Histo Characteristic Patterns Flashcards
1
Q
Follicular plugging
A
Pityriasis rubra pilaris (PRP), lichen planopilaris (LPP), lichen sclerosus, lupus erythematosus (LE), perforating folliculitis
2
Q
Cornoid lamella
A
Porokeratosis
3
Q
Compact parakeratosis with retained KHG
A
Axillary granular parakeratosis
4
Q
‘Checkerboard’ and ‘shoulder’ parakeratosis
A
PRP
5
Q
Mounds of parakeratosis
A
Psoriasis
6
Q
Focal parakeratosis
A
Guttate psoriasis, pityriasis rosea, pityriasis lichenoides
7
Q
Confluent parakeratosis
A
Psoriasis, Bowen’s disease, necrolytic migratory erythema (NEM) in glucagonoma syndrome
8
Q
Columns of parakeratosis
A
Verruca vulgaris (VV), porokeratosis
9
Q
Alternating parakeratosis
A
Actinic keratosis (AK)
10
Q
Sandwich parakeratosis
A
Tinea
11
Q
Confluent hyperkeratosis
A
Lichen planus (LP)
12
Q
Massive orthokeratosis
A
Acquired digital fibrokeratoma
13
Q
‘Church spire’ papillomatosis
A
Acrokeratosis verruciformis
14
Q
Papillomatosis
A
Acanthosis nigricans, VV, seborrheic keratosis (SK), acrochordon
15
Q
Neutrophils in crust
A
Candidiasis, psoriasis, impetigo, tinea, syphilis
16
Q
Munro microabscess in cornified layer
A
Psoriasis (plate-like neutrophils in multilayered scale)
17
Q
‘Claw’ (epidermis) clutching a ‘ball’ (dermis)
A
Lichen nitidus
18
Q
Epidermal necrosis
A
Herpes simplex (HSV) infection, toxic epidermal necrolysis, erythema multiforme (EM), NEM, hydroa vacciniforme, graft-versus-host disease (GVHD), acute fixed drug reaction (FDE)
19
Q
Atrophic epidermis
A
Porokeratosis, atrophic AK, radiation dermatitis, lichen sclerosus, LE, dermatomyositis, poikiloderma, necrobiosis lipoidica, GVHD
20
Q
Upper pallor with normal- appearing lower epidermis
A
NEM, +/- acrodermatitis enteropathica
21
Q
Windblown appearance
A
Bowen’s disease
22
Q
Subcorneal/intragranular split with acantholytic cells (cling on)
A
Pemphigus foliaceous (sometimes can look like impetigo if neutrophils within blister cavity)
23
Q
Eosinophilic spongiosis (hAPPIE)
A
Arthropod bite, pemphigoid, pemphigus, incontinentia pigmenti (IP), eruption (drug), contact dermatitis
24
Q
Foam cells in epidermis
A
Balloon cell nevus
25
Dyskeratotic or necrotic keratinocytes
EM, pityriasis lichenoides et varioliformis acuta (PLEVA), paraneoplastic pemphigus, acrodermatitis enteropathica, acute FDE, IP, NEM, GVHD, radiation dermatitis
26
Vacuolated keratinocytes (‘empty shells’)
Tissue processing artifact, freezing artifact, epidermolytic hyperkeratosis
27
Elongated keratinocytes
Electrodessication artifact
28
Acantholytic cells
Darier’s disease, Hailey-Hailey disease, HSV infection, transient acantholytic dermatosis (Grover’s disease), pemphigus (acantholysis involves hair follicles), warty dyskeratoma, acantholytic SCC or AK
29
Koilocytes
HPV infection
30
Multinucleated keratinocytes
HSV (steel gray nuclei)
31
Epidermotropic lymphocytes
Cutaneous T-cell lymphoma (CTCL)
32
Pagetoid cells
Bowen’s disease, melanoma, recurrent nevus, Paget’s disease, CTCL, lymphomatoid papulomatosis (LyP), Langerhans cell histiocytosis (LCH)
33
Dilapidated brick wall
Hailey-Hailey disease
34
Pautrier microabscesses
CTCL
35
Tombstoning of basal cells
Pemphigus vulgaris
36
Clumped keratohyaline granules (KHG)
Epidermolytic hyperkeratosis, verruca (HPV infection)
37
