Index

Page numbers followed by f refer to figures; page numbers followed by t refer to tables; page numbers followed by b refer to boxes.

A

AAD (acroangiodermatitis), 507, 507f–508f
Absidia infection, 280
Acanthamoeba See Amebiasis
Acantholysis, in pityriasis rubra pilaris, 25, 25f
Acantholytic acanthoma, 326
clinical features of, 326
differential diagnosis of, 326
microscopic findings in, 326, 326f
Acantholytic actinic keratosis, 333–334, 333f
Acantholytic dermatosis, transient, 241–242
clinical features of, 241
differential diagnosis of, 242
vs. Hailey-Hailey disease, 55, 55f
vs. pemphigus, 44–45
vs. prurigo simplex, 8–9
microscopic findings in, 241–242, 242f
Acantholytic dermatosis of genitocrural region, 55
Acantholytic seborrheic keratosis, 328, 328f, 330
Acanthoma
acantholytic, 326
clinical features of, 326
differential diagnosis of, 326
microscopic findings in, 326, 326f
clear cell (pale cell), 331
clinical features of, 331
differential diagnosis of, 331
microscopic findings in, 331, 331f
epidermolytic, 326–327
clinical features of, 326
differential diagnosis of, 327
microscopic findings in, 326, 327f
large-cell, 330–331
vs. actinic keratosis, 334
clinical features of, 330
microscopic findings in, 330–331, 331f
pilar sheath, 359–360
clinical features of, 359
differential diagnosis of, 359–360
microscopic findings in, 359, 359f
Acanthosis nigricans, 134–136
clinical features of, 134–135
differential diagnosis of, 135–136
“malignant, ”, 134–135
microscopic findings in, 135, 135f
pseudo-, 134
Achromic nevus, 228
Ackerman, L. V., 341
Acne
agminata See Lupus miliaris disseminatus faciei
conglobata, 208
keloidalis nuchae, 205
clinical features of, 205, 450
differential diagnosis of, 205
microscopic findings in, 205, 205f
rosacea, 202–204
clinical features of, 202–203
Demodex mites in, 203, 203f
differential diagnosis of, 203–204
erythematous telangiectatic, 202–203, 203f
glandular hyperplastic, 202–203, 203f
microscopic findings in, 203
papulopustular, 202–203, 203f
vulgaris, 202
clinical features of, 202
differential diagnosis of, 202
microscopic findings in, 202, 202f
Acneiform dermatoses, 202–209
acne (folliculitis) keloidalis nuchae as, 205
acne vulgaris as, 202
chloracne as, 204–205
disseminate and recurrent infundibulofolliculitis as, 206
eosinophilic (pustular) folliculitis as, 206–207
follicular occlusion disease as, 207–209
keratosis pilaris and related lesions as, 206
perioral/periorbital dermatitis as, 204
pseudofolliculitis barbae as, 205
rosacea as, 202–204
Acnitis See Lupus miliaris disseminatus faciei
Acquired elastotic hemangioma, 489, 489f
Acquired immunodeficiency syndrome (AIDS)-related Kaposi sarcoma, 496–498, 500f
Acquired perforating dermatosis, 144
Acquired tufted angioma, 481, 482f
Acral arteriovenous tumor, 485, 486f
Acral erythema, due to antineoplastic agents, 167–168
Acral hyperkeratosis, focal, 237
clinical features of, 237
differential diagnosis of, 237
microscopic findings in, 237
Acral hypokeratosis, circumscribed, 237–238
clinical features of, 237
differential diagnosis of, 238
microscopic findings in, 237–238, 237f
Acral keratodermas, 237–238
acrokeratoelastoidosis and focal acral hyperkeratosis as, 237
circumscribed acral hypokeratosis as, 237–238
Acral lentiginous melanoma
clinical features of, 686
differential diagnosis of, 691
microscopic findings in, 688, 688f
