Pathology of Pigmented Skin Lesions Flashcards
Tumours above the basement membrane are in-situ/invasive
In-situ
Tumours that have penetrated the basement membrane are invasive/in-situ
Invasive
Freckles are an adaptive response to what?
UV exposure
Actinic lentigines are commoner in which age type?
Older people
Most babies are born with a congenital naevus. True/false?
False - 1-2%
How are acquired naevi formed?
By a breakdown in melanocyte to keratinoyte ratio during infancy
Naevi have a high malignant potential. True/false?
False
How do acquired naevi develop from childhood to adulthood?
Go from junctional to compound to intradermal
Do dysplastic familial naevi carry a high risk of melanoma?
Yes - up to 100%
How do halo naevi present?
With depigmentation around the border due to it being overrun by lymphocytes
Blue naevi consist of what kind of cells?
Pigment rich dendritic spindle cells
Spitz naevi closely mimic a melanoma. True/false?
True
Melanomas are commoner in which gender?
Females
What is the most common cause of a melanoma?
UV exposure (sunburn)
What are some signs of a melanoma?
New pigmented lesion in adulthood Ulceration Bleeding Change in shape Irregular pigmentation Satellite nodules
What are the four main types of melanoma?
Superficial spreading
Acral lentiginous
Lentigo maligna
Nodular
What is the commonest type of melanoma?
Superficial spreading
Superficial spreading, acral lentiginous and lentigo malinaallgrow as a papule/macule?
Macule - no bump
If the melanoma has become nodular will it be invasive?
Yes
A nodular melanoma is in what phase all the time?
Vertical growth
What are the two most factors in melanoma prognosis?
Breslow depth
Ulceration
What is Breslow depth?
The distance between the granular layer and the deepest point of the tumour in mm
The Breslow depth is 3mm. What is the survival rate?
55%
How do malignant melanomas spread?
From local dermal lymphatics to regional lymph nodes and then through the blood
