Melanocytic Lesions Flashcards
dermatologic term for freckles
ephelis
*gives a hint that this person is more suceptible to UV damage
How do ephilies come about ?
harmless lesions that appear upon exposure to sunlight
common harmless melanocytic lesions that appear on sun-exposed skin, usually on the face and dorsum of the hands
actinic lentigines
*also called age spots or liver spots
completely macular and often multiple and unlike freckles, these dont wax and wane with sun exposure
actinic lentigines
common, harmless lesion taht may be seen either on the LIP or INTRAORALLY.
-tan to dark brown , uniformly pigmented, demarcated margins
melonotic macule
is there a change with sun exposure with melanotic macule?
no
what could the presence of a melanotic macule represent?
post-traumatic melanosis
what is the histo of maleanotic macules?
- no evidence of nevus cells or clustering of melanocytes
- inc amount of melanin pigment in the basal layer or within melanophages in the superficial connective tissue
what is the tx for melanotic macules on the vermillion zone?
excised for cosmetic purposes and tissue submitteed for microscopic purposes
what is the tx for melanic macules on intraoral sites
excised to rule out early melanoma
path term for a mole
acquired melanocytic nevus
probably the most common of all human “tumors”
acquired melanocytic nevus
how many acquired melanocytic nevi does an average caucasians have?
20
when do acquired melanocytic nevi develop?
first year of life through the forth decade
where do acquired melanocytic nevi develop?
head and neck region and often involute (regress) with aging
what type of acquired melanocytic nevi are the first stage?
junctional (appear flat and usually are dark in color)
the other stages are compound and intradermal
where does a compound (stage 2) nevus come from?
evolves from a junctional nevus as the patient grows older
- proliferation of nevus occurs with some of the nevus cells “dropping off” into the superficial connective tissue
- may see elevation and hair
where do intradermal nevi (stage 3) come from?
proliferate to the extent that they are completely contained within the dermal connective tissue
-elevated with a variable degree of pigmentation (many are normal skin colored)
-migrate deeper into the skin
actinic nevi larger than _____ are reason for concern
6mm
actinic melanocytic nevus are ususally where in the oral cavity
- infrequently in oral cavity
- located on hard palate or attached gingiva but any site can be affected
what is the tx for acquired melanocytic nevi?
- no tx indicated unless chronically irritated, an esthetic concern or changes in size or color
- risk of transformation to malignancy is very low (1 in 3,000)
type of melanocytic nevus is present at birth in 1% of newborns
congenital melanocytic nevi
what are the size categories for congenital melanocytic nevi?
small is less than 15 mm
large is greater than 15 mm
do congential melanocytic nevi have hair?
yes
what is a large congenital nevus also called?
garment nevus or bathing trunk nevus
-due to the extensive involvement of the patients skin
what is the risk of malignant transformation for congenital melanocytic nevi?
low (1%) for small nevi
2-3% for large nevi
what is the tx for congential melanocytic nevus?
- close clinical follow up
- staged excision for large
- excision for small
type of nevus that may affect an cutaneous or mucosal site, inclue oral or conjunctival mucosa
-appear bluish or blue-grey due to the depth of the melanin pigment
blue nevus
why do blue nevi appear blue?
tyndall effect (depth of the melanin pigment)
when do blue nevi usually appear?
forth decade of life
how big are blue nevi?
less than 1 cm
what is the histology of a blue nevus?
- collection of dendritic melanocytes within the sonnective tissue
- typically the liesional cells contain abundant melanin pigment
- no melanic atypia should be seen
what is the tx of blue nevus?
- simple excision
- excellent px
- recurrence is rare
- malignant ransformation is rare
malignancy of melanocytic differentiation
melanoma
how common is melanoma
3rd most common skin cancer
melanoma is what percent of skin cancers?
5%
BUT
it is 75% of deaths due to skin cancer (very deadly)
are males or females more likely to get melanomas?
females under age 40
males over age 40
overall, slight male predominance
what re the risk factors of melanoma?
- fair skinned pt, 40-70 years of age
- history of blistering sun burn early in life
- indoor occupation, outdoor recreation
- family history of melanoma
- personal history of melanoma
- high risk locations (BANS) [back, arms, neck, scalp]
what are the melanoma ABCDE’s?
asymmetry border irregularity color variegation diatmeter greater than 6mm (size of pencil eraser) evolving - enlarging or changing color
what are the growth phases of melanoma?
radial - spreads laterally
vertical - extends deeper into the connective tissue
what is the precursor of melanoma?
lentigo maligna (hutchinson’s freckel)
what are the 4 types of melanomas?
- lentigo maligna melanoma
- superficial spreading melanoma
- nodular melanoma
- acral lentiginous melanoma
essentially melanoma in a purely radial growth phase “melanoma insitu”
-affects older ppl with fair complexion
lentigo maligna
where does lentigo maligna usually occur?
facial skin
-large macular lesion with irregular borders and uneven pigmentation
what % of melanomas are lentigo melanomas?
5%
when do lentigo melanomas occur?
15 years before the vertical growth phase
-nodularity in previously flat lentigo maligna signals vertical growth phase
most common (70%) melanoma that occurs in the interscapular area in men and back of the legs in women (15-20% in head and neck region)
superficial spreading melanoma
what do superficial spreading melanomas begin as?
macule or plaque
type of melanoma that appears as rapidly growing nodule that almost immediately in the vertical growth phase
- little if any radial growth phase
- usually deeply pigmented (may be amelanotic and therefore resembles pyogenic granuloma)
nodular melanoma
what % of melanomas are nodular melanomas?
15%
type of melanoma that affects palms, soles, and oral mucosa.
-most common clinicopathologic type of melanoma in persons of color
acral lentiginous melanoma
what % of melanomas are acral lentiginous melanomas
8%
what does acral lentiginous melanomas begin as?
darkly pigmented macule with irregular borders
-mucosal melanoma is more aggressive than cutaneous melanoma
what is ORAL acral lentiginous melanoma?
- male predilection
- 5th - 7th decade
- 70-80% are found on the hard palate or max alveolar mucosa
- pain is uncommon unless it is ulcerated
what is the tx of melanoma?
- surgical excision
- chemo, radiation, immunotherapy have little impact on the disease
- developments in genotype-directed and immunotherapy have led to prolonged survival
-MOST OF TX IS BASED ON SIZE (remove what you can see plus a border beyond that) (1cm margins)
what does the px of melanomas depend on?
DEPTH OF INVASION!
- .75mm - 96% 10ys
- .76 - 1.69mm - 89% 10ys
- 1.7 - 3.59mm - 67% 10ys
- over 3.6mm - 26% 10ys
what is the px for ORAL melanoma?
POOR
-10-25% 5ys
may be due to difficulty in achieving wide surgical margins and early metastisis
