Disorders of Pigmentation and Melanocytes Flashcards Preview

2nd U2 Path > Disorders of Pigmentation and Melanocytes > Flashcards

Flashcards in Disorders of Pigmentation and Melanocytes Deck (25):
1

What cells are responsible for skin pigmentation?

Melanocytes

2

Where are melanocytes located within the skin?

Epidermis

3

Embryologically, where are melanocytes derived from?

Neural crest cells

4

Where is melanin synthesized within the melanocyte?

Melanosomes

5

What precursor molecule is used to synthesize melanin?

Tyrosine

6

A patient presents with a localized loss of skin pigmentation. It was found that an autoimmune destruction of the patient’s melanocytes was occurring. What is the mostly likely diagnosis for this patient?

Vitiligo

7

What enzyme defect is seen with albinism?

Trosinase—impairing melanin production

8

What are the 2 forms of albinism?

Ocular form—involving just the eyes

Oculocutaneous form—involving the skin and the eyes

9

Patients who have albinism are at an increased risk of developing what 3 cancers?

Squamous cell carcinoma
Basal cell carcinoma
Melanoma

10

What causes the darkening of then skin, causing a freckle?

Increased number of melanosomes

Melanocytes are NOT increased

11

A mask-like hyperpigmentation of the cheeks that has an association to pregnancy and oral contraceptives?

Melasma

12

A benign neoplasm of melanocytes?

Nevus (Mole)

13

A nevus that is present at birth and is often associated with hair growth?

Congenital nevus

14

What is the most common nevus (mole) in children?

Junctional nevus

15

What is the most common nevus (mole) in adults?

Intradermal nevus

16

What are the characteristics of a nevus?

Flat macule or raised papule that is symmetric, with sharp boarders, even distribution of color, and

17

What type of nevus is a precursor to melanoma?

Dysplastic nevus

18

A malignant neoplasm of melanocytes that is the most common cause of death from a skin cancer?

Melanoma

19

What are the 4 major risk factors for the development of melanoma?

Prolonged exposure to sunlight
Albinism
Xeroderma pigmentosum
Dysplastic nevus syndrome

20

What is the presentation of melanoma?

Asymmetric
Irregular Borders
Non-uniformed Color
Diameter > 6mm

“ABCD”

21

What are the two growth phases of melanoma?

Radial growth
Vertical growth

22

What is radial growth of melanoma and its risk of metastasis?

Horizontal growth along the epidermis and superficial dermis

Low risk of metastasis

23

What is vertical growth of melanoma and its risk of metastasis?

Growth that occurs deep into the dermis of the skin

24

What are the 4 variants of melanoma?

Superficial spreading
Lentigo maligna melanoma-radial growth
Nodular-early vertical growth
Acral lentiginous

25

Where does the variant, acral lentiginous, of melanoma arise?

On the plams or soles and occurs more in dark-skinned individuals