Integumentary DLA

Question 1

What is hyperkeratosis?

Answer 1

Thickening of the stratum corneum

Question 2

What is parakeratosis?

Answer 2

Retention of nuclei in the keratinocytes of the stratum Corneum

Question 3

What is acanthosis?

Answer 3

Increase in thickness of the stratum spinosum

Question 4

What is acanthylosis?

Answer 4

Broken bonds between cells of the epidermis leading to separation of these cells from each other

Question 5

Describe basal cell carcinoma

Answer 5

• UV light
• proliferation of basal stem cells
• Dark nuclei with sparse poorly defined cytoplasm
• Cells at the periphery has a characteristic palisades appearance
• Central cells are more randomly arranged
• Invades the dermis and deeper lying structures
• Does not typically metastasize

Question 6

What are the predisposing factors of squamous cell carcinoma?

Answer 6

• sunlight (UV)
• industrial carcinogens
• chronic ulcers
• tobacco chewing
• burns
• ionizing radiation
• betel nut chewing
• arsenic exposure

Question 7

What is most common location of squamous cell carcinoma?

Answer 7

More common in head and neck region (likely due to excessive sunlight exposure)

Question 8

What is squamous cell carcinoma?

Answer 8

• Malignant tumor of keratinocytes
• exposure to UV with DNA damage (inactivation of P53 gene)
• loss of elderly in nuclear size and shape
• Hyperkeratosis and Parakeratosis
• Common in elderly (above 70 years)
• fair skinned > dark skinned

Question 9

Describe the histological evaluation of squamous cell carcinoma

Answer 9

Dermis deeply infiltrated by islands and sheets of malignant squamous cells

The islands have undifferentiated cells, resembling basal cells, around the parameter

Islands show squamous differentiation with formation of squamous pearls or swirls

Question 10

What is malignant melanoma?

Answer 10

• malignant transformation of melanocytes
• causes highest number of skin cancer related deaths in US
• more common in whites, Australia/ South Africa
• etiology- exposure to sunlight (UV) light : types- Acute, intermittent, blistering
• increased number of melanocytes with large atypical morphology- arranged at the dermo-epidermal junction

May invade the dermis- metastases(fatal)

Question 11

What is melan A?

Answer 11

Immunohistocheemistry marker, a specific antibody that stains malignant melanoma cells

Question 12

What is albinism?

Answer 12

Genetic (autosomal recessive)

• loss of pigmentation of the skin, hair, and eyes
• Lack of tyrosinase
• types: ocular, oculocutaneous

Question 13

What are the long term implications of albinism?

Answer 13

• skin cancers
• reduced visual acuity/photophobia (macular hypoplasia)
• social stigma

Question 14

What is Vitiligo?

Answer 14

• Depigmentation disorder
• auto-immune
• destruction of melanocytes
• types: focal, segmental, generalized

Question 15

How can vitiligo be treated?

Answer 15

Medical:
-topical steroid therapy

• Psolaren photochemotherapy
• Depigmentation

Surgical:
-Autologous skin graft

• Micropigmentation
• Melanocytes transplants

Question 16

What is Psoraisis?

Answer 16

A chronic inflammatory and hyper proliferative disorder of the skin

• Clinically manifested as well-circumscribed, erythema toes and itchy plaques covered with slavery scales( knees, elbows, lower back, scalp)
• Epidural turnover averages 8-10 days

Characterized by hyperkeratosis and parakeratosis

Question 17

What are the predisposing factors of psoriasis?

Answer 17

• genetic background

- inciting background (stress)

Question 18

Explain the pathogenesis of psoriasis

Answer 18

• Exogenous/endogenous antigens: predisposing factors
• Antigen presentation by APCs: Langerhans cells
• T-lymphocyte-mediated immune response
• Cytokine secretion
• Inflammation & cellular hyperproliferation
• Clinical lesions of psoasis

Question 19

What is parakeratosis?

Answer 19

Retention of nuclei in the stratum corneum

Question 20

What causes epidermal removal in psoarisis?

Answer 20

Parakeratosis

• prominent itchy areas with increased skin scaling and peeling
• epidermal hyperplasia- increased rate of proliferation

This leads to shedding of the epidermis constantly, resulting in scales seen as whitish patches

Question 21

What is Bollous pemphigod?

