24: Skin Flashcards
Mast cells filling the papillary dermis. The inset shows mast cells staining red in Leder stain. What spectrum of diseases involve mast cell proliferation?

Urticaria pigmentosa

Icthyosis vulgaris
Thickened stratum corneum, thin/absent stratum granulosum, rest of epidermis is normal thickness. What disease?

Icthyosis vulgaris
Clumped tonofilaments in keratinocytes of the stratum spinosum makes their cytoplasm relatively clear. In the outer stratum spinosum, the clumped fibrils are further compacted and whorl about the nuclei. These cells separate from each other to produce epidermolysis. What disease is shown?

Epidermolytic hyperkeratosis
Suprabasal cleft (arrows) with a few dyshesive (acantholytic) keratinocytes surmounted by hyperkeratosis and parakeratosis. The cleft is not a vesicle because true vesicles contain inflammatory cells and tissue fluid. Dyskeratosis is present above the cleft. What disease?

Darier disease
Large, confluent, sharply demarcated, erythematous plaques on the trunk

Psoriasis
Microscopic examination of a lesion demonstrates that the rete ridges are uniformly elongated, as are the dermal papillae, giving an interlocking pattern of alternately reversed “clubs.” Suprapapillary thinning and striking parakeratosis cause scales on the surface. What disease?

Psoriasis
The clubbed papillae contain tortuous dilated venules as part of the venulization of capillaries. The papilla to the right has one cross-section of its superficial capillary venule loop, which is normal. The papilla in the center shows numerous cross-sections of its venule, indicating striking tortuosity. What disease?

Psoriasis
Neutrophils migrate into the epidermis, emerging from the venulized capillaries at the tips of the dermal papillae. They migrate to the upper stratum spinosum and stratum corneum (arrows). In some forms of psoriasis, pustules are common clinical lesions. What disease?

Psoriasis
Suprabasal dyshesion leads to an intraepidermal blister containing acantholytic keratinocytes with a row of tombstone cells remaining. What disease?

Pemphigus vulgaris
Direct immunofluorescence examination of perilesional skin reveals IgG antibodies in the intercellular substance of the epidermis, yielding a lace-like pattern outlining the keratinocytes.

Pemphigus vulgaris
Dyshesion in the outer stratum spinosum and stratum granulosum. Dyshesive and dyskeratotic keratinocytes in the stratum granulosum (arrows). What disease?

Pemphigus foliaceus
Multiple tense bullae on an erythematous base and erosions, distributed primarily on the medial thighs and trunk

Bullous pemphigoid
A subepidermal blister has an edematous papillary dermis as its base. The roof of the blister consists of the intact, entire epidermis, including the stratum basalis. Inflammatory cells, fibrin and fluid fill the blister. What disease?

Bullous pemphigoid
Direct immunofluorescence study discloses linear deposition of immunoglobulin G (IgG) (and C3) along the dermal–epidermal junction. Ultrastructurally, these antibodies and complement are present in the lamina lucida.

Bullous pemphigoid
Pruritic, symmetric, grouped vesicles on an erythematous base are seen on the elbows and knees

Dermatitis herpetiformis
Dermal papillary abscesses of neutrophils with vesicle formation at the dermal–epidermal junction are characteristic

Dermatitis herpetiformis
Direct immunofluorescence reveals immunoglobulin A (IgA) deposited in dermal papillae in association with anchoring fibrils and elastic tissue fibers. This is the site of neutrophil infiltration and subepidermal vesicle formation. What disease?

Dermatitis herpetiformis
Steroid-responsive “target” papules, characterized by central bullae with surrounding erythema, appeared after antibiotic therapy

Erythema multiforme
Perivascular and periappendageal lymphocytic inflammation is present in the superficial and deep dermis. A hair follicle plugged with keratin is present near the right edge. What disease?

Lupus erythematosus.
An active lesion shows striking basal vacuolization, with keratinocyte necrosis (arrow) forming a dense eosinophilic body (apoptotic/fibrillary/colloid body) that is surrounded by lymphocytes (satellitosis).

Lupus erythematosus
Basal cell necrosis with resultant basal keratinocytic migration and synthesis of new basement mem- brane zone leads to thickening of the epidermal basement membrane zone (BMZ), as evident in this periodic acid–Schiff (PAS) stain. Notice the vacuoles (arrows) on either side of the BMZ, an indicator of cellular injury.

Lupus erythematosus

Lichen planus
A cell-rich, band-like, lymphocytic infil- trate disrupts the stratum basalis. Unlike lupus erythematosus, there is usually epidermal hyperplasia, hyperkeratosis and wedge-like hyper- granulosis

Lichen planus





























































