is a potentially deadlyand aggressive neoplasm resulting

from the malignant transformation of

melanocytes.• The incidence of melanoma is

increasing faster than any other

cancer.




• Treatment of melanoma of head and neck is a




Treatment of melanoma of head and neck is a

complex issue.

• The behaviour of this malignancy is aggressive, and it

has overall worst prognosis than that of other skinsites.

• Histological involvement ofregional lymph nodes by

metastases of malignant melanoma in the head and

neck region is very poor prognostic sign.

• Accurate localization of pathologically involved

cervical lymph nodes is crucial in the treatment of

these patients.

LYMPHATIC REGIONS OF




LYMPHATIC REGIONS OF

NECK

• Lymphatic tissue in the neck accounts for one-third of all nodal tissue in the entire body.

• Most cervical lymph nodes are located in the

anterior triangle traversing the carotid sheath

from the skull base to the thoracic inlet.

• Most head and neck surgeons, radiologists,

and oncologists refer to „„nodal levels‟‟ to

describe nodal groups involved by diseaseand encompassed by neck dissections.

• The six cervical lymph node levels are as

follows:




CLASSIFICATION OF NECK




CLASSIFICATION OF NECK

DISSECTIONS

MODIFICATIONS IN NEW




MODIFICATIONS IN NEW

CLASSIFICATION

•The three most significant changes in therevised classification were

• (i) the way in which various SNDs aredescribed,

• (ii) the use of radiologically depicted anatomic

structures to define boundaries betweenvarious neck levels and sublevels toaccurately designate imaged nodes, and

• (iii) the introduction of sublevels into the

classification system, since certain zoneshave been identified within the six levels thatmay have biologic significance independent of the large zone in which they lie.

• These three modifications comprise




These three modifications comprise

• sublevel IA (submental nodes) and IB(submandibular nodes),

• sublevel IIA and IIB (together comprisingthe upper jugular nodes), and

• sublevel VA (spinal accessory nervenodes) and VB (transverse cervical andsupraclavicular nodes).

• Each variant is depicted by SND and theuse of parentheses to denote the level or sublevel of nodes removed, e.g., SND (I –III).




RADICAL NECK DISSECTION

• consists of the removal of all fivelymph node levels of one side of the

neck (levels I –V) and removal of the

sternocleidomastoid muscle, theinternal jugular vein, and the spinal

accessory nerve.

MODIFIED RADICAL NECK




MODIFIED RADICAL NECK

DISSECTION

• Modified radical neck dissectioninvolves the excision of all lymphnodes routinely removed during

radical neck dissection but withpreservation of one or more of thenonlymphatic structures (e.g., spinalaccessory nerve, internal jugular

vein, sternocleidomastoid muscle)routinely removed during a radicalneck dissection.




SELECTIVE NECK DISSECTION

• SND is any type of cervical lymphadenectomyin which one or more of the lymph node

groups that are routinely removed in a radical

neck dissection are preserved.

• Determining which lymph node groups toremove is based on the pattern of metastases,

which is predictable relative to the location of

the primary site of the neoplasm.

• Each variant is depicted by „„SND‟‟ as well as

parentheses to denote the levels or sublevels

of removed nodes, e.g., SND (I –III), SND (II –

IV), or SND (VI).

EXTENDED RADICAL NECK




EXTENDED RADICAL NECK

DISSECTION

• Extended radical neck dissectionincludes either lymph node groups

or nonlymphatic structures that are

not routinely removed in standardradical neck dissection.







ELECTIVE NECK DISSECTION

•Tumor thickness is the most important factor in

determining whether or not to perform END.

• All patients with histologically confirmed melanoma

thicker than 0.7mm with Clark level of 4 are

candidates for END.

EXTENT OF PAROTID GLAND SURGERY

Patients with thick melanomas (>4mm) are likely to

undergo total parotidectomy.

