The basics: Diagnostic terms, skin anatomy, and stains

The basics

Diagnostic terms, skin anatomy, and stains

Tammie Ferringer and Christine J. Ko

Glossary of terms

Acantholysis

• Loss of cell–cell adhesion

Acanthosis

• Increase in thickness of the epidermis

• Regular (all rete pegs descend to the same level) or irregular (rete pegs descend to different levels in the papillary dermis)

Fig 1-1 Acantholysis, pemphigus vulgaris

Fig 1-2 Acanthosis, psoriasis

Fig 1-3 Anaplasia, Bowen’s disease

Fig 1-4 Apoptosis, outer root sheath, catagen follicle

Fig 1-5 Asteroid body, sarcoidosis

Fig 1-6 Ballooning degeneration, herpes simplex

Anaplasia

• Atypical nuclei (abnormal size, shape, staining) and pleomorphism (variation in nuclear characteristics)

Apoptosis (pronounced apohtosis)

• “Programmed cell death”

• “Dead red” keratinocytes with pyknotic nuclei

• Although the term is often applied to any necrotic or dyskeratotic keratinocyte, it is best reserved for physiologic programmed cell death or pathologic processes that produce death through a similar pathway

Arborizing

• Branching, often refers to rete or vasculature

Asteroid body

• Collections of eosinophilic material seen in sporotrichosis

• Also refers to star-shaped intracytoplasmic inclusions seen in giant cells of sarcoidosis or berylliosis or other granulomatous processes

Atrophy

• Decrease in thickness of epidermis

Ballooning degeneration

• Destruction of epidermis by dissolution of cell attachments and intracellular edema

Caterpillar body

• Pale pink linear basement membrane material within epidermis, seen in porphyria cutanea tarda

• Represents degenerated type IV collagen

Civatte/colloid bodies

• Pink, globular remnants of keratinocytes

Collagen entrapment

• Collagen fibers surrounded by histiocytes/spindle cells (collagen balls)

Cornoid lamellae

• 45° angle parakeratosis in a column above a focus with a diminished granular layer and underlying dyskeratotic cells

Corps ronds/grains/dyskeratosis

• Corps ronds = rounded nucleus with halo of pale to pink dyskeratotic cytoplasm

• Grain = dark blue flattened nucleus surrounded by minimal cytoplasm

• Dyskeratosis = abnormal, individual-cell keratinization

Cowdry A body

• Also known as the Lipshutz body

• Intranuclear pink inclusions of herpesvirus infection

Cowdry B body

• Intranuclear pink inclusions of adenovirus and poliovirus infection

Crust

• Serum/fluid with inflammatory cells/debris in stratum corneum

Donovan body

• Intracytoplasmic collections of bacteria seen in granuloma inguinale

Dutcher body

• Intracytoplasmic pink masses of immunoglobulin that invaginate into the nucleus of plasma cells and appear to be intranuclear

Effacement

• Loss of normal rete pattern

Eosinophilic spongiosis

• Spongiosis with eosinophils in the epidermis

Epidermolytic hyperkeratosis

• Coarse, irregular hypergranulosis associated with disruption of cell membranes

• Associated with keratin 1 and 10 mutations

Epidermotropism

• Lymphocytes in epidermis with relative absence of spongiosis: term usually reserved for mycosis fungoides

Erosion

• Partial loss of epidermis

Exocytosis

• Lymphocytes in the epidermis with associated spongiosis: term usually used when discussing spongiotic dermatitis

Festooning

• Papillary dermis retains an undulating pattern (often used to describe porphyria cutanea tarda)

Flame figure

• Collagen encrusted with major basic protein from eosinophils

Foam cell

• Lipid-laden histiocyte

Follicular mucinosis

• Alteration of hair sheath anatomy by pools of mucin

Granulomatous

• Composed of granulomas (collections of histiocytes)

Grenz zone

• Uninvolved area of dermis beneath the epidermis or adjacent to a hair follicle (border zone)

Guarnieri body

• Eosinophilic inclusions of smallpox

Henderson–Paterson body

• Intracytoplasmic oval, pink inclusions of molluscum infection

Hyper-/hypogranulosis

• Increased/decreased granular layer

Hyper-/hypopigmentation

• Increased/decreased melanin pigment

Interface

• Generally refers to the dermoepidermal junction

Kamino body

• Dull pink to amphophilic basement membrane material within the epidermis in a Spitz nevus

Karyorrhexis

• Fragmentation of neutrophils (leukocytoclasis). (If neutrophils resemble ants with segmented bodies, then karyorrhexis resembles dismembered ants and scattered ant heads)

Koilocytes

• Keratinocytes with clear cytoplasm and shrunken “raisin-like” pyknotic nuclei

Leishman–Donovan body

• Intracytoplasmic collections of amastigotes in leishmaniasis

Lentiginous epidermal hyperplasia

• Elongated bulbous rete

Lentiginous melanocytic growth pattern

• Proliferation predominantly along the dermoepidermal junction

Leukocytoclasia

• Fragmentation of neutrophils, also referred to as karyorrhexis

Lichenoid dermatitis

• Interface dermatitis with destruction of the basal layer and Civatte body formation (Figure 1.7)

Fig 1-7 Civatte bodies, lichen planus

Fig 1-8 Collagen entrapment, dermatofibroma

Fig 1-9 Cornoid lamellae, porokeratosis

Fig 1-10 Corps ronds/grains, Darier’s disease

Fig 1-11 Eosinophilic spongiosis, incontinentia pigmenti

Fig 1-12 Epidermolytic hyperkeratosis

Fig 1-13 Epidermotropism, mycosis fungoides

Fig 1-14 Lymphocyte exocytosis, subacute spongiotic dermatitis

Fig 1-15 Flame figure, Wells’ syndrome

Fig 1-16 Foam cells, verruciform xanthoma

Fig 1-17 Follicular mucinosis, alopecia mucinosis

Fig 1-18 Granulomas, sarcoid

Fig 1-19 Hyper-hypogranulosis, lichen planus

Fig 1-20 Kamino bodies, Spitz nevus

Fig 1-21 Karyorrhexis, leukocytoclastic vasculitis

Fig 1-22 Leishman–Donovan bodies, leishmaniasis

Fig 1-23 Medlar bodies, chromomycosis

Fig 1-24 Munro microabscess, psoriasis

Fig 1-25 Necrobiosis, necrobiosis lipoidica

Lichenoid infiltrate

• A band-like infiltrate, generally composed predominantly of lymphocytes, located at the dermoepidermal junction

Medlar body

• Brown, round structure resembling overlapping copper pennies

• Divide by septation, resembling a hot-cross bun

Metachromasia

• The property of staining a different color from the stain itself (i.e., the purple color of mast cell granules with the blue stain methylene blue)

Michaelis–Gutman body

• Intra- and extracellular calcified, concentric circular structures, seen in malakoplakia

Munro microabscess

• Collection of neutrophils in the stratum corneum, as seen in psoriasis

Necrobiosis

• Pale-staining smudged necrotic collagen

Negri body

• Inclusions within neurons seen in rabies infection

Orthokeratosis

• Stratum corneum without retained nuclei

Pagetoid cells

• Large cells with abundant cytoplasm within the epidermis

Pagetoid scatter

• Buckshot scatter of atypical cells within the epidermis

Fig 1-26 Pagetoid cells and pagetoid scatter, Paget’s disease

Palisading

• Picket fence-like arrangement at the periphery

Papillary mesenchymal body

• Structure that resembles the whorl of plump mesenchymal cells normally present in the hair papilla (seen in trichoblastoma and trichoepithelioma)

Fig 1-27 Palisading, gout

Fig 1-28 Papillary mesenchymal body, trichoepithelioma

Fig 1-29 (a) PEH, syringosquamous metaplasia following trauma. (b) Elastic fiber trapping in PEH

Fig 1-30 Pseudohorn cyst, seborrheic keratosis

Papillomatosis

• Exophytic finger-like projections

Parakeratosis

• Stratum corneum with retained nuclei

Pigment incontinence

• Melanin within dermal macrophages and free within the dermis

Pleomorphism

• Variation in nuclear size/shape

Psammoma body

• Extracellular laminated, calcified structures seen in meningioma, papillary thyroid carcinoma, ovarian carcinoma

Pseudoepitheliomatous hyperplasia (PEH)

• Prominent acanthosis of the adnexal epithelium and epidermis, mimics squamous cell carcinoma

• Often associated with trapping of elastic fibers

Pseudohorn cyst

• Keratin-filled cystic structure that is the result of cutting through invaginations of the stratum corneum (similar to a horn cyst, but connects to the surface)

Reticular degeneration

• Destruction of epidermis with cell membranes remaining in a net-like pattern

Reticulated

• Network of interconnecting strands (net-like)

Russell body

• Intracytoplasmic pink collections of immunoglobulins in plasma cells, seen in rhinoscleroma and other conditions with many plasma cells

Schaumann body

• Laminated calcified structure seen in sarcoidosis

Shadow cells

• Cells with barely visible outlines of nuclei

Spongiform pustule of Kogoj

• Neutrophils in the stratum spinosum, associated with spongiosis at periphery (typical of psoriasis)

Spongiosis

• Intercellular edema in epidermis with stretching of cell–cell junctions

Squamotization (or squamatization)

• Loss of cuboidal/columnar basal cells, with deepest layer now being polyhedral, pink squamous cells

