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Flashcards in Dermatopathology I Deck (51):

5 layers of skin

Stratum Corneum
Stratum Lucidum (thick skin only)
Stratum Granulosum
Stratum Spinosum
Stratum Basale



Thickening of the stratum corneum



Flattened, keratinocyte nuclei w/in the stratum corneum, where nuclei are not normally present



Hyperkeratosis of anuclear keratinocytes within the stratum corneum



Thickened stratum spinosum



Loss of cohesion between keratinocytes due to dissolution of intercellular connections. Keratinocytes separate and "round up"



Abnormally or prematurely cornified (keratinized) keratinocytes in the epidermis that stain pink on H and E



Intercellular edema between keratinocytes. Edema may cause keratinocytes to become elongated and stretched, hallmark of eczema



Irregular undulation of the epidermal surface


Dermal Atrophy

Decreased thickness of dermis



Accumulation of interstitial fluid


Solar Elastosis

Accumulation of basophilic (grey/blue) material in the upper dermis due to sun damage



Acumulation of dense, eosinophilic (pink/red) acellular material



Hyalinzed collagen with decreased fibrosis



contains acid mucopolysaccharide and stains pale blue, smudgy, threadlike, or granular on H and E


1. what do layers of epidermis represent?
2. how long does it take?

1. vertical maturation from undifferentiated basal cells to fully differentiated cornified cells
2. 25 days (shorter in inflammation)


1. When does it appear (mostly)?
2. What is it?

1. birth
2. defective desquamatization --> build up of compacted scale


Ichthyosis Vulgaris
1. What does it look like grossly?
2. Histo?

1. fish-like scales
2. orthokeratosis; thinning or loss of granular layer


Benign Epithelial Neoplasms (4)

1. Seborrhic keratosis
2. Acanthosis nigricans
3. Fibroepithelial Polyp
4. Epithelial cysts (wen)/ Follicular cyst


Seborrheic Keratosis
1. Gross look
2. who gets it?
3. Histo look (4 features)

1. stuck on plaque, waxy apperance; anywhere except palms and soles
2. pts > 30 y/o
3. Hyperkeratosis; papillomatosis, keratinocytes appear basaloid (dark oval, little cytoplasm); string sign (sharp demarcation of the base of epidermal proliferation)


Acanthosis Nigricans
1. Gross look
2. Where is it found?
3. Hist look
4. Who gets it?

1. velvety, papillomatous, hyperpigmented plaques
2. creases of axilla and neck
3. basal layer hyper-pigmentation, papillomatosis, hyperkeratosis
4. benign type: children (assoc w/ obesity/endocrine/hereditary)
Malignant type: middle age and up


Epidermal Inclusion Cyst (Wen)
1. Gross look
2. Histo look

1. papule w/ dimple in middle
2. epithelium lined with granular layer; lots of keratin debris in the middle


Fibroepithelial Polyp
1. Gross look
2. Histo look

1. skin tag
2. papillomatosis, loose stroma in the middle, polypoid in nature;
outgrowth of fibroblasts and collagen with vessels covered with normal or acanthotic epidermis


Premalignant and Malignant Epithelial Neoplasms (3)

1. Actinic keratosis
2. Squamous cell Carcinoma
3. Basal cell Carcinoma


Actinic Keratosis (AK)
1. Gross look
2. What happens with age?
3. Can be a precursor to what?
4. Treatment
5. Histo look

1. common scaly erythematous patch located on sun-damaged skin
2. it becomes more common
3. squamous cell carcinoma
4. cryotherapy or topical chemotherapeutics to prevent progression to squamous cell carcinoma
5. basal layer atypia with overlying parakeratosis


Squamous Cell Carcinoma
1. Who gets it? Where?
2. What is the most important cause?
3. What are other common etiologies?
4. What % metastasize?
5. Gross look?
6. Histo?

1. older individuals, sun-exposed sites
2. UV light that mutates p53
3. industrial exposure, chronic wounds, burn scars, arsenic, ionizing radiation
4. less than 5%
5. hyperkeratotic, ulcerated, sometimes verrucous papules and nodules
6. keratin pearls, islands of squamous cells extending from epidermis demonstrating atypia


Squamous Cell Carcinoma in Situ
1. define
2. What is Bowen's disease?
3. What is Bowenoid Papulosis?

1. Squam cell carc confied to the epidermis
2. full thickness epidermal atypia with apoptotic cells (clinically a plaque-like lesion)
3. similar histologically to Bowens; HPV induced (on genitals); frequently multiple papules, may spontaneously regress or progress


SCC Variants
1. Verrucous carcinoma
2. Spindle cell carcinoma
3. Keratoacanthoma

1. aggressive variant; clinically and histo similar
2. poorly differentiated cells that mimic sarcoma or melanoma histo; need immunostains to differentiate
3. cup shaped rapidly growing squamous neoplasm; some resolve spontaneously


Basal Cell Carcinoma
1. Gross look
2. Histo look
3. Who gets it?
4. Common mutations?

1. pearly, pink papule with overlying telangiectasia
2. retraction artifact, islands of basaloid cells in dermis, peripheral palisading of nuclei
3. older individuals at sun exposed sites, immunosuppressed, in DNA mismatch repair syndromes (xeroderma pigmentosa)
4. PTCH gene, p53


Nevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome)
1. How is it acquired?
2. What is it?
3. What else accompanies it?

