Fig 11.2 Photomicrograph of skin biopsy from a patient with cutis laxa. Elastic van Gieson stain demonstrates epidermal atrophy and absence of elastic fibers in the superficial dermis.

Fig 11.3 Photomicrograph of skin biopsy from a patient with focal dermal hypoplasia (Goltz syndrome) demonstrating focal thinning of the dermis and clusters of fat cells in the reticular dermis. Clinically the lesion was linear and striate.

Fig 11.4 Photomicrograph of skin biopsy from a patient with restrictive dermopathy demonstrating thinning of the epidermis, decreased elastin, and a reduction in numbers of adnexal structures which are poorly differentiated.

Fig 11.5 Photomicrograph of skin biopsy from a patient with poikiloderma demonstrating epidermal atrophy. The dermis shows numerous small telangiectatic vessels associated with some melanophages and loss of skin appendages.

Fig 11.6 Photomicrograph of skin biopsy from a patient with ichthyosis vulgaris demonstrating compact orthokeratosis and reduced granular layer.

Fig 11.7 Photomicrograph of skin biopsy from a patient with lamellar ichthyosis demonstrating orthokeratosis with focal hypergranulosis and an elongated rete ridge.

Fig 11.8 Photomicrograph of skin biopsy from a patient with congenital ichthyosiform erythroderma demonstrating parakeratosis, acanthosis, hypergranulosis and dermal lymphocytic infiltrate.

Fig 11.9 Electron micrograph of skin biopsy from a patient with lamellar ichthyosis demonstrating abnormal lipid lamellae.

Fig 11.10 Photomicrograph of skin biopsy from a baby with harlequin ichthyosis demonstrating massive compact orthohyperkeratosis extending into dilated hair follicles.

Fig 11.11 Photomicrograph of skin biopsy from a patient with bullous ichthyosiform erythroderma demonstrating marked hyperkeratosis. The granular layer and superficial stratum spinosum show vacuolar change, lysis and coarse basophilic clumps. Inset shows keratohyaline clumps.

Fig 11.12 Photomicrograph of skin biopsy from a patient with bullous ichthyosiform erythroderma demonstrating vacuolar change, lysis and coarse basophilic clumps.

Fig 11.13 Electron micrograph of skin biopsy from a patient with bullous ichthyosiform erythroderma demonstrating perinuclear aggregates of keratin in keratinocyte of the superficial stratum spinosum.

Fig 11.14 Photomicrograph of skin biopsy from a patient with Sjogren–Larsson syndrome demonstrating papillomatosis, acanthosis, hyperkeratosis and thickening of the granular layer.

Fig 11.15 Photomicrograph of skin biopsies demonstrating histochemical staining for alcohol dehydrogenase activity on frozen sections. A normal control is shown on the left. The biopsy from a patient with Sjogren–Larsson syndrome demonstrating absent alcohol dehydrogenase activity. is shown on the right. The technique is a useful screening test in patients suspected of having Sjogren–Larsson syndrome.

Fig 11.16 Photomicrograph of skin biopsy from a patient with neutral lipid storage disease demonstrating hyperkeratosis and vacuolation of basal keratinocytes.

Fig 11.17 Photomicrograph of frozen section of a skin biopsy from a patient with neutral lipid storage disease stained with Oil Red O demonstrating accumulation of fat in basal keratinocytes.

Fig 11.18 Photomicrograph of frozen section of a skin biopsy from a patient with neutral lipid storage disease stained with Oil Red O demonstrating accumulation of fat in sweat glands.

Fig 11.19 Photomicrograph of blood film from a patient with neutral lipid storage disease stained with Oil Red O demonstrating accumulation of lipid vacuoles in lymphocytes.

Fig 11.20 Photomicrograph of skin biopsy from a patient with Netherton’s syndrome demonstrating parakeratosis, psoriasiform acanthosis and a superficial band-like perivascular lymphocytic infiltrate in the dermis. The inset shows a hair demonstrating trichorrhexis invaginata which is pathognomonic for Netherton’s syndrome.

Fig 11.21 Photomicrograph of skin biopsy from a patient with Omenn syndrome demonstrating scattered dyskeratotic cells in the epidermis and a lichenoid dermal lymphocytic infiltrate which is epidermotropic and with exocytosis of lymphocytes in the epidermis. The infiltrate may also contain occasional eosinophils.

Fig 11.22 Photomicrograph of skin biopsy from a patient with KID syndrome demonstrating papillomatosis, parakeratosis and a mild lymphocytic infiltrate in the dermis. The features are not specific.

Fig 11.23 Photomicrograph of skin biopsy from a patient with palmo-plantar keratoderma demonstrating marked hyperkeratosis, hypergranulosis and epidermal hyperplasia.

Fig 11.24 Photomicrograph of skin biopsy from a patient with pachonychia congenita demonstrating marked intracellular edema of cells in the upper malpighian layer.

Fig 11.25 Electron micrograph of skin demonstrating the normal basement membrane zone. Hemidesmosomes can be seen on the lower border of the basal keratinocyte from which anchoring filaments traverse the lamina lucida to attach to the anchoring fibrils in the dermis. Keratin filaments can be seen in the keratinocyte.

Fig 11.26 Diagrammatic representations of: A. Basement membrane zone. B. Basement membrane zone demonstrating the location of protein antigens which are useful in distinguishing the different subtypes of epidermolysis bullosa. C. The level of split in epidermolysis bullosa simplex. D. The level of split in junctional epidermolysis bullosa. E. The level of split in dystrophic epidermolysis.

