Melanomas are malignant tumors derived from melanocytes. The most common site of involvement is the skin, although occasionally primary melanoma develops in other organs (eye, oral and nasal mucosa, vulval and anorectal mucosa, other gastrointestinal mucosa and the central nervous system (CNS)). Melanomas are a major cause of premature death from cancer. Recognized risk factors include personal or family history of melanoma, large numbers of naevi and/or dysplastic naevi, giant congenital melanocytic naevi, fair complexion, a tendency to sunburn, solar-damaged skin, a history of non-melanoma skin cancer, and immunodeficiency. The most common sites for melanoma are the legs of women and the backs of men, despite these not being the sites of greatest sun exposure. Early detection is associated with improved survival Any malignancy will grow, grow irregularly, and function abnormally. Melanomas produce pigment in varying amounts and may elicit an immune response that will be reflected in the clinical appearance. Some melanomas may lack pigment. A small but significant number of melanomas are undiagnosable clinically.

1. M A L I G N A N T M E L A N O M A
O R A L PAT H O LO G Y S E M I N A R
BY A K S H D E E P S I N G H
S D C B D S 3 R D Y E A R

2. I N T R O D U C T I O N
• Malignant melanoma is a neoplasm of epidermal
melanocytes.
• It is one of the more biologically unpredictable
and deadly of all human neoplasms.
• It is third most common cancer of skin.

3. E T I O L O G Y
• ENVIRONMENTAL FACTORS
1 . S U N E X P O S U R E
2 . A R T I F I C I A L U V S O U R C E S
3 . S O C I O E C O N O M I C S TAT U S
4 . FA I R S K I N , F R E C K L E S , R E D H A I R
5 . N U M B E R O F M E L A N O C Y T I C N E V I
• GENETIC FACTORS
1 . FA M I L I A L M E L A N O M A
2 . X E R O D E R M A P I G M E N TO S A

4. PAT H O G E N E S I S
• R A D I A L G R O W T H P H A S E
• V E R T I C A L G R O W T H P H A S E

5. C L A S S I F I C AT I O N
 CL ARK SYSTEM
• L E V E L I - T U M O U R I N S I T U
• L E V E L I I
• L E V E L I I I
• L E V E L I V
• L E V E L V

7. C L I N I C A L F E AT U R E S
• S U P E R F I C I A L S P R E A D I N G M E L A N O M A
• M o s t c o m m o n c u t a n e o u s m e l a n o m a
• E x i s t s i n r a d i a l g r o w t h p h a s e a l s o k n o w n a s p a g e t o i d m e l a n o m a i n
s i t u .
• P r e s e n t s a s t a n , b r o w n , b l a c k , o r a d m i x e d l e s i o n s p e c i a l l y o n b a c k .
• A l s o o c c u r s o n s k i n o f h e a d , n e c k , c h e s t a n d a b d o m e n a n d
e x t r e m i t i e s .
• Ve r t i c a l g r o w t h p h a s e i s c h a r a c t e r i s e d b y i n c r e a s e i n s i z e , c h a n g e
i n c o l o u r, n o d u l a r i t y a n d u l c e r a t i o n .

8. N O D U L A R M E L A N O M A
• A c c o u n t s f o r 1 3 % c a s e s .
• N o r a d i a l g r o w t h p h a s e , o n l y v e r t i c a l g r o w t h p h a s e .
• P r e s e n t s a s s h a r p n o d u l e w i t h v a r y i n g d e g r e e o f p i g m e n t a t i o n .
• T h e y m a y b e p i n k ( A m e l a n o c y t i c ) o r b l a c k .
• O c c u r s o n s k i n o f b a c k , h e a d , n e c k a n d i s r e p o r t e d m o r e i n m e n .

9. L E N T I G O M A L I G N A
• A k a m e l a n o t i c f r e c k l e o f H u t c h i n s o n .
• A c c o u n t s f o r 1 0 % o f c a s e s .
• S h o w s f e m a l e g e n d e r p r e d i l e c t i o n .
• M a c u l a r l e s i o n s o n s k i n o f m i d d l e a g e d a n d e l d e r l y w h i c h a l s o
c a n o c c u r i n e y e a n d m u c o u s m e m b r a n e .
• I t h a s a l s o b e e n r e p o r t e d a s p r i m a r y l e s i o n i n p a r o t i d g l a n d .

10. A C R A L L E N T I G I N O U S M E L A N O M A
• O c c u r s o n p a l m s a n d s o l e s a s w e l l a s t o e s a n d f i n g e r s .
• M e c h a n i c a l s t r e s s l e a d t o e r o s i o n a n d u l c e r a t i o n .
• S u b u n g a l m e l a n o m a i s p r e s e n t a s p i g m e n t a t i o n o f n a i l b e d a n d
a r e m i s t a k e n f o r h e m a n g i o m a s .
• E x t r e m e l y p r o g r e s s i v e .

11. M U C O S A L L E N T I G I N O U S
• D e v. F r o m m u c o s a l e p i t h e l i u m t h a t l i n e s r e s p i r a t o r y , G I a n d G U
s y s t e m s .
• A c c o u n t s f o r 3 % c a s e s .
• S i t e s – m u c o s a l s u r f a c e s i n c l u d i n g c o n j u n c t i v a , o r a l c a v i t y,
o e s o p h a g u s , v a g i n a , u r e t h r a , p e n i s a n d a n u s .

12. A M E L A N O T I C
• E r y t h e m a t o u s / p i n k , s o m e t i m e s e r o d e d n o d u l e s .
• O f t e n c o n f u s e d w i t h o t h e r t u m o u r s .
• O n l y h i s t o p a t h o l o g i c a l e x a m i n a t i o n p r o v i d e s r i g h t d i a g n o s i s .

13. C R I T E R I A F O R C L I N I C A L
D I A G N O S I S O F M E L A N O M A
ABCDE RULE
• A s y m m e t r y
• B o r d e r i r r e g u l a r i t y
• C o l o u r i r r e g u l a r
• D i a m e t e r
• E l e v a t i o n

14. O R A L M A N I F E S TAT I O N S
• P r i m a r y o r a l m e l a n o m a s a r e t w i c e a s c o m m o n i n m e n t h a n
w o m e n .
• Pa l a t e , m a x i l l a r y a n d m a n d i b u l a r g i n g i v a , b u c c a l m u c o s a ,
t o n g u e , l i p s , a n d f l o o r o f m o u t h .
• A p p e a r s a s d e e p l y p i g m e n t e d a r e a a t t i m e s u l c e r a t e d a n d
h a e m o r r h a g i c .
• A m e l a n o t i c m e l a n o m a a c c o u n t s f o r 5 - 3 5 % o f a l l o r a l m e l a n o m a s
w h i c h a p p e a r a s w h i t e m u c o s a c o l o u r e d o r r e d m a s s .

15. H I S T O PAT H O L O G Y
• M a l i g n a n t c e l l n e s t s o r c l u s t e r s i n o r g a n o i d f a s h i o n m e l a n o m a
h a s l a r g e n u c l e o l i w i t h p r o m i n e n t n u c l e o l i .
• C Y TO P L A S M i s e o s i n o p h i l i c .
• C e l l s w h e n b e c o m e s p i n d l e i s i n t e r p r e t e d a s a g g r e s s i v e f i n d i n g .
• I n t r a - e p i . C o m p o n e n t i s c h a r a c t e r i s e d b y l a r g e , e p i t h e l i a l
m e l a n o c y t e s d i s t r i b u t e d i n s o c a l l e d p a g e t o i d m a n n e r w h i c h
s p r e a d s w i t h i n e p i d e r m i s i s k n o w n a s B U C K S H OT S C AT T E R .
• M a c r o p h a g e s a n d m e l a n o p h a g e s a r e s o m e t i m e s p r e s e n t .
• M e l a n i n p i g m e n t i s u s u a l l y s c a n t y.

16. • N o d u l a r m e l a n o m a s h o w l a r g e e p i . m e l a n o c y t e s w i t h i n C T.
• S m a l l o v o i d s p i n d l e s h a p e d c e l l m a y b e p r e s e n t .
 L E N T I G O M A L I G N A A K A F R E C K E L S O F H U TC H I N S O N
• A t y p i c a l m e l a n o c y t e s w i t h i n b a s a l l a y e r .
• E p i . i s g e n e r a l l y a t r o p h i c .
• I n v a s i o n o f s p i n d l e s h a p e d c e l l s i n t o d e r m i s .
• I n f i l t r a t i o n o f l y m p h o c y t e s a n d h i s t i o c y t e s i s e v i d e n t .