skin Flashcards
1
Q
What is the largest organ in the body?
A
The skin is the largest organ in the body.
2
Q
Why is the skin so important?
A
The skin serves several important functions, including protection against external threats, body temperature regulation, sensation, and vitamin D synthesis.
3
Q
What are primary skin disorders?
A
Primary skin disorders refer to conditions that primarily affect the skin itself, such as acne, eczema, psoriasis, and dermatitis.
4
Q
What are cutaneous manifestations of systemic illnesses?
A
Cutaneous manifestations of systemic illnesses are skin manifestations that occur as a result of underlying systemic conditions. For example, a malar rash or butterfly rash can be a cutaneous manifestation of lupus.
5
Q
Give an example of a skin manifestation related to a systemic illness.
A
Generalized intractable pruritus (severe itching) can be a cutaneous manifestation of chronic renal failure.
6
Q
What are some examples of skin manifestations associated with specific conditions?
A
Some examples include splinter hemorrhages seen in bacterial endocarditis or vasculitis, half and half nails, which can be indicative of certain systemic disorders, and dermatitis herpetiformis, which is associated with celiac disease (gluten sensitivity).
7
Q
How are skin disorders diagnosed?
A
The diagnosis of skin disorders, like all pathology in medicine, can be approached using the surgical sieve or a structure-based approach. These methods involve a systematic examination of the skin, taking into account various factors such as appearance, distribution, and associated symptoms.
8
Q
What are the three main layers of the skin?
A
The skin is composed of three main layers: the epidermis, dermis, and subcutis (also known as the hypodermis).
9
Q
What is the epidermis?
A
The epidermis is the outermost layer of the skin. It is primarily made up of epithelial cells and serves as a protective barrier against external factors.
10
Q
What is the dermis?
A
The dermis is the middle layer of the skin. It contains connective tissue, blood vessels, hair follicles, sweat glands, sebaceous glands, and nerve endings.
11
Q
What structures can be found within the dermis?
A
Within the dermis, you can find blood vessels, which supply nutrients and oxygen to the skin, and hair shafts, responsible for hair growth. The dermis also contains arrector pili muscles responsible for causing hair to stand on end (goosebumps).
12
Q
What is the subcutis or hypodermis?
A
The subcutis, also known as the hypodermis, is the deepest layer of the skin. It consists of fat cells, connective tissue, and larger blood vessels. It provides insulation and cushioning to the body.
13
Q
What type of epithelium makes up the epidermis?
A
The epidermis is composed of keratinizing, stratified squamous epithelium.
14
Q
How does the epidermis cover the body?
A
The epidermis forms a continuous layer that covers the surface of the body.
15
Q
What are the natural openings in the epidermis?
A
The epidermis has natural openings for hair follicles and sweat ducts, which are collectively known as the acrosyringium.
16
Q
What are the main cell types found within the epidermis?
A
Keratinocytes: These are the most abundant cells in the epidermis and produce the protein keratin, which provides strength and protection.
Melanocytes: Melanocytes produce the pigment melanin, which determines skin color and provides protection against UV radiation.
Langerhans cells: Langerhans cells are immune cells that help protect against pathogens and foreign substances.
Merkel cells: Merkel cells are involved in the sensation of touch and are located in the deepest layer of the epidermis.
17
Q
What is the outermost layer of the epidermis called?
A
The outermost layer of the epidermis is called the horn cell layer or stratum corneum. It is composed of dead, flattened keratinocytes that are continuously shed and replaced.
18
Q
Which layer of the epidermis is located just beneath the stratum corneum?
A
The layer beneath the stratum corneum is known as the granular cell layer or stratum granulosum. It consists of keratinocytes that have begun to produce keratin and undergo changes in their cellular structure.
19
Q
What is the layer beneath the stratum granulosum called?
A
The layer beneath the stratum granulosum is called the prickle cell layer or stratum spinosum. It is characterized by cells with spiny projections, which are cell-to-cell connections called desmosomes.
20
Q
What is the innermost layer of the epidermis?
A
The innermost layer of the epidermis is called the basal cell layer or stratum basale. It is made up of a single layer of columnar or cuboidal cells that actively divide and produce new keratinocytes.
21
Q
Describe the characteristics of the cells in the stratum basale.
A
The stratum basale is composed of a single layer of squamous cells that are columnar or cuboidal in shape. These cells appear basophilic (blue) and can exhibit variable pigmentation due to melanin. They are attached to the basement membrane by hemidesmosomes.