Squamous eddies
Irritated seborrheic keratosis (SK), inverted follicular keratosis (IFK), SCC, trichoblastoma
38
Horn pseudocysts
SK, IFK, trichoepithelioma, microcystic adnexal carcinoma
39
Basilar hyperpigmentation
Dermatofibroma, SK, acanthosis nigricans
40
Flattened (tabled) rete ridges
Dermatofibroma
41
‘Saw-toothed’ rete ridges
LP
42
Vacuolar interface change
LE, LP, GVHD, dermatomyositis, acute FDE, lichen nitidus, erythema dyschromicum perstans (ashy dermatosis), lichenoid keratosis, lichen sclerosus, EM, PLEVA
43
Thick basement membrane
LE
44
Grenz zone
Lepromatous leprosy, granuloma faciale, lymphocytoma cutis (bottom heavy), leukemia cutis (top heavy)
45
Subtle amorphous pink deposits in papillary dermis
Macular amyloidosis
46
Band-like lymphocytic infiltrate
LP, EM, lichen sclerosus, benign lichenoid keratosis, lichen striatus, halo nevus
47
Upper dermal edema
Polymorphous light eruption (PMLE), Sweet’s syndrome, lichen sclerosus, langerhans cell histiocytosis
48
Melanin incontinence
Macular amyloidosis, LE, atrophic LP, ashy dermatosis, FDE, dermatomyositis, postinflammatory hyperpigmentation, +/- IP
49
Subepidermal split with prominent eosinophils
Bullous pemphigoid, pemphigoid gestationis, bullous drug eruption
50
Subepidermal split with prominent neutrophils
Dermatitis herpetiformis, bullous SLE, linear IgA bullous disease (LABD)
51
Neutrophils in dermal papillae
Dermatitis herpetiformis
52
Subepidermal split with prominent lymphocytes
Bullous LP, PMLE, lichen sclerosus
53
Subepidermal vesicles with scant inflammation
Porphyria cutanea tarda (PCT)
54
Subepidermal vesicles with mast cells
Bullous mastocytosis
55
Fibrous stroma
Syringoma, trichoepithelioma, morpheaform BCC, microcystic adnexal carcinoma
56
‘Bubble gum’ pink stroma
Neurofibroma
57
Lymphocytes around sweat glands
Lichen striatus
58
Sweat glands with neutrophils
Neutrophilic eccrine hidradenitis
59
Necrosis of sweat glands
Coma blister
60
Invaginated pilosebaceous unit with dark-staining ducts
Supernumerary nipple
61
Extravasated red blood cells
Pityriasis rosea, PLEVA, stasis dermatitis, pigmented purpuric dermatoses, vascular neoplasms, vasculitis, granuloma faciale (GF)
62
Hemosiderin
Hemochromatosis, pigmented purpuric dermatosis, stasis dermatitis, GF, pityriasis lichenoides, vascular neoplasms, vasculitis
63
Vertically-oriented collagen
Acquired digital fibrokeratoma
64
Collagen trapping at periphery
Dermatofibroma
65
Keloidal collagen
Dermatofibroma, keloid
66
Necrobiosis
Granuloma annulare (GA), necrobiosis lipoidica diabeticorum (NLD), rheumatoid nodule, necrobiotic xanthogranuloma (NXG)
67
Horizontal ‘sandwich’ necrobiosis without palisading
NLD
68
Dermal fibrosis
Angiofibroma, fibrous papule, hypertrophic scar, blue nevus, keloid, radiotherapy, morpheaform BCC, desmoplastic trichoepthelioma, syringoma
69
Dermal necrosis
Epithelioid sarcoma, malignant atrophic papulosis (Degos)
70
Clumped calcified elastic fibers
Pseudoxanthoma elasticum (PXE)
71
Vasculitis
GF, erythema elevatum diutinum (EED), polyarteritis nodosa (PAN), Henoch-Schonlein purpura, urticarial vasculitis, acute hemorrhagic edema of infancy
72
Nuclear dust
Sweet’s syndrome, leukocytoclastic vasculitis, GF, PAN, pyoderma gangrenosum (PG)
73
Deep pink nodules
Nodular amyloidosis
