Acantholytic cell :
Refers to an epithelial cell that has undergone dyshesion (i.e separation
from another epithelial cell) by dissolution of intercellular bridges and
has consequently become round.
Characterized by suprabasilar clefting with acantholytic and dyskeratotic cells at all levels of the epidermis.
Example: Darier's disease,
Increase in keratinocyte population of spinous layer with
thickening of the epidermis. This may be papillomatous or psoriasiform.
Cell death, in which the cells becomes condensed and then
fragment into smaller bodies by an active budding process.
pyknotic nuclear remanants.
In the skin, these apoptotic bodies are known
as Civatte bodies.
Apoptotic bodies extruded into the papillary dermis,
are known as Colloid bodies, these contain immunoglobulins, particularly
Ballooning degeneration : This is intracellular edema with cellular
swelling and is often secondary to viral injury or nutritional
Basket weave pattern :
This applies to the normal appearance of the cornified layer in
the section of skin (except for that of the palms and
'Bottom- Heavy' Infiltrate:
Dense lymphoid infiltrate may be found in
lower dermis in the following conditions- Cutaneous lymphoma ; Herpes
folliculitis ; Hidradenitis suppurativa (mixed infiltrate and scarring).
Bulla: A noncystic, transparent fluid filled elevation 1 cm or larger in
This refers to a dermis
that appears focally hypercellular on scanning magnification and is not usually due to usual inflammatory
infiltrate. Example: Incomplete granuloma annulare ; Interstitial granulomatous
dermatitis; Interstitial granulomatous drug reaction ; Resolving
vasculitis ; Folliculitis (at deeper levels) ; Subtle breast carcinoma
recurrence; Desmoplastic melanoma; Kaposi sarcoma (early stage).
'Chunks of coal': Large atypical lymphoid cells within a heavy mixed
infiltrate occur in
Compact orthokeratosis : This denotes normal configuration of the stratum corneum on palms and soles and in pathological condition such as lichen
simplex chronicus wherein the cornified cells are closely packed together.
This is localized faulty keratinization
characterized by a thin column of parakeratotic cells with an absent or
decreased underlying granular zone and vacuolated or dyskeratotic cells
in the spinous layer.
Exmple: Porokeratosis and it variants.
Corps Ronds : These are found as solitary cells or sometimes small groups
of separated cells in the upper malpighian layer and stratum corneum.
have a small pyknotic nucleus, a clear perinuclear halo and brightly
Crust : A heap composed of inspissated plasma that contains white blood
cells, red blood cells or both (also called scab). Example. Impetigo
Dyskeratosis: Described as cell death associated with premature keratinization below the level of the stratum granulosum.
Epidermotropism: This is directed emigration of lymphocytes into the
epidermis, usually involving only the lower one- third to half of the
epidermis. The cells have a tendency to aggregate. Spongiosis is usully
not prominent. Example: Mycosis fungoides.
Exocytosis: Random immigration of inflammatory cells through the
epidermis, some cells reach the surface. This is common in inflammatory dermatoses.
Example. Spongiotic Drug Reaction.
Grains: These are small cells with elongated nuclei and scanty cytoplasm
in the upper layers of the epidermis.
Hypergranulosis: Increase in thickness of the granular layer. Example. Lichen Planus
This is defined as increased thickness of stratum corneum, either by normal or abnormal keratinocytes.
Example. Lichen Planus
Laminated Orthokeratosis: Refers to configuration of the stratum corneum
in some pathological states such as icthyosis vulgaris and X- linked
icthyosis wherein the cornified cells are arranged in plate-like fashion.
This denotes thickening of the skin characterized
clinically by induration, hyperpigmentation and accentuation of the
normal skin markings.
A lesion less than 1.0 cm in greatest dimension ; Flush with the level
of surrounding normal skin; Colour differs from that of the
surrounding normal skin ; Example. Traumatic senile purpura.
A solid or cystic elevation 1.0 cm or more, but less than 2.0 cm
Orthokeratosis: This is defined as a process of normal keratinization
which leads to the production of a stratum corneum composed of anucleate
A solid or cystic elevation less than 1.0 cm in diameter.
Papillomatosis (Church Spiring): Increase in keratinocytes
with formation of projections (papillae) from the surface of skin.
Example. Verruca vulgaris, Seborrheic keratosis.
Parakeratosis : This is a process of keratinization in which the
keratinocytes retain their nuclei. This is abnormal in skin but normal in
Patch : A lesion 1.0 cm or larger in greatest dimension
; Flush with the level of surrounding normal skin ; colour differs from that of
the surrounding normal skin ; Example. Mongolian Spot.
Pigmentary incontinence : Basal layer damage results in damage to melanocytes with loss of pigment into the dermis where it is taken up by
A lesion that rises slightly above the surface of the skin and is
larger than 1.0 cm in greatest dimension. Example. Psoriasis.
Psoriasiform Hyperplasia: Increase in keratinocytes with elongation of
dermal papillae. Example. Psoriasis.
An elevation formed
of pus. Example. Drug Eruption.
Satellite Cell Necrosis: Single cell death in the epidermis in
association with one or more lymphocytes, the implication being that the
lymphocytes have trigerred the apoptosis pathway.
Scale: A collection of dry horn composed of abnormally shed or
accumulated stratum corneum. It is visible on the skin surface as a
flake. Example. Psoriasis.
Spongiosis: Widening of the interspaces between keratinocytes
due to edema fluid without detachment of cells from each other.
Squirting dermal papillae: Dermal papillae rise high and the epidermal
region over the dermal papillae are thinned.
The dermal papillae contain
prominent blood vessels.
The term 'squirting dermal papillae' has been
used to describe a phenomenon where neutrophils are discharged from these
vessels resulting in collection of neutrophils in association with
Refers to intraepidermal collections of three or more nested
melanocytes on H and E sections.
Transepithelial elimination: A biological phenomenon whereby materials
foreign to the skin (Example. Elastic fibers, collagen, erythrocytes, amyloid,
bone, calcium salt , mucin, fungi etc) are eliminated through pores
between cells of the epidermis or hair follicle or are carried up between
cells as a passive phenomenon, during maturation of the epidermal cells.
This phenomenon is observed in the following lesions - Necrobiosis
lipoidica; necrobiotic xanthogranuloma ; perforating folliculitis ;
Pseudoxanthoma elasticum ; Reactive perforating collagenosis. etc
Tumour: A solid or cystic elevation 2.0 cm or more in diameter .
Ulcer: A lesion in which there has been destruction of the epidermis and
which goes into the papillary or reticular dermis or even deeper. It
usually heals with scarring
Formation of vacuoles within the cells. This is often noted in the basal keratinocytes.
Vesicle: A noncystic transparent fluid filled elevation 1.0 cm in
greatest dimension. Example. Herpes Simplex.