melanocytic lesions Flashcards
what is the dermatologic term for “freckles”?
Ephelis (ephelides)
what is a Actinic Lentigo?
Common, harmless melanocytic lesions that appear on sun-exposed skin, usually the face and dorsum of the hands
Actinic Lentigines are also called what?
“Age spots” or “liver spots”
clinical characteristics of Actinic Lentigines:
Completely macular, often multiple
Unlike freckles, lentigines don’t wax and wane with sun exposure
_________ are common, harmless lesion that may be seen either on the lip or intraorally
Melanotic Macule
characteristics of Melanotic macules:
A) Tan to dark brown, uniformly pigmented, demarcated margins
B) No change with sun exposure
C) Could represent post-traumatic melanosis
Microscopically, Melanotic macules shows no evidence of ______ cells or an increased numbers of ___________
no evidence of nevus cells or increased numbers of basilar melanocytes
in Melanotic Macules, which areas of the skin are melanin deposits elevated?
in the basal layer or within melanophages in the superficial connective tissue
what is the treatment for Melanotic Macules? Why should these lesions be microscopically examined?
Lesions on vermilion zone of lip are often excised for cosmetic purposes
Tissue should be submitted for microscopic examination
Intraoral lesions may need to be excised to rule out early melanoma
T/F: Acquired Melanocytic Nevi are extremely common lesions
true
what are Acquired Melanocytic Nevi also called?
moles
how prevalent are Acquired Melanocytic Nevi? At what ages do they appear?
Average of 20/person in caucasians
May develop from the first year of life through the fourth decade
Often involute with aging
How are Acquired Melanocytic Nevi designated?
Designated as junctional, compound and intradermal, depending on where the collection of nevus cells is located microscopically
clinical characteristics of Junctional Nevi
the first stage
appear flat and usually are dark in color
A __________ nevus may evolve from a junctional nevus as the patient grows older
compound
clinical characteristics of a Compound nevus:
Proliferation of nevus occurs, with some of the nevus cells “dropping off” into the superficial connective tissue
May begin to show elevation clinically
With time, nevus cells may proliferate to the extent that they are completely contained within the dermal connective tissue, thus the term “________ nevus”
intradermal
T/F: A intradermal nevus is elevated, with a dark pigmentation
FALSE
they are elevated, but many are normal skin color
how can a nevus be differentiated from carcinomas?
A nevus will have adnexal elements- they have hairs
carcinomas lack hair
where can melanocytic nevi be found in the oral cavity?
Usually located on the hard palate or attached gingiva, but potentially any site can be affected
Treatments for melanocytic nevi:
No treatment is absolutely necessary
Risk of malignant transformation to melanoma for an individual nevus is about 1 in one million
what clinical changes would signal the need for an excision biopsy of a Nevus?
Changes in a nevus or chronic irritation of a nevus would be reasons for excisional biopsy
how is a Congenital Melanocytic Nevus different from an Acquired one?
Congenital nevi are present at birth
how are congenital melanocytic nevi classified?
Designated as “large” and “small”
what is the risk for malignancy in CONGENITAL melanocytic nevi?
1% for small congenital nevi
15% for large
___________ Appear bluish or blue-gray due to the depth of the melanin pigment (Tyndall effect)
Blue Nevi
what areas do Blue Nevi effect? at what age do they usually appear?
- May affect any cutaneous or mucosal site
- Usually appear in the fourth decade of life
Histological characteristics of Blue Nevi:
A) Microscopically shows a collection of dendritic melanocytes within the CONNECTIVE TISSUE
B) NO melanocytic atypia should be seen
T/F: the reoccurrence rate of excised Blue nevi is relatively high
false
reoccurrence is rare
what are 2 other names for LARGE congenital melanocytic nevi?
large congenital nevus is also known as “garment” nevus or “bathing trunk” nevus
- due to the extensive involvement of the patient’s skin
how large are blue nevi?
Less than one cm. in diameter
T/F: the overlying epithelium of a Blue Nevi lesion is completely uninvolved
True
the blue nevi lesions are isolated to the connective tissue
What is the prognosis/treatment/reoccurrence of blue nevi?
Treatment consists of simple excision
Prognosis is excellent
Recurrence is rare
__________ are a Malignancy of melanocytic differentiation
Melanoma
T/F: Melanomas are the 2nd most common form of skin cancer
FALSE
they are the 3rd most common
Melanomas make up __% of all skin cancers, and account for ___% of death due to skin cancer
5% of skin cancers
65% of deaths due to skin cancer
list the 3 most common skin cancers (in order of prevalence)
Basal cell = most common
Squamous cell = 2nd most common
Melanoma = 3rd most common
T/F: there has been a 40% increase in the prevalence of Melanomas in the last decade
TRUE
40% increase between 2003 and 2015
what population groups are at an elevated risk for developing melanomas?
Fair-skinned patient, 40-70 years of age
risk factors for melanoma include what?
A) history of blistering sunburn early in life
B) Indoor occupation; outdoor recreation
C) Family history of melanoma
D) Personal history of melanoma
what are the “ABCDE’s” of melanomas?
Asymmetry Border irregularity Color variation Diameter greater than 6 mm (size of a pencil eraser) Evolving – enlarging or changing color
T/F: Melanoma lesions will grow laterally in early stages, then grow into the deeper tissues later in the progression
True
what is a Lentigo Maligna?
Essentially a melanoma in a purely radial growth phase
who is at risk for developing a Lentigo Maligna? where do they usually occur?
- Affects older individuals who have a fair complexion
- Develops on facial skin
what are the clinical characteristics of a Lentigo Maligna?
A) Large macular lesion with irregular borders
B) uneven pigmentation
Lentigo Malignas account for roughly __% of all melanomas
5%
what physical change signals a change in a Lentigo Maligna has entered a VERTICAL growth phase?
Nodularity in previously flat lentigo
T/F: most lentigo Malignas take 5 years before entering a vertical growth phase
FALSE
takes an average of 15 years
Superficial Spreading Melanomas account for ___% of all melanomas
70% of melanomas
where are Superficial Spreading Melanomas usually found?
Interscapular area of men; legs of women
15-20% in the head and neck region
Nodular Melanoma make up ___% of all melanomas
15%
what do Nodular Melanomas look like? where are they usually found?
Appear as a rapidly growing nodule
33% develop in the head and neck region
T/F: Nodular melanomas can be amelanotic
True
some nodular melanomas don’t produce melanin
What is a differential diagnosis for an amelanotic Nodular melanoma?
can resemble a pyogenic granuloma
Nodular Melanomas will typically NOT grow in what direction?
Will NOT grow LATERALLY/radially
- usually grow vertically
Acral Lentiginous Melanomas make up ___% of all melanomas
8%
Acral Lentiginous Melanomas are the MOST COMMON melanoma in what population group?
Most common clinicopathologic type of melanoma in persons of color
where are Acral Lentiginous Melanomas typically found? what is their appearance?
- Affects palms, soles and oral mucosa
- Begins as a darkly pigmented macule with irregular borders and undergo shape change
what is the most common INTRAORAL melanoma?
Acral Lentiginous Melanoma
what type of biopsy is necessary in ALL cases of melanomas?
Sentinel node biopsy
even in absence of local metastasis
the prognosis for a patient with a melanoma is dependent on what?
Depends on depth of invasion
what is the prognosis for a melanoma that has invaded less than .75mm? how about .75-1.7 mm? larger than 1.7?
Up to 0.75 mm - 96% 10-year survival
- 76-1.69 mm - 89% 10-year survival
- 7-3.59 mm - 67% 10-year survival
what is considered the “critical” invasion depth for a melanoma?
(in other words, after what depth does the risk of metastasis sharply rise?)
1 mm