ANATOMICAL SITES




ANATOMICAL SITES

•The skin of head and neck can

be divided into 6 anatomical

sites as management of

melanoma is site specific.

1. Forehead, Upper Face &

Lower Face

2. Coronal Preauricular Scalp

3. Posterior Scalp

4. Upper Neck5. Inferior Anterior Neck

6. Upper & Lower Posterior neck







SLNB has certain limitations in management of head & neck

melanomas:

Increased incidence of nodal recurrence in SLN negative

patients.

Possibility of false negative results.

Difficult identification of SLN if they are located close to the

primary site

SLN found in multiple node fields in contrast to melanomas

located on extremities which usually drain to only one field.

SLN in parotid region, which are often very small may be

difficult to find and their removal may put the facial nerve at

risk.





INTRODUCTION

Primary oral malignant melanoma (OMM)is a rare neoplasm, accounting for 0.5% ofall oral malignancies.

The most frequently affected oral sites arethe palate and the maxillary gingiva.

CLINICAL FEATURES




CLINICAL FEATURES

• According to Tanaka et al, oral melanomas could beclassified into five types, based on their clinicalappearance: pigmented nodular, nonpigmented nodular, pigmented macular, pigmented mixed and nonpigmented mixed

• The clinical coloration of oral melanomas has a widerange, which can appear as black, gray, purple, andeven reddish.

• While some lesions are uniform in color, others exhibitmarked variations.

• The tumors are asymmetric, irregular in outline, andoccasionally multiple.

• Their surface architecture ranges from macular toulcerated and nodular.

• Pain is present in advance cases.

HISTOLOGIC FEATURES




HISTOLOGIC FEATURES

• The 1995 WESTOP (Western Society of Teachers of Oral

Pathology) Banff Workshop on OMM drew attention to the

fact that most OMMs are discovered and biopsied in an

advanced stage, which probably contributes to the

heterogeneity of microscopic patterns.

• Like cutaneous melanoma, OMM probably has in manycases an initial phase characterized by radial growth

followed by a phase of invasion of the underlying tissues

(the so-called „vertical growth phase‟).

• OMMs can be histologically subclassified into:

(1) in situ melanoma

(2) melanomas with an invasive pattern.

(3) melanomas with a combined pattern of invasive melanoma

with in situ componen.t




• OMM does not fit well into any of the classicalcutaneous melanoma categories like

superficial spreading melanoma (SSM),

nodular melanoma (NM) and acral lentiginous

melanoma (ALM).• There is, however, often some similarity to

ALMand NM.

DIAGNOSIS




DIAGNOSIS

• The so called ABCDE checklist that is commonly used

in the identification process of cutaneous melanoma

could also be of some help in the diagnosis of oral

melanoma .

• When an oral pigmentation cannot be confidently

diagnosed as benign on clinical grounds, a biopsy ismandatory in order to exclude OMM.

• Sentinel-node biopsy or lymphoscintigraphy, which is

beneficial in staging of cutaneous melanoma, has less

value in staging or treating oral melanoma. Complexand ambiguous drainage patterns may result in the

bypass of some first-order nodes and in the

occurrence of metastasis in contralateral nodes.

STAGING SYSTEM




STAGING SYSTEM

• The histological microstaging system of Clark, used in

cutaneous melanoma, cannot be applied to oral

mucosa because of the lack of histologic landmarks

analogous to papillary and reticular dermis.




• The American Joint Committee onCancer (AJCC) does not have

published guidelines for the staging

of oral malignant melanomas.

MANAGEMENT




MANAGEMENT

• Ablative surgery with tumor -free margins remains the

treatment of choice. Early surgical intervention when

local recurrence is detected enhances survival,

because the dismal outcomes are associated with

distant metastasis.

• Prophylactic neck dissection (ie, elective neckdissection) is not advocated as a treatment for oral

melanoma.



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Melanotic Lesions of Head and Neck Region