22
Q
What is the main component of the stratum spinosum?
A
The stratum spinosum is the thickest layer of the epidermis, consisting of 5-10 cell layers. Its primary cell type is polyhedral squamous cells known as keratinocytes. These cells appear pink (eosinophilic) and become flatter as they move closer to the skin surface.
23
Q
What is the characteristic feature of the cells in the stratum granulosum?
A
The stratum granulosum typically consists of 1-3 layers of flattened cells that contain keratohyaline granules. These granules are basophilic and contain lipids, contributing to the waterproofing function of the skin.
24
Q
Where is the stratum lucidum found, and what are its characteristics?
A
The stratum lucidum is found exclusively in acral sites, such as the palms and soles, which have a thickened layer of keratin. It is a clear layer of dead keratinocytes.
25
Describe the characteristics of the cells in the stratum corneum.
The stratum corneum consists of polyhedral eosinophilic keratinocytes that are packed with keratin filaments. These cells lack a nucleus and exhibit a basket weave pattern of keratin arrangement.
26
How are keratinocytes held together?
Keratinocytes, the most dominant cell type in the epidermis, are held together by desmosomes. Desmosomes are specialized cell junctions that provide strong adhesion between adjacent keratinocytes, contributing to the structural integrity of the epidermis.
27
How are keratinocytes anchored to the basement membrane?
Keratinocytes are anchored to the basement membrane by hemidesmosomes. Hemidesmosomes are specialized adhesion structures that connect the basal cells of the epidermis to the underlying basement membrane, providing stability and support.
28
What is the significance of desmosomes in the epidermis?
Desmosomes play a crucial role in maintaining the "spongiotic" nature of the epidermis by highlighting the prickles or spines observed between keratinocytes. These desmosomal connections contribute to the strength and flexibility of the skin.
29
What role do keratinocytes play in re-epithelization and repair?
Keratinocytes are actively involved in the process of re-epithelization and repair. When the skin is injured or damaged, keratinocytes proliferate and migrate to cover the wound, facilitating the regeneration and healing of the epidermis.
30
What is the origin of melanocytes?
Melanocytes are dendritic cells that originate from the neural crest during embryonic development. They are not epithelial cells but rather neural crest-derived cells.
31
Where are melanocytes located within the skin?
Melanocytes are located in the basal layer of the epidermis, which is the innermost layer. They occur approximately every 1 in 4 basal cells (keratinocytes).
32
How do melanocytes appear under microscopic examination?
Melanocytes are smaller than basal cells and can be identified by their elongated oval nuclei with a surrounding clear space, known as a halo.
33
What is the role of melanocytes in skin coloration?
Melanocytes produce melanin within melanosomes, which are pigment-containing organelles. The melanin is then transferred to neighboring basal cells, including those in hair follicles, contributing to the coloration of the skin, hair, and eyes.
34
What is the function of melanin?
Melanin acts as a natural pigment that absorbs harmful ultraviolet (UV) rays from the sun. It helps protect the skin from UV-induced damage, including sunburn and DNA damage.
35
What are Langerhans cells?
Langerhans cells are dendritic antigen-presenting cells. They play a role in the immune response by capturing antigens and presenting them to other immune cells.
36
Where are Langerhans cells located?
Langerhans cells are found in the mid to upper spinous layer of the epidermis and also in the dermis. They are also present in various types of squamous epithelium, other epithelial tissues, and lymphoid organs.
37
What is the significance of Langerhans cells in pathology?
Langerhans cells are involved in various pathological conditions. Dysfunction or abnormal behavior of Langerhans cells has been associated with certain skin diseases and immune disorders.
38
Can Langerhans cells be easily seen on routine histological staining?
Langerhans cells cannot easily be seen on routine hematoxylin and eosin (H&E) staining. Special staining techniques, such as immunohistochemistry, are often required to visualize and identify these cells.
39
What is the origin of Merkel cells?
Merkel cells originate from the neural crest, similar to melanocytes. They are specialized cells involved in sensory perception.
40
Where are Merkel cells located within the skin?
Merkel cells are located in the basal layer of the epidermis, similar to melanocytes and Langerhans cells.
41
What is the function of Merkel cells?
Merkel cells function as slowly adapting mechanoreceptors responsible for tactile sensation. They are associated with sensory nerve endings and play a role in the perception of touch and pressure.
