Shared Flashcard Set

Details

Dermatology
Dermatopathology and Skin Neoplasms (Unit 3)
21
Pathology
Graduate
10/25/2010

Additional Pathology Flashcards

 


 

Cards

Term
Psoriasis (Vulgaris)
Definition
Genetic, systemic, inflammatory (T CELL MEDIATED); can be triggered by environmental/social conditions (strep, trauma, stress, diet, rare light sensitive manifestation)

Red macules -> non-scaly papules -> scaly papules -> plaques

Clinical exam: silvery scales, well demarcated pink patches, commonly involves elbows and knees, scalp, behind ear; see guttate/drop-sized papules with post-strep manifestation; nail changes - pitting, oil drop sign, onycholysis

DDX: Dermatitis, Dandruff (scalp), fungal infection (onycholysis)

Prognosis/Course: good, but erythroderma (widespread skin invovlement) can be fatal, can get psoratic arthritis (involving DIP joints), pustular psoriasis (acceleration of course with many neutrophils), linear plaques (Koebner phenomenon) from external trauma

Histology: regular epidermal hyperplasia due to increased epidermal cell proliferation (shortened lifespan), parakeratosis, hypogranulosis, dilated capillary loops, munro microabscesses (pustular form)

Rx: sunlight/UVA and UVB (some exceptions), fish and omega 3 oils, topical steroids, coal tar, calcipotriene, retinoids, methotrexate, cyclosporine, biologics
Term
Lichen Planus
Definition
Inflammatory process - idiopathic or induced by drugs, Hep C

Flat pink macules -> violaceous papules with polygonal outline and flat top (goes away after a year) -> persistent rubbing -> hypertrophic lichen planus (may last years)

Clinical Exam: favors flexual surfaces of skin and buccal mucosa; polygonal, purple, pruritic, papules; can form plaques; can see permanent alopecia if scalp follicles involved (pseudopelade of brocq), destroyed nail matrix (anonychia); Wickham's striae (overlying network of white lines)

Histology: hypergranulosis, inflammation in a band between dermis and epidermis, sawtoothing of epidermis

Can see extensive, ulcerative form on palms, soles, mucous membranes = erosive lichen planus

Rx: topical steroids, prednisone, retinoids, UVA
Term
Psoriasiform Dermatitis - Lichen Simplex Chronicus
Definition
Aka circumscribed neurodermatitis - eruption caused by habitual itching of a single localized area (pts get great pleasure out of itching)

Clinical Exam: papular lesions (red, brown, hard, dome shaped, crusted/warty surface), intense itching

Histology: irregular epidermal hyperplasia

Rx: steroids, antihistamines, anesthetics, behavioral modification
Term
Pityriasis Rosea
Definition
Benign, self-limited (6 wks), papulosquamous eruption (unknown etiology - maybe viral? more frequent in spring and fall)

Clinical Exam: Single 2-10cm lesion (HERALD PATCH) appears and then get eruption of smaller lesions; fine, wrinkled scales at border of plaque (collarette scale); christmas tree distribution

Histology: superficial perivascular/interstitial lymphocytic infiltrate, edema, epidermal hyperplasia

Rx: recognize dx and reassure pt, antihistamines and steroids to control itch, UVB, benign neglect!
Term
Contact Dermatitis (Allergic)
Definition
Delayed type IV hypersensitivity rxn (common agents - poison ivy/oak, nickel, perfume, soap, detergent, cosmetics) - skin rash that develops from contact with previously encountered agent

Clinical Exam: multiple tiny vesicles; red, swollen, warm, itchy (may see fever, lymphadenopathy, malaise) - Dx with patch testing

Histology: spongiosis (tissue edema), rupture of keratinocytes, widening of extracellular spaces
Term
Atopic Dermatitis
Definition
AKA Eczema; relapsing, inflammatory, immune mediated (IgE) immediate hypersensitivity reaction; children may outgrow it; associated with asthma, allergic rhinitis

Clinical Exam: itching, lichenfication, dry, scaly patches and plaques in flexural areas

Histology: intracellular edema, exocytosis of lymphocytes

Rx: emollients, steroids, antihistamines, UVB, avoid scratching and secondary infection
Term
Molluscom Contagiosum
Definition
Pox virus infection - can be an STD in adults; seen more in children and HIV population

Clinical Exam: skin-colored, smooth, dome-shaped papules with central umbilication and filled with cheesy material; numerous lesions may signal immunocompromise

Histology: large basophilic and eosiniphilic inclusion bodies in keratinocyte cytoplasm (molluscum bodies)

Rx: cryotherapy, TCA currettage, examine and treat any sexual partners
Term
Verruca/Condyloma/Accuminata
Definition
HPV-related (infects keratinocytes)

Clinical Exam: papules on skin and mucous membranes, cauliflower-like warts, may see mosaic warts with punctate hemorrhages (DDX: squamous cell carcinoma)

Histology: virally-infected keratinocytes

Rx: cryotherapy, canthrone, TCA, pulse dye laser therapy, bleomycin
Term
Tinea Versicolor
Definition
Infectious disease, caused by yeast (Malassezia furfur) proliferating in stratum corneum

Clinical Exam: white or light brown macules on trunk (hypopigmentation), get dust-like scales if you scratch it

Dx: scrape scales from lesion, place in KOH and examine for spores and hyphae - "spaghetti and meatballs appearance"

Rx: localized - topical antifungals, selenium sulfide shampoo; widespread - ketoconazole, fluconazole, itraconazole; wash clothes to get rid of yeast
Term
Tinea
Definition
Infection process caused by superficial fungi

Clinical Exam: multiple possible morphologies, many only involve 1 hand, centered in follicles, seen more on scalp, inguinal region, hands, feet, nails, dermatophytes (athelete's foot!)

Dx: KOH prep/culture (see hyphae)

Rx: Antifungals, keep area dry, powder
Term
Erythrasma
Definition
Caused by corynebacterium minutissiumum, common in diabetics and warm climates

Clinical Exam: slowly enlarging pink/brown patch that dominates flexor surface, asymptomatic

Dx: bacterial make porphyrins - will fluoresce!

Rx: erythromycin
Term
Scabies
Definition
Infectious, caused by mite (sarcoptes scabiei - lays eggs in skin); get itching (worse at night and with hot water) due to hypersensitivity rxn to mite feces

Associated with unclean conditions, spread from person-person

Clinical Exam: papules, vesicles, nodules (digital interwebs, breasts, genitals, chest)

Dx: KOH prep, look for burrows and lesions on areolas or penis

Rx: Ivermectin, permethrin; be sure to treat contacts
Term
Norwegian Scabies
Definition
Seen in immunocompromised, pts with decreased cutaneous sensation, or those who can't scratch effectively

Extensive crusted lesions with huge numbers of mites

AKA crusted scabies
Term
Erythema Multiforme
Definition
Immune-mediated disorder from drugs (PCN, sulfa, phenytoin), infection (HSV, mycoplasma), vaccination or malignancy

Clinical Exam: Raised, erythematous plaques with TARGET PATTERN

Several classifications - EM major, Stevens-Johnson Syndrome, Stevens-Johnson Syndrome/TEN overlap, Toxic Epidermal Necrolysis

Histology: superficial, perivascular lymphocytic infiltrate; epidermal necrosis - necrotic keratinocytes, subepidermal blisters with lymphocytes, basal vacuolar change (dermis/epidermis border)
Term
Seborrheic Keratosis
Definition
Benign neoplasm of epidermal keratinocytes

See hyperpigmented papules/plaques (appear to be "stuck on"), in middle aged + elderly (NOT children)

DDX: verruca, actinic keratosis, nevi, melanoma, basal cell carcinoma

Horn cysts observed when lesion is pushed down

Paraneoplastic sign: when numerous ones acutely erupt = sign of Lesar-Trelat; signals an underlying malignancy (gastric carcinoma)
Term
Actinic Keratosis
Definition
Premalignant epidermal neoplasm caused by UV exposure; presents as a rough, erythematous plaque or papule on sun-damaged skin

Fair complexions at higher risk!

Dx: clinical or by biopsy

Rx: sunprotection, 5-fluorouracil, cryosurgery, chemical peel

Pathology: epidermal atrophy, atypical keratinocytes confined to lower third of epidermis, hyperchromic nuclei
Term
Squamous Cell Carcinoma
Definition
Malignant neoplasm of keratinocytes caused by UV exposure/ionizing radiation, X-rays, and chemical carcinogens; can also develop from lesions of DLE, Lichen Planus, draining sinuses, or old burn scars

Second most common skin cancer

Can be in situ or invasive; well or poorly differentiated

Appears as a hyperkeratotic, indurated
plaque or nodule (scaling and crusting) that bleeds or ulcerates and becomes painful

May see malignant keratinocytes in dermis and vessels (where they don't belong)

Rx: surgery, MOHS, sunprotection, radiation
Term
Basal Cell Carcinoma
Definition
Malignant, poorly-healing plaque/papule with a pearly, translucent character, overlying telangiectasia, ulceration and/or crusting; may bleed; usually due to sun exposure

Most common skin cancer!

Slow growing, generally not metastatic but can cause local damage, usually don't do serious harm

Rx: surgical (ED+C, excision), MOHS, radiation, photodynamic therapy, immunotherapy -> high cure rate

Pathology: picket fencing, basophilic cells palisading with retraction, uniform size, polygonal, variable mitotic rate, oval nuclei with inconspicious nucleoli

Keratotic and morphea forms more aggressive
Term
Nevi
Definition
Benign neoplasms of modified melanocytes of neural crest origin

Different kinds: common acquired, congenital, blue nevi, Spitz nevi

See "nests" in epidermis

Dysplastic nevi may become melanoma
Term
ABCDEs of Skin Evaluation
Definition
A - Asymmetry (should be symmetrical)
B - Border (smooth and distinct is good)
C - Color (one uniform color is good; red, white, blue or black is bad)
D - Diameter (should be less than 5mm)
E - Evolving and Erythema (should have no erythema, and should not be changing)

ex: Nevi will pass ABCDEs, Melanoma will not
Term
Melanoma
Definition
Aggressive melanocytic malignancy; risk factors include sun exposure, fair skin, family history, xeroderma pigmentosa, dysplastic nevi, lots of nevi

Pathology: melanocytes with marked atypia (hyperchromic nuclei, vacuolated cytoplasm, prominent nucleoli, pleomorphism) w/ pagetoid spread

Use ABCDEs to evaluate
Biopsy - always get everything out, never do shave biopsies (then you can't gauge thickness)

SINGLE MOST PROGNOSTIC INDICATOR IN MALIGNANT MELANOMA IS TUMOR THICKNESS (DEPTH OF INVASION)
Supporting users have an ad free experience!