Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
33 Cards in this Set
- Front
- Back
what is vitiligo?
|
depigmentation of skin
usually due to loss of melanocytes |
|
describe skin lesions in vitiligo
|
asx, flat, well-demarcated macules or patches of depigmentation
usually on hand, wrist, perioral, periorbital, axilla, anogenital regions |
|
how does vitiligo differ from albinism?
|
albinism- melanocytes present but not prod melanin
vitiligo-no melanocytes present |
|
why do ppl of diff races have varying shades of skin?
|
differences in amt of melanosomes produced; NOT a diff in number of melanocytes
|
|
what is melasma
|
HYPERmelanosis
"mask of pregnancy" "chloasma" exclusively in women: pregnant, oral contraceptives, menopause |
|
describe skin lesions in melasma
|
sharply demarcated, blotchy brown macules
symmetrically distributed cheeks, forehead (upper lip, neck) |
|
freckles
what distinguishes them from lentigo? |
small macules due to incr melanin prod
intensify with sun (v. lentigo) |
|
acanthosis nigricans
|
hyperpigmentation
flexural folds (axilla, groin, neck) NO melanocytic hyperpasia important cutaneous marker for assoc conditions (pineal, pituitary tumors) |
|
2 types of acanthosis nigricans; what is each type associated with?
|
benign (80%) childhood to puberty; AD, variable penetrance; obesity, endocrine disorders
malignant (20%); acquired in middle aged to older; often assoc with GI adenocarcinoma |
|
where are tattoo particles deposited?
|
papillary dermis
|
|
why do tattoos fade?
|
taken up by histiocytes
when histiocytes die, rel particles which are taken by new histiocytes--> less concentrated |
|
nevocellular nevi; types
|
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 |
|
junctional nevocellular nevus
|
"mole"
melanocytes transformed to round cells growing in aggregates along dermoepidermal jxn early developmental stage |
|
compound nevocellular nevus
|
more raised and dome-shaped
still symmetrical with uniform pigmentation formed when junctional nevi grow into underlying papillary dermis |
|
intradermal nevocellular nevus
|
epidermal aggregates lost completely to dermis
often removed for cosmetic reasons mature, deep, small, prod little pigment, grow in cords |
|
why is the maturation process of nevi important diagnostically?
|
distinguishes benign nevi from melanomas which have little to no maturation
|
|
dysplastic nevus
|
most common nevus
occurs on trunks small, macular occur throughout life sims- NOT premalignant |
|
malignant melanoma
|
neoplasm of melanocytes
skin, eye, mucous mbrs(rare) primarily adults 80-90% de novo; 10-20% next to melanocytic nevus |
|
what is malignant lentigo?
|
melanoma in situ
radial growth, no metastasis with time, usually has vertical, metastatic component |
|
where do malignant melanomas freq metastasize? and how?
|
widely
regional lymph nodes liver lungs brain hematogenous spread |
|
where is the highest incidence of malignant melanoma in males and females? what does this suggest? which ethnic group?
|
males: trunk
females: leg suggests assoc with sun exposure caucasians |
|
what does it mean if the prevalence of a disease is equal to the incidence?
|
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 |
|
what are the 4 cardinal signs of malignant melanoma?
|
1. asymmetrical
2. irregular borders 3. uneven pigmentation 4. maculopapular |
|
clinical warning signs of malignant melanoma?
|
enlargement of pre-existing mole; itching/pain in pre-existing mole; dev new pigmented lesion in adulthood; irregular borders; varied pigmentation
|
|
how is a malignant melanoma lesion removed? how does this compare to a nevus?
|
mal mel: excised (diagnostic)
then biopsied to confirm nevus: shaved off |
|
what is pagetoid spread? what is this a feature of?
|
when melanocytes are found in the stratum corneum with the keratin
malignant melanoma |
|
what factors are of prognostic significance in malignant melanoma?
|
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 |
|
what are fibroepithelial polyps?
|
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 |
|
where do epithelial inclusion cysts occur and what causes them?
|
obstruction of hair follicle
seen on face and upper extremity |
|
what are epithelial cysts filled with and what is a consequence of trauma?
|
filled with keratin
trauma can lead to chronic inflamm reaction, granuloma formation to keratin released |
|
what are all cysts lined with? why do they grow?
|
epithelium; cyst grows b/c epithelium grows...eventually attenuated
|
|
hemangioma
|
red
thick vessel walls, clustered freq due to exaggerated reaction and not neoplastic most common benign tumor in kids |
|
xanthomas
|
yellow
central nucleus |