74
Smooth muscle bundles
Supernumerary nipple, leiomyoma (fascicles and bundles)
75
Calcification
Pilomatricoma, PXE, calciphylaxis, osteoma cutis, cysts, panniculitis, calcinosis cutis, subepidermal calcified nodule
76
Increased mucin deposition
LE, dermatomyositis, scleromyxedema, scleredema diabeticorum, BCC (some), mucopolysaccharidosis, reticular erythematous mucinosis, GA (not NLD), pretibial myxedema, focal mucinosis, follicular mucinosis
77
Pool of mucin
Myxoid cyst, mucocele, focal cutaneous mucinosis, mucinous carcinoma
78
Ductal cells floating in mucin
Eccrine mucinous carcinoma
79
Tadpole-shaped ducts
Syringoma
80
Extracellular pool of lipid
Eruptive xanthoma
81
Empty vacuoles in dermis and epidermis
Freeze artifact
82
Pink to purple reticular network in dermis
Gel foam artifact
83
Drag marks
Cutting artifact (knife mark artifact)
84
Tiny black particles around blood vessels
Argyria
85
Black amorphous deposits around blood vessels
Lead tattoo
86
Tiny wispy gold to black granules in mouth
Amalgam tattoo
87
Nerve bundles
Amputation neuroma, supernumerary digit
88
Stromal retraction
BCC
89
Basaloid islands (jigsaw puzzle)
Cylindroma
90
‘Cluster of grapes’ (low power)
Merkel cell carcinoma
91
Hyalinized droplets
Cylindroma
92
‘Cannon’ or ‘blue balls’ in dermis
Eccrine spiradenoma
93
Circular basaloid rosettes
Eccrine spiradenoma
94
Spindle and epithelioid melanocytes ‘raining’ down
Spitz nevus
95
Lichenoid infiltrate
LP, lichenoid drug eruption, lichen sclerosus, secondary syphilis (with plasma cells), GVHD, pityriasis lichenoides, lichen striatus, CTCL
96
Interstitial dermatitis
GA, Well’s syndrome, Sweet’s syndrome, interstitial drug reaction, urticaria
97
Coat-sleeving or perivascular cuffing of lymphocytes
Erythema annulare centrifugum (no epidermal change)
98
Superficial and deep lymphocytic infiltrate
PMLE, secondary syphilis, gyrate erythemas, athropod bites, LE (latter includes periadnexal infiltrate)
99
Deep infiltrate around sweat glands
Lichen striatus
100
‘Naked’ granulomas
Sarcoidosis, tuberculosis, tuberculoid leprosy
101
Single filing or ‘indian’ filing of cells
GA, congenital melanocytic nevus, lymphoma, leukemia, glomus cell tumor, metastatic breast carcinoma
102
Increased mast cells
Urticaria, neural tumors (i.e. neurofibroma), mucinous areas
103
Increased plasma cells
Mucous membrane (normal), secondary syphilis, syringocystadenoma papilliferum, hidradenitis suppurativa, acne keloidalis nuchae, NLD, LE, Rosai-Dorfman disease
104
Basaloid cells
BCC, SK, trichoepithelioma, eccrine tumors
105
Diffuse dermal mast cells
Mastocytosis (ie. urticaria pigmentosa)
106
Cells with reniform nuclei
Langerhans cell histiocytosis (abundant pale cytoplasm)
107
Spindle-shaped cells with elongated, wavy nuclei
Neurofibroma
108
Round monotonous cells
Glomus cell tumor, poroma, mastocytosis (blue-purple granules)
109
Pink granular cytoplasm
Granular cell tumor
110
Clear cells
Clear cell acanthoma, trichilemmoma, clear cell hidradenoma, metastatic renal cell carcinoma, clear cell SCC, balloon cell nevus, Paget’s disease, clear cell syringoma, eccrine carcinoma
111
Small cells
Lymphocytoma cutis, cutaneous B cell lymphoma, metastatic small cell carcinoma, CTCL, merkel cell carcinoma
112
Foamy macrophages
