Dermatopathology

Outline

• Benign epithelial tumors• Acne• Keloids• Disorders of pigmentation• Disorders of sunlight exposure• Chronic dermatoses• Disorders of epidermal Appendages• Infections

Seborrheic keratosis.(stuck on appearance)

Seborrheic keratosis.

Seborrheic keratosis.,Summary• Proliferation of squamous cells

• Multiple,velvet like, tan to brown colored lesions• Chest ,face ,back• “Stuck on” appearance• Biopsy shows melanin in the cytoplasm• Non malignant

• Not related to seborrheic dermatitis• Not related to actinic keratosis

Acne,summary

• Acute and chronic inflammation• Adolescent, young people

• excessive production of sebum• Infection and inflammation

• Propionebacterium acnes

Keloid

Proliferation and increased deposition of collagen in the dermis. Keloids.

How does Keloid differ from hypertrophic scars?

Benign nevus

Benign nevus

Halo nevus, Freckles,

Vitiligo, antibodies against melanocytes

Tatoos, Gross and microscopic

Diseases associated with sun exposure

• Melanoma• Actinic keratosis• Squamous cell carcinoma• Basal Cell carcinoma• Basal cell carcinoma is the most common.• Melanoma is the most aggressive

Melanoma

Excisional biopsy from Melanoma

Note the prominent nuclear material and pleomorphism

Melanoma

• Most important signs are change in color,size or shape

• The extent of vertical growth or depth of the tumor is a predictor of tumor activity

Basal Cell carcinoma

Basal Cell carcinoma

• Slow growing

• Rare metastasis• Pearly, silvery tumors

• May ulcerate(rodent ulcers)

Squamous cell carcinoma of the skin

Squamous cell carcinoma of the skin

• P53 mutation• Actinic keratoses

Psoriasis

Psoriasis

• Chronic dermatoses• Also arthritis, enteritis, myopathy• Elbow ,knees,scalp• Silver scales on the skin• Nail changes are common(onycholysis

separation of nail plate from nail bed)• Morphology :extensive sacles or parakeratosis.

Lifting of the scales leads to bleeding(Auspitz sign)

Molluscum Contagiosum

Molluscum Contagiosum

• Single most important risk factor, AIDs

• Etiologic agent Pox virus

• Characteristic umbilicated lesions.

Erythema Nodusom

Erythema Nodusom

• Commonest example of a panniculitis• Inflammatory reaction affecting subcutaneus

fat.• Streptpyogenes,Histoplasmosis,Sarcoidosis,Co

ccidiodomycosis,OCPs,sulphanamides Crohn’s disease)

• Red, itchy, painful skin lesions common on the shin.

Toxic epidermal necrolyis

TEN,SJS and Erythema multiformes

Recognize and identify the distinguishing feature of• Erythema

multiformes(etiology,drugs,mycoplasma,Herpes simplex,E.T.C) Appearance target lesions.

Variant of erythema multiformes • TEN (Toxic epidermal necrolysis)>30% BSA(body

surface area affected)• Steven-Johnson Syndrome>10% BSA affected

Purpura

Petechia, purpura, Echymosis

• List the distinguishing features of petechiae ,Purpura and Echymosis.

Impetigo

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pants

Thank you!!!