Dermatopathology Flashcards by Daniel Kruger

What is vitiligo?

Macules or patches of skinw with loss of pigment

areas affected: hands, wrists, perioral, and anogenital regions

Autoimmune? - don’t know what causes it.

Often found in type 1 diabetes, hashiomotos, and addisons disease

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Freckles vs Lentigo?

Freckles are hyperpigmented lesions. They darken in sunlight

Lentigo is hyperpigmented lesion due to increase number of melanocytes along the basement membrane. They do not darken in sunlight

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What happens in acute inflammatory process? What conditions does this encompass?

Acute inflammatory process lasts a few days to several weeks. Where micoscopic findings show neutrophils, edema, epidermal, vascular or subcutaneous injury occurs.

This encompasses many conditions
- uticaria
- acute eczematous dermatitis
- erythema multiforme.

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What is uriticaria? What type of immune reaction is it?

Uriticaria is an acute inflammatory process. Also called hives
It is an acute pruritic disease of short duration
It is a type I immune reaction
- Local accumulation and degranulation of mast cells with histamine release and edema.
Skin findings - pruritic nodule, edematous swelling (wheals) and plaques, formation of bullae
Microscopic findings - perivascular edema
Cause? - drugs, household exposures (new soaps) insect bites, foods

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What is a morbilliform rash?

A “measles like” rash.

Causes - drug reactions, especially antibiotics such as sulfa, and “cillins”.

Starts on chest and spreads outward.

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What is an exanthem? What is an enathem? What are they both caused by

Exanthem- Body-wide macular/papular rash

enanthem - lesions that occur in the mouth or in mucous mmebranes, - usually more vesicular

Both occur due to a virus

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What is acute eczematous dermatitis? characteristics? What can it progress to?

Also known as eczema.

This is a rash that is characterized by erythema, edema, and veiscle formation

This can progress to oozing and crusting of papules and vesicles - watery and oozy.

Chronic raised plaques

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What does microscopy of acute eczematous dermatitis show? What is the pathology and types?

Shows distinct eosinophilia and epidermal spongiosis

Pathology - antigen take up by lengerhans cell and is presented to T cell, upon rexposure to T cell release of cytokines occurs
- types: allergic contact dermatitis, atopic dermatitis, irritant related dermatitis

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What is Erythema multiforme? Most common cause?

This is a hypersensitivity reaction to infections. (HSV-90% of cases, mycoplasma), drugs (sulfonamides, penicillin, salicylates). Can also be seen in carcinomas and collagen vascular diseases

Skin findings
- macules, papules, vesicles and bullae = multiforme, usually semetric involvement of the extremities
- It can form multiple types of morphology in one area

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What are the different variants of erythema multiforme?

Steven Johnson Syndome

Toxic epidermal necrolysis

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What is Steven Johnson syndrome? How do they present?

Steven-Johnson syndrome is a form of erythema-multiforme. Also known as EM major

Patients present with
- fever
- Rash that involves lips and oral mucosa
- Risk of secondary infection leading to sepsis
- 10% of epidermal detachment

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What is toxic epidermal necrolysis?

A form of erythema multiform that leads to diffuse sloughing and necrosis of cutaneous and mucosal epithelium. More than 30% epidermal detachment

Microscopy reveals – diffuse epidermal necrosis leading to blister formation, perivascular lymphocytes and dermal edema

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What are chronic inflammatory skin conditions? Examples?

Conditions that last for several months to years

Chronic inflammation = thickening of the skin

Psorasis, seborrheic dermatitis

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What is psoriasis? What sign is associated with it? Where are the common areas?

A skin condition that involves epidermal and dermis with epidermal hyperplasia and hyperkeratosis “thickening”

Skin findings - red plaques covered with silvery white scales. Removal of these scales causes petechial bleedings = Auspitz sign

Commonly affects elbows, knees, scalp, lumbosacral region, may involves nails-pitting of the nails

Microscopic elongated dermal papillae with thinning of overlying epidermis

Psoriatic arthritits related to ankylosing spondylitis - Positive for HLA B27

Treated with biologics

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What is related to ankylosing spondylitis? What is the gene marker?

Psoriatic arthritis is related to ankylosing spondylitis. Positive for HLA B27

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What is dermatitis herpetiformis? What is it related to? What antibody is it related to?

This is a skin disease that is characterized by pruritic vesicular dermatosis

These are burning and itching lesions on the extensor surfaces, knees, elbows, back and buttocks

Related to gluten insensitivity - celiac sprue

Microscopy reveals cleft formation with dense neutrophilic infiltratoin and microabscess formation

Antiendomysial IgA antibody in the serum.

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What is seborrheic dermatitis? What causese it? What are forms of it?

Another chronic skin condition that is of unkown etiology

Moist, greasy macule and papule on erythematous base, scales, and crust

Dandruff and cradle cap are forms of it

What is a seborrheic keratosis? Microscopic findings? Is it benign or malignant?

This is a dark brown papule with a stuck on appearence. Not related to seborrheic dematitis

Can be flat, or raised, sharpyl demarcated lesion with pink to brownish black pigmentation

Benign,

Microscopic findings- sheets of basal-like cells, hyperkeratosis, keratin filled cysts

Find in middle aged and older adults

What is an actinic keratosis? What does the microscopic view show?

A rough, sandpaper like lesion that can produce a horn

Microscopic - shows dysplasia of keritinocytes in the basal portion of the epidermis

Caused by UV exposure, precancerous lesion that can turn into squamous cell carcinoma.

What do blistering (Bullous) diseases involve? How do you differentiate types?

Bullae involve oral mucosa and skin

Genearl microscopic findings include acantholysis which leads to bullae formation

Pemphigus and pemhigoid

What are the general microscopic findings of Bullous diseases?

Acantholysis - this leads to bullae formation

What does nikolsky sign positive indicate?

Indicates pemphigus.

These are flaccid bullae that READILY rupture and leave erosion (+)

What are the 4 types of pemphigus? Most common type?

Pemphigus Vulgaris, Pemphigus vegetans, Pemphigus foliaceous, pemphigus erythematosis

Most common type is pemphigus vulgaris. 80% of cases.

These are nikolsky sign positive.

Pemphigus vulgaris. Where are the lesions located? What antibody is associated with it?

80% of cases of pemphigus

Begin on oral mucosa with later involvement of skin of scalp, face, chest, axillae and groin

Antibody to demoglein 3 (intracellular cement)

exam: flaccid bullae which readily rupture and leave erosion (nikolsky sign positive)

Microscopic: suprabasal bullae with intercellular deposits of igG and C#

Where does pemphigus foliaceoius occur?

On scalp, face, and chest, seen in south america

Pemphigus erythematosis, where does it occur?

malar area of the face. AKA butterfly rash of lupus

Where is pemphigus vegetans located? What skin lesion does it cause?

Groin, axillae Wart like plaques

What are bullous pemphigoid? How do you differentiate it from pemhigus

These are bullae that occur in elderly. **They do not rupture easily and don't have an erythematous base. Negative nikolsky** **From an antibody against hemodesmosomes** Appear in a linear pattern at basement membrane on microscopy, Oral mucosa involvement is less than with pemphigus

What are Nevi? Microscopy? Examples?

These are common moles, aka benign skin neoplasms of melanocytic origin Microscopic morphology: nests of uniform round cells with inconspicuous nucleoi and few if any mitotic figures examples: Melanocytic nevus (common mole), dysplastic nevus, blue nevus

What is a nevi erupting in one of the ares of th ebody not exposed to sun and occuring after the age of 30 need evaluation for?

melanoma

What is a dysplastic nevus? What are they precursors to?

A nevi with cellular atypia **without invasion.** These are precursors to melanoma. They are variable in pigmentation, greater than 5mm in size, with irregular borders Microscopic view: same as general nevus with fusion and coaslence of nest cells. Cellular atypia is present.

What is dysplastic nevus syndrome?

**A familial melanoma syndrome** **Autosomal dominant with high penetrance** Usually fair skinned with multiple irregular nevi with variegated color HIGH RISK FOR MALIGNANT MELANOMA increased risk of pancreatic cancer if one family member has this, others are most likely to get it.

What are Blue nevi? What is the blue caused by? Benign or malignant?

Nevi that have deep dermal involvement Blue pigmentation is due to deep involvement with melanocyte involvement These are benign Women\> men, Asian\>caucasion\>african american

what are the 3 malignant skin neoplasms?

BCC, SCC, melanoma

What are the characteristics of basal cell carcinoma? Who do they occur in? How do you treat them?

These are the most common type of skin cancer, that usually occur in sun exposed areas such as the nose, lip, and ear. older patients progressive invasion of surrounding tissue but does not metastasize **They are flat, pearly, papule, with subepidermal blood vessles (telangiesctasia), occasional scaly edge, well circumscribed, can ulcerate** microscopic features: nests of neoplastic cells resembling basal epidermal cells, embeeded in mucoid matrix. treatment: excision

What is squamous cell carcinoma?

The second most common type of skin cancer, occurs in the elderly in sun exposed areas such as the head, hands, and face. Can be caused by chemical exposures (arsenic, ionizing radiation, tars and oils) rareley metastasizes but 50% mortality over 5 years when metastasis occurs into the lymph AK is precusor **sharly circumscribed, soft or firm red nodules with crusted center, painless nodule, may ulcerate** **microscopic: invasive squamous cells into the dermis, keratin pearls and intracellular bridges.**

What is malignant melanoma? Cause? tumor marker? what growth pattern is associated with metastasis?

A malignant tumor of melanocytes. 4% of all cancer incidence greatest incidence in sun exposed areas of fair skinned individuals Pathology: UV radiation damages DNA of melanocytes s-100 tumor marker * growth patterns * radial-horizontal growth - not associated with metastasis * **vertical - grows downward into dermis - high association with metastasis.**

What are the risk factors for melanoma?

Sun exposure familial link hystory of dysplastic or giant nevi

what are the characteristics of melanoma? How is it staged?

**6mm in size with irregular borders (ABCDEs)** **microscopic: large cells with prominent nucleoli forming poorly defined nests** Staging- depth of penetration important - breslow criteria less than 1.7mm is favorable prognosis

What are the warning signs of melanoma?

Increasing size of the nevus itching or pain associated with nevus change in size, shape, or color growth of new nevus

ABCDE?