Answer 21

• damage to hemidesmosomes- separation of epidermis & dermis
• Chronic autoimmune blistering disease: skin & mucous membranes (bulla large fluid filled vesicles)
• Antibodies (IgG) specific to hemidesmosomes bind to basement membrane and stimulate leukocytic infiltration
• Eosinophils releases proteases that degrade hemidesmosomes
• Fluid accumulation-blistering formation
• Characteristic by large blisters that don’t easily rupture

Question 22

What is Pemphigus vulgaris?

Answer 22

Pemphix(blister/bubble)

• Rare autoimmune disorder affecting epidermis and mucosal epithelium
• Desmosomes- separation of the stratum spinosum keratinocytes one from another
• Antibodies target cadherins and desmoplakins and desmogleins
• Atrophy of the prickle cell layer
• Blister formation: easy to rupture- Nikolsky’s sign, skin shears off easily

Question 23

What causes ACNE?

Answer 23

Inflammation of a sebaceous gland

• Affects 85-100% of people at some point in life
• Genetic predisposition
• Common in adolescents (prior to onset of puberty- adrenal androgens): in all age groups
• Affects face, back, chest upper arm- areas with increased sebaceous glands

Question 24

What are wound healing?

Answer 24

Skin damage in motion a sequence of events that repairs the skin to its normal (or near normal) structure and function

2 types:

• epidermal wound healing
• deep wound healing

Question 25

Contrast epidermal and deep wound healing

Answer 25

Epidermal wound healing- occurs following wounds that affect only the epidermis Deep wound healing- occurs following wounds that penetrate the dermis

Question 26

What is epidermal wound healing?

Answer 26

- In response to an injury, the basal cells of the epidermis surrounding the wound, break contact with the basement membrane, enlarge and migrate across the wound - The cell migrate from opposite sides until they meet (in a sheet-like formation) - Epidermal growth factor stimulates basal stem cells to divide and replace the lost cells, that have moved into wound - These new cells divide to thicken the new epithelium

Question 27

What is deep wound healing?

Answer 27

- As the injury involves multiple tissue layers, healing process is more complex. Healing involves scar formation and can include loss of function - This type of healing occurs in 4 phases: - Inflammatory phase(up to 3 days after wound) - Migratory phase - Proliferative phase(from the 3rd day to weeks after the wound )( type III collagen dominant) - Maturation phase

Question 28

Describe the inflammatory phase of deep wound healing

Answer 28

Blood clot is formed and loosely attaches the cut edges. Vasodilation and increased permeability helps neutrophils and monocytes(which become macrophages) to enter the area and eliminate microbes, foreign material and dying tissue. Mesenchymal cells develop into fibroblasts

Question 29

Describe the migratory phase of deep wound healing

Answer 29

As the clot becomes a scab, epithelial cells migrate beneath it to bridge the wound. Fibroblasts synthesize scar tissue (collagen and glycoprotein ) and damaged vessels regrow This now constitutes the granulation tissue

Question 30

Describe proliferative phase of deep wound healing

Answer 30

Growth of the epithelial tissue at random. Continued growth of vessels

Question 31

Describe the maturation phase of the deep wound healing

Answer 31

Scab sloughs off. Epidermis restored to normal thickness. Collagen is more organized. Fibroblasts decrease and blood vessels stabilize. This type of scar- fibrosis

Question 32

Contrast hypertrophy scar and keloid scar

Answer 32

Hypertrophic scar- raised more than normal, but within original wound boundary -Mainly type III collagen in well organized rows Keloid scar- in excess of the boundary, and extending into surrounding tissue -Mainly highly disorganized types I and III collagen - More common in persons who are darker skinned - Common location#- ear, neck, sternum, upper extremities

Question 33

What is the purpose for a rule of nine’s?

Answer 33

Used to describe burn coverage over the body(and indirectly severity)

Question 34

What are first degree burns?

Answer 34

Partial thickness epidermis only Heals spontaneously

Question 35

What are secondary degree burns?

Answer 35

Partial thickness epidermis and dermis Epithelial water barrier disrupted Heals spontaneously

Question 36

What is a third degree burn?

Answer 36

Full thickness epidermis, dermis and subcutaneous tissue Water barrier disrupted , nerves and blood vessels destroyed. Does not heal spontaneously, fluid loss is extensive