Skin Pathology Flashcards
What are the layers of the epidermis?
Stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale
come, lets get sun burned
excoriation
traumatic lesion breaking the epidermis and causing a raw linear area; often self-induced
lichenification
thickened, rough skin; usually the result of repeated rubbing
macule
circumscribed, flat lesion distinguished from surrounding skin by color
onycholysis
separation of nail plate from nail bed
papule
elevated, dome-shaped of flat-topped lesion
plaque
elevated, flat-topped lesion usually greater than 5mm
scale
dry, horny, platelike, excrescence, usually the result of imperfect cornification
pustule
discrete, pus-filled, raised lesion
vesicle (blister)
fluid-filled raised lesion
wheal
itchy, transient, elevated lesion with variable blanching and erythema formed as the result of dermal edema
acanthosis
diffuse epidermal hyperplasia
dyskeratosis
abnormal, premature keratinization within cells below the stratum granulosum
erosion
discontinuity of the skin showing incomplete loss of the epidermis
exocytosis
infiltration of the epidermis by inflammatory cells
hydropic swelling
intracellular edema of keratinocytes, often seen with viral infections
hypergranulosis
hyperplasia of the stratum granulosum, often due to intense rubbing
hyperkeratosis
thickening of the stratum corneum, often associated with qualitative abnormality of the keratin
lentiginous
a linear pattern of melanocyte proliferation within the epidermal basal cell layer
papillomatosis
surface elevation caused by hyperplasia and enlargement of contiguous dermal papillae
parakeratosis
keratinization with retained nuclei in the stratum corneum. normal in mucous membranes
spongiosus
intercellular edema of the epidermis
ulceration
discontinuity of the skin showing complete loss of the epidermis revealing dermis or subcutaneous
vacuolization
formation of vacuoles within or adjacent to cells; usually basement membrane
what are the disorders of pigmentation and melanocytes
freckles (ephelis) lentigo melanocytic nevus dysplasic nevus melanoma
what are the benign epithelial tumors?
seborrheic keratoses
acanthosis nigricans
fibroepithelial polyp
epithelial or follicular inclusion cyst
what are the premalignant and malignant epithelial tumors?
actinic keratosis
squamous cell carcinoma
basal cell carcinoma
what are the tumors of the dermis?
benign fibrous histiocytomas (dermatofibroma)
dermatofibrosarcoma protuberans
what are the tumors of cellular migrants to the skin?
mycosis fungoides
mastocytosis
what is a lentigo?
localized melanocytic hyperplasia
congenital nevus
present at birth
deep dermal and subcutaneous growth
includes neurovascular bundles
increased risk of melanoma
blue nevus
non-nested dermal infiltration often associated with fibrosis
highly dendritic, heavily pigmented cells
black-blue nodule, often confused with melanoma
spitz nevus
fascicular growth
large, plump cells with pink-blue cytoplasm; fusiform cells
common in children
red-pink nodule often confused with hemangioma
halo nevus
lymphocytic (T-cell) infiltration surrounding nevus cells
host immune response against nevus cells and surrounding normal melanocytes
dysplastic nevus
coalescent intraepidermal nests
cytologic atypia
potential marker or precursor for melanoma
malignant melanoma
most deadly of all skin cancers
strongly linked to sun exposure
inherently immunogenic due to T-cell response
what is the pathological marker for melanoma?
HMB-45 (monoclonal antibody)
seborrhetic keratosis
waxy exophytic lesions common in older people
mostly found on the trunk
confused with melanoma
What is Leser-Trelat sign?
crops of seborrhetic keratosis that may indicate cancer
acanthosis nigricans
mostly benign aquired tumor associated with obesity or DM
rarely inherited (AD)
20% associated with malignancy (GI cancer)
fibroepithelial polyp
skin tag or acrochordon
epithelial inclusion cyst
also called a sebaceous cyst or a wen
collections of skin cells that have a tendency to become infected
what are the different adenexal appendages?
eccrine poroma cylindroma syringoma sebaceous adenoma pilomatricoma
what cell signaling molecule is key in the development of normal tissue homeostasis?
what occurs if this pathway is mutated?
SHH binding to PTCH
BCC occurs with mutation
benign fibrous histiocytoma (dermatofibroma)
dermal neoplasm
asymptomatic and non-tender lesions that may change in size over time
associated with antecedent trauma suggesting abnormal response to injury
mneumonic for painful skin lesions
“GLEN DAB”
Glomus tumor (under the nail)
Leiomyoma
Eccrine spiradenoma
Neurofibroma
Dermatofibroma
Angiolipoma
Blue rubber bleb nevus
dermatofibrosarcoma protuberans
primary fibrosarcoma of the dermis
translocation involving genes COL1A1 and PDGFB
mycosis fungoides
cutaneous CD4 T-cell lymphoma
circulating phase = sezary syndrome
mastocytosis
cutaneous cases termed urticaria pigmentosum
increased mast cells in the skin
predominantely children
associated with RTK mutation
What is Darier sign?
localized area of dermal edema and erythema that occurs when mastocytosis lesional skin is rubbed
What are the disorders of epidermal maturation?
ichthyosis
what are the acute inflammatory dermatoses?
urticaria
acute eczematous dermatitis
erythema multiforme
what are the chronic inflammatory dermatoses?
psoriasis
seborrheic dermatitis
lichen planus
what are the blistering diseases?
pemphigus bullous pemphigus dermatitis herpteiformis epidermolysis bullosa porphyria
what are the disorders of epidermal appendages?
acne vulgaris
rosacea
what are the panniculitis disorders?
erythema nodosum
erythema induratum
what are the infectious disorders?
varrucae
molluscum contagiosum
impetigo
superficial fungal infections
ichthyosis
a group of inherited disorders apparent soon after birth characterized by excessive keratin buildup resulting in fish-like scales
acquired variants may be manifestations of malignancy
urticaria
characterized by mast cell degranulation and resultant dermal microvascular hyperpermeability
FcERI receptor binds to Fc portion of IgE
Type 1 hypersensitivity
what are the subtypes of acute eczematous dermatitis?
allergic contact dermatitis atopic dermatitis drug-related dermatitis photoeczematous dermatitis primary irritant dermatitis
erythema multiforme
uncommon self-limited type 4 hypersensitivity reaction to certain infections and drugs
bulls-eye lesion
what infections cause erythema multiforme?
herpes simplex mycoplasmal histoplasmosis coccidoidomycosis typhoid leprosy
what drugs cause erythema multiforme?
sulfonamides penicillin barbiturates salicylates hydantoins antimalarials
what diseases present with erythema multiforme?
SLE
dermatomyositis
polyarteritis nodosa
psoriasis
chronic inflammatory dermatosis with autoimmune basis
pink-salmon colored plaques with loosely adherent silver-white scales
cytology shows monroe microabcesses
15% have associated arthritis
30% have nail changes (yellow-brown)
What is Auspitz sign?
small bleeding points after removing scales from psoriasis plaques
what is the Koebner phenomenon?
what disorders are associated with this phenomenon?
appearance of new lesions after cutaneous injury on previously healthy skin
psoriasis
dermatofibroma
lichen planus
what is treatment for psoriasis?
anti-TNF and anti-IL17 therapy
CD4 target
seborrhetic dermatitis
chronic inflammatory dermatosis in areas with high density sebaceous glands
cytology shows CD4 or neutrophils
what diseases are associated with seborrhetic dermatitis?
HIV with low CD4
Parkinson’s disease
Lichen planus
pruritic, purple, polygonal, planar, papules and plaques
involves skin and mucousa
spontaneously resovles 1-2 years after onset with residual post-inflammatory hyperpigmentation
SCC associated with chronic mucosal lesions
pemphigus
blistering disorder caused by autoantibodies that result in dissolution of intercellular attachments within the epidermis and mucosal epithelium
IgG autoantibodies against desmogleins
bullous pemphigoid
generally affects elderly patients
caused by autoantibodies that bind to proteins required for adherence of basal keratinocytes to basement membrane
dermatitis herpetiformis
rare disorder characterized by urticaria and grouped vesicles
associated with celiac disease and responds to gluten-free diet
granular deposits of IgA that localize to the dermal papillae
epidermolysis bullosa
blanket term for disorders caused by inherited defects in structural proteins that lend mechanical stability to the skin
prone to blisters at or soon after birth
porphyria
inborn or acquired disturbances of porphyrin metabolism
urticaria and vesicles associated with scarring - exacerbated by sun exposure
acne vulgaris
chronic inflammatory dermatitis associated with P. acnes bacteria
also caused by hormal fluctuations and androgens
treat with abx and retinoids
rosacea
chronic inflammatory dermatitis associated with increased/abnormal catheliciden and peptides
associated with activation of TLR
persistent erythema and rhinophyma
panniculitis
inflammation of subcutaneous fat layer
erythema nodosum
type of panniculitis
mneumonic for causes: NO cause found in 60% of cases Drugs Oral contraceptives Sarcoidosis or Lofgren's syndrome Ulcerative colitis, crohn's, bechet's Micro: TB, viral, bacterial and parasitic
erythema induratum
uncommon panniculitis that affects adolescents and menopausal women
possible primary vasculitis of deep vessels supplying fat nodules of subcutaneous skin
erythematous nodules that ulcerate
what bacteria are known to cause impetigo?
S. aureus and group A beta hemolytic strep
what are toxic epidermal necrolysis (TEN) and steven johnson syndrome (SJS)?
severe adverse cutaneous drug reactions
potentionally fatal
hemorrhagic erosions, erythema and severe epidermal detachment presenting as blisters
SJS less severe covering <10% of the body
TEN most severe covering >30% of the body
actinic keratosis
premalignant tumor
tendency to progress to SCC
hard, horn-like lesion
what condition is associated with subcorneal acantholysis?
pemphigus foliaceous
what condition is associated suprabasal acantholysis?
pemphigus vulgaris
what conditions are associated with subepidermal acantholysis?
bullous pemphigoid
dermatitis herpetiformis
