Dermatopathology

Question 1

Excoriation

Answer 1

Traumatic lesion breaking the epidermis and causing a raw linear area (i.e., deep scratch); often self-induced

Question 2

Lichenification

Answer 2

Thickened and rough skin characterized by prominent skin markings (as lichen on a tree trunk); usually the result of repeated rubbing

Question 3

Macule

Answer 3

Circumscribed lesion, 5 mm or smaller in diameter, characterized by flatness and distinguished by coloration (patch is greater than 5 mm)

Question 4

Onycholysis

Answer 4

Separation of nail plate from nail bed

Question 5

Papule

Answer 5

Elevated dome-shaped or flat-topped lesion 5 mm or less across (nodule is greater than 5 mm)

Question 6

Plaque

Answer 6

Elevated flat-topped lesion, usually greater than 5 mm across (may be caused by coalescent papules)

Question 7

Pustule

Answer 7

Discrete, pus-filled, raised lesion

Question 8

Scale

Answer 8

Dry, horny, platelike excrescence; usually the result of imperfect cornification

Question 9

Vesicle

Answer 9

Fluid-filled raised lesion 5 mm or less across (Bulla is greater than 5 mm. Blister is the common term for either.)

Question 10

Wheal

Answer 10

Itchy, transient, elevated lesion with variable blanching and erythema formed as the result of dermal edema

Question 11

Acantholysis

Answer 11

-Loss of intercellular cohesion between keratinocytes

Question 12

Acanthosis

Answer 12

Diffuse epidermal hyperplasia

Increased spinosum

Question 13

Dyskeratosis

Answer 13

Abnormal, premature keratinization within cells below the stratum granulosum

Question 14

Erosion

Answer 14

Discontinuity of the skin showing incomplete loss of the epidermis

Question 15

Exocytosis

Answer 15

Infiltration of the epidermis by inflammatory cells

Question 16

Hydropic swelling (ballooning)

Answer 16

Intracellular edema of keratinocytes, often seen in viral infections

Question 17

Hypergranulosis

Answer 17

Hyperplasia of the stratum granulosum, often due to intense rubbing

Question 18

Hyperkeratosis

Answer 18

Thickening of the stratum corneum, often associated with a qualitative abnormality of the keratin

Question 19

Lentiginous

Answer 19

A linear pattern of melanocyte proliferation within the epidermal basal cell layer

Question 20

Papillomatosis

Answer 20

Surface elevation caused by hyperplasia and enlargement of contiguous dermal papillae

Question 21

Parakeratosis

Answer 21

Keratinization with retained nuclei in the stratum corneum. On mucous membranes, parakeratosis is normal.

Question 22

Spongiosis

Answer 22

Intercellular edema of the epidermis

Question 23

Ulceration

Answer 23

Discontinuity of the skin showing complete loss of the epidermis revealing dermis or subcutis

Question 24

Vacuolization

Answer 24

Formation of vacuoles within or adjacent to cells; often refers to basal cell-basement membrane zone area

Question 25

Poison Ivy

Answer 25

- Acute Allergic contact dermatitis - pruitic vesticulobullous eruption - Micro: spongiosis, intre-epidermal vesicles * Inflammatory infiltrate in upper dermis - Caused by Poison Ivy, poison oak, poison sumack: rxn to haptan - Delayed type hypersensitivity: CD4 Th1 cells respond to antigens and secrete inflammatory cytokines

Question 26

Pemphigus vulgaris

Answer 26

- blistering disorder - autoantibodies to desmoglein of desmosomes - dissolution of intercellular attachments within the epidermis and mucosal epithelium, - oral ulcers that may persist for months before skin involvemen - superficial vesicles and bullae that rupture easily, leaving shallow erosions covered with dried serum and crust - pustules on the groin, axillae, and flexural surfaces. - acantholysis, the dissolution, or lysis, of the intercellular adhesions that connect squamous epithelial cells - Keratinocytes become rounded - Basal keratinocytes remain attacked while others separate: "row of tombstones" - Positive Nikolsky's sign

Question 27

Erythema Multiforme

Answer 27

- hypersensitivity reaction to certain infections and drugs * herpes simplex, mycoplasmal infections, histoplasmosis, * sulfonamides, penicillin, barbiturates, salicylates - Typical lesion is erythematous papule w/ central vesicle giving a target appearance - Multiple subepidermal blisters w/ dermal edema - Mononuclear dermal infiltrate w/ necrotic keratinocytes - More severe forms: Steven Johnson's and TENS

Question 28

Psoriasis

Answer 28

-Common chronic inflammatory dermatosis -Red papules & plaques covered by white adherent scales - most frequently affects the skin of the elbows, knees, scalp, lumbosacral areas, intergluteal cleft, and glans penis. - Nail changes occur in 30% of cases of psoriasis: pitting, dimpling, separation of the nail plate, or thickening -pustular psoriasis multiple small pustules form on erythematous plaques. -acanthosis, with regular downward elongation of the rete ridges -The stratum granulosum is thinned or absent, and extensive overlying parakeratotic scale is seen -hinning of the portion of the epidermal cell layer that overlies the tips of dermal papillae -dilated, tortuous blood vessels within these papillae. -Koebner's sign: trauma causes it to occur there Awwswuts: removing plaqe causes bleading

Question 29

Seborrheic keratoses

Answer 29

- common epidermal tumors in middle-aged or older individuals - numerous on the trunk, although the extremities, head, and neck - appear as round, flat, coin-like, waxy plaques that vary in diameter - uniformly tan to dark brown and usually have a velvety to granular surface. - Histology: hyperkeratosis acanthosis, papillomatosis, melanocytic hyperplasia and horn cysts - mutations in the fibroblast growth factor receptor-3 (FGFR3) gene are found in many sporadic seborrheic keratoses - part of a paraneoplastic syndrome (Leser-Trélat sign), possibly under the stimulation of transforming growth factor-α

Question 30

Bullous Pemphigoid

Answer 30

- Autoimmune disorder w/ antibodies agains hemidesmosomes * Attach the epidermal basment membrane - Eosinophils in tense blisters - Less severe than pemphigus vulgaris: spares oral mucosa - NEGATIVE nikolsky's sign

Question 31

Dermatitis Herpetiformis

Answer 31

- Itchy pruritic papules and vesicles - Often on elbows, knees, back, and butt - Deposits of IgA at tips of dermal papillae - Associated w/ celiac disease

Question 32

Lichen Planus

Answer 32

-Puritic, purple, polygonal, papules -Sawtooth infiltrate of lymphocytes at dermal-epidermal junction -Associated w/ HepC Also in mouth

Question 33

Actinic Keratosis

Answer 33

- Premalignant lesions caused by sun exposure - Small, rough, erythematous or brownish papules - Cutaneous horn - Risk of carcinoma proportional to epithelial dysplasia

Question 34

Acanthosis nigricans

Answer 34

- Hyperplasia of stratum spinosum - Associated w/ hyperinsulinemia (Cushing's or diabetes) & visceral malignancy - brown to black, poorly defined, velvety hyperpigmentation - usually in body folds: neck, the axilla, groin, umbilicus, forehead

Question 35

Erythema nodosum

Answer 35

- Inflammatory lesions of subcutaneous fat - Usually on anterior shins - Associated w/ coccidiomycosis, histoplasmosis, TB, leprosy, strep, and sarcoidosis

Question 36

Squamous Cell Carcinoma

Answer 36

- Common. Associated w/ excessive sun or arsenic exposure - Commonly on hands or face - locally invasive but rarely metastasize - Ulcerative red lesions - Associated w/ chronic draining sinuses - Histology: keratin pearls - invasive tongue - Actinic keratosis is precursor to squamous cell carcinoma - Keratoacanthoma is variant that grows rapidly and regresses spontaneously - Positive for H&E test

Question 36

Basal Cell Carcinoma

Answer 36

- Most common in sun exposed ares of body - Locally invasive, by almost never metastasizes - Rolled edges under central ulceration - pearly papules commonly w/ telangiectasis - Palisading nuclei - -Negative for all 3 tests

Question 37

Melanoma

Answer 37

- Common tumor w/ significant risk of metastasis - Associated w/ sun exposure: fair skin increased risk - Depth of tumor correlates w/ risk of metastasis - ABCD: asymmetry, border irregularity, color variation, diameter