Path I: Skin Lecture Ii

Front 1

what is vitiligo?

Back 1

depigmentation of skin
usually due to loss of melanocytes

Front 2

describe skin lesions in vitiligo

Back 2

asx, flat, well-demarcated macules or patches of depigmentation
usually on hand, wrist, perioral, periorbital, axilla, anogenital regions

Front 3

how does vitiligo differ from albinism?

Back 3

albinism- melanocytes present but not prod melanin
vitiligo-no melanocytes present

Front 4

why do ppl of diff races have varying shades of skin?

Back 4

differences in amt of melanosomes produced; NOT a diff in number of melanocytes

Front 5

what is melasma

Back 5

HYPERmelanosis
"mask of pregnancy"
"chloasma"
exclusively in women: pregnant, oral contraceptives, menopause

Front 6

describe skin lesions in melasma

Back 6

sharply demarcated, blotchy brown macules
symmetrically distributed
cheeks, forehead (upper lip, neck)

Front 7

freckles
what distinguishes them from lentigo?

Back 7

small macules due to incr melanin prod
intensify with sun (v. lentigo)

Front 8

acanthosis nigricans

Back 8

hyperpigmentation
flexural folds (axilla, groin, neck)
NO melanocytic hyperpasia
important cutaneous marker for assoc conditions (pineal, pituitary tumors)

Front 9

2 types of acanthosis nigricans; what is each type associated with?

Back 9

benign (80%) childhood to puberty; AD, variable penetrance; obesity, endocrine disorders

malignant (20%); acquired in middle aged to older; often assoc with GI adenocarcinoma

Front 10

where are tattoo particles deposited?

Back 10

papillary dermis

Front 11

why do tattoos fade?

Back 11

taken up by histiocytes
when histiocytes die, rel particles which are taken by new histiocytes--> less concentrated

Front 12

nevocellular nevi; types

Back 12

benign neoplasms of melanocytes (nevus= any congenital skin lesion)
occur in children to young adults, go away with age

tan to brown, uniform pigmentation, small, solid, macule or papule, well-defined borders

junctional, compound, intradermal

Front 13

junctional nevocellular nevus

Back 13

"mole"
melanocytes transformed to round cells growing in aggregates along dermoepidermal jxn
early developmental stage

Front 14

compound nevocellular nevus

Back 14

more raised and dome-shaped
still symmetrical with uniform pigmentation
formed when junctional nevi grow into underlying papillary dermis

Front 15

intradermal nevocellular nevus

Back 15

epidermal aggregates lost completely to dermis
often removed for cosmetic reasons
mature, deep, small, prod little pigment, grow in cords

Front 16

why is the maturation process of nevi important diagnostically?

Back 16

distinguishes benign nevi from melanomas which have little to no maturation

Front 17

dysplastic nevus

Back 17

most common nevus
occurs on trunks
small, macular
occur throughout life
sims- NOT premalignant

Front 18

malignant melanoma

Back 18

neoplasm of melanocytes
skin, eye, mucous mbrs(rare)
primarily adults
80-90% de novo; 10-20% next to melanocytic nevus

Front 19

what is malignant lentigo?

Back 19

melanoma in situ
radial growth, no metastasis
with time, usually has vertical, metastatic component

Front 20

where do malignant melanomas freq metastasize? and how?

Back 20

widely
regional lymph nodes
liver
lungs brain
hematogenous spread

Front 21

where is the highest incidence of malignant melanoma in males and females? what does this suggest? which ethnic group?

Back 21

males: trunk
females: leg
suggests assoc with sun exposure
caucasians

Front 22

what does it mean if the prevalence of a disease is equal to the incidence?

Back 22

incidence= new cases in pop/yr
prevalence= new cases in pop

if equal means that ppl who get disease in a yr are dying because prevalence is staying the same

Front 23

what are the 4 cardinal signs of malignant melanoma?

Back 23

1. asymmetrical
2. irregular borders
3. uneven pigmentation
4. maculopapular

Front 24

clinical warning signs of malignant melanoma?

Back 24

enlargement of pre-existing mole; itching/pain in pre-existing mole; dev new pigmented lesion in adulthood; irregular borders; varied pigmentation

Front 25

how is a malignant melanoma lesion removed? how does this compare to a nevus?

Back 25

mal mel: excised (diagnostic)
then biopsied to confirm

nevus: shaved off

Front 26

what is pagetoid spread? what is this a feature of?

Back 26

when melanocytes are found in the stratum corneum with the keratin
malignant melanoma

Front 27

what factors are of prognostic significance in malignant melanoma?

Back 27

clinical stage (IV is distant metastasis; 5 yr survival rate drops from 98% at stage 1 to 15% in stage 4)
also, tumor thickness (breslow level?) and presence of ulceration

Front 28

what are fibroepithelial polyps?

Back 28

skin tags
(acrochrodon
fibroma molle
squamous papilloma)
neck and groin in older ppl (areas of rubbing)
many have pedicles
composed of fibrovascular cores covered by squamous epithelium

Front 29

where do epithelial inclusion cysts occur and what causes them?

Back 29

obstruction of hair follicle
seen on face and upper extremity

Front 30

what are epithelial cysts filled with and what is a consequence of trauma?

Back 30

filled with keratin
trauma can lead to chronic inflamm reaction, granuloma formation to keratin released

Front 31

what are all cysts lined with? why do they grow?

Back 31

epithelium; cyst grows b/c epithelium grows...eventually attenuated

Front 32

hemangioma

Back 32

red
thick vessel walls, clustered
freq due to exaggerated reaction and not neoplastic
most common benign tumor in kids

Front 33

xanthomas

Back 33

yellow
central nucleus