Skin pathology Flashcards
1
Q
Excoriation
A
Lesion disrupting epidermis that causes a raw linear area
Often self-induced
2
Q
Lichenification
A
Thickened, roughened skin with prominent markings
3
Q
Usually the result of repeated rubbing
A
Lichenification
Hypergranulosis
4
Q
Macule or patch
A
Circumscribed flat lesion distinguished form surrounding skin color
5
Q
Onycholysis
A
Separation of nail from nail bed
6
Q
Papule or nodule
A
Elevated, dome shaped or flat topped lesion
7
Q
Plaque
A
Elevated, flat-topped lesion
8
Q
Wheal
A
Itchy, transient, elevated lesion
9
Q
Pustule
A
Discrete, pus-filled, raised lesion
10
Q
Scale
A
Dry, horny, platelike excrescence
11
Q
Usually the result of imperfect cornification
A
Scale
12
Q
Acanthosis
A
Diffuse epidermal hyperplasia
13
Q
Characteristic features of acanthosis
A
Epidermal thickening
Variable degree of hyperkeratosis
14
Q
Acantholysis
A
Intracellular detachment
15
Q
Dyskeratosis
A
Abnormal, premature keratinization with cells below stratum granulosum
16
Q
Erosion
A
Discontinuity of skin, showing incomplete loss of epidermis
17
Q
Exocytosis of skin
A
Infiltration of epidermis by inflammatory cells
18
Q
Hydropic swelling/ballooning
A
IC edema of keratinocytes
19
Q
Hypergranulosis
A
Thickening of stratum granulosum
20
Q
Hyperkeratosis
A
Thickening of stratum corneum
21
Q
Lentiginous
A
Linear pattern of melanocyte proliferation within the epidermal basal layer
22
Q
A
23
Q
Papillomatosis
A
Surface enlargement caused by hyperplasia and enlargement of contiguous dermal papillae
24
Q
Parakeratosis
A
Keratinization with retained nucleus in the stratum corneum
25
Where parakeratosis is normal
Mucous membranes
26
Spongiosis
IC edema of the epidermis causes separation of epithelial cells, particularly in prickle cell layer
27
Ulcerations
Discontinuity of skin marked by complete loss of the epidermis, revealing dermis or subq
28
Vacuolization of skin
Formation of vacuoles within or adjacent to cells
29
General characteristics of acute inflammatory dermatoses
Inflammatory infiltrates
Edema
Variable degree of epidermal, vascular, or subq injury
30
Urticaria
Dilation of vascular structure in the superficial dermis
31
Cause of urticaria
Localized mast cell degranulation with dermal microvascular hyperpermeability
32
Pathogenesis of urticaria
Antigen-induced release of vasoactive mediators
33
Defect in hereditary angioneurotic edema
Inherited deficiency of C1 inhibitor results in excessive activation of early components of the complement system
34
Microscopic features of urticaria
Superficial dermal edema --> spaces between collagen bundles
Dilated lymphatics and vasculature
Normal epithelium
35
General characteristics of dermatitis
Erythematous, papulovesicular, weeping lesions
36
Pathogenesis of allergic contact dermatitis
T-cell mediated inflammatory reactions --> type IV hypersensitivity
37
Pathogenesis of atopic dermatitis
Skin barrier dysfunction due to mutation in filaggrin, an epidermal barrier protein
Inflammation from invading T cells
38
Lab findings in atopic dermatitis
Increased IgE
Eosinophilia
39
Pathophysiology of irritant contact dermatitis
Nonimmunologic response to chemicals or physical agents
40
Common symptoms for all types of dermatitis
Pruritus
Red, papulovesicular, oozing, crusted lesions
41
Self-limited type IV hypersensitivity
Erythema multiforme
42
Characteristic lesions in erythema multiforme
Targetoid
43
Pathogenesis of erythema multiforme
Keratinocyte injury mediated by CD8+ T cells
44
Variants of erythema multiforme
Stevens-Johnson syndrome
Toxic epidermal necrolysis
Overlap
45
Important inciting agent of Stevens-Johnson syndrome
Medications, including sulfonamides
46
Lesions in Stevens-Johnson syndrome
Erosions and hemorrhagic crusts around the lips and oral mucosa and in the perineal area
Cover <10% of body surface area
47
Possible consequence of secondary infection in Stevens-Johnson syndrome
Sepsis
48
Most common cause of toxic epidermal necrolysis
Drug-induced
49
Possible consequences of toxic epidermal necrolysis
Sepsis or death
50
Lesions in toxic epidermal necrolysis
Widespread erythema and necrosis -- >30% body surface
bullous detachment of the epidermis and mucous membrane with exfoliation
51
Koebner phenomenom
Lesions can be induced in susceptible individuals with local trauma
52
Microscopy in psoriasis
Acanthosis
Downward elongation of rete ridges
Parakerotic scale
Thin or absent stratum granulosum
Suprapapillary plates
Auspitz sign
Small aggregates of neutrophils
53
Two types of small neutrophil aggregates seen in psoriasis
Munro microabscesses
spongiform pustules
54
Munro microabscesses
Neutrophils that form small aggregates within the parakeratotic stratum corneum in psoriasis
55
Spongiform pustules
Neutrophils form small aggregates within the superficial epidermis
56
Six P's of lichen planus
Pruritic
Purple
Polygonal
Planar
Papules
Plaques
57
Description of lesions in lichen planus
Itchy, violaceous, flat-topped, popules that coalesce focally and form plaques
Wickham striae
58
Pathogenesis of lichen planus
Expression of altered antigens in the basal epidermal cells or DE junction elicits CTL response
59
Skin lesion associated with HCV
Lichen planus
60
Histological features of lichen planus
Interface dermatitis
Saw-toothing
Civatte/colloid bodies
Hypergranulosis
Hyperkeratosis
61
Rare progression of lichen planus in oral mucosa
Squamous cell carcinoma
62
Caused by colonization of the skin by certain fungal species of genus Malassezia in response to increased sebum production
Seborrheic dermatitis
63
Gross appearance of seborrheic dermatitis
Moist/greasy macules and papules on erythematous, yellow, often greasy base associated with scaling and crusting
64
Herald patch in pityriasis rosea
Well-demarcated, thin, oval to round plaque that is usually pink and erythematous
65
Collarette scale in pityriasis rosea
Ring of tissue-like scale that remains attached within the border of the plaque
66
AN inflammatory reaction in the subq adipose tissue
Panniculitis
67
Two forms of panniculitis
Erythema nodusum
Erythema induratum
68
Clinical presentation in panniculitis
Poorly defined, exquisitely tender, symmetric, erythematous plaques and nodules
69
Pathogenesis of panniculitis
Type IV hypersensitivity to microbial or drug-related antigens
70
Microscopy in early septal panniculitis
Edema, fibrin, and neutrophils in CT septae
71
Microscopy in later septal panniculitis
Lymphocytes, macrophages, and multinucleated giant cells in CT septae
72
Skin disorders with IgG autoantibodies against Dsg1
Pemphigus foliaceus
Impetigo
Scalded skin syndrome
73
Skin disorder with IgG autoantibodies against Dsg1 and Dsg3
Pemphigus vulgaris
74
Skin disorder with autoantibodies against BPAG2
Bullous pemphigoid
75
Skin disorder with IgA autoantibodies to fibrils
Dermatitis herpetiformis
76
Hallmark of pemphigus
Acantholysis
77
Characteristics suprabasal acantholytic blister
Pemphigus vulgaris
78
Reticular pattern in immunofluorescence staining
Deposition of immunoglobulin along plasma membranes of keratinocytes in pemphigus
79
Subepidermal non-acantholytic blisters on microscopy
Bullous pemphigoid
80
On microscopy, fibrin and neutrophils accumulate selectively at tips of dermal papillae
Dermatitis herpetiformis
80
Skin lesions associated with celiac disease
Dermatitis herpetiformis
80
Continuous and linear deposition of IgG and complement in epidermal basement membrane on immunofluorescence
Bullous pemphigoid
81
Characteristic presence of grouped vesicles
Dermatitis herpetiformis
82
Gross appearance of dermatitis herpetiformis
Bilateral, symmetrical, and grouped
Vesicles and plaques that are extremely pruritic
83
Discontinuous, granular deposits of IgA at tips of dermal papillae on immunofluorescence
Dermatitis herpetiformis
84
Pathogenesis of dermatitis herpetiformis
IgA autoantibodies against gliadin in celiac disease cross react with reticular fibers of dermis
85
Types of epidermolysis bullosa
Simplex/epidermolytic
Junctional
Scarring dystrophic
Mixed
86
Disease caused by inherited defects in structural proteins that lend mechanical stability to the skin
Epidermolysis bullosa
87
Non-inflammatory blistering disorders
Epidermolysis bullosa
Porphyria
88
Epidermolysis bullosa type where cleavage occurs in the epidermis
Simplex/epidermolytic
89
Disease caused by mutation in genes for keratins 5 and 14 of basal epithelial cells
Simplex type of epidermolysis bullosa
90
Epidermolysis bullosa type where cleavage occurs in the lamina lucida of the dermis
Junctional type
91
Mutation in junctional type of epidermolysis bullosa
Genes encoding for laminin usually, or for BPAG2
92
Epidermolysis bullosa type where cleavage occurs within the sub-lamina densa
Scarring dystrophic
93
Mutation causing scarring dystrophic type of epidermolysis bullosa
Gene for collagen type VII
94
Pigments normally present in hemoglobin, myoglobin, and cytochromes
Porphyrins
95
Five major types of porphyria
Congenital erythropoietic
Erythrohepatic protoporphyria
Acute intermittent
Porphyria cutanea tarda
Mixed
96
Most common porphyria
Porphyria cutanea tarda
97
Deficiency in porphyria cutanea tarda
Hepatic uroporphyrinogen decarboxylase activity
98
Cutaneous manifestations in porphyria cutanea tarda
Blistering skin lesions, often on hands
Photosensitization
99
Microscopy in lentigo
Linear, non-nested, melanocytic hyperplasia, restricted to basal cell layer
100
Diffuse light to dark brown area of pigmentation of the central face
Melasma
101
Acquired disease of progressive melanocyte loss due to T cell mediated destruction
Vitiligo
102
Fluoresce when illuminated by Wood lamp examination
Patches seen in vitiligo
103
Inheritance pattern of oculocutaneous albinism
Autosomal recessive
104
Pathogenesis of albinism
Normal melanocytes and melanosomes
Reduced or absent melanin due to abnormal synthesis because of tyrosinase deficiency
105
Location of tyrosinase gene
Chromosome 11q14:3
106
Condition associated with albinism
Chediak-Higashi syndrome
107
Pathogenesis of nevus
Acquired activating mutations in components of RAS signaling pathway
108
Nest of nevus cells that grow along the dermo-epidermal junction
Junctional nevi
109
Nuclei in junctional nevi
Uniform and rounded
Inconspicuous nucleoli
Little to no mitotic activity
110
Nests of nevus cells that grow into the underlying dermis with both dermal and epidermal components
Compound nevi
111
Nevus cells in the dermis, epidermal nests may be lost entirely
Intradermal/dermal nevi
112
Gross appearance of dysplastic nevus
Larger, >5 mm
Variegated pigmentation
Irregular borders
113
Microscopy of dysplastic nevus
Nuclear enlargement
Irregular, angulated nuclear contours
Hyperchromasia
114
Embryonic origin of melanocytes
Neural crest
115
Non-sun-exposed skin areas where melanoma can occur
Oral and anogenital mucosa
Esophagus
Meninges
Uvea
116
Syndrome caused by defect in nucleotide excision repair that is precursor to melanoma
Xeroderma pigmentosum
117
Two general pathogenesis of melanoma
Mutations that disrupt cell cycle control genes
Mutations that activate pro-growth signaling pathways
118
Mutation that disrupt cell cycle control genes that can lead to melanoma
CDKN2A gene mutation
119
Encodes for P15, P16, and ARF tumor suppressors
CDKN2A
120
Mutations that activate pro-growth signaling pathways that can lead to melanoma
Aberrant increases in RAS and PI3K/AKT
Activation mutations in BRAF
Mutations that activate telomerase
121
Serine/threonine kinase downstream of RAS that can be mutated in melanoma
BRAF
122
Most consistent clinical signs of melanoma
>10 mm
Color change and variations
Irregular and notched borders
123
Warning signs of melanoma (ABCDEs)
Asymmetry
Borders, irregular
Color, variegated
Diameter, increasing
Evolution
124
Macular area correlates with what phase of melanoma
Radial growth
125
Raised areas corresponding to nodular aggregates of malignant cells correlates with what phase of melanoma
Vertical
126
Clinicopathological classes of the radial phase of melanoma
Lentigo maligna
Superficial spreading
Acral/mucosal lentiginous
127
Melanoma unrelated to sun exposure
Acral/mucosal lentiginous
128
Microscopy in radial phase of melanoma
Nests of malignant cells in epidermis only
129
Heralds vertical growth phase of melanoma
Appearance of nodule that correlates with emergence of tumor subclone with metastatic potential
130
Most important prognostic indicator predicting melanoma metastasis
Breslow thickness
131
Distance from superficial epidermal granular layer to site of deepest intradermal tumor cells
Breslow thickness
132
Melanoma cell histology
Large nuclei with irregular contours and prominent red/eosinophilic nucleoli
133
Melanocyte markers
HMB-45
S-100
134
Fontana-Masson silver stain in melanoma
Fine black dusting of melanin pigment within the cytoplasm of neoplastic cells
135
Tumor depth in melanoma associated with favorable prognosis
<1.7 mm
136
Round, flat, coin-like, waxy plaque with dark keratin-filled surface plugs
Seborrheic keratosis
137
Pathogenesis of seborrheic keratosis
Activating mutations of FGFR3, a receptor tyrosine kinase
138
Characteristic histological features of seborrheic keratosis
Horn cysts
Invagination cysts
139
Invagination cysts in seborrheic keratosis
Invaginations of keratin into the
main mass
140
Horn cysts in seborrheic keratosis
Small keratin filled cysts
141
Skin presentation associated with Leser-Trelat
Seborrheric keratosis
142
Cancer associated with Leser-Trelat
Carcinomas of GI tract --> stomach
143
Cutaneous sign of underlying benign and malignant conditions
Acanthosis nigricans
144
Thickened, hyperpigmented skin with a velvet-like texture, usually in flexural areas
Acanthosis nigricans
145
Benign type of acanthosis nigricans is associated with these conditions
Obesity
Insulin resistance
Endocrine abnormalities --> diabetes, pineal tumor, pituitary tumor
146
Malignant type of acanothsis nigricans is associated with these conditions
Underlying cancers --> GIT adenocarcinomas
147
Pathogenesis of acanthosis nigricans
Increased growth factor receptor signaling in skin
148
Histology of fibroepithelial polyp
Fibrovascular cores by benign squamous epithelium
149
Skin condition that may be associated with diabetes, obesity, and intestinal polyposis
Fibroepithelial polyps
150
Premalignant conditions associated with SCC
Xeroderma pigmentosum
Actinic keratosis
151
In situ lesion of sharpy defined, red, scaling plaques
SCC
152
Invasive lesion that is usually nodular with hyperkeratotic scale that may ulcerate
SCC
153
Invasion of dermis by sheets and islands of neoplastic epidermal cells with variable degrees of differentiation with keratin pearls
SCC
154
Characteristics of invasive tumor cells in SCC
Enlarged nuclei with angulated contours and prominent nucleoli
155
What test may be needed to confirm diagnosis of poorly differentiated SCC
Immunohistochemical stains for keratin
156
Syndromic associations of BCC
Gorlin syndrome
Nevoid BCC syndrome
157
Germline mutation in PTCH gene
Gorlin syndrome
158
Pathogenesis of BCC
Mutations leading to uncontrolled hedgehog signaling pathway
159
Pearly nodules with telangiectasis
BCC
160
Rodent ulcers in BCC
Extensive local invasion after years of neglect or if unusually aggressive
161
Histology of multifocal superficial pattern of BCC
Multifocal growths originate from epidermis and extend over skin surface
162
Histology of nodular lesion pattern of BCC
Grow downwards and extend into the dermis as cords and islands of atypical basophilic cells with hyperchromatic nuclei
163
Palisading of peripheral tumor cells and separation artifacts are seen in what skin cancer
BCC
164
Hyperkeratotic lesions, <1cm, with sandpaper like consistency
Actinic keratosis
165
Cytological atypia in the lowermost layers of the epidermis
Actinic keratosis
166
Histological findings in dermis in actinic keratosis
Superficial dermis contains thickened, pale, blue-gray elastic fibers
167
Lymphoma of skin homing CD4+ T cells
Mycosis fungoides
168
Scaly red-brown patches, raised scaling plaques, and fungating nodules
Mycosis fungoides
169
Pautrier microabscesses
T cell invades the epidermis as single cells in small clusters in mycosis fungoides
170
Spectrum of disorders characterized by increased numbers of mast cells in the skin and other organs
Mastocytosis
171
Urticaria pigmentosa
Cutaneous form of mastocytosis that primarily affects children
172
Darier sign
Localized area of dermal edema and erythema (wheal) when lesional skin is rubbed
173
Dermatographism
Area of dermal edema, resembling a hive, resulting from localized stroking of normal skin
174
Mutations causing mastocytosis
KIT mostly
PDGFR-alpha receptor tyrosine kinases
175
Giemsa staining in mastocytosis
Purple metachromatic granules within the cytoplasm of mast cells
176
Histology of macrocytosis
Numerous ovoid cells with uniform, centrally located nuclei in dermis
177
Site of damage in alopecia areata
Bulb region of anagen hair follicles, resulting in shortened anagen cycle
178
Most common type of hair loss
Androgenetic alopecia or male pattern baldness
179
Nonscarring progressive miniatruization of the hair follicle
Androgenetic alopecia
180
Androgen chiefly responsible for the follicular pathology
DHT
181
Treatment for androgenetic alopecia
Minozidil
finasteride
182
Chronic and debilitating inflammatory disorder of the hair follicles
Hidradenitis suppurativa
183
Characteristics of lesions in hidradenitis suppurativa
Inflammatory nodules, subq abscesses, and sinus tracts
184
Primary pathogenesis of hidradenitis suppurativa
Hyperkeratotic plugging of the terminal hair follicle resulting in follicular duct rupture
185
Clinical hallmark of noninflammatory acne vulgaris
Comedone
186
Follicular papules contain a central black keratin plug due to the oxidation of melanin pigments
Open noninflammatory acne vulgaris
187
Follicular papules without visible central keratin plug, as it is trapped beneth the epidermal surface
Closed noninflammatory acne vulgaris
188
Inflammatory acne vulgaris
Papules
Pustules
Nodules
189
Four factors of pathogenesis of acne vulgaris
Hyperkeratinization
Hypertrophy of sebaceous glands
Lipase synthesizing bacteria
Secondary inflammation
190
Lipase synthesizing bacteria in acne vulgaris
Cutibacterium acnes
Propionibacterium acnes
191
4 stages of rosacea
-Flushing episodes
-Persistent erythema and telangiectasia
-Pustules and papules
-Rhinophyma
192
Permanent thickening of the nasal skin by confluent erythematous papules and prominent follicles due to hypertrophy of sebaceous glands and follicular plugging by keratotic debris
Rhinophyma stage of rosacea
193
Associated with chronic hyperkeratosis leading to fish-like scales
Ichthyosis
194
Pathogenesis of ichthyosis
Degective keratinocyte desquamation leading to retention of an abnormally formed scale
195
Mutation in ichthyosis
Loss of function mutations in the filaggrin gene
196
Acquired non-inherited variant of ichthyosis
Ichthyosis vulgaris
197
Possible associations of ichthyosis vulgaris
Lymphoid and visceral malignancies
198
Inheritance of xeroderma pigmentosum
Autosomal recessive with 100% penetrance
199
Eye changes in xeroderma pigmentosum
-Conjunctival injection with photophobia and melanosis
-Corneal scarring
-Pterygium
-Cancer of the eyelid
