pathology of the skin

1. Hongxiang Chen M.D., Ph.D.
Professor, Chief Physician，Ph.D.
Supervisor

2. Dermatopathology Glossary of
Terms
1
Section
Dermatopathology and Skin Biopsy
Procedure

3.  diagnose
 identifying the etiological agents in infectious
diseases
 combined with clinical signs, some diseases can
be clarified or excluded
 provide a valuable reference for a physician to
rule out the differential diagnosis
The role of dermatopathology

4. diagnosis
pathological
finding
clinical
observation
The role of dermatopathology

5. 1. punch biopsy
2. shave biopsy
3. incisional biopsy
4. complete excision
5. curettage

6.  Punch biopsy:
includes the full thickness skin and even subcutaneous fat;
inflammatory skin conditions and skin tumors.

7.  Shave biopsy:
a small razor;
skill;
only a small fragment of a protruding tumor or
lesions located in the epidermis or superficial
dermis

8.  Incisional biopsy:
the most frequently used technique;
the size and depth of the wedge-shaped incision
can be controlled more easily as clinical
requirement

9.  Complete excisional biopsy:
the same as incisional biopsy, except the entire
lesion or tumor is removed;
can be used in small and easily excisable lesions;
the patient specifically asks for the procedure;
the borders of lesion or atypical pigmented lesions
need to be evaluated further

10.  Curettage biopsy:
occasionally used for biopsy purpose;
it is not the preferrd biopsy technique due to the
damage to the architecture of the skin tissues as a
result of the procedure.

11. the biopsied samples
10% formaldehyde
HE staining or in 2%
glutaraldehyde (some
tissue components can
be be better seen with
special staining methods)
avoid secondary
degeneration
for immunofluorescence
testing or for electron
microscopic examination

12. Dermatopathology Glossary of
Terms
2
Section
Dermatopathology Glossary of Terms

15. Abnormally increased thickness of the horny cell layer.

16. The nuclei remain in the cells of the horny cell layer because of
incomplete keratinization of the keratinocytes,usually accompanied
by hyperkeratosis and hypogranulosis

17. Wedge-shaped or columnar parakeratosis arising from epidermal invagination;
a characteristic of porokeratosis.

18. The thickened keratins plugging the orifice of follicles or sweat pores.
It is seen in lupus erythematosus,lichen sclerosus et atrophicus,pityriasis rubra
pilaris,porokeratosis,lichen pilaris,lichen spinulosis,etc.

19. The abnormally premature keratinization of individual keratinocytes in the epidermis or adnexa.
It can manifest as corps ronds,corps grains,keratin pearls,colloid body,viral inclusion body,etc.

20. (2)
(1)

21. Corps ronds:
Usually found in the horny layer, granular layer and in the upper part of the
spinous layer. These dyskeratotic cells are recognized by large,round, basophilic,
pyknotic nuclei in the center with a perinuclear halo and outermost basophilic
cytoplasm.
These changes are seen mainly in keratosis follicularis (Darier’s disease),warty
dyskeratoma,transient acantholytic disease (Grover’s disease),and focal
acantholytic dyskeratoma.
Corps grains:
Corps grains are found in horny layer that may resemble parakeratosis but these
cells are larger and characterized by clear nuclei with surrounding dyskeratotic
materials (either basophilic or eosinophilic) and sometimes accompanied by
perinuc-lear halo.
They are seen in keratosis follicularis (Darier’s disease) and warty dyskeratoma.

22. A group of concentric or laminated keratinocytes.
The center is gradually or fully keratinized with homogenous eosinophilic apoptotic
cells.
Keratin pearls are commonly seen in well-differentiated squamous cell carcinomas.

23. Also called Civatte body.
These often appear as single or multiple bodies that are composed of
homogenous,eosinophilic,round,degenerated keratinocytes with or without shrunken
nuclei in the basal cell layer,the prickle layer and the papillary dermis.
These bodies are seen in lichen planus,lupus erythematosus,erythema multiforme,
graft-versus-host disease,as well as other conditions.

24. These are homogeneous,eosinophilic bodies in virus-infected keratinocytes.
They are easily seen in herpes simplex,herpes zoster,molluscum contagiosum,
orf,milker’s nodules,etc.

25. A decreased thickness of the granular layer,frequently accompanied by
parakeratosis.
It often occurs in psoriasis,ichthyosis vulgaris,etc.

26. Normally the granular layer is composed of one to three rows of spinous keratinocytes.
This abnormally increased thickness of granular layer is called hypergranulosis,and is
usually accompanied by hyperkeratosis.
It is found in hyperkeratotic dermatoses such as lichen planus,lichen simplex chronicus,
primary cutaneous amyloidosis,etc.