Table 11.1 Basement membrane zone immunoreactivity in epidermolysis bullosa subtypes (see text)

Fig 11.27 Photomicrograph of a frozen section of a skin biopsy from a patient with epidermolysis bullosa simplex demonstrating an apparent split between the epidermis and the dermis.

Fig 11.28 Photomicrograph of a frozen section of a skin biopsy from a patient with epidermolysis bullosa simplex stained immunohistochemically for the basement membrane antigen GB3 demonstrating positive staining in the base of the split. The split is so low in the epidermis that the cleavage appears to be subepidermal.

Fig 11.29 Photomicrograph of a frozen section of a skin biopsy from a patient with epidermolysis bullosa simplex stained immunohistochemically for the LH7.2 antigen (collagen type VII) demonstrating positive staining in the base of the split. The split is so low in the epidermis that the cleavage appears to be subepidermal.

Fig 11.30 Electron micrograph of a skin biopsy from a patient with epidermolysis bullosa simplex demonstrating that the split is within the basal keratinocyte. A fragment of the keratinocyte can be seen in the lower part of the split.

Fig 11.31 Electron micrograph of a skin biopsy from a patient with the Dowling–Meara form of epidermolysis bullosa simplex demonstrating clumped tonofilaments in the basal keratinocyte.

Fig 11.32 Photomicrograph of skin biopsy from a patient with the plakophilin-deficient form of epidermolysis bullosa simplex demonstrating an intraepidermal split. Desmosomes are absent in the superficial layers of the epidermis.

Fig 11.33 Photomicrograph of skin biopsy stained immunohistochemically to demonstrate plakophilin. Normal desmosomes can be seen as fine granular accentuation of staining between keratinocytes.

Fig 11.34 Photomicrograph of skin biopsy from the patient shown in Fig 11.32 stained immunohistochemically to demonstrate plakophilin demonstrating absent staining.

Fig 11.35 Electron micrograph of skin biopsy from the patient shown in Figs 11.32 and 11.34 showing an intercellular junction in which there is clumping of intermediate filaments and no desmosomes are seen.

Fig 11.36 Photomicrograph of a frozen section of a skin biopsy from a patient with junctional epidermolysis bullosa demonstrating a split between the epidermis and the dermis.

Fig 11.37 Photomicrograph of a frozen section of a skin biopsy from a patient with junctional epidermolysis bullosa stained immunohistochemically for the basement membrane antigen GB3 which identifies laminin 5 demonstrating absent staining for laminin 5.

Fig 11.38 Photomicrograph of a frozen section of a skin biopsy from a patient with junctional epidermolysis bullosa stained immunohistochemically for LH7.2 (collagen type VII) demonstrating positive staining in the floor of the split.

Fig 11.39 Electron micrograph of skin biopsy from a patient with junctional epidermolysis bullosa demonstrating the split has occurred through the lamina lucida between the basal keratinocyte and the basement membrane. There is a poorly formed hemidesmosome in the center which lacks a sub-basal plate.

Fig 11.40 Electron micrograph of unrubbed skin biopsy from a patient with junctional epidermolysis bullosa demonstrating poorly formed hemidesmosomes and absent sub-basal plates.

Fig 11.41 Electron micrograph at very high power of unrubbed skin biopsy from a patient with junctional epidermolysis bullosa demonstrating poorly formed hemidesmosomes and absent sub-basal plates.

Fig 11.42 Photomicrograph of skin biopsies stained immunohistochemically for GB3 antigen, The section on the left is a normal control. The section on the right is from a patient with junctional epidermolysis bullosa with pyloric atresia and demonstrates a split with positive staining in the floor of the blister.

Fig 11.43 Photomicrograph of skin biopsies stained immunohistochemically for alpha-6 beta-4 integrin. The section on the left is a normal control. The section on the right is from the same patient as shown in Fig 11.41 and demonstrates absent staining for alpha-6 beta-4 integrin.

Fig 11.44 Photomicrograph of a frozen section of a skin biopsy from a patient with dystrophic epidermolysis bullosa demonstrating a split between the epidermis and the dermis.

Fig 11.45 Photomicrograph of a frozen section of a skin biopsy from a patient with dystrophic epidermolysis bullosa. The section on the left shows immunohistochemical staining of the biopsy for GB3 and demonstrates positive staining in the roof of the blister. The section on the right has been stained immunohistochemically for LH7.2 antigen (collagen type VII) and demonstrates absent staining for LH7.2.

Fig 11.46 Electron micrograph of a skin biopsy from a patient with dystrophic epidermolysis bullosa demonstrating failure of the basement membrane to adhere to the underlying dermis because of reduced anchoring fibrils. The basement membrane can be seen in the roof of the split.

Fig 11.47 Photomicrograph of skin biopsy from a patient with dystrophic epidermolysis bullosa who developed a verruciform xanthoma demonstrating hyperkeratosis, parakeratosis and verrucous acanthosis. The papillary dermis is filled with numerous large xanthoma cells. The lesion presented as a warty lesion on the thigh with a clinical differential diagnosis of squamous cell carcinoma.

Fig 11.48 Photomicrograph of skin biopsy from a patient with transient bullous dermolysis stained immunohistochemically for LH7.2 (collagen type VII) demonstrating positive staining in basal keratinocytes.

Fig 11.49 Electron micrograph of skin biopsy from a patient with transient bullous dermolysis demonstrating perinuclear accumulation of type VII collagen.

Fig 11.50 Photomicrograph of skin biopsy from a patient with porokeratosis demonstrating a cornoid lamella overlying an atrophic segment of epidermis.