Acral nevus, 672, 672f
Acral persistent papular mucinosis, 162
Acroangiodermatitis (AAD), 507, 507f–508f
Acrochordons, 439–440
clinical features of, 439–440
differential diagnosis of, 440
microscopic findings in, 440, 440f
pseudosarcomatous fibroepithelial polyps as, 557f, 571–573, 572f–573f
Acrodermatitis
chronica atrophicans, 275–276
continua of Hallopeau, 21–22
enteropathica, 85–86
clinical features of, 85
differential diagnosis of, 85–86
microscopic findings in, 85, 86f
Acrokeratoelastoidosis, 237
clinical features of, 237
differential diagnosis of, 237
microscopic findings in, 237, 237f
Acrokeratosis verruciformis of Hopf, 238
clinical features of, 238
differential diagnosis of, 238
vs. seborrheic keratosis, 329–330
microscopic findings in, 238, 238f
Acropustulosis, of infancy, 58–59, 59f
Acrospiroma, 385–386
clinical features of, 385
differential diagnosis of, 385–386
microscopic findings in, 385, 385f
Actinic cheilitis, vs. lichen planus, 28
Actinic cicatricial pemphigoid, 28–29
Actinic dermatitis, chronic
clinical features of, 177
differential diagnosis of, 179
microscopic findings in, 178, 178f
Actinic granuloma, 189–190
clinical features of, 189
differential diagnosis of, 190
vs. granuloma annulare, 189
microscopic findings in, 189, 189f–190f
Actinic keratosis, 331
acantholytic, 333–334, 333f
atypical basilar keratinocytes in, 332–333, 333f
bowenoid, 336
clinical features of, 332
with cutaneous horn formation, 332–333, 333f
differential diagnosis of, 334
vs. pemphigus, 44–45
vs. squamous cell carcinoma, 340
with full-thickness atypia, 332–333, 333f
lichenoid, 333–334, 334f
vs. lichen planus, 28
microscopic findings in, 332–334
progression to squamous cell carcinoma of, 332, 334
Actinic prurigo
clinical features of, 176–177
differential diagnosis of, 178–179
microscopic findings in, 177, 177f
Actinic reticuloid
clinical features of, 177
differential diagnosis of, 179
vs. mycosis fungoides, 634
microscopic findings in, 178, 178f
Actinomyces israelii See Actinomycosis
Actinomycetoma, 288
Actinomycosis, 271–272
clinical features of, 271
differential diagnosis of, 271–272
vs. nocardiosis, 271–273
microscopic findings in, 271, 272f
Acute febrile neutrophilic dermatosis, 78–79
clinical features of, 78
differential diagnosis of, 78–79
microscopic findings in, 78, 78f
treatment of, 78
Acute generalized exanthematous pustulosis (AGEP), 174
clinical features of, 174
differential diagnosis of, 174
microscopic findings in, 174, 174f
Acute hemorrhagic edema, 69
Acute lymphoblastic leukemia, 650–652, 652f
Acute myeloid leukemia, 650–652, 652f
ADAMTS13, 64–65
Addison disease, pigmentation disorders in, 222–223
Adenoid basal cell carcinoma, 346–347
Adenoid cystic carcinoma, 390
clinical features of, 390
differential diagnosis of, 390
metastatic, 412–429, 415f
microscopic findings in, 390, 390f
“Adenolipoma”, 560
Adenoma
papillary eccrine, 384–385
clinical features of, 384
differential diagnosis of, 384–385
microscopic findings in, 384, 384f
sebaceous, 373–375
clinical features of, 373–374
differential diagnosis of, 374–375
vs. sebaceous hyperplasia, 371
microscopic findings in, 374, 374f
sebaceum, 445–446, 446f
sebocrine, 374
tubular apocrine, 386
clinical features of, 386
differential diagnosis of, 386
vs. papillary eccrine adenoma, 384–385
microscopic findings in, 386, 387f
Adenosquamous carcinoma, 343
clinical features of, 343
