Oral Mucosa: Pigmented Lesion

Question 1

What can cause a “furry” appearance on the tongue?

Answer 1

Overgrowth of filiform papillae on tongue = dark furry appearance

Question 2

Sources of pigment in the mucosa?

Answer 2

Melanin (majority)
Haemosiderin = breakdown product of RBCs
Amalgam or heavy metals
Chromogenic bacteria

Question 3

What is haemosiderin? Features?

Answer 3

Breakdown product of RBCs
Iron stored
Brown pigment

Question 4

What is melanin?

Features?

Answer 4

Produces by melanocytes (or nevus cells)
Useful at absorbing UV light
Found in basal 3rd of epithelium
Black/brown

Melanin is transferred to adjacent keratinocytes via membrane bound organelles called melanosomes
Orangey brown pigment on histology
Increased melanin production without increased number of melanocytes (if increase in melanocytes - sign of abnormality)

Question 5

Examples of heavy metals?

What can heavy metals lead to?

Answer 5

Lead, bismuth, mercury, silver, arsenic and gold
May leach into mucosa from restorations and crowns
Deposited due to drugs containing heavy metals e.g. peto-bismal (med for stomach ache, diarrhoea) combines with sulphur in saliva bismuth sulphide (insoluble)

Question 6

How are people exposed to heavy metals?

Answer 6

Manufacture of ammunition, dental x-ray films, plumbing, ceramic glazing
Jobs: Lead miners, plumbers, mechanics, glass manufacturers, construction workers, welders, making paints and pigments

Question 7

What is argyria?

Answer 7

When someone has had too much silver = accumulates in skin

Question 8

Chromogenic bacteria features?

Answer 8

Bacteria that produce pigment
Aspergillus and actinomyces
Often seen in hairy tongue
Bacterial enzymes act on iron in saliva = tissues go brown or black

Question 9

Oral pigmented lesions classification - exogenous?

Answer 9

Amalgam tattoo
Foreign body tattoo
Heavy metal (occupation or drugs)
Black hairy tongue (bacteria)

Question 10

Oral pigmented lesions classification - endogenous?

Answer 10

Developmental:
Physiological (melanin)
Peutz jehger's syndrome (melanin)
Haemachromatosis (haemosiderin)
Pigmented naevus (melanin)

Acquired:
Addison's disease (melanin)
Drug induced (melanin)
Post inflammatory (melanin)
Smoker's melanosis (melanin)
Melanotic macule (melanin)

Neoplastic
Melanoma (melanin) - rare

Question 11

How to form a diagnosis for pigmented lesions?

Answer 11

HISTORY:
Name, age, occupation
History of lesion - how long, one area or several, symptoms, size, does it go away
MH
Drug history
DH
SH
Extra oral and intraoral examination

Question 12

Amalgam tattoo - how can they occur?

Answer 12

Amalgam gets into tissues by leaching out of restoration
If tooth extracted with amalgam restoration and restoration crumbled = amalgam in socket if not irrigated
Deep class II - amalgam pushed down into the gingival crevice

Question 13

How to manage amalgam tattoo?

Answer 13

Reassure pt no complications
Refer for biopsy if irregular borders
Can do periapical radiograph and see if radiopaque material in tissues = amalgam

Question 14

What else can cause foreign body tattoos?

Answer 14

Pencil lead - do not chew

Lead toxicity - blue/black line around gingival margin - looks similar to amalgam tattoo on histology

Question 15

Black hairy tongue features?

Answer 15

Affects posterior dorsal tongue
Decrease in normal desquamation process - associated with soft diet, smoking, antibiotic use
Elongated filiform papillae - can be black, brown, white
Discolouration caused by chromogenic bacteria, chlorhexidine, foods, smoking

Question 16

How to manage black hairy tongue?

Answer 16

Difficult to treat - recommend tongue scraper
Avoid smoking, chlorhexidine
May resolve after finishing broad spec antibiotics
NO BIOPSY NEEDED

Question 17

Peutz-Jegher syndrome features?

Answer 17

Genetic disorder - autosomal dominant
Pigmented mucocutaneous macules/freckles, GI polyps, usually small intestine with normal increased risk of malignant change associated with polyps
Freckles around mouth but mostly limited to lips, present in childhood = dentist should refer
Melanotic spots characteristically mall and multiple
V obvious around lips
Syndrome has higher risk of developing cancer

Question 18

Peutz-jegher syndrome freackles histology?

Answer 18

Increased melanin

Question 19

Haemochromatosis?

Answer 19

Genetic disorder - autosomal recessive
Accelerated rate of intestinal iron absorption
Raised serum ferritin and transferrin saturation
Accumulation of iron
Leads to bronze skin pigmentation, liver cirrhosis, diabetes
mellitus
Bronze skin due to build up of haemosiderin
Treated with regular venesection = blood removal

Question 20

Melanocytic nevus?

Answer 20

= Mole in mouth
Well defined, black/brown
Usually on palate

If raised/poorly defined = could be melanoma = biopsy

Question 21

In nevus, what also produces melanin? What does this mean?

Answer 21

In nevus melanin is also synthesised by nevus cells which are derived from the neural crest
Found in skin and mucosa
Can produce different histological types of naevus:
- Junctional (epithelium)
- Intradermal/mucosal (CT)
- Compound (both)

All are benign, excise if rase concern

Question 22

Addison’s disease - what is it? What can it cause?

Answer 22

Destruction of adrenal cortex = produces cortisol
Most are autoimmune disease
Lack of adrenocortical hormone:
- Increased production of adrenocorticotropic hormone (ACTH) by anterior pituitary gland
- This induces melanocyte stimulating hormone = increase pigmentation of skin and oral mucosa

Question 23

Addison’s disease - dental relevance?

Answer 23

Diffuse brown patches on buccal mucosa, palate and tongue and gingivae
Extraoral sites - palmar creases, new scars

Pt will need steroid cover
Risk of adrenal crisis = BG drops, BP drops, can faint and go unconscious

Pigmentation around mouth and inside mouth

Question 24

Melanotic macule (freckle)?

Answer 24

Brown/black macules in oral cavity
Lighter brown than nevi and different histology
Pt reassurance

Question 25

Drug induced pigmented lesions - what medications can cause discolouration?

Answer 25

Minocycline = antibiotic for acne = stains bone (blue/grey) - sometimes does not go once stop medication

Antimalarials: quinacrine, chloroquine
Tetracycline
Oral contraceptives
Clofazimine
Bleomycin
Cyclophosphamide 
Chemotherapy drugs

Question 26

How to manage drug induced pigmentation?

How is it causes?

Answer 26

Talk with GP

Increased production of melanin
Deposition of heavy metal in tissues (exogenous pigment)
Deposition of iron atfer damage to mucosal vessels

Question 27

Post inflammatory pigmented lesions - how does this occur?

Answer 27

Melanin can drop into the lamina propria
Basal cell loss

= Brown patch e.g. within lichen planus

Question 28

What percentage of smokers will have smokers melanosis?

Answer 28

20% of smokers

Question 29

Malignant melanoma features?

Answer 29

<1% of all oral malignancies
Proliferation of malignant melanocytes along the junction between the epithelial and CT, as well as within the CT
Anterior palate and anterior gingvae common sites
Starts at T3 = aggressive
4th-7th decade
Men>women
Asymp, slow growing brown or black patch with asymmetric and irregular borders VS rapidly enlarging mass associated with ulceration, bleeding, pain, bone destruction
Some are non-pigmented (amelanotic)
Aggressive and often fatal disease (worse prognosis than skin lesions)

Question 30

5yr survival rate of malignant melanoma?

Answer 30

15%

Question 31

Kaposi sarcoma features?

Answer 31

Malignant tumour
Associated with immunosuppression 
Hallmark of AIDS
Caused by HHV8
Black/purple lesions orally, gingivae most commonly
Forms vascular spaces filled with blood

Question 32

Kaposi’s sarcoma tx?

Answer 32

Excision +/- chemotherapy/radiotherapy

Question 33

Other oral manifestations of AIDS?

Answer 33

Acute pseudomembranous candidiasis
Oral hairy leukoplakia
ANUG