Patho-Derma

Question 1

NEVUS
Difference between melanocytic and dysplastic

Size
Pigmentation
Border
Atypia and mitosis
Increased melanoma risk

Answer 1

Melanocytic
<6mm
Uniformly pigmented
Regular, well defined borders

Dysplastic
Increased melanoma risk
>5mm
Variegated pigmentatiin
Irregular borders
With atypia and mitosis
Melanin incontinence (dec. Tyrosinase)

Question 2

Most deadly skin cancer

Most important risk factor: sun exposure

Favorable: thin breslow thickness, <1/mm2 mitosis, brisk TILs, ansence of regression and ulceration

Identify if radial or vertical growth
Dx
Management

Answer 2

MELANOMA
Dx: melanin stains, immunostains (S100, HMB45)
Tx: Wide excision surgery

Early

• epidermis and superficial dermis
• radial growth only (superficial spreading)

Advanced

• epidermis, dermis and other structures
• radial and vertical (nodular; metastatic potential) growth

Question 3

Benign skin tumor
Small pore-like ostia on hand lens inspection

Paraneoplastic: Leser trelat sign in GI malignancies

Answer 3

Seborrheic keratoses

Morphology
Basaloid cells: pigment
Hyperkeratosis: keratin
Horn cyst: keratin filled
Invagination cyst

Question 4

Thickenes
Hyperpigmented
Velvet-like

Benign: metabolic
Malignant: GI malignancy

Answer 4

ACANTHOSIS NIGRICANS

Morphology
Undulation of papillae
Hyperkeratosis
Basaloid cell with ni melanocytic hyperplasia

Question 5

Premalignant lesion to SCC
In sun damaged skin

Morphology:
Atypical dyskeratotic cells in basal epidermis
Dermal chrinic inflammatory infliltrate
Solar elastosis

Answer 5

ACTINIC KERATOSIS

Question 6

Pearly papules
Telangiectasia
Rodent ulcer

Most common invasive cancer
Locally aggressive

Answer 6

BASAL CELL CARCINOMA

Nests of basaloid cells
Stromal retraction

Question 7

Plaques to nodules with ulceration
Associated with HPV 5 and 8

2nd most common cancer in sun exposed
Metastasis is common

Answer 7

SQUAMOUS CELL CARCINOMA

Keratin pearl formation
Full thickness of epidermis and dermis
Hallmark: dotted or coiled vessels

Question 8

ACUTE inflammatory dermatoses

Urticaria

• wheals
• type I hypersensitivity

Acute eczematous dermatitis

• hyperkeratosis, acanthosis, spongiosis
• type IV hypersensitivity

Erythema multiforme

• target lesions, interface dermatitis
• SJS (<10%, mucosa), TEN (>15%, DEJ)
• type IV (CD8 t cell)

Answer 8

CHRONIC INFLAMMATORY DERMATOSES

Psoriasis

• salmon colored, +Auspitz sign
• type IV (CD4 TH1 TH17, CD8)
• test tubes in a rack appearance

Seborrheic dermatitis
-follicular lipping (PMNs + Sebum)

Lichen planus
-6Ps: pruritic, purple, plaques, planar papules, polygonal

Question 9

Civatte or colloid bodies

-anucleate basal cells in papillary dermis

Answer 9

LICHEN PLANUS

Question 10

Difference of Staphylococcal scalded skin from TEN

Answer 10

SSS- split jn stratum granulosum

TEN- dermoepidermal junction

Question 11

Blistering Diseases

Pemphigous Vulgaris
Bullous Pemphigoid
Dermatitis Herpetiformis

Differentiate in

1. Target compound
2. Location
3. Antibodies
4. Fluorescence pttern
5. Cardinal histologic changes
6. Nikolsky sign

Answer 11

1. Desmosomes | Hemidesmosomes | Reticulin
2. Suprabasilar | Subepidermal | Subepidermal
3. IgG | IgG | IgA
4. Lacelike | Linear | Granular
5. Acantholysis | basal cell layer vacuolization | fibrin and PMNs at tip of dermal papillae
6. +, -,-

Question 12

Non Inflammatory Blistering

Answer 12

Epidermolysis Bullosa
-defect in keratin, laminin, BPAGs, or Type VII collagen

Porphyria
-heme metabolism (late)

Question 13

SKIN INFECTIONS

Acne Vulgaris
Verrucae
Molluscum contagiosum
Impetigo (contagiosa, bullosa)

Differentiate in

1. Etiologic agent
2. Gross findings
3. Histologic changes

Answer 13

1. P. acne | HPV | Pox Virus | GAHBS | S. aureus
2.
Comedones
Gray white papules pebbly surface
Pruritic pink central umbilication
Honey colored crust
Bullae
3.
Comedogenesis
Papillomatous, koilocytic atypia
Molluscum bodies, granulosum and corneum
Neutrophils, beneath corneum