differential diagnosis of, 343
microscopic findings in, 343, 343f
Adipocytic proliferations, patterns of growth in, 554–565, 555f
with brown fat, 557f
with mature adipocytes, 556f
with numerous lipoblasts and/or nuclear atypia, 557f
with prominent myxoid components, 556f
with sparse adipocytes, 558f
Adipocytic pseudotumors, 570–574
massive localized lymphedema as, 574, 574f–575f
nevus lipomatosus as, 556f, 570–571, 571f–572f
pseudosarcomatous fibroepithelial polyps (acrochordons) as, 557f, 571–573, 572f–573f
tumefactive localized lipedema as, 573–574, 573f
Adipocytic tumors
angiomyolipoma (perivascular epithelioid cell tumor) as, 565
hibernomas as, 564–565
lipoblastoma as, 556f–557f, 564, 564f
lipoma as, 560–564
liposarcoma as, 557f, 565–570
Adnexal carcinoma, microcystic, 391–392
clinical features of, 391
differential diagnosis of, 391–392
vs. trichoadenoma, 360
vs. trichoepithelioma, 364
microscopic findings in, 391, 391f–392f
Adnexal tumors, nevus sebaceus associated with, 371, 372f
Adult colloid milium
clinical features of, 126, 148
differential diagnosis of, 126, 127f, 150
microscopic findings in, 148–149
Adult T-cell leukemia/lymphoma (ATLL), 645–646
clinical features of, 645–646
differential diagnosis of, 646
microscopic findings in, 645–646, 645f–646f
AFLH (atypical follicular lymphoid hyperplasia), 624
African histoplasmosis, 286
African Kaposi sarcoma, 496–498, 500f
AFX See Atypical fibroxanthoma (AFX)
AGEP See Acute generalized exanthematous pustulosis (AGEP)
Aggressive angiomyxoma, 461–462
clinical features of, 461
differential diagnosis of, 462
microscopic findings in, 461, 461f
Aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma
clinical features of, 642
differential diagnosis of, 644
microscopic findings in, 643
AIDS (acquired immunodeficiency syndrome)-related Kaposi sarcoma, 496–498, 500f
AITCL See Angioimmunoblastic T-cell lymphoma (AITCL)
Albinism, 225–226
clinical features of, 225
differential diagnosis of, 226
microscopic findings in, 225–226, 226f
oculocutaneous, 225
rufous, 225
tyrosinase-positive, 225–226, 226f
ALCL See Anaplastic large-cell lymphoma (ALCL)
Alkaptonuria, ochronosis due to, 134, 135f
Allergic contact dermatitis, 1–2, 2f–3f
Allergic granulomatosis, 76
clinical features of, 76
differential diagnosis of, 76
microscopic findings in, 76, 76f
Alopecia(s)
androgenetic, 212–213
clinical features of, 212
differential diagnosis of, 213
vs. alopecia areata, 210–211, 211f
microscopic findings in, 212–213, 213f
areata, 209–211
acute, 210, 210f
chronic, 210, 210f
clinical features of, 209–210
differential diagnosis of, 210–211, 211f
syphilitic vs., 210–211
microscopic findings in, 210
subacute, 210, 210f
frontal fibrosing, 213–214
clinical features of, 213
differential diagnosis of, 214
microscopic findings in, 213–214, 214f
“hot comb”, 214–215
lipedematous, 573
mucinosa, 209
clinical features of, 209
differential diagnosis of, 209
microscopic findings in, 209, 209f
and mycosis fungoides, 629–630
neoplastica, 402–404, 403f
nonscarring, 209–213
due to anagen and telogen effluvium, 212
androgenetic, 212–213
areata, 209–211
mucinosa (follicular mucinosis), 209
due to trichotillomania, 211–212
scarring, 213–216
central/centrifugal, 214–216
clinical features of, 214–215
differential diagnosis of, 215–216
microscopic findings in, 215, 215f–216f
frontal fibrosing, 213–214
clinical features of, 213
