Dermatopathology Flashcards
(104 cards)
1
Q
Freckle (Ephelis)?
A
- Most common pigmented lesion of childhood
- 1mm to several tan to reddish brown after sun exposure
- Fades and darkens cyclically with seasonal changes
2
Q
What are Cafe au lait spots and when are they seen?
A
- Similar histology to freckles but larger and arise indpenendently of sun
- Seen in neurofibromatosis
- Contain aggregated melanosomes in cytoplasm of melanocytes
3
Q
What is Lentigo, what does it look like, and its histo?
A
- Benign localized hyperplasia of melanocytes
- Initiated in infancy and chilhood and occurs at all ages
- 5-10 mm oval tannish brown macules or patches found on mucous membranes and skin
- Do NOT darken with sun
- Histo: Linear melanocytic hyperplasia, restricted to cell layer above the BM
4
Q
What is a melanocytic nevus? What is the mutation? What does it look like?
A
- Mole, benign growth acquired by mutations in RAS or BRAF signaling paths
- <6mm tannish brown uniformly pigmented flat macule or elevated papule with well defined roun borders
5
Q
Histology of a melanocytic nevus?
A
- Superficial nests : Large round cells with increased melanin
- Deeper: cords or single cells, smaller cells with decreased pigment
- Deepest: fusiform fasicles resembling neural tissue
- Helpful in differentiating benign nevi from melanoma
6
Q
Junctional nevi?
A
Nests at dermoepidermal junction
7
Q
Compound nevi?
A
- nests or cords grow into underlying dermis and nests in epidermis and dermis
8
Q
Intradermal nevi?
A
- no epidermal nests usually older lesions
9
Q
What is a dysplastic nevi? What mutations?
A
- multiple can increase risk of melanoma
- not all dysplastic nevi lead to melanoma and not all melanoma comes from dysplastic nevi
- NRAS & BRAF
10
Q
What does the histology of dysplastic nevi look like?
A
- larger than acquired nevi >5 mm can be hunreds
- Variegated pigmentation irregular borders of lesions
- Enlarged epidermal nests that may coalesce with other nests
11
Q
What is lentiginous hyperplasia?
A
- single nevus cells replacec basal cells along E-D junction
- Histology seen in dysplastic nevi
12
Q
What is Atypia?
A
- Ig nuclei with irregular angulated nuclear contour hyperchromasia
13
Q
Melanoma location?
A
- Skin
- Oropharynx
- GIGI tracts
- Esophagus
- Meninges
- Uvea of eye
14
Q
If melanoma is inherited what is the pattern?
A
- AD 10-15% of people
- majority sporadic though
15
Q
Melanoma risk factors?
A
- light complexion hair eyes
- history of blistering subnurns
- proximity to equator
- Indoor occupation outdoor hobbies
- Family hx of melanoma or dysplastic nevi
- PJrecurosor lesions
- XP
16
Q
Where will melanoma show up more likely on african americans and asians?
A
- Soles
- Mucous membranes
- Palms
- Nail beds
17
Q
Driver mutations in melanoma? What does it encode?
A
- CDKN2A in 40% AD familial melanomas and 10% in sporadic
- p15. p16 ARF
- Increased RAS and P13K/AKT signaling activation of pro growth signaling
- BRAF in 40-50% melanomas
- Activate telomerase TERT in 70% tumors
18
Q
What is radial growth?
A
- Horizontal spread of melanoma within the epidermis and superficial dermis, cells lack the ability to metastasize
- lentigo maligna: indolent lesion on face of older men can stay in growth phase for several decades
- Superficial spreading is the most common and related to sun exposure
- Acral/mucosal lentiginous: melanoma un related to sun exposure
19
Q
What is vertical growth?
A
- tumor cells invade down into dermal layers as expansible mass after an unpredictable amount of time in radial phase
- appearance of nodule and correlates with emergence of tumor subclone with metastatic potential
- Probability of metastasis in a lesion correlates with depth of invasion
20
Q
Favorable prognosis with melanoma?
A
- thinner tumor depth
- NO mitosis
- Brisk tumor infiltrating lymphocyte response
- NO regression
- Lack of ulceration
21
Q
What are the types of benign epithelial tumors?
A
- Seborrheic keratoses
- Acanthosis nigricans
- Fibroepithelial polyp
- Epithelial or follicular inclusion cyst (Wen)
22
Q
What is Seborrheic Keratoses? Mutation?
A
- Middle age or older individuals arises spontaneously in the trunk primarily, extremities, head and neck
- Round flat coin like waxy papules that are tan dark brown, velvet or granular surface
- pore like ostia impacted with keratin
- horn cysts
- Mutation is FGFR-3
23
Q
Dermatosis papulosa nigra?
A
- people of color get multiple small lesions on their face
- (seborrheic keratosis)
24
Q
What is Leser-Trelat sign?
A
- Paraneoplastic syndrome, sudden appearance of large numbers of Seb Ks
- assoc with carcinomas of GI tract
25
Acanthosis nigrican?
* cutaneous sign of several underlying benign and malignant conditions
* Thickened hyperpigmented skin with velvet like texture in flexural areas or intertriginous areas
* 80% assoc. with obesity and diabetes
* Remaining cases with cancer such as GI adenocarcinomas
* familial form FGFR3
* DM2 mutation in IGFR1
26
Acanthosis nigricans histology?
* Epidermis and underlying elnarged dermal papillae undulate sharply into numerous peaks and valleys
* Variable hyperplasia with hyperkeratosis and slight basal cell layer hyperpigmentation
* no melanocytic hyperplasia
27
What is a Fibroepithelial polyp? Histology? Tx?
* aka Acrochordon, squamous papilloma, skin tag
* assoc diabetes, obesity and intestinal polyposis
* Soft flesh colored bag like tumors attached by slender stalk
* Fibrovascular cores covered by squamous epithelium
* Torsion leading to ischemic necrosis to removal
28
What is epithelial or follicular inclusion cyst (Wen)?
* Invagination and cystic expansion of epidermis or hair follicle
* Subject to traumatic rupture spilling keratin into dermis
* extensive and painful granulomatous inflammatory responses
29
Adnexal tumors?
* hundreds of neoplasms arising from or showing differentiation toward cutaneous appendages
* Nondescript flesh colorerd solitary or multiple papules and nodules
30
What is Cowden syndrome?
* Multiple trichilemmomas
* loss of function in PTEN
* Increase risk for endometrial cancer and breast cancer
* (adnexal tumor)
31
What is Cylindroma?
* Ductal differentiation on forehead or scalp
* "Jigsaw puzzle"
* Turban tumor : CYLD
* CYLD assoc genetic syndroms like familial trichoepithelioma and brooke spiegler
32
Eccrine poroma?
palms and soles where there are increased sweat glands
33
Syringoma?
* Eccrine differentiation small tan papules lower eyelids
* (adnexal tumors)
34
Sebaceous adenoma?
* Muir Torre syndrome
* Hereditary nonpolyposis colorectgal carcinoma (Lynch Syn.)
* DNA mismatch repair proteins
* Adnexal tumor
35
Pilomatricoma?
* follicular differentiation
* CTNNB1 encoding B-catenin
* Hair growth and maintenance
* Adnexal tumor
36
Premalignant and Malignant epidermal tumors?
* Actinic Keratosis
* SCC
* BCC
37
Actinic Keratosis?
* Sun damaged skin hyperkeratosis on the face arms and dorsum of hands
* Lightly pigmented people, ionizing radiation exposure, industrial hydrocarbons, arsenic
* Progressively worsens to SCC if given enough time
* \<1 cm tan to brown red or skin colored, sandpaper consistency
* Cutaneous horn due to excessive keratin production
* Dyskeratosis with intracellular bridges, blue gray elastosis, parakeratosis
* Actinic Chelitis: similar lesions on lips
38
What are the first and second most common tumor arising in sun exposed areas?
1. BCC
2. SCC
39
Epidermodysplasia verruciformis? What does it have increased risk for?
* HPV is implicated in cause
* Increased risk for cutaneous SCC
40
SCC mutation?
* Acquired defects in precursor AK, TP53 mutations
* p53 dysfunction is an early event
* Mutations in RAS and decreasing notch signaling
41
What is XP?
* XPA gene mutation in NER pathway with decrease repair of pyrimidine dimers and increased SCC risk
42
How do in situ lesions in SCC look?
* sharply defined red scaling plaques
* atypical enlarged and hyperchromatic nuclei involving all levels of epidermis
43
How do SCC invasive lesions look?
* Lesions are nodular, keratin production may ulcerate
* anaplastic cells and dyskeratosis seen
44
BCC timeline?
* Slow growing
* Rarely metz
* Cured by local excision
45
BCC what gene is disrupted?
* Unbridled Hedgehog signaling with the PTCH gene
46
What is the Nevoid basal cell carcinoma syndrome and its other names?
* Gorlin syndrome
* Basal cell nevus syndrome
* AD multiple BCC \<20 yo plus medulloblastoma, ovarian fibromas, odontogenic keratocysts, pits of palms and soles
47
What does BCC look like?
* Pearly papules, telangiectasia, rodent ulcers
* Basophilic basasloid cells, hyperchromatic nuclei, peripheral palisading
48
What are the tumors of the dermis?
* Benign Fibrous Histiocytoma
* Dermatofibirosarcoma Protuberans
49
What is Benign Fibrous Histiocytoma? Where is it found, what does it look like, what does histo look like?
* Benign dermal neoplasm of uncertain origin
* Adults, and middle age women particularly on legs
* Asx or tender may or may not increase in size over time
* Many have hx of antecedent trauma with abnormal response to injury and inflammation
* Firm town brown papules less than 1 cm flatten with time
* Benign spindle shaped cells well defined non encapsulated mass in mid dermis
50
Psuedoepitheliomatous hyperplasia?
* overlying epidermal hyperplasia downward elongation of hyperpigmented rete ridges
51
Dermatofibrosarcoma Protuberans (DFSP)? Describe timeline, translocation, and histology?
* Well differentiated primary fibrosarcoma of skin
* Slow growing locally aggressive can recur and it rarely metastisizes
* translocation is COL1A1 and PDGFB that promotes tumor cell growth
* Protuberant nodule found on trunk a firm indurated plaque may or may not ulcerate
* Closely packed fibroblasts arranged radially (Storiform)
* Honeycomb pattern deep extension from dermis into subQ fat
52
Tumors of cellular Migrants to skin?
Mycosis Fungoides
Mastocytosis
53
Mycosis Fungoides? What happens if not treated? What does it look like? What syndrom is associated with it?
* CD4 t cell
* remains localized for many years and can eventually evolve into systemic lymphoma
* Usually \>40yo truncal lesions that are scaly red brown patches
* Raised scaling plaques (can be confused with psoriasis)
* Fungating nodules
* Sezary syndrome: erythroderma diffuse erythema and scaling of entire body
54
What do sezary cells look like?
* Markedly folded nuclear membrane
* Hyperconvoluted or cerebriform controur (cloverleaf)
* Band like aggreates within superficial dermis
* Pautrier microabscesses small clusters of cells (neutrophils) in epidermis
55
What is Mastocytosis?
* Urticaria pigmentosa: cutaneous form seen in kids, \>50% of cases
* multiple wiely distributed lesions round oval red brown nonscaling papule and smll plaqes
56
What is a solitary mastocytoma?
* usually seen in young kids
* Pink tan brown nodule
* +/- pruritic blister
57
Darier sign?
* localized area of dermal edema nd erythema when skin in rubbed (wheel)
58
Dermatographism?
* area of edema resembling a hive resulting from stroking of skin with pointed instrument
59
What are the systemic symptoms of mastocytosis?
* Pruritis and flushing
* Rinorrhea
* GI or nasal bleed
* Bone pain
* Osteoperosis due to excessive histamine release in BM
60
Mutation in mastocytosis?
* KIT receptor tyrosine kinase has a point mutation causing increased mast cell growth/survival
61
Ichthyosis?
* impaired epidermal maturation with chronic excessive keratin buildup that results in clinically fish like scales
62
What is ichthyosis vulgaris?
* AD or acquiried
* Congenital ichthyosiform erythroderma (AR)
* Lamellar ichthyosis (AR)
* X linked ichythyosis
63
Acute Inflammatory Dermatoses?
* Urticaria
* Acute Eczematour Dermatitis
* Erythema Multiforme
64
What is causes urticaria to occur?
* Most commonly it is result of antigen induced release of vasoactive mediators from mast cells
65
What is Spongiosis?
* Acute eczematous dermatitis edema in intracellular spaces pushing them apart in the stratum spinosum
66
What is erythema multiforme?
* Uncommon self limited hypersensitivity rxn to infections and drugs
* Infections: HSV, mycoplasma, histoplasmosis, coccidiodomycosis
* Drugs: sulfonamindes, PCN, barbiturates, salicylates
* Cancer: carcinoma and lymphoma
* Collagen vascular dz: SLE dermatomyositis, polyarteritis nodosa
67
\_\_\_\_\_\_ is Keratinocyte injury mediated by CD8 cytotoxic T lymphocytes.
* Erythema multiforme
68
What is interface dermatitits?
* dermal edema and lymphocyte infiltration along dermoepidermal junction
* associated with dermal edema and degenerating keratinocytes
69
What is Steven Johnson?
* One of the diverse arrays of lesions of multiforme
* Children have extensive skin involvement plus oral mucosa, conjunctiva, urethra, genital and perianal areas
* Secondary infections lead to life threatening sepsis
70
What is toxic epidermal necrolysis?
* part of the diverse array of multiforme lesions
* diffuse necrosis and sloughing of cutaneous and mucosal epithelia
* looks like extensive burns
71
what are the chronic inflammarory dermatoses?
* Psoriasis
* Seborrheic dermatitis
* Lichen planus
72
Psoriasis description?
* pink to salmon colored plaque covered by loose silver scale
* Elbow knees scalp lumbosacral region, intergluteal cleft glans penis
* 30% with nail changes, pitting, dimpling, yellow brown discoloration, oncolysis, thieckening, crumbling
73
Munro microabscesses?
* Seen in psoriasis
* small PMN aggregates in parakeratotic stratum corneum
74
Auspitz sign?
* Seen in psoriasis
* Multiple minute bleeding points when scale lifted from the plaue
75
What tx has good response in psoriasis?
TNF and IL-17 inhibitors
76
Seborrheic dermatitis?
* Seen in regions with increased sebaceous glands such as scalp forehead, external auditory canal, retroauricular area, nasolabial folds, presternal area
* NOT dz of sebaceous gland but inflammation of epidermis
* Assoc with parkinson's
* Ldopa tx improves
77
What is follicular lipping?
* Mounds of parakeratosis containig neutrophils and serum are present at ostia of hair follicles
78
What is a common clinical expression of sesborrheic dermatitis?
* Dandruff
79
What are the six P's of Lichen Planus?
* Pruritic
* Purple
* Polygonal
* Planar
* Papules
* Plaques
80
What is lichen planus?
* Self limited DO of skin and mucosa resolving sponeantously in 1-2 yrs
81
What is itchy violaceous?
* flat topped papules that may coalesce
* Wickham striae: papules highlighted with white doets created by areas of hypergranulosis
* Darkly pigmented individuals lesions have dark nrown color due to release of melanin into dermis as basal layer is destroyed
* Multiple symmetrical lesions especially on extremeties wrist elbows and glans penis
* 70% cases have oral mucosal lesions with white reticulated net like appearance
82
Lichen planus histology?
* Sawtoothing: angulated zigzag contour of dermoepidermal interface
* Colloid or Civatte bodies: anucleated necrotic basal cells incorporated into inflammed papillar dermis
83
What are the examples of Blistering (Bullous) Dz?
* Inflammatory blistering Do:
* Pemphigus
* Bullous Phemphigoid
* Dermatitis Herpetiformis
* Noninflammatory blistering DOs
* Epidermolysis bullosa and porphyria
84
Pemphigus, what is it, how do you treat, what causes?
* autoantibodies dissolution of intracellular attachments within epidermis and mucosal epithelium, fatal without tx
* IgG autoantibodies disrupt intracellular adhesions causing blisters
* Immunosuppressives
85
What is the most common type of pemphigus?
* Pemphigus vulgaris
* Mucosa and skin of face scalp axilla groin and trunk and _points of pressure_
* superficial vesicles rupture easily shallow erosions with dried serum and crusts
86
Pemphigus vegetans
rare large moist verrucous vegetating plaques studded with pustules on the groin, axilla and flexural surfaces
87
Pemphigus foliaceus?
* Benign
* Brazil
* seen on scalp face chest and back
* Erythema and crusting
88
Pemphigus erythromatosus?
* localized less severe form of foliaceous on the malar area of the face
89
Paraneoplastic pemphigus is assoc with what malignancy?
* NHL
* Lymphoid neoplasms
90
Bullous pemphigoid?
* Seen in the elderly on flexor surfaces
* Ab's deposit at dermoepidermal junctions
* DONT rupture easily
* subepidermal nonacantholytic blisters
91
Dermatitis herpetiformis?
* urticarial and grouped vesicles men in the 3rd 4th decade
* bilateral symmetric group lesions on extensor surfaces
* Assoc with celiac dz,
* develop IgA Ab's to Gluten and the Abs cross react with reticulin forming a subepidermal blister
92
Epidermolysis Bullosa?
* Group of disorders with inherited defects in structural proteins
* Blisters at sites of pressure rubbing or trauma
* EM to differentiate the types
93
What is Porphyria?
* group of inborn or acquired disturbances in porphyrin metabolism
94
What are the four stages of Rosacea? What should be assoc. with it?
1. flushing
2. persistent erythema and telangiectasia
3. pustules and papules
4. Rhinophyma (permanent thickening of nasal skin)
Assoc with high curaneous levels of antimicrobial peptide cathelicidin
95
Open comedone vs closed?
* Open: central black keratin plug
* Closed: keratin plug trapped beneath epidermal surccace, with the potential for follicllar rupture and inflammation
96
What is the tx for acne vulgaris?
* abx for P acnes
* 13-cis-retionic acid (isoretinoin)
97
What is the histopathology of erythema nodosum? What is it associated with?
* early lesions the CT septae are widened by edema, fibrin exudation and neutrophilic infiltration
* Later infiltration of lymphocytes, histiocytes, and multinucleated giant cells and the occasional eospinophil is associated with septal fibrosis
Associated with Panniculitis, inflammation of rxn in SubQ adipose tissue, the most common form
98
What is erythema induratum?
* Uncommon type of panniculitis seen in adolescents and menopausal females
* Primary vasculitis of deep vessels supplying fat lobules of SubQ leading to fat necrosis and inflammation
* Erythematous slightly tender nodule that ulcerates
* Early lesions have necrotizing vasculitis of small too medium arteries and veins in the deep dermis and SubQ
99
Weber-Christian Disease?
* Relapsing febrile nodular panniculitis
* A rare form of lobular nonvasculitic panniculitis, seen in children and adults
* Crops of erythematous plaques or nodules seen on LE
* Deep seated foci of inflammation contining aggregates of foamy macrophages with lymphocytes neutro and giant cells
100
Factitial panniculitis?
Form of secondary panniculitis caused by sself inflicted trauma or injection of foreign or toxic substances
101
What is HPV 16 assoc with?
In situ SCC of genitalia and with bowenoid papulosis
102
HPV 5 & 8 are assoc with what ?
* SCC especially with epidermodysplasia verruciformis
* Develop multiple flat warts some progress to carcinioma
103
Molluscum contagiosum?
* common self limited poxvirus infection
* brick shaped virus, dumbbell shaped DNA core
* Direct contact children and young adults
* Trunk and anogenital regions
* Firm prurutic pink skin colored umbilicated papules with curd like material
104
What causes Impetigo?
Staph aureus toxin that cleaves desmoglein 1
