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Melanoma. Almost 30% of all melanomas arise in the head and neckWidespread use of sunscreen has not lowered the incidence.Incidence is increasing almost 5% per yearApproximately 47,000 new cases in 2001. Predisposing Factors. Sun ExposureAge, frequency, severity of exposure may play a roleSunsc
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1. Melanoma Alan L. Cowan
Anna M. Pou
2. Melanoma Almost 30% of all melanomas arise in the head and neck
Widespread use of sunscreen has not lowered the incidence.
Incidence is increasing almost 5% per year
Approximately 47,000 new cases in 2001
3. Predisposing Factors Sun Exposure
Age, frequency, severity of exposure may play a role
Sunscreen use may not be protective
Familial Melanoma / DNS
Family members have almost 50% chance of developing melanoma
Lesions may be multiple and in sun shielded areas
Xeroderma Pigmentosa
Predisposes to several types of skin cancer
Skin malignancies often appear by age 10
4. Sunlight UVB (280-320nm)
Causes direct DNA damage
Originally thought to be primary factor
Blocked by current sunscreens
UVA (320-400nm)
Causes indirect DNA damage via free radicals
Some now consider as more important than UVB
Sunscreen has little UVA protection
5. Types of Melanoma Superficial Spreading
Most common
Cells atypical but uniform in appearance
Nodular
Early invasion due to vertical growth
Acral Lentiginous
Appears on palms and soles
Histology shows heavily pigmented dendritic processes in the basal layer
6. Types of Melanoma Desmoplastic
May lack pigment
Peri-neural invasion is classic
Histologic exam may show “school of fish” appearance
Lentigo Maligna Melanoma
May remain in-situ for decades
Can spread along hair follicles
Mucosal
Often lack melanin
Conventional staging system does not apply
Site of lesion corresponds to prognosis
Nasal cavity best prognosis, 31% at 5-yrs
Paranasal sinuses worst prognosis, 0% at 5-yrs
7. Diagnosis History
Family History
Sun exposure
Bleeding, pain
Physical
ABCD
Histology
H&E
S-100, HMB-45
8. Biopsy Excisional
Recommended for small lesions
Margins of 2mm
Incisional
For larger lesions
Does not alter draining lymphatics
Punch
Same as incisional
Shave
Contraindicated
Needle
Contraindicated
9. Clark staging Based upon histologic level of invasion
Level I – Epidermis only (in situ)
Level II – Invades the papillary dermis, but not to the papillary-reticular interface
Level III – Invades to the papillary-reticular interface, but not into the reticular dermis
Level IV – Into the reticular dermis
Level V – Into subcutaneous tissue
10. Breslow staging Based upon absolute depth of invasion
Stage I – < 0.75 mm
Stage II – 0.76 – 1.5 mm
Stage III – 1.51 – 4.0 mm
Stage IV - > 4.0 mm
11. AJCC staging
12. AJCC staging
13. AJCC staging
14. Prognosis by AJCC stage Stage I
< 0.75 – 96 %
0.75 – 1.5 – 87 %
Stage II
1.5 – 2.49 – 75 %
2.5 – 3.99 – 66 %
> 4.0 – 47 %
Stage III
One node 45 %
Two nodes < 20 %
Stage IV
8 – 10 %
Percentages are five year survival except stage IV lesions which represent one year survival