differential diagnosis of, 214
microscopic findings in, 213–214, 214f
lichen planopilaris as, 213–214
due to metastatic tumor, 402–404, 403f
pseudopelade of Brocq as, 214
totalis, 209–210
universalis, 209–210
α1-antitrypsin deficiency panniculitis, 94
clinical features of, 94
differential diagnosis of, 94
microscopic findings in, 94
treatment of, 94
Alternaria alternata infection, 281
Alveolar rhabdomyosarcoma, 585–586, 586f
Amebiasis, 307
clinical features of, 307
differential diagnosis of, 307
microscopic findings in, 306f, 307
American leishmaniasis, 303
Amiodarone, pigmentary changes due to
clinical features of, 171
differential diagnosis of, 173
microscopic findings in, 172, 172f
Amyloid, 123
Congo red staining of, 125–126, 125f
crystal violet staining of, 125–126, 126f
Amyloidosis, 123–126
within basal cell carcinoma, 123, 124f
clinical features of, 123–124
differential diagnosis of, 126
macular, 123–124, 124f
microscopic findings in, 124–126
nodular, 124–125, 125f
primary systemic, 124–125, 125f
Amyloidosus, lichen, 124, 125f
Anagen effluvium, 212
in alopecia areata, 210
clinical features of, 212
differential diagnosis of, 212
microscopic findings in, 212
Anagen follicles, 210
Anaplastic large-cell lymphoma (ALCL), 639–640
clinical features of, 639
differential diagnosis of, 640
vs. Hodgkin disease, 652
vs. lymphomatoid papulosis, 639
microscopic findings in, 639–640, 639f–640f
primary, 639
secondary, 639
ANCA (antineutrophil cytoplasmic antibodies)
in microscopic polyangiitis, 69
in Wegener granulomatosis, 75
Ancell-Spiegler syndrome, 380–381
Ancient melanocytic nevus, 676
Ancylostoma braziliense, larva migrans due to, 298–299, 299f
Ancylostoma caninum, larva migrans due to, 298–299, 299f
Androgenetic alopecia, 212–213
clinical features of, 212
differential diagnosis of, 213
vs. alopecia areata, 210–211, 211f
microscopic findings in, 212–213, 213f
Anetoderma, 150–151
clinical features of, 150–151
differential diagnosis of, 151
microscopic findings in, 151, 151f
pilomatricoma with, 365
Aneurysmal dermatofibroma, 442–443, 443f
Aneurysmal fibrous histiocytoma, 442–443, 443f
Angioendotheliomas, papillary endovascular, 491–492, 493f
Angioendotheliomatosis
malignant See Intravascular large B-cell lymphoma
reactive, 512
clinical features of, 512, 512f
vs. intravascular large B-cell lymphoma, 625–626
microscopic findings in, 512, 512f–513f
Angiofibroma, 444–446
clinical features of, 445
differential diagnosis of, 446
vs. superficial acral fibromyxoma, 447
microscopic findings in, 445–446, 446f
of tuberous sclerosis, 445–446, 446f
Angiofollicular lymph node hyperplasia (Castleman disease), 615–616
clinical features of, 615
differential diagnosis of, 616
microscopic findings in, 615–616, 616f
Angiohistiocytoma, multinucleate cell, vs. atypical hemangioma, 486–489, 488f
Angioimmunoblastic T-cell lymphoma (AITCL), 646–647
clinical features of, 646–647
differential diagnosis of, 647
microscopic findings in, 646–647, 647f
Angiokeratoma, 490–491, 492f
corporis diffusum
clinical features of, 138, 490, 492f
differential diagnosis of, 139
microscopic findings in, 138, 138f, 490–491, 492f
Angioleiomyoma, 582
clinical features of, 582
differential diagnosis of, 583–584
microscopic findings in, 582–583, 583f
Angiolipoleiomyoma See Angiomyolipoma
Angiolipoma, 556f, 560, 561f
cellular, 558f, 560, 562f
dedifferentiated, 556f
Angiolymphoid hyperplasia with eosinophilia, 483–484, 484f
Angioma, acquired tufted, 481, 482f
Angiomatoid nevus, 676–677, 677f
Angiomatoid Spitz nevus, 677
Angiomatosis(es), 490
bacillary (epithelioid), 263–264
clinical features of, 263, 508, 508f
differential diagnosis of, 263–264
vs. Kaposi sarcoma, 264, 508, 508f–509f
electron microscopy of, 263, 264f, 508, 509f
microscopic findings in, 263, 264f, 508, 509f
Warthin-Starry stain for, 263, 488f, 508, 509f
cutaneous reactive, 512
Angiomatous nodule, epithelioid, 484–485
Angiomyofibroblastoma, 461–462
clinical features of, 461
differential diagnosis of, 462
microscopic findings in, 462
Angiomyolipoma, 565, 584
clinical features of, 565, 584
differential diagnosis of, 584
vs. angiolipoma, 560, 562f
vs. metastatic tumors, 419, 423f
immunohistochemistry of, 562f
microscopic findings in, 562f, 565, 584, 584f
PEComa subtype of, 515, 565, 566f–567f
with sparse adipocytes, 558f
Angiomyoma, 582
clinical features of, 582
differential diagnosis of, 583–584
microscopic findings in, 582–583, 583f
Angiomyxoma
aggressive, 461–462
clinical features of, 461
differential diagnosis of, 462
microscopic findings in, 461, 461f
superficial, 461–462
clinical features of, 461
differential diagnosis of, 462
microscopic findings in, 461–462, 464f
Angiosarcoma, 502–506
behavior of, 503
classic form of, 504, 504f–505f
clinical features of, 502–503
“brawny induration” (erysipelas-like), 502–503, 503f
in chronic lymphedema (Stewart-Treves syndrome), 502–503, 503f
hemangioma-like, 502–503, 504f
ulcerated mass as, 502–503, 503f
differential diagnosis of, 508–510
vs. atypical fibroxanthoma, 465
vs. meningoceles, 510, 511f
vs. papillary intravascular endothelial hyperplasia, 508–510, 511f
epithelioid, 504, 505f
granular cell, 504, 505f
microscopic findings in, 504, 504f–505f
minimal-deviation (hemangioma-like)
clinical features of, 502–503, 504f
differential diagnosis of, 504
microscopic findings in, 504, 505f
pleomorphic, 504, 506f
spindle cell
differential diagnosis of, 504–506, 506f
microscopic findings in, 504, 505f
Anhidrotic ectodermal dysplasia, 240
Annular elastolytic giant cell granuloma, 189–190
clinical features of, 189
differential diagnosis of, 190
vs. granuloma annulare, 189
microscopic findings in, 189, 189f–190f
Annular erythemas, 15–17
erythema annulare centrifugum as, 15–16, 15f–16f
erythema gyratum repens as, 17
erythema (chronicum) migrans as, 16–17, 16f–17f
Anthrax, 260
clinical features of, 260
differential diagnosis of, 260
microscopic findings in, 260
Antimetabolites, reactions to, 168t
Antineoplastic agents, reactions to, 167–169
clinical features of, 167–168, 168t
differential diagnosis of, 168–169
microscopic findings in, 168, 168f–169f
Antineutrophil cytoplasmic antibodies (ANCA)
in microscopic polyangiitis, 69
in Wegener granulomatosis, 75
Antiphospholipid syndrome, 64–65, 65f
Aplasia cutis congenita, 238–239
clinical features of, 238
differential diagnosis of, 239
microscopic findings in, 238–239, 238f–239f
Apocrine adenoma, tubular, 386
clinical features of, 386
differential diagnosis of, 386
vs. papillary eccrine adenoma, 384–385
microscopic findings in, 386, 387f
Apocrine carcinoma, ductopapillary, 392, 393f
vs. metastatic papillary carcinoma, 414, 417f
Apocrine cystadenoma, 378–379
clinical features of, 378
differential diagnosis of, 379
microscopic findings in, 378–379, 379f
Apocrine hidrocystoma, 378–379
clinical features of, 378
differential diagnosis of, 379
microscopic findings in, 378–379.htm#f0240">379f
Apocrine miliaria, 9
Apocrine nevus, 378
clinical features of, 378
differential diagnosis of, 378
microscopic findings in, 378, 378f
Apocrine-related inflammatory lesions, 216–217
Fox-Fordyce disease as, 216
Appendage(s), non-neoplastic diseases of, 201–220
acneiform dermatoses as, 202–209
alopecias as
nonscarring, 209–213
scarring, 213–216
apocrine and eccrine-related inflammatory lesions as, 216–217
Appendageal tumors, 357–399
with hair follicle differentiation, 358–370
sebaceous, 370–377
sweat gland, 377–394
Areola, leiomyoma of, 582
clinical features of, 582
microscopic findings in, 582
Argyria
clinical features of, 174
differential diagnosis of, 175
microscopic findings in, 174–175, 175f
Arsenical keratoses, 332, 334
Arteriovenous hemangioma, 485, 486f
Arteriovenous tumor, acral, 485, 486f
Arthritis
psoriatic, 22
rheumatoid, 120
Arthropod bite reactions, 301–302
bullous, 301–302, 302f
clinical features of, 301
differential diagnosis of, 302
due to insects, 301
microscopic findings in, 301–302, 301f
due to spiders, 301–302, 302f
due to ticks, 301–302, 303f
Arthropod bite–like reactions, in leukemia cutis, 650, 650f
Asboe-Hansen sign, 41–42
Ascorbic acid deficiency, 87–88
clinical features of, 87
differential diagnosis of, 88
microscopic findings in, 87, 87f
Ash leaf macules, of tuberous sclerosis, 227–228
clinical features of, 227
differential diagnosis of, 227–228
microscopic findings in, 227, 228f
Ashy dermatosis, 32–33
clinical features of, 32–33
differential diagnosis of, 33
microscopic findings in, 33, 33f
Aspergillosis
clinical features of, 279
microscopic findings in, 279–280, 280f
Asteroid bodies, in sporotrichosis, 287–288
ATLL See Adult T-cell leukemia/lymphoma (ATLL)
Atopic dermatitis, 4
clinical features of, 4
differential diagnosis of, 4
microscopic findings in, 4
Atrial myxoma, embolus from, 67f
Atrophic lichen planus, 27, 27f
Atrophie blanche, 66
clinical features of, 66
differential diagnosis of, 66
microscopic findings in, 66, 66f
Atrophoderma of Pasini and Pierini, 117
clinical features of, 117
differential diagnosis of, 117
microscopic findings in, 117, 118f
Atrophoderma vermiculata, 206
Atypical dermatofibroma, 443–444, 443f
Atypical fibroxanthoma (AFX), 463–465
clear cell, 464
clinical features of, 463–464
differential diagnosis of, 465
vs. dermatofibroma, 444
vs. malignant fibrous histiocytoma, 465–466
vs. squamous cell carcinoma, 340
immunohistochemistry of, 464–465
metastasis of, 464
microscopic findings in, 464–465, 464f–465f
variants of, 464, 464f–465f
Atypical follicular lymphoid hyperplasia (AFLH), 624
Atypical hemangioma, 485–489
clinical features of, 485, 486f
differential diagnosis of, 486–489, 488f–489f
microscopic findings in, 485, 487f
“Atypical” lipoma, 556f, 560, 561f
Atypical mycobacterial infections, 266
mimicking Kaposi sarcoma, 508
Atypical vascular lesion, 512–513
Auchmeromyia luteola, myiasis due to, 300
Auspitz sign, 22–23
Autoeczematization reactions, 6, 7f
Azzopardi phenomenon
in metastatic small-cell neuroendocrine carcinoma of lung, 424f
in primitive neuroectodermal tumor, 548

B

Bacillary angiomatosis (BA), 263–264
clinical features of, 263, 508, 508f
differential diagnosis of, 263–264
vs. Kaposi sarcoma, