Skin Cancer Flashcards
What % skin cancer is BCC, SCC
BCC 80%, SCC 20%
Genetic conditions that cause BCC
Xerodermum pigmentosum and basal nevus syndrome
Causes SCC
HPV, smoking cause SCC of the lip, scars or inflammatory conditions, thermal and electrical burns
Most common cause of skin cancer
UVA and UVB rays
What is congenital melanocytic nevi
nevus or mole present at birth, is a type of mole that can develop into melanoma
Sizes of congenital melanocytic nevi
moles that can develop into melanoma
size small <1.5cm
Medium 1.5-20cm
Large >20cm large has 1% Chance of becoming melanoma
Common acquired nevi
a mole that can develop into melanoma that develops later in life
Types of common acquired nevi (3)
Junctional , compound and intradermal
________ typically small (<6mm)are well circumscribed, flat lesions with smooth surfaces that are brown or black and circular, found above the basement layer
Junctional nevi (nevi that can become melanoma)
………. contain melanocyte clusters in the dermis and epidermis. Small well-circumscribed slightly raised papules that often contain excess hair, surface is rough and colour is tan to brown throughout. These lesions may become nodular
Compound nevi (nevi that become melanoma)
_______small well circumscribed dome shaped lesions that range from flesh to brown, they may contain excess hair. Rarely transform into melanoma
intradermal nevi (nevi that can become melanoma)
skin cancer is most common in ages —–
50+
dysplastic nevi
aka atypical moles have one off more clinical features of melanoma:
- Asymmetry
- Irregular borders
- colour variation
- diameter >6mm
dysplastic nevus syndrome characteristics
what can it turn into and how commonly?
- Moles have distinct pathologic features
- pts have 50+ moles
- pts have 1, 1st degree or 2nd degree relative with melanoma
- dysplastic nevus syndrome has up to 100% chance of becoming melanoma
4 functions of the skin
- Produces vitamin D which is absorbed by the GI tract
- Protects internal organs from outside pathogens
- Regulates temperature through perspiration
- Provides receptors for heat, cold, pain and sensation
layers of the skin from most deep to superficial
basement membrane
subcutaneous
dermis
epidermis
what layer of the skin contains nerves, blood vessels and fat tissue and areolar connective tissue that lies below the dermis layer
subcutaneous
what layer of the skin onnective tissue layer contains blood and lymphatic vessels, nerves, nerve endings and hair follicles
dermis
the 2 divisions of the dermis layer %
Upper layer 20% is called the papillary layer and contains dermal papillae, ridges that are responsible for fingerprints
The lower 80% is called the ticular layer containting hair follicles, sebaceous (oil) and subdiferour (sweat) glands and their ducts, nerve endings and blood vessels
5 divisions of the epidermis layer
stratum basale, stratum granulosum, stratum corneum, stratum spinosum, stratum lucidum
What layer of the epidermis is the following: contains stem cells able to produce karatinocytes and provides a barrier between the host and the environment and cells that give rise to hair follicles, it contains melanocytes, and merkel cells ( in the areas where hair doesnt grow),merkel cells are function in he sensation of touch, Merkel cell cancers are lethal even more lethal than melanoma
Stratum basale
what layer of the skin is the following: contains rows of keratinocytes, that have a spiny appearance microscopically
stratum spinosum of the epidermis
what layer of the skin is the following: this layer contains 3-5 rows of somewhat flattened cells, the keratinocytes produce keratinohyalin which is a precursor to keratin
stratum granulosum of the epidermis
what layer of the skin is the following: only found in areas where thick skin is present (palms of hands and soles of feet) contain 3-5 rows of clear, flat cells that contain eleidin, another keratin precursor
Stratum lucidium of the epidermis