1. autosomal dominant; mutation in PTCH gene
2. multiple BCC before age 20
3. medulloblastomas, ovarian fibromas, odontogenic keratocyts


1. Histo
2. what do they make? how?

1. clearish cells in basal layer with dark nuclei
2. melanin pigment; tyrosinase


Tumors of Melanocytes (4)

Freckle (ephelis)
Melanocytic nevi


1. Gross look
2. what happens?
3. histo look

1. small, tan-red to light brown macule on sun exposed area
2. increased melanin pigment within basal keratinocytes
3. melanocytes may be enlarged but normal density


1. gross look
2. who gets them? where?
3. histo look

1. small, oval tan-brown
2. any age can get them, on mucous membranes
3. melanocytic hyperplasia along basal layer


Melanocytic Nevi
1. gross look
2. Histo look of common type
3. Histo look of dysplastic nevi

1. tan to brown macules and papules
2. junctional (at top), compound, and intradermal: nests of melanocytes
3. single and cytologically atypical melanocytes (enlarged, angulated nuclear contours, hyperchromasia), in addition to nests w/ architectural atypia


Dysplastic Nevi
1. prognosis
2. increased risk of what?
3. histo look?
4. What mutation is common in Dysplastic Nevus Syndrome?

1. mostly completely benign
2. melanoma
3. larger nests, some hyperchromatic cells, nests may grow together
4. CDKN2A;


1. What is critical in treatment?
2. Two growth phases
3. Prognostic indicators
5. Histo look

1. early recognition and surgical excision
2. Radial (lentigo maligna, superficial spreading)
Vertical growth phase: nodular or progression of radial growth phase melanoma
3. depth (Breslow), # of mitotic figures, ulceration
4. Asymmetrical, Border, Color, Diameter, Evolving
5. spreading of melanocytes into epidermis; upward migration


Pathogenesis of Melanoma
1. 2 most important predisposing factors
3. What is the mutation in familial melanomas?
4. What is the mutation in sporadic forms?
5. What is the drug and what does it target?

1. inherited genes
2. sun exposure (relationship not straight forward)
3. CDKN2A --> loss of p16/INK4
4. BRAF, p16, CKIT (non-sunexposed)
5. Zelboraf targets the BRAF mutation


Staging of Melanoma
1. Stage 1
2. Stage 2
3. Stage 3
4. Stage 4

1. confined to skin; 74% 5 year
2. confined to skin, 34% 5 year
3. nodal involvement 30-70% 5 year
4. distant skin or visceral metastasis 9-19% 5 year


Dermal Neoplasms (3)

Keloid Scar
Dermatofibrosarcoma protuberans


1. Gross look
2. what sign is diagnostic?
3. what is it caused by?
4. Histo look (4)

1. pink-brown papule/nodule most common on lower extremities
2. dimple sign- compressing skin around it causes nodule to dimple inward
3. secondary to old bug bite/irritation
4. pigmented basal layer of epidermis
5. collagen trapped into little balls
6. tabled ridges of epidermis protruding into dermis
7. boomerang shaped spindled fibrohistiocytes


Dermatofibrosarcoma Protuberans (DFSP)
1. Gross look
2. Who gets it?
3. Histo look (2)
5. What is it?

1. Large nodule w/ multiple protuberances
2. trunk of young to middle-aged adults
3. Storiform- irregularly whorled pattern of fibroblasts/ basket weave look
4. dense proliferation of fibroblasts;
5. low grade sarcoma of skin


1. What causes it?
2. What happens when it is removed?
3. Histo look?
4. gross look

1. Reaction to injury
2. comes back, usually worse
3. thick bundles of collagen
4. large mass at site of injury


Tumors of Cellular Immigrants (3)

1. Cutaneous T cell lymphoma (Mycosis Fungoides most common)
2. Mastocytosis: Uticaria Pigmentosa
3. Mastocytosis: Solitary Mastocytoma


Mycosis Fungoides
1. Gross look
2. Prognosis
3. Histo look
4. notable histo finding

1. presents as plaques, looks like psoriasis or dermatitis
2. slow growing neoplasm
3. Atypical T cells line up on dermal-epidermal junction and fill the superficial dermis; cerebreform nuclei (convoluted and wrinkly)
4. Pautrier's microabscess- groups of atypical T cells in epidermis


Uticaria Pigmentosa
1. Gross look
2. who gets it?
3. Histo look?

1. Red macules
2. pts usually born with it
3. infiltration of lots of mast cells


Adnexal Neoplasms (3)

1. Trichilemmoma- Cowden's Syndrome
2. Cylindroma "Turban Tumor"
3. Sebaceous Neoplasms (adenoma, carcinoma, Mui-Torre)


1. Gross look
2. What mutation gives you Cowden's syndrome?
3. What is increased in cowden's syndrome

1. multiple small papules around the face; worty lesion that is benign; has a pink waxy outline
3. risk of breast, endometrial, thyroid cancer


1. AKA
2. What is it?
3. What does it look like histo?

1. Turban tumor
2. basaloid neoplasm
3. basal cell carcinoma, but Cylindroma lacks retraction cells; has pink sheet/background instead


Sebaceous Neoplasm
1. if you have multiple, what is it associated with?
2. What does that cause? why?
3. Where does sebaceous neoplasm show up?

1. Muir-Torre Syndrome
2. non-polyposis colorectal cancer; germ-line defects in DNA mismatch repair
3. on the face


Erythema Nodosum
1. What is it?
2 Gross look
3. Histo look
4. Who gets it?
5. Associated with what?

1. folliculitis, inflammation in the adipose tissue underneath the dermis
2. red annular patches with rings, can be large
3. lympho-histiocytic with giant cells
4. younger women, tends to be bilater
5. pregnancy, birth control, NSAIDs