Squamous eddies

• Circular whorls of squamous cells

Storiform

• Cartwheel or basket-weave pattern

Fig 1-31 Reticular degeneration, variola

Fig 1-32 Russell body, rhinoscleroma

Fig 1-33 Shadow cells, pilomatricoma

Fig 1-34 Squamous eddies, irritated seborrheic keratosis

Fig 1-35 Verocay body, schwannoma

Vacuolar change

• Formation of clear spaces within the basal layer

Verocay body

• Structure composed of two nuclear palisades enclosing pink cytoplasmic processes, seen in schwannoma

Villus

• Projection of papillary dermis covered by a layer of epidermal cells into a cavity

Normal skin anatomy

Scalp skin

• Numerous follicles that extend down into the panniculus

• Associated sebaceous glands, arrector pili muscles

Facial skin

• Thin epidermis

• Basket-weave stratum corneum

• Hair follicles and sebaceous glands numerous in the dermis

• Demodex mites common

• Eyelid and ear skin have many vellus hair follicles

• In the upper dermis of eyelid skin, skeletal muscle bundles are present

• On the conjunctival surface of the eyelid, stratum corneum and hair follicles are absent, but goblet cells are present

Skin of the trunk

• Very thick dermis, especially in skin from the back

• Scattered hair follicles and sebaceous glands

• Projections of fat extend upward to envelop adnexae

Fig 1-36 Villi, warty dyskeratoma

Fig 1-37 Normal scalp with follicles rooted in the fat

Fig 1-38 Sun-damaged facial skin

Fig 1-39 Sun-damaged skin. Solar elastosis spares papillary dermis

Fig 1-40 Eyelid

Areolar skin

• Slight acanthosis of the epidermis with basilar hyperpigmentation

• Sometimes there is a central invagination of the epidermis that leads to a follicle and sebaceous glands

• Smooth muscle bundles in the mid–deep dermis

• Apocrine glands in the reticular dermis

Fig 1-41 Eyelid

Fig 1-43 Areolar skin, smooth muscle bundles

Acral skin

• Compact eosinophilic stratum corneum

• Slight papillomatosis present on dorsal surfaces

Volar skin

• Compact eosinophilic hyperkeratosis with underlying stratum lucidum

• No hair follicles or sebaceous glands

• Eccrine glands numerous

• Meissner and Pacinian corpuscles may be seen

Fig 1-44 Volar skin, thick stratum corneum and deep Pacinian corpuscles

Fig 1-45 Volar skin, stratum lucidum

Fig 1-46 Volar skin, eccrine glands and Pacinian corpuscle

Mucosa

• Absent granular layer

• Keratinocytes are large and pale (filled with glycogen)

• Dilated vessels in the submucosa

• Smooth muscle bundles may be present

Fig 1-47 Mucosa

Fig 1-48 Smooth muscle in submucosa

Fig 1-49 Nasal turbinate mucosa: erectile tissue with mucous glands

Fig 1-50 Fetal mesenchyme

Fig 1-51 Fetal periderm

Nasal turbinate

• Erectile tissue with fibrous septa and vascular sinusoids

• Mucous glands

Fetal skin

• Stellate and spindled fibroblasts (mesenchyme)

• Densely cellular

Hair anatomy

Infundibulum

• From epidermis down to insertion of sebaceous gland

• Intraepidermal portion = acrotrichium

• Keratinizes in the pattern of the normal epidermis with a granular layer (keratohyaline granules)

Isthmus

• From the insertion of the sebaceous gland to the insertion of the arrector pili muscle (bulge)

• Keratin is formed in the absence of a granular layer = trichilemmal keratinization

• The inner root sheath is lost at this level and the outer root sheath develops an inner corrugated, dense pink cornified layer; peripheral palisading of the outer root sheath is seen

Stem

• From the insertion of the arrector pili muscle (bulge) to Adamson’s fringe

• Only present in anagen hairs

Adamson’s fringe

• The point above which hair cornifies

• Dermatophytes only infect cornified hair above Adamson’s fringe

• Above Adamson’s fringe, Huxley’s layer of the inner root sheath no longer has trichohyalin granules

• Hair tends to retract from the inner root sheath above Adamson’s fringe

• The inner root sheath is fused and blue-gray at this level and trichohyalin granules are not seen

• The outer root sheath is composed of pink cells with peripheral palisading

Bulb

• Below the stem portion of the anagen hair follicle

• From Adamson’s fringe to the base of the follicle

• The bulb has three zones: matrix, supramatrix, keratogenous zone

• Matrix: from base to critical line (widest point of the bulb and papillae)

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Tags: Dermatopathology

Apr 26, 2016 | Posted by admin in Dermatology | Comments Off

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