42
In which areas of the body are Merkel cells more abundant?
Merkel cells are found in increased numbers in specific regions of the body, such as the digits (fingers, toes), lips, and areas with high tactile sensitivity.
43
Can Merkel cells be easily visualized on routine histological staining?
Similar to Langerhans cells, Merkel cells cannot be readily seen on routine H&E staining. Special staining techniques, such as immunohistochemistry, are typically employed to identify and visualize these cells.
44
What is the composition of the basement membrane?
The basement membrane is primarily composed of type IV collagen, which provides structural support and stability.
45
What is the role of the basement membrane in resisting shearing forces?
The basement membrane possesses the ability to resist shearing forces. This property helps maintain the structural integrity of tissues and prevents the separation of epithelial and connective tissue layers.
46
What is the structural significance of the basement membrane?
The basement membrane acts as a structural scaffold that provides support and anchorage for epithelial cells. It helps maintain tissue architecture and separates epithelial tissue from underlying connective tissue.
47
How does the basement membrane control epithelial-mesenchymal interactions?
The basement membrane plays a crucial role in regulating the interactions between epithelial and mesenchymal cells. It acts as a barrier, preventing the invasion of mesenchymal cells into epithelial tissue and maintaining tissue organization.
48
What is the composition of the dermis?
The dermis is primarily composed of dense connective tissue, which includes collagen, elastin, and extracellular matrix components. These provide strength, elasticity, and support to the skin.
49
What are the functions of the dermis?
The dermis plays a vital role in supporting the overlying epidermis. It houses various structures, including nerves, blood vessels, lymphatics, and mechanoreceptors/thermoreceptors. It also contains epidermal appendages such as hair follicles, sebaceous glands, and sweat glands.
50
What types of cells are found in the dermis?
The dermis contains various cell types, including fibroblasts (responsible for synthesizing collagen and other extracellular matrix components), histocytes (tissue-resident macrophages), vascular smooth muscle cells, leucocytes (lymphocytes, mast cells, plasma cells), as well as transient cells such as eosinophils and neutrophils. Adipocytes, which are fat cells, may also be present in certain regions of the dermis.
51
What are the characteristics of fibroblasts in the dermis?
Fibroblasts in the dermis are spindle-shaped cells that are responsible for synthesizing the extracellular matrix and collagen. They play roles in processes such as inflammation, wound healing, and angiogenesis. Fibroblasts are not terminally differentiated and are the most common cell type in connective tissue.
52
What are histiocytes and their role in the dermis?
Histiocytes are fully differentiated cells that originate from monocytes in the bone marrow and migrate to the dermis. They are part of the immune system and are involved in antigen presentation. Histiocytes remove debris through phagocytosis. They can vary in size and appearance and have bean-shaped nuclei. In certain circumstances, histiocytes can form giant cells. Pathological conditions can be associated with histiocytes as well.
53
What are the components of the pilosebaceous unit?
The pilosebaceous unit consists of hair follicles, sebaceous glands, and the arrector pili muscle. It is responsible for hair growth, sebum production, and controlling hair movement.
54
What is the function of hair follicles?
Hair follicles are structures within the skin that produce and support hair growth. They are responsible for the formation of hair shafts, which provide protection and sensory functions.
55
What are sebaceous glands and their role?
Sebaceous glands are small glands attached to hair follicles that secrete sebum, an oily substance that lubricates and moisturizes the skin and hair.
56
What is the role of the arrector pili muscle?
The arrector pili muscle is a small muscle attached to the hair follicle. When stimulated, it contracts, causing the hair to stand upright, resulting in what is commonly known as "goosebumps."
57
What are the types of sweat glands found in the skin?
There are two types of sweat glands: eccrine and apocrine. Eccrine sweat glands are distributed throughout the body and are responsible for regulating body temperature. Apocrine sweat glands are mainly found in the axillary and genital areas and produce a thicker, odorless sweat that is associated with emotional sweating.
58
What is the composition of hair and how is it formed?
Hair is formed from keratin, and there are no living cells within the hair shaft itself. The hair follicle, located in the dermis, produces the hair shaft.
59
What determines the color of hair?
The type and quantity of melanin within the hair shaft determine its color. Different types and amounts of melanin result in various hair colors, ranging from blonde to brown, black, or red.
60
What is the hair growth cycle?
Hair has a cycle of its own, which includes three phases: anagen (active growth), catagen (transition), and telogen (resting). Each hair follicle goes through these phases independently, leading to continuous hair growth and shedding.
61
What are sebaceous glands and their appearance?
Sebaceous glands are formed from sebocytes, specialized cells that produce sebum, a lipid-based secretion. These glands appear foamy due to the presence of lipid droplets within their cells.
62
How do sebaceous glands connect with the hair follicles?
Sebaceous glands drain into the hair follicle via the sebaceous duct located at the isthmus of the follicle. Multiple sebaceous glands can be associated with a single hair follicle.
63
Where are eccrine sweat glands found and what is their function?
Eccrine sweat glands are found all over the body. They are composed of cuboidal cells surrounded by myoepithelial cells. Their primary function is temperature regulation through the production of sweat, which evaporates from the skin surface and helps cool down the body.
64
Where are apocrine sweat glands found and what is their function?
Apocrine sweat glands are found in specific locations such as the axilla (armpit), groin, and nipple regions. They are composed of columnar cells and have a "decapitation" secretion. Unlike eccrine glands, apocrine glands are not involved in temperature regulation. Instead, they are responsible for producing sweat that is associated with body odor.
65
What is a hypertrophic scar?
A hypertrophic scar is scar tissue that forms as a result of a wound but does not extend beyond the margin of the initial injury. It appears as a raised, thickened area within the boundaries of the original wound.
66
What is a keloid scar?
A keloid scar is scar tissue that extends beyond the margin of the original injury. It appears as firm, smooth nodules that may be larger than the initial wound. Keloid scars can be raised, red, and extend beyond the boundaries of the original wound.
67
What is the primary function of the skin?
The primary function of the skin is to serve as a protective covering for the body.
68
How does the skin provide protection?
The skin acts as a barrier, providing protection against external physical, chemical, and microbial factors. It helps waterproof the body, preventing excessive water loss and protecting against dehydration.
69
What is the skin's role in anti-microbial defense?
The skin has antimicrobial properties that help defend against harmful microorganisms. The acidic pH of the skin, along with the presence of natural oils and antimicrobial peptides, helps inhibit the growth of bacteria and other pathogens.
70
How does the skin contribute to thermoregulation?
The skin plays a crucial role in thermoregulation by regulating body temperature. It can release heat through sweat production and dilation of blood vessels to cool the body, or conserve heat by constricting blood vessels and reducing sweat production in colder environments.
71
How does the skin sense temperature, touch, and pain?
The skin contains sensory receptors that enable us to perceive temperature, touch, and pain. Nerve endings in the skin detect stimuli and transmit signals to the brain, allowing us to sense and respond to our environment.
72
Does the skin serve any social functions?
Yes, the skin can play a role in social interactions and attraction. It contributes to our appearance and can convey emotions and attractiveness.
73
Can the skin absorb and secrete substances?
The skin has some absorptive and secretory functions. It can absorb certain substances, such as medications or chemicals, through its outer layer. It also secretes sweat, oils (sebum), and other substances that contribute to skin health and function.
74
What is the role of the skin in vitamin D metabolism?
The skin is involved in the synthesis of vitamin D when exposed to sunlight. UV radiation triggers a reaction in the skin that converts a precursor molecule into vitamin D, which is important for calcium absorption and bone health.
75
What is thermoregulation?
Thermoregulation is the process by which the body maintains its temperature within a narrow range, typically above the ambient temperature. It involves a balance between heat production and heat loss.
76
How does the skin contribute to thermoregulation?
The skin plays a major role in thermoregulation. It regulates heat loss and heat conservation through mechanisms such as cutaneous blood flow, sweating, and piloerection.
77
What is the role of cutaneous blood flow in thermoregulation?
Cutaneous blood flow is regulated to promote either heat loss or heat conservation. Increased blood flow (vasodilation) near the skin's surface enhances heat loss through conduction and convection, while decreased blood flow (vasoconstriction) helps conserve heat.
78
How does sweating help in thermoregulation?
Sweating is a mechanism for heat loss through evaporative cooling. As sweat evaporates from the skin's surface, it absorbs heat from the body, thereby cooling it down. This process is aided by the latent heat of vaporization.
79
What is piloerection, and how does it contribute to thermoregulation?
Piloerection refers to the raising of hairs on the skin. In humans, it is not as prominent as in other animals but can still occur. Piloerection helps trap air near the skin, acting as insulation and reducing heat loss from the body.
80
What is the role of the hypothalamus in thermoregulation?
The hypothalamus is a key control center in the brain that regulates body temperature. It receives input from temperature receptors throughout the body and orchestrates various responses to maintain thermal balance.
81
What is cancer?
Cancer refers to the abnormal growth of cells that multiply in a disorderly manner and continue to do so even after the removal of the stimulus that caused the change.
82
How does cancer behave in terms of boundaries?
Cancer has no respect for boundaries and can invade nearby tissues and organs if left untreated.
83
What are the three main types of primary skin cancer?
The three main types of primary skin cancer are squamous cell carcinoma, basal cell carcinoma, and melanoma.
84
What is squamous cell carcinoma?
Squamous cell carcinoma is a type of skin cancer that arises from the squamous cells in the epidermis. It is often associated with chronic sun exposure and can appear as scaly, red patches or raised growths on the skin.
85
What is basal cell carcinoma?
Basal cell carcinoma is the most common type of skin cancer. It develops in the basal cells of the epidermis and usually appears as a waxy, pearly bump or a flesh-colored patch that may bleed or develop a crust.
86
What is melanoma?
Melanoma is a highly aggressive form of skin cancer that originates from the pigment-producing melanocytes. It often presents as an irregularly shaped mole with uneven coloration, and it has the potential to spread to other parts of the body.
87
Which skin cancers arise from cells within the epidermis?
Squamous cell carcinoma, basal cell carcinoma, and melanoma all originate from cells within the epidermis.
88
What is squamous cell carcinoma (SCC)?
Squamous cell carcinoma is a type of skin cancer that develops from the squamous cells in the epidermis. It is typically associated with chronic sun exposure and can appear as scaly, red patches or raised growths on the skin.
89
What is basal cell carcinoma (BCC)?
Basal cell carcinoma is the most common type of skin cancer. It originates from the basal cells of the epidermis and usually presents as a waxy, pearly bump or a flesh-colored patch that may bleed or develop a crust.
90
What is melanoma?
Melanoma is an aggressive form of skin cancer that arises from the pigment-producing melanocytes. It often appears as an irregularly shaped mole with uneven coloration, and it has the potential to metastasize to other parts of the body.
91
What is cutaneous metastasis?
Cutaneous metastasis refers to the spread of cancer from its primary site to the skin. Any cancer can potentially metastasize to the skin, but certain cancers are more likely to do so, including melanoma, lung cancer, colon cancer, breast cancer, and ovarian cancer.
92
Which type of oral cavity cancer is known to metastasize to the skin?
Squamous cell carcinoma (SCC) of the oral cavity has the potential to metastasize to the skin, resulting in cutaneous metastasis.
93
What is Basal Cell Carcinoma (BCC)?
Basal Cell Carcinoma (BCC) is the most common type of skin cancer in the Western world. It arises from the basal cells of the epidermis.
94
Where is Basal Cell Carcinoma commonly found?
Basal Cell Carcinoma commonly occurs on the head and neck, especially in areas exposed to sunlight, such as the face.
95
Does Basal Cell Carcinoma metastasize to other organs?
Basal Cell Carcinoma typically does not spread to other organs (metastasize). It tends to grow locally and invade surrounding tissues.
96
Is Basal Cell Carcinoma usually a solitary or multiple lesion?
Basal Cell Carcinoma often presents as multiple lesions rather than a single lesion.
97
Does Basal Cell Carcinoma have a tendency to recur?
Yes, Basal Cell Carcinoma has a tendency to recur after treatment. Regular follow-up and surveillance are important to monitor for recurrence.
98
Can Basal Cell Carcinoma be disfiguring if located on the face?
Yes, Basal Cell Carcinoma on the face can be disfiguring due to its potential to invade surrounding structures and the need for surgical removal, which may cause cosmetic changes.
99
What is the main cause of Basal Cell Carcinoma?
The primary cause of Basal Cell Carcinoma is prolonged exposure to ultraviolet (UV) radiation from sunlight or tanning beds.
100
What is Squamous Cell Carcinoma (SCC)?
Squamous Cell Carcinoma (SCC) is the second most common type of skin cancer. It originates from the squamous cells of the epidermis.
101
Does Squamous Cell Carcinoma have a higher tendency to metastasize compared to Basal Cell Carcinoma?
Yes, Squamous Cell Carcinoma has a higher propensity to metastasize to regional lymph nodes and distant organs such as the lung, liver, and brain, making its prognosis worse compared to Basal Cell Carcinoma.
102
Where is Squamous Cell Carcinoma commonly found?
Squamous Cell Carcinoma commonly occurs on sun-exposed areas, particularly the head and neck.
103
What are the risk factors for Squamous Cell Carcinoma?
Prolonged exposure to UV radiation (sunlight, tanning beds)
Previous history of skin cancer or pre-malignant lesions
Fair skin
Immunosuppression (e.g., organ transplant, immunosuppressant drugs)
Xeroderma pigmentosum (a rare genetic disorder affecting DNA repair)
Smoking
Exposure to arsenic
Aging
104
How does Squamous Cell Carcinoma differ from Basal Cell Carcinoma in terms of prognosis?
Squamous Cell Carcinoma generally has a poorer prognosis than Basal Cell Carcinoma due to its higher metastatic potential.
105
What is Melanoma?
Melanoma is a type of skin cancer that develops from melanocytes, the pigment-producing cells in the skin.
106
What is the incidence and mortality rate of Melanoma in the UK?
Melanoma is the 5th most common cancer in the UK and the 20th most common cause of cancer death. Its incidence rates have increased by 135% since 1990, and it caused approximately 1,000 deaths in 2017.
107
Where does Melanoma commonly occur on the body?
Melanoma most commonly occurs on the trunk (including the back and chest) and the legs. However, it can also develop in other areas of the skin, including the face, neck, and extremities.
108
What are the risk factors for Melanoma?
UV radiation exposure, including from sunlight and sunbed use (tanning beds)
Skin phototype I/II, which refers to fair skin that burns easily and tans minimally
Red or blonde hair
Blue or blue-grey eyes
History of sunburns
Having more than 100 moles
Family history of melanoma
Conditions such as Crohn's disease and HIV/AIDS, which can weaken the immune system
109
How does Melanoma compare to Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC) in terms of prognosis?
Melanoma generally has a worse prognosis compared to BCC and SCC due to its higher propensity to metastasize. Early detection and treatment are crucial for improving the prognosis of Melanoma.
110
What are the different types of Melanoma?
Superficial spreading melanoma
Nodular melanoma
Acral lentiginous melanoma
Subungual melanoma
Lentigo maligna melanoma
111
What is Superficial Spreading Melanoma?
Superficial spreading melanoma is the most common type of melanoma. It typically grows horizontally along the top layer of the skin before penetrating deeper. It can occur anywhere on the body and is often associated with prolonged sun exposure.
112
What is Nodular Melanoma?
Nodular melanoma is an aggressive type of melanoma that grows vertically into the deeper layers of the skin. It appears as a raised, dome-shaped nodule and can develop rapidly.
113
What is Acral Lentiginous Melanoma?
Acral lentiginous melanoma is a type of melanoma that affects the palms of the hands, soles of the feet, or under the nails. It is not strongly associated with sun exposure and can occur in individuals with darker skin tones.
114
What is Subungual Melanoma?
Subungual melanoma is a type of melanoma that develops under the nails. It can cause discoloration, streaks, or pigmented bands in the nail. It is relatively rare but can be aggressive.
115
What is Lentigo Maligna Melanoma?
Lentigo maligna melanoma typically occurs in older individuals and is commonly found on sun-exposed areas, such as the face and neck. It often develops from a pre-existing pigmented lesion known as lentigo maligna.
116
What are the characteristic features of melanoma?
Highly atypical melanocytes, prominent nucleoli, and dusty melanin pigmentation.
117
At what age can melanoma occur?
Melanoma can occur at any age.
118
Which skin types are more at risk for melanoma?
The fairer the skin, the more at risk. Skin phototypes I, II, and III are particularly vulnerable.
119
Are acral sites at risk for melanoma?
Yes, acral sites are at risk, especially in higher skin phototypes.
120
What is the main risk factor for melanoma?
UV radiation exposure is the primary risk factor for melanoma.
121
How is the prognosis of melanoma determined?
The prognosis is based on Breslow thickness, which is measured from the granular cell layer to the deepest point of the tumor in millimeters.
122
What is the prognosis for melanoma with a Breslow thickness of less than 1mm?
The risk of metastasis is small, and the prognosis is excellent.
123
What is the prognosis for melanoma with a Breslow thickness greater than 4mm?
The risk of metastasis is high, and the prognosis is poor.
