Class: Exam 2 Pigmented Lesions Flashcards
Describe Nevi
Nevus cells migrate from neural crest to skin and occasionally mucous membranes
Are Nevi acquired or found at birth?
Both
Congenital –> Present at birth, about 1% of newborns, larger (“garmet nevus”)
Acquired –> genetic influence and the average person has about 15
name the 4 different acquired Nevi
- Junctional nevus
- Intradermal nevus
- Compound nevus
- Blue nevus
Describe junctional nevus
flat macule
nevus cell in basal epithelium at “junction” of epithelium and connective tissue
Describe intradermal nevus
(intramucosal nevus)
nodule +- hair
Nevus cells in dermis or lamina propria
Describe compound nevus
nodule
combination of junctional and intradermal
Describe blue nevus
dendritic nevus cells deep within connective tissue
Define Melanocanthoma
Reactive proliferation of intraepithelial dendritic melanocytes
Reactive! Not neoplastic
Where and within what population is Melanocanthoma most likely?
Blacks
Cheek
Treatment of Melanoacanthoma
resolves when irritant is removed
Define Ephelis
Freckle
Localized overproduction of melanin
**Not an increase in number of cells
Where is Ephelis most common?
H&N skin
Is very common
Describe clinical features of Ephelis
Very common Flat Tan macules Multiple Sun activated
Define Actinic or senile lentigo
“age spots”
“Liver spots”
From chronic UV damage - Not seen intraorally
Where and within what population is Actinic or senile lentigo most common?
after 40 yrs
90% of elderly
Increasinly found in face, hands and arms
Clinical features of Actinic or senile lentigo
flat evenly discolored macules
Multiple
Define or describe Melanotic macule
tan to brown flat macule
Like a big freckle but NOT SUN RELATED
15% multiple
Average size 6.8 mm
Where and within what population is Melanotic macule most commonly found?
Female 2:1
Average age 43 (1-80)
Lower lip (33%)
Palate and Gingiva
What is the 3rd most common skin cancer?
Malignant melanoma (» basal cell carcinoma, > squamous cell carcinoma)
Define Malignant melanoma
Malignancy of melanin-producing cells
What is the likelihood of a caucasian today developing melanoma during their lifetime?
less than 1 in 100
Sites where malignant melanoma is found?
25% H&N
40% extremities
What are the 5 etiological factors of malignant melanoma
- Risk factors = UV radiation damage from sun
- Acute sun damage (burns, blistering) probably more important than chronic exposure
- Fair complexion, blond hair, blue eyes
- Multiple moles, freckling, dysplastic nevi
- Family history
Clinical features of malignant melanoma
The ABCD
- Asymmetry - lesion asymmetric as well as surface with elevated, nodular areas
- Borders - irregular and often notched
- Color - > variation, red, tan, brown, black
- Diameter - history of growth or change or >6 mm
Biologic growth phases (the two directional patterns of growth displayed by melanomas)
Radial
Vertical
Explain the radial growth phase
Malignant cells spread laterally through the epithelium, lesion remains flat but size increase
- can remain for years
- 75-85% of malnomas have radial growth phase
Explain the vertical growth phase
Malignant cell grow down and invade producing a mass or tumor
List the 5 distinct clinicopathologic types of melanomas
- Superficial spreading melanoma
- Nodular melanoma
- Lentigo maligna melanoma
- Acral lentiginous melanoma
- Oral
What is the most common form of melanoma
Superficial spreading melanoma
70% of cutaneous melanomas
Where are superficial spreading melanomas commonly found and what growth phase do they exhibit
Increased in trunk, 28% H&N
- Short radial growth phase, develop nodule/vertical growth
What percentage of cutaneous melanomas do nodular melanomas make up
about 15%
Where are nodular melanomas found commonly?
30% in H&N
Clinical features of nodular melanomas
Produce exophytic, pigmented nodules but rarely no pigment (amelanotic)
- Very short or non-existent radial growth
What percentage of cutaneous melanomas do lentigo maligna melanomas make up?
5-10%
Where and within what population are Lentigo maligna melanomas commonly found?
Increase in age
Sun exposed areas of face
Clinical features and growth phase of Lentigo maligna melanomas
Extremely long radial growth phase which may last 15-20 years
(lentigo maligna/hutchinson’s freckle)
- Ultimately develops nodules/vertical growth
Describe acral lentiginous melanoma
small subset affecting palms, soles, subungual and mucous membranes
Oral melanomas have what growth phase?
Most have radial growth (>50%) and many similar to acral lentiginous melanoma
where are oral melanomas found commonly?
Palate
Maxillary gingiva
Treatment of Melanomas
Excision (resection) with minimum of 1cm margin
+- lymph node dissection
+- adjunctive chemotherapy, radiation and immunotherapy
Prognosis of Melanomas
- Depth of invasion is probably most important factor influencing survival
- Metastasis decreases survival, many patients have a sentinel lymph node biopsied as a staging procedure
- Prognosis also affected by site affected and type of melanoma
What is the overall survival for melanoma
79% for 10 years
What is the survival percentage for oral melanomas
Much worse…
Multifocal pigmentation
- Physiologic
- Drugs
- Addison’s Disease
- Peutz-Jeghers Syndrome
Any condition characterized by cafe au lait spots - Smoker’s melanosis
- Melanoma
- Kaposi’s sarcoma
- Petechiae, ecchymosis, purpura
What drugs are involved in multifocal pigmentation
Antimalarials
antiarrythmics (quinidine)
tranquilizers (thorazine)
cis-platinum
Describe Addison’s disease and it’s relation to Multifocal pigmentation
Adrenocortical insufficiency triggers hypothalamus to stimulate anterior pituitary to produce ACTH (and MSH- melanin stimulating hormone)
Describe Peutz-Jeghers Syndrome
Autosomal dominant
- Skin and mucosal freckles, intestinal polyps (small bowel)(very low rate of malignant degeneration but will produce symptoms of obstruction)
- oral and perioral freckles, > lips and cheeks
What conditions are characterized by cafe au lait spots
Neurofibromatosis
McCune Albright Syndrome (polyostotic fibrous dysplasia)
Where is Smoker’s melanosis found commonly
Palate, gingiva