Xanthomas (eruptive, tuberous, tendinous, planar), verruciform xanthoma, xanthelasma, xanthoma disseminatum, AFX, juvenile xanthogranuloma (JXG), NXG, leprosy, pancreatic panniculitis
113
Touton giant cell
Xanthelasma, AFX, NXG
114
Ground glass giant cell
Multicentric reticulohistiocytosis, reticulohistiocytic granuloma
115
Purple osteoclast-like giant cell
Giant cell tumor of tendon sheath, malignant fibrous histiocytoma
116
Bizarre multinucleated giant cell
Malignant fibrous histiocytoma, pleomorphic lipoma
117
Parasitized histiocytes His GiRL
Histoplasmosis, granuloma inguinale, rhinoscleroma, leishmaniasis
118
Ghost cells
Pilomatricoma
119
Fibroblast with red inclusion body
Infantile digital fibromatosis
120
Bizarre spindle cells
Liposarcoma, leiomyosarcoma, AFX, radiation dermatitis
121
Melanin clumps (casts) in follicle
Trichotillomania
122
Trichomalacia (deformed shaft)
Trichotillomania
123
Necrosis of hair follicles
HSV
124
Tiny vellus hairs
Accessory tragus (rim periphery), xanthelasma, vellus hair cyst
125
‘Swarm of bees’ (lymphocytic inflammation at hair bulb)
Alopecia areata
126
Lymphocytes and plasma cells around follicles
Acne keloidalis nuchae
127
Free hair shafts surrounded by multinucleated giant cells
Acne keloidalis nuchae, folliculitis decalvans
128
Eosinophils around hair follicle
Eosinophilic folliculitis
129
Mucin within follicle
Follicular mucinosis
130
Cartilage often present
Accessory tragus, chondrodermatitis nodularis helicis (CNH), chondroid syringoma
131
Degenerated cartilage
Relapsing polychondritis, CNH
132
Ghost-like fat cells
Pancreatic panniculitis (with basophilic calcium deposition)
133
Cystic spaces in fat
Cold panniculitis
134
Fat necrosis
Erythema induratum (basophilic), lupus panniculitis (latter with lymphoid follicle-like aggregates, lymphoplasmacytic infiltrate)
135
“Needle-shaped” clefts in fat
Subcutaneous fat necrosis, sclerema neonatorum, post-steroid panniculitis
136
‘Swiss cheese’ appearance
Paraffinoma or sclerosing lipogranuloma
137
Fat high up in lesion
Accessory tragus
138
Widened septae with giant cells
Erythema nodosum
139
Dense neutrophilic inflammation
alpha-l-antitrypsin deficiency
140
Lipomembranous changes
Lipodermatosclerosis
141
Chicken wire pattern (linear collapsed vessels)
Myxoid liposarcoma
142
Clear multivacuolated cells in fat
Hibernoma
143
Hyalinized vessel walls (with thick red color around vessels)
Atrophie blanche
144
Promontory sign, slit-like spaces
Kaposi sarcoma
145
Atypical endothelial cells with dissecting vascular spaces
Angiosarcoma
146
Intravascular thrombi
Cryoglobulinemia, purpura fulminans, antiphospholipid syndrome, disseminated intravascular coagulation, coumadin necrosis, atrophie blanche
147
Telangiectatic vessels in pale acellular dermis
Radiation dermatitis
148
Hob nailing (endothelial cells protrude into vessel)
Angiolymphoid hyperplasia with eosinophilia
149
Staghorn appearance
Hemangiopericytoma
150
Recanalizing thrombus
Masson’s tumor (intravascular endothelial hyperplasia)
151
Spindle cells with RBCs ‘sandwiched’ in between
Kaposi sarcoma
152
Polypoid collection of vessels
Pyogenic granuloma
153
Proliferation of thick-walled vessels with hemosiderin
Stasis dermatitis
154
Dilated engorged vessels with surrounding edema
Granulation tissue
