Dermatopathology Flashcards
1
Q
traumatic lesion breaking the epidermis and causing a raw linear area (i.e., deep scratch); often self-induced
A
excoriation
2
Q
thickened, rough skin (similar to a lichen on a rock); usually the result of repeated rubbing
A
lichenification
3
Q
circumscribed, flat lesion distinguished from surrounding skin by color
macules = 5mm or less
patches = greater than 5mm
A
macule, patch
4
Q
separation of nail plate from nail bed
A
onycholysis
5
Q
elevated dome-shaped or flat-topped lesion
papules = 5mm or less
nodules = greater than 5mm
A
papule, nodule
6
Q
elevated flat-topped lesion, usually greater than 5mm across
A
plaque
7
Q
discrete, pus-filled, raised lesion
A
pustule
8
Q
dry, horny, platelike excrescence
usually the result of imperfect cornification
A
scale
9
Q
fluid-filled raised lesion
vesicle = 5mm or less
bulla = greater than 5mm
blister = common term for either
A
vesicle, bulla, blister
10
Q
itchy, transient, elevated lesion with variable blanching and erythema formed as the result of dermal edema
A
wheal
11
Q
diffuse epidermal hyperplasia
A
acanthosis
12
Q
abnormal, premature keratinization within cells below the stratum granulosum
A
dyskeratosis
13
Q
discontinuity of the skin showing incomplete loss of the epidermis
A
erosion
14
Q
infiltration of the epidermis by inflammatory cells
A
exocytosis
15
Q
intracellular edema of keratinocytes, often seen in viral infections
A
hydropic swelling
16
Q
hyperplasia of the stratum granulosum, often due to intense rubbing
A
hypergranulosis
17
Q
thickening of the stratum corneum, often associated with a qualitative abnormality of the keratin
A
hyperkeratosis
18
Q
linear pattern of melanocyte proliferation within the epidermal basal cell layer
A
lentiginous
19
Q
surface elevation caused by hyperplasia and enlargement of contiguous dermal papillae
A
papillomatosis
20
Q
keratinization with retained nuclei in the stratum corneum
on mucous membranes = normal
A
parakeratosis
21
Q
intercellular edema of the epidermis
A
spongiosis
22
Q
discontinuity of the skin showing complete loss of the epidermis revealing dermis or subcutis
A
ulceration
23
Q
formation of vacuoles within or adjacent to cells
often refers to basal cell-basement membrane zone area
A
vacuolization
24
Q
appear AFTER sun exposure
fade and darken cyclically with season changes
A
freckle (ephelis)
25
increase melanin pigment in basal keratinocytes
hyperpigmentation
26
in neurofibromatosis: similar histology to freckle
larger, arise independently of sun exposure
contain aggregated melanosomes (macromelanosomes) in cytoplasm of melanocytes
café au lait spots
27
benign localized hyperplasia of melanocytes
initiated in infancy/childhood
do NOT darken when exposed to sunlight
linear melanocytic hyperplasia
restricted to cell layer immediately above basement membrane
lentiginous
lentigo
28
mutations in RAS or BRAF
p16/INK4a permanent growth arrest
uniformly pigmented
well defined rounded borders
melanocytic nevus (mole)
29
nests at dermoepidermal junction
junctional nevus
30
nest in epidermis & dermis
compound nevi
31
no epidermal nests
usually older lesions
intradermal nevi
32
superficial: nests, large-rounded cells, increased melanin
deeper: cords or single cells, smaller, decreased pigment
deepest: fusiform, fascicles resembling neural tissue
melanocytic nevus benign histo
33
AD, \>50% chance developing melanoma by age 60
CDKN2A or CDK4 gene
dysplastic nevus syndrome
34
mutations in NRAS & BRAF
larger than acquired nevi, \>5mm, can be hundreds
variegated pigmentation, **irregular** borders
**lentiginous hyperplasia**: single nevus cells replace basal cells along E-D junction
**atypia**: large nuclei, irregular angulated nuclear contour, hyperchromasia
lymphocytic infiltrates, **melanin incontinence**
linear fibrosis
**shouldering**: junctional component \> 2 rete ridges beyond dermal component
dysplastic nevi
35
most deadly of all skin cancers
mutations caused by UV radiation in sunlight
melanoma
36
Light complexion, hair, eyes
History of blistering sunburn(s)
Proximity to the equator
Indoor occupation; outdoor hobbies
Family history of melanoma or dysplastic nevi
Precursor lesions (congenital or dysplastic nevi)
*Xeroderma pigmentosum*
melanoma risk factors
37
blacks and Asians
palms, soles, mucous membranes, nail beds
acral melanoma (acral lentiginous melanoma)
38
**A**symmetry
Irregular **B**orders
Variegated **C**olor
Increasing **D**iameter
**E**volution/changeover time (esp rapid)
**Any pigmented lesion with diameter \>6mm, any change, itching or pain**
ABCDEs of melanoma
39
disrupt cell cycle control genes: **CDKN2A** in 40% familial, 10% sporadic → encodes p15, p16, ARF
activate pro-growth signaling: increase **RAS** & **P13K/AKT** signaling; **BRAF** 40-50% of melanomas, 15-20% **RAS**
activate telomerase: **TERT** in 70%
mutations in melanoma
40
horizontal spread
lack capacity to metastasize
lentigo maligna: indolent lesion on face of older men
superficial spreading: most common type, sun-exposed skin
acral/mucosal lentiginous: unrelated to sun exsposure
radial growth melanoma
41
vertical downward growth into deeper dermis
appearance of **_nodule_** correlates with emergence of tumor subclone with metastatic potential
probability of metastasis correlates with depth
vertical growth melanoma
42
distance from superficial epidermal granular cell layer to deepest intradermal tumor cells
Breslow thickness
43
thinner tumor depth
NO mitosis
brisk tumor infiltrating lymphocyte response
NO regression
lack of ulceration
favorable melanoma prognosis
44
metastases
and degree of LN involvement correlates with overall survival
poor melanoma prognosis
45
middle age or older
arise spontaneously, mainly trunk
_dermatosis papulosa nigra_: POC, mult small lesions on face
round, flat, **coin-like, waxy papules**; tan-dark brown
**velvety** or granular surface
**_pore-like ostia impacted with keratin_**
**horn cysts**
mutations in **FGFR-3**
seborrheic keratoses
46
paraneoplastic syndrome
sudden appearance of large # of seborrheic keratoses
associated with **carcinomas of GI tract**
Leser-Trélat sign
47
cutaneous sign of several underlying benign & malignant conditions
**thickened, hyperpigmented** skin with **velvet-like texture** in **flexural** areas; **intertriginous** areas
**80%** assoc with benign condition (obesity & diabetes)
mutation in FGFR3 or increase stimulation IGFR1
acanthosis nigricans
48
head, neck, trunk, face & **intertriginous** areas; middle age –elderly
assoc **diabetes, obesity, & intestinal polyposis**
soft, flesh-colored, slender stalk
fibroepithelial polyp (acrochordon, skin tag)
49
invagination & cystic expansion of epidermis or hair follicle
subject to traumatic rupture, spill **keratin** into the dermis → extensive & painful **granulomatous** inflammatory **response**
epithelial or follicular inclusion cyst (Wen)
50
multiple **trichilemmomas**, loss of function in ***PTEN***
↑ risk for endometrial cancer, **breast cancer**, etc
Cowden syndrome
51
ductal differentiation, forehead or scalp; **“jigsaw puzzle”**
tumors coalesce, multiple confluent nodules, **hat-like** growth, multiple potato-like tumors, ***CYLD** (tumor suppressor gene)*
*CYLD* assoc genetic syndromes: Familial Trichoepithelioma & **Brooke-Spiegler Syndrome** (CYLD cutaneous syndrome)
cylindroma
52
**Muir-Torre** syndrome (internal malignancies)
hereditary nonpolyposis colorectal carcinoma syndrome (**Lynch syndrome**)
DNA mismatch repair proteins
sebaceous adenoma
53
gene PTCH
nevoid basal cell carcinoma syndrome
54
CDKN2
familial melanoma syndrome
55
internal malignancy (colon)
Muir-Torre syndrome
56
sun damaged skin, hyperkeratosis
progressively worsen → **squamous cell carcinoma (SCC)**
\<1cm, tan-brown, red or skin colored, rough sandpaper-like consistency
**cutaneous horn**: excessive keratin production
**dyskeratosis** (pink cytoplasm), intracellular bridges, blue-gray **elastosis** (sun damage), **parakeratosis**
_actinic cheilitis_: similar lesions on the **lips**
actinic keratosis
57
2nd most common tumor arising in sun exposed areas
\<5% metastasize to regional LN
DNA damage induced by UV light
immunosuppression, chemotx, organ transplant (infection-HPV 5 & 8)
epidermodysplasia verruciformis: AR, HPV implicated, increase cutaneous SCC
squamous cell carcinoma
58
**TP53** mutations high in Caucasians (p53 dysfunction)
mutations in **RAS** signaling & **decrease Notch** signaling
squamous cell carcinoma mutations
59
AR, ***XPA*** **gene**, mutation in nucleotide excision repair pathway, accurate repair of pyrimidine dimers, ↑SCC risk
xeroderma pigmentosum
60
**sharply defined, red, scaling plaques**
atypical (**enlarged & hyperchromatic**) nuclei involve **all levels** of epidermis
in situ squamous cell carcinoma lesions
61
**nodular, keratin** production (**hyperkeratotic scale**), may **ulcerate**
anaplastic cells, **dyskeratosis** (single-cell keratinization)
invasive squamous cell carcinoma lesions
62
most common invasive cancer
slow growing, rarely metastasize
sun exposed sites, immunosuppression, xeroderma pigmentosum
basal cell carcinoma
63
unbridled **_Hedgehog**_ signaling, _**PTCH_** gene
basal cell carcinoma gene
64
aka **Gorlin** syndrome = **basal cell nevus** syndrome
AD, **mult BCC \<20yo**, plus medulloblastoma, ovarian fibromas, odontogenic keratocysts, pits of palms & soles
nevoid basal cell carcinoma syndrome
65
**pearly** papules, **telangiectasias**, **rodent ulcers**
basophilic/basaloid cells, hyperchromatic nuclei, **_peripheral palisading_** (arranged radially with their long axes in parallel alignment)
artificial clefts separate stroma from tumor
basal cell carcinoma characteristics
66
benign dermal neoplasm of uncertain origin
adults, legs of young-middle age women
asymp/tender, +/-size over time, indolent
**dimple sign**: lateral pressure on the skin produces a depression
firm, tan-brown papules, \<1cm, become flattened with time
benign **spindle-shaped** cells, well defined, non-encapsulated mass in mid dermis
overlying epidermal hyperplasia, downward elongation of hyperpigmented rete ridges = **pseudoepitheliomatous hyperplasia**
benign fibrous histiocytoma (dermatofibroma)
67
well differentiated primary _fibro_**_sarcoma_** of the skin
slow growing, locally aggressive, can recur, rarely metz
translocation ***COL1A1*** & ***PDGFB***
“protuberant” nodule, usually trunk, firm indurated plaque +/-ulcerate
closely packed fibroblasts arranged radially, ie blades of a **pinwheel**= **storiform** (school of fish)
**honeycomb pattern** = deep extension from the dermis into the subQ fat
dermatofibrosarcoma protuberans (DFSP)
68
CD4+ T helper cells in skin
remains localized for many years, may ***eventually*** evolve into **systemic lymphoma**
\>40yo, truncal lesions, **scaly, red-brown patches** (can be confused with psoriasis), fungating nodules
prognosis: % of body surface involved, & progression from patch →plaque →nodule
eczema-like lesions = early stages; multiple tumor nodules = systemic spread
mycosis fungiodes (cutanteous T-cell lymphoma)
69
topical steroids or UV light
treatment for mycosis fungiodes, Sézary syndrome
70
**erythroderma**, diffuse erythema & scaling of entire body surface
**Sézary cells**: markedly folded nuclear membrane, hyperconvoluted or **cerebriform** contour
**Band-like aggregates** within the superficial dermis
**Pautrier microabscesses**: small clusters of cells in the epidermis
Sézary syndrome
71
cutaneous form, children, \>50% of mastocytosis cases
multiple, widely distributed lesions, round-oval, red-brown, nonscaling papule & small plaques
urticaria pigmentosa
72
young kids, pink-tan brown nodule, +/- pruritic or blister formation
solitary mastocytoma
73
released when mast cells degranulate
histamine, heparin
74
localized area of dermal edema & erythema (wheal) when skin is rubbed
darier sign
75
area of dermal edema resembling hive
result of local stroking skin with pointed instrument
dermatographism
76
_pruritus & flushing_; triggered by certain foods, temperature changes, alcohol, rugs (morphine, codeine, aspirin); _rhinorrhea_; rarely _GI or nasal bleeding_; _bone pain_
**osteoporosis** in premenopausal women & men due to excessive histamine release in BM
mastocytosis systemic symptoms
77
impaired epidermal maturation, chronic excessive keratin buildup (**_hyperkeratosis_**) that results in clinically **fish-like scales**
defective desquamation → retain abnormally formed scale
buildup of compacted stratum corneum
*ichthyosis vulgaris* (AD or acquired) - may be associated with _lymphoid & visceral malignancies_
ichthyosis
78
acute lesions characterized by inflammatory infiltrates (lymphocytes & macrophages)
chronic lesions assoc with changes in epidermal growth or dermal fibrosis
inflammatory dermatoses
79
**localized mast cell degranulation** → dermal microvascular hyperpermeability
**_antigen-induced release of vasoactive mediators from mast cells_**
**wheals**: pruritic edematous plaques
**angioedema**: (closely related to urticaria) edema of the deeper dermis & subQ fat
macro: small, pruritic papules to large edematous plaques
micro: sparse superficial perivenular infiltrate of mononuclear cells
urticaria
80
follows exposure to different antigens
type I hypersensitivity reaction
mast cell-dependent, IgE-dependent urticaria
81
results from substances that directly incite the degranulation of mast cells (opiates, certain antibiotics, radiographic contrast media)
mast cell-dependent, IgE-independent urticaria
82
triggered by local factors that increase vascular permeability
exposure to chemicals/drugs: **aspirin** (inhibit cyclooxygenase & arachidonic acid production)
hereditary angioneurotic edema: def of C1 inhibitor → excessive activation of early components of complement system
mast cell-independent, IgE-independent urticaria
83
**external** application of **Ag** (poison ivy) *or* **internal circulating Ag** (**ingested** food or drug)
urushiol in **poison ivy/oak** (Rhus toxicodendron)
**T-cell mediated inflammatory rxn - _type IV_ hypersensitivity**
TX: palliative; topical steroids
red, papulovesicular, oozing & crusted (impetiginization) lesions (if persists, dev _acanthosis_ & _hyperkeratosis_→ raised scaling plaques)
acute eczematous dermatitis
84
acute eczematous dermatitis, **edema** in intracellular spaces, splaying them apart, particularly in stratum spinosum → intraepidermal vesicles
spongiosis
85
**self-limited hypersensitivity rxn** to certain infections & drugs
_infections_: herpes simplex, mycoplasma, histoplasmosis, coccidiodomycosis, typhoid, leprosy
_drugs_: sulfonamides, PCN, barbiturates, salicylates, hydantoins, antimalarials
_cancer_: carcinomas & lymphomas
_collagen vascular dz_: SLE, dermatomyositis, polyarteritis nodosa
CD8+ cytotoxic T lymphocyte mediated
targetoid lesions
interface dermatitis, Stevens-Johnson, toxic epidermal necrolysis
erythema multiforme
86
children, extensive skin involvement plus _oral mucosa_, _conjunctiva_, _urethra_, _genital_ & _perianal areas_
secondary infections can lead to life-threatening sepsis
Steven-Johnson
87
autoimmune basis
**Koebner phenomenon**: induce psoriatic lesions in susceptible pts by local trauma, starts a self-perpetuating local inflammatory response
**pink to salmon** colored plaque covered by **silver scale**
30% with _nail changes_: pitting, yellow-brown discoloration, oncolysis
elongation of rete ridges “test tubes in a rack”
extensive _parakeratotic scale_
munro microabscesses: small PMN aggregates in parakeratotic stratum corneum
Auspitz sign: mult, minute, bleeding points when scale lifted from plaque
psoriasis
88
mulitple, minute, bleeding points when scale lifted from plaque
Auspitz sign
89
**TNF** & **IL-17** inhibitors
psoriasis treatment
90
in areas with increase sebaceous glands
inflammation of epidermis (NOT disease of sebaceous glands)
increase sebum production
_Parkinson's disease_: increase sebum production secondary to dopamine def (tx levadopa)
**follicular lipping**: mounds of parakeratosis containing neutrophils and serum at ostia of hair follicles
seborrheic dermatitis
91
Pruritic
Purple
Polygonal
Planar
Papules
Plaques
6 P's of Lichen Planus
92
Pruritic, Purple, Polygonal, Planar, Papules, Plaques
self limited resolves spontaneously
_SCC_ can rarely occur in chronic cases
_Koebner phenomenon_ (also seen in psoriasis)
itchy **violet**, flat-topped **papules**, that may coalesce
**Wickham striae**: papules highlighted with white dots, areas of hypergranulosis
**sawtoothing**: angulated zigzag contour of dermoepidermal surface
**Civatte bodies**: anucleate, necrotic basal cells in dermis
lichen planus
93
produce dramatic lesions which can be fatal if untreated
blisters occur at different levels of skin
histologic assessment essential for accurate diagnosis
bullous diseases
94
**autoantibodies dissolution of intracellular attachments**
may be **fatal** without tx
**IgG autoantibodies** disrupt intracellular adhesions → blisters
**Net-like pattern of intercellular IgG deposits;** _vulgaris_ = all levels, _foliaceus_ = superficial
**Tx**: immunosuppressives
**acantholysis:** dissolution of intercellular bridges connecting squamous epith cells (acantholytic cells dissociate from one another, become rounded)
pemphigus
95
most common
_mucosa_ & skin of scalp, face, axilla, groin, trunk, & _points of pressure_
histo: “tombstones”; immunofluor: fishnet-like pattern
superficial vesicles rupture easily → shallow erosions with dried serum & crust
pemphigus vulgaris
96
rare
large moist verrucous (_wart-like_) vegetating plaques with pustules
groin, axilla, & _flexural_ surfaces
pemphigus vegetans
97
**elderly**; _flexor_ surfaces
_BPAGs_: bullous pemphigoid antigens, components of hemidesmosomes
do NOT rupture easily; subepidermal, **non**acantholytic blisters
bullous pemphigoid
98
urticarial & grouped vesicles; men
B/L, symmetric, grouped lesions on **extensor** surfaces of elbows, knees, upper back, butt
assoc with **celiac disease**: dev **IgA Abs** to gluten, Abs cross react with **reticulin** → **subepidermal** blister
dermatitis herpetiformis
99
inherited defects in structural proteins
**blisters** at sites of **pressure**, **rubbing**, **trauma** at _birth_
electron microscopy to differentiate types
epidermolysis bullosa
100
group of inborn/acquired disturbances in porphyrin metabolism
**porphyrins**: pigments normally present in **Hgb**, **myoglobin**, & **cytochromes**
urticaria & vesicles assoc with **scarring**, exacerbated by **sunlight**
porphyria
101
middle age/older; females
4 stages: 1. flushing, 2. persistent erythema & telangiectasia, 3. pustules/papules, 4. **rhinophyma** (permanent thickening of nasal skin)
assoc with high cutaneous levels of antimicrobial peptide **_cathelicidin_**
rosacea
102
**open comedones**: central black keratin plug
**closed comedones**: keratin plug trapped under epidermal surface
**multifactorial**: 1. _keratin_ blocks sebum outflow, 2. sebaceous gland _hypertrophy_, 3. _propionibacterium acnes_ colonize hair follicles, 4. secondary _inflamm_ of follicles
_acne congloblate_: severe variant, sinus tract formation & dermal scarring
acne vulgaris
103
antibiotics for propionibacterium acnes, 13-cis-retinoic acid (isoretinoin) → antisebaceous action
acne vulgaris tx
104
inflammatory rxn in subQ adipose tissue
erythema nodosum (most common)
erythema induratum
panniculitis
105
poorly defined, **exquisitely tender** erythematous plaques & nodules, more readily palpated (ropy) than seen
delayed hypersensitivity rxn to microbial or drug related antigens
infectious **β-hemolytic streptococcal infection, tuberculosis**, or less commonly coccidiodomycosis, histoplasmosis, & leprosy
drugs: sulfonamides, oral contraceptives
sarcoidosis, IBD, & certain malignant neoplasms
erythema nodosum
106
uncommon; adolescents, menopausal females
NOT assoc with any disease
primary **vasculitis of deep vessels** supplying fat lobules of the subQ → **fat necrosis & inflammation**
erythematous, slightly tender nodule that usually **ulcerates**
_early lesions_: **necrotizing vasculitis** of sm-med arteries & veins in deep dermis & subQ
granulomatous inflammation & zones of **caseous necrosis** involving fat lobule
erythema induratum
107
warts
squamoproliferative DOs caused by **HPV**
**anogenital** warts: HPV types **6** & **11**
HPV type **16** assoc with **in situ SCC** of the genitalia and **bowenoid papulosis** (genital lesions of young adults with the histo appearance of carcinoma in situ, usually regress spontaneously)
HPV subtypes **5** & **8** related to **SCC**, esp indv with **epidermodysplasia verruciformis - d**ev mult flat warts, some progress to carcinoma
_keratohyaline_ granules, _verrucous_ or _papillomatous_ epidermal _hyperplasia_, _koliocytosis_ (cytoplasmic vacuolization)
verrucae
108
common, self limited **poxvirus** infection
virus is brick shaped, dumbbell shaped DNA core
trunk & anogenital regions
firm, pruritic, pink-skin colored **umbilicated** papules; curd-like material can be expressed from umbilication
Giemsa or H&E: molluscum bodies= ellipsoid, homogeneous, _cytoplasmic inclusion_
molloscum contagiosum
109
common superficial bacterial infection of skin; highly contagious
***Staphylococcus aureus*** → toxin causing epidermal injury
toxin cleaves **desmoglein 1**
**e**rythematous macule initially, then mult small pustules which break → shallow erosions
**Honey colored crust**: drying serum, if crust not removed, new lesions form around periphery & extensive epidermal damage may occur
impetigo
110
confined to stratum corneum
Tinea capitis: scalp
Tinea barbae: beard
Tinea corporis: common; on body surface
Tinea cruris: inguinal areas of obese men during warm weather
Tinea pedis: bacterial superinfection
Tinea versicolor: upper trunk; Malassezia furfur (yeast)
superficial fungal infections