27. Prominent increased thickness of the prickle cells layer of the epidermis.

28. The upward projection of the dermal papilla frequently accompanied by hyperkeratosis and
elongation of the rete ridges resulting in an uneven morphology of the epidermis.
These patterns are seen in verruca vulgaris,condyloma accum-inatum,seborrheic keratosis,
sebaceous nevus,and acanthosis nigri-cans,etc.

29. A condition coexisting with hyper-keratosis,hypergranulosis,acanthosis,and
papillomatosis.
It is found in verruca vulgaris,verrucous tuberculosis cutis,verrucous nevus,etc.

30. This is the irregular downward growth of the epidermis,with prominent acanthosis and
elongation and widening of the rete ridges that may reach the level of the sweat glands.
It is quite similar under microscopy to squamous cell carcinomas,but the cells are better
differentiated and are never atypical,in comparison to the latter.
This pattern is associated with chronic inflammatory responses such as verrucous
tuberculosis cutis,deep fungal infection,the borders of the chronic cutaneous ulcers,etc.

31. The prominent thinning of the epidermis and disappearance of rete ridges give rise to a
smudged appearance for the dermoepidermal junction that can eventually become a line.
It is most common in atrophic dermatoses,lichen sclerosis et atrophicus,scleroderma,etc.

32. This condition describes the widening of the intercellular spaces due to intercellular edema,in
the course of which the intercellular bridge becomes clear,like a sponge.
It is seen in dermatitides such as eczema,contact dermatitis,etc.
this includes intercellular and intrac-ellular edema.
In most cases intercellular and intracellular edema coexists.
Spongiosis

33. Under this condition the intrac-ellular edema is so conspicuous that the cells are expanding
and the bridge between cells disappears,which results in an acantholysis and the eventual
formation of intraepidermal vesicles or bullae.
The acantholytic spinous cells are round like a balloon floating in the vesicles or bullae,and
so were called ballooning cells.
These cells are diagnostic for cutaneous viral infections and the process is termed ballooning
degeneration.

34. With the increase of intracellular edema,the keratinocytes eventually break down to form
a multilocular blister,in which those remnants of cell membrane that survive partial
rupture become the septate of a set of blisters that appears as a network.
This phenomenon can be seen in eczema,irritant contact dermatitis,erythema multiforme,
viral infections,etc.

35. This is also called epidermolytic hyperkeratosis,and is characterized by the
accumulation of vacuolated cells containing basophilic keratohyaline granules in the
cytoplasm of the granular and suprabasal cell layers,usually accompanied by
hyperkeratosis and acanthosis.
It is typically seen in congenital bullous ichthyosiform erythroderma,epidermolytic
keratosis palmaris et plantaris,and systemic epidermal nevus.

36. The formation of intraepidermal clefts,vesicles,or bullae because of the separation of the
desmosomes between spinous cells is called acantholysis.It usually occurs in pemphigus
vulgaris,familial benign chronic pemphigus,follicular keratosis(Darier’s disease),etc.
Isolated or even clusters of acantholysed spinous cells (which are usually large and round
with oval nuclei surrounded by condensed eosinophilic cytoplasm) now float in cavities
termed acantholytic cells.
This set of circumstances is seen in all types of pemphigus,viral bullae,follicular

37. Dermal papilla protruding into the clefts or cavities of epidermis formed by acantholysis
because of disease processes.
They are usually covered by a single layer of basal cells or a few layers of epidermal cells

38. Also called vacuolar degeneration or hydropic degeneration.It manifests as the formation of
vacuoles or spaces beneath the basal cell layer due to the degeneration of the basal cells
which leads to the disappearance of the basal cell layer.
As a result,the epidermis contacts the dermis directly and the dermo-epidermal junction is ill-
defined.Finally,the subepidermal clefts or bulla are formed that frequently accompanied by
perfusion of melanin into the dermis.
It is found in quite a few inflammatory dermatoses that possess interface changes such as
lichen planus,lichen striatus,lichen nitidus,lichen sclerosus et atrophicus,lupus
erythematosus,dermatomyositis,erythema multiforme,fixed drug eruption,primary
cutaneous amyloidosis,etc.

39. koilocytes are found in the granular layer or the upper or middle parts of the spinous
layer of the epidermis.
These cells are variable sized vacuolated keratinocytes with pale cytoplasm,and possess
shrunken nuclei surrounded by perinuclear halos as seen physiologically in lips and vulva
mucosa and pathologically in papillomavirus infection such as condyloma acuminatum,
verruca plana,etc

40. Vesicle
＜0.5cm
A fluid-filled cavity whose diameter is greater than 0.5 cm (some authors refer to greater
than 1cm).
It can be found at the subcorneal,intraepidermal,suprabasilar and subepidermal levels

41. Aggregation of neutrophils in the parakeratotic stratum corneum.
It is characteristic of psoriasis vulgaris.Besides this,it can also be seen in impetigo,
Reiter’s syndrome,and seborrheic dermatitis.

42. Aggregation of neutrophils in the sponge-like areas of the granular layer and/or in the
upper parts of the spinous layer.
It is seen in pustular psoriasis,palmoplantar pustulosis,impetigo herpetiformis and Reiter’s
syndrome.

43. Clusters of atypical lymphocytes in the spinous layer,which are surrounded usually by a
clear space,as seen in mycosis fungoides.

44. Melanin increasing in the basal cell layer.
It is seen in seborrheic keratosis,dermatofibroma, acanthosis nigricans, Addison’s disease,
post-inflammatory pigmen-tation,etc.

45. Hypopigmentation
Describes decreased melanin in the basal cell layer,such as in vitiligo.

46. melanophages
This is caused by damage to the basal cell layer which results in the deposition of melanin
in the superficial dermis.
The melanin are phagocytosed by macrophages or dissociated in the dermis.The cells that
have phagocytosed melanin are called melanophages.
Pigment incont-inence occurs in incontinentia pigmenti,lichen planus,lupus erythematosus,
fixed drug eruption,etc.

47. Refer to the loss of differentiation in normal cells and is characteristic of tumor cells.
The anaplastic cells are characterized by large,polymorphic nuclei with
hyperchromasia and distinctly atypical mitoses. It occurs in malignant tumors.

48. Squamous eddies
These consist of keratinocytes arranged in concentric circles or whorls.
Those keratinocytes possess eosinophilic and pale cytoplasm without dyskeratotic or
atypical mitoses.
These eddies can be found in inverted follicular keratosis.

49. A nodular proliferation arising from variable proportions of epithelioid cells,histiocytes,
and multinucleated giant cells

50. This usually refers to granulomata,where the degenerated collagen in the central area
is surrounded by palisading cells and chronic inflammatory infiltration of the outer
zone,including epithelioid cells,histiocytes,lymphocytes,and giant cells.
It is typically seen in granuloma annulare,necrobiosis lipoidicus,rheumatoid nodule,
and gout.

51. The thickness of the dermis is decreased due to attenuation of the collagen or elastic
fibers or both.
It is frequently accompanied by the atrophy or disappearance of the follicles and
sebaceous glands.
Good examples are macular atrophy and linear atrophy.

52. Homogenization
The dermal connective tissues manifest as an amorphous homogenous
eosinophilic appearance.
It is seen in lichen sclerosus et atrophicus,and in scleroderma.

53. This condition manifests as a glassy semi-translucent material found in tissues or in cells.
This hyaline material appears as a light red homogenous refringent substance when
stained with hematoxylin-eosin (HE),as in the case of keloid.
In some cases,such hyalines can be found in plasma cells,for example in leprosy and
rhinoscleroma,where they are known as Russell bodies.

54. In this case the fibrinoid substance is widespread among the degenerated collogenous
fibers or around the damaged vessel walls,which manifests as refringent,eosinophilic and
homogenous appearance,as seen in rheumatoid nodules,lupus erythematosus,
leukocytoplastic vasculitis

55. This refers to the fractured,twisted,basophilic appearance of the elastic fibers.
It is seen in pseudoxanthoma elasticum,acrokeratoelastoidosis,etc.

56. Here the normal eosinophilic appearance of connective tissues is replaced with
homogenous or granular gray-blue amorphous materials in the upper dermis.
It is seen in actinic keratosis,actinic granuloma,etc.

57. This produces a mass of weak eosinophilic,sometimes basophilic,amorphous,
homogenous colloidal substances with prominent peripheral clefts, in which the
remnants of nuclei can be seen sometimes.
It is found in colloid milium,etc.

58. This term refers to the deposition of light red,homogenous amyloid substances in the
dermal papilla or the walls of small blood vessels.
A cleft can always be seen because of the retraction of the amyloid substances during the
process of tissue fixation and dehydration.The amyloid substances are metachromasia
and purple stained with crystal violet.They are yellow when stained with Van Gieson.
This degeneration is seen in cutaneous amyloidosis.

59. This condition manifests when the deposition of mucin among the dermal collagens
results in the splitting up of collagen bundles into fibers and also results in the widening
of spaces between the fibers.
The main components of mucin are acid mucopolysaccharide and proteins.They appear
pale blue when stained with hematoxylin-eosin (HE) and blue with Asian blue.
These occur in pretibial myxedema,lichen myxedematosus,etc.

60. 微信号：patrickwb
hongxiangchen@hotmail.com