Chapters 24- Skin Flashcards
What is the alternative name for freckle
Ephelis
What is the hyperpigmentation seen in ephelis caused by
Increased in melanin pigmentation in the basal keratinocytes seen after sun exposure
How are ephelis differentiated from cafe Australia last spots
Cafe at lait spots (commonly seen in neurofibromatosis) appear independent to sun exposure
What are the feature of cafe at lait spots
Aggregated Melanosomes in the cytoplasm of melanocytes
What are the characteristics of lentigo
- Benign Local hyperplasia of melanocytes
- Do not darken with sunlight
What condition is described histologically as :
-Linear (nonnested) melanocytes hyperplasia restricted to the cell layer immediately above the basement membrane
Lentigo
What condition is leniginous/lentigo seen in
Single layer proliferation in the basal cell layer during melanocytic tumors
Melanocytic Nevus aka moles are caused by distruption in which pathway
RAS signaling pathway
What is being described as:
- tan-brown, uniformally pigmented
- Flat macules or elevated papules
- Well rounded borders
Melanocytic nevus aka moles
What is the location for junctional Nevi
Dermoepidermal junction
What are the locations of compound nevi
Nests or cords growing into underlying dermis (so nests in dermis and epidermis)
What is the location of intradermal nevi
No epidermal nests, usually older lesions
What is the the description of nests and their locations in melanocytic nevi aka mole
Superficially: large round cells with increased melanin
Deep: fusiform, nervelike look, much smaller
*Big pigmented cell in the deeper portions are more common with a melanoma
What is the stain commonly seen used to look at melanocytes
S-100
Dysplasia nevi are caused by mutations in which genes
NRAS and BRAF
Patients with dysplastic nevi are increased risk for which condition
Melanoma
What is the inheritance of dysplastic nevi syndrome
Autosomal dominant
What are patients with dysplastic nevus syndrome at increased risk for
> 50% develop melanoma by age 60
What are the physical and histological features of dysplastic nevi
- Larger than acquired nevi
- Irregular borders, variation in pigmentation
- Melanin incontinence (loose melanin)
- Ig nuclei, irregular angulated nuclear contour, hyperchromic is
Which condition leads to shouldering of the melanocytes and what is it
Dysplastic nevus
Shouldering: junctional component is >2 rete ridges beyond dermal component of the nevus
What is the most deadly of all skin cancers and what is the common cause
Melanoma caused by exposure to UV radiation in the sunlight leading to DNA damage
Which condition should be suspected if there is any pigmented lesion with a diameter >6mm, any change, itching or pain
Melanoma
What are the genes commonly seen to be disrupted in melanomas
- CDKN2A (40% of familial cases)
- BRAF (40-50% of cases)
- TERT aka telomerase (70% of cases)***
Most common
Which condition should be suspected if there is HMB-45+ cell in the lymph node
Melanoma
Which condition should be suspected if there is prominent red nucleoli
Melanoma
What is meant by radial growth of a melanoma and what is its risk to metastasize
Horizontal spread
-lack of capacity to metastasize
What is meant by vertical growth of melanoma and what is the risk to metastasize
Downward invasion, has the ability to metastasize
What is the probability of a melanoma to metastasize and what is measured by
Probability is correlated with the depth of invasion, which is known as the Breslow thickness (distance from superficial epidermal granular layer to the deepest intradermal tumor cells)
If there is vertical growth of melanocytes, but neurotization is absent, which condition is suspected
Melanoma
*Melanocytic nevi if it is present
What are seborrheic keratosis
Benign epithelial tumors
What are the definition of dermatosis puluposa nigra
In people of color, multiple small lesions on the face (Morgan Freeman)
What are the physical features of seborrheic keratosis
Round, flat, waxy papule, tan brown
- “stuck on” appearance
- Horn cysts
- Pore like Ostia impacted with keratin
- “Coin like lesion”
Which mutation is seen in seborrheic keratosis
FGFR-3
What is the lesser-treat sign
-Paraneoplastic syndrome seen as a sudden appearance of large numbers of seborrheic keratosis
Which conditions are associated with acanthosis nigrans
Obesity and Diabetes
GI adenocarcinomas
What is cowden syndrome
PTEN mutation resulting in:
- Multiple tricilemmomas
- Increased risk for endometrial and breast cancer
What is the genetic defect in a patient with turban tumor
Aka cylindroma or adnexal Tumor
-CYLD
What are clindroma
Adnexal tumor that has ductal differentiation with forehead, scalp
“Aka jigsaw puzzle”
What eccrine poroma
Adnexal tumors where there are palms and soles and the sweat glands are located
What are syringoma
Adnexal tumors where the eccrine differentiation is on the lower eyelids
What are sebaceous adenoma
Adnexal tumor
What is Muir-Torre syndrome
DNA mismatch repair leading to:
- Sebaceous adenomas
- Hereditary nonpolyposius colorectal -carcinoma syndrome
What is pilomatricoma and what is the genetic mutation
Adnexal tumor with follicular differentiation
*CTNNB1 mutation encoding Beta-catenin
What is the mechanism that xeroderma pigmentosum can lead to melanomas
Defective nucleotide excision repair leading to mealanomas and other skin cancers
Ghost cells are seen in which condition
Pilomatrixoma
How can you tell the difference between a squamous and basal cell carcinoma histologically
Squamous cell will be pink (think keratin) while Basal cell will be blue
What is the cause of actinic keratosis (AK)
Sun damaged skin, leading to hyperkeratosis
What is the general appearance of actinic keratosis (AK)
<1 cm, tan-brown, red or skin colored, rough sand paper like consistency
What condition can someone with actinic keratin be at risk for
Squamous cell carcinoma (SCC)
Which other conditions can be seen as the result of the hyperkeratosis in actinic keratosis
- Cutaneous horn
- dyskeratosis
- intracellular Bridges
- blue-grey elastosis
- Parakeratosis
What is the amount of sunlight that matters in the case of squamous cell carcinoma
Total lifetime sun exposure
Which form of skin cancer has the propensity to metastisize
Squamous cell carcinoma
Which conditions place a patient at a higher risk for developing squamous cell carcinoma
- Immunosuppression, chemo, organ transplant
- Epidermodysplasia verruciformis (AD, associated with HPV)
- Tabacco and betel nut
- Cutaneous squamous cell carcinoma
Which mutation is commonly seen in those with squamous cell carcinoma of the skin
TP53
What is the link between squamous cell carcinoma and xeroderma pigmentosum
INherited mutation in the nucleotide excision repair pathway increases the risk for SCC
How are squamous cell carcinomas in situ of the skin presented
- Sharply defines, red, scaling plaques
- atypical nuclei at all levels of the dermis
What is the histological findings in the case of squamous cell carcinoma
Anaplastic cells (looks like nothing normally there) -Dyskeratosis (Single layer of keratinization)
What is the propensity for basal cell carcinoma to metastasize
Very rare, slow growing tumor
Which pathways are seen to be dysfunctional in basal cell carcinoma
Hedgehog signaling, PTCH **
What is the inheritance of Nevoid basal cell carcinoma syndrome (NBCCS)
Aka Gorlin syndrome
Autosomal dominant
What conditions are those with Gorlin syndrome at risk for
Aka nevoid basal cell carcinoma syndrome (NBCCS)
- Multiple basal cell carcinomas before the age of 20
- Medulloblastoma
- Ovarian fibroma
- odontogenic keratocysts
What is the description of appearance for basal cell carcinomas
Pearly papules, telangiectasias, rodent ulcers
What are the histological findings in the cause of basal cell carcinomas
- Basophilic/basaloid cells
- Hyperchromatic nuclei
- Peripheral palisading
Which condition is indicated by the dimple sign
Dermatofibroma
What is the common finding in the history of a patient with dermatofibroma
Young-middle aged women with an antecedent trauma
Which cells are present in a dermatofibroma
Factor 8a postive dermal dendritic cells
What are the physical characteristics of a dermatofibroma
- Firm, tan-brown papule
- <1 cm
- Becomes flattened with time
What is the histological findings with a dermatofibroma
Benign spindle shaped cells, well defined, non-encapsulated mass in the mid dermis
-Pseudoepitheliomatous hyperplasia
Which gene is mutated in dermato fibrosarcoma protuberans (DFSP)
COL1A1 and PDGFB
What are the characteristics of the dermatofibrosarcoma protuberans
“Protuberant” nodule, well differntiated, slow growing, locally aggressive and can recur
What is the histological finding indicative of dermatofibrosarcoma protuberans
Storiform, aka packed fibroblasts in the shape of pin wheels blades, or swarms of fish
*May contain a honeycomb pattern that extensors into the subQ fat (Swiss cheese look)
What is the cell type seen in the skin with mycosis fungicides
CD4 T cells
What is Sezary syndrome
Erythrderma, diffuse erythema, scaling over the body associated with mycosis fungoides
What are the characteristics of Sezary cells
- Folded nuclear membrane withe hyperconvoluted or cerebriform contour
- Band like aggregates within the superficial dermis **
During mastocytosis, which products are being released
Mast cell degranulation results in the release of histamine, heparin
Patients with mastocytosis are at an increased risk of developing which condition
Osteoporosis
Which gene is commonly seen to be mutated in mastocytosis
KIT receptor tyrosine kinase
What is darier sign
Localized area of dermal edema and wheal when the skin is rubbed in pts with mastocytosis
Which stain can be used to seen cells in mastocytoma
Giemsa sign
Which condition is characterized by fish like scales
Ichthyosis
*Due to the impaired epidermal maturation leading to excessive keratin buildup
Acute eczematous dermatitis is characterized by which cell
T cell mediated Type 4 hypersensitivity rxn (Poison ivy urushiol)
Erythema multiforme is characterized by which cell
CD8 T cells
Which condition is characterized by targetoid lesions
Erythema multiforma with CD8 cells causing apoptosis
Which condition is characterized by scalp, forehead macules/papules on an erythematous yellow, greasy base that is associated with crusting and scaling
Seborrheic dermatitis
Which condition is characterized by pink to salmon colored plaque covered by loosely adherent silver scale
Psoriasis
Which alleles are assocaited with psoriasis
HLA-C
HLA-Cw*0602
What is koebner phenomenon
Psoriatic lesions in patients by local trauma that starts a self perpetuating local Inflammatory process
Which conditions is charactertic rete ridges with “tubes in a rack” with regards to histology
Psoriasis
Those patients with lichen planus are increased risk for which condition
Squamous cell carcinoma
What are the characteristic findings in lichen planus
6 “Ps”
- Pruritic
- Purple
- Polygonal
- Planar
- Papules
- Plaques
What are Wickham striae and which condition is it seen in
Papules highlighted with white dotes, created by areas of hypergranulosis in highly pigmented individuals
What is the cause of pemphigus
Autoantibodies dissolution of intracellular attachments with the epidermis and mucosal epithelium
What is the prognosis of pemphigus
Fatal if untreated
What is the findings in pemphigus
Net like pattern of intercellular IgG deposits (disrupt intracellular adhesions leading to blisters)
What is the most common location for pemphigus
Pemphigus vulgaris (80%) which is the scalp, face, groin, trunk, points of pressure
*Leads to shallow erosions with dried serum and crust
Patients with pemphigus are at higher risk of which conditions
Associated with paraneoplastic conditions: malignancies, NHL, lymphoid neoplasms
Bulbous pemphigus is commonly seen in which patients and in which locations
Inner thighs, flexor surfaces of forearms, axillary, groin and lower abdomen of elderly pts
What are the antigens present in bulbous pemphigoid
BPAGS
What are the characteristics of bollous pempohigoid
Do not rupture easily, subepidermal
Dermatitis herpetiformis is associated with which conditions
- Celiac
- IgA autoantibodies to gluten
Patients with antibodies to gluten cross react with what
Reticulin leading to subepidermal blister
Porphyria is associated with which findings
- Disturbances in the porphyrin metabolism, which are normally found in HbG, myoglobin, cytochromes
- Uticaria and vesicles associated with scarring and exacerbation by sunlight
Erythema nodosum is associated with which conditions
- Beta hemolytic strep infections
- TB
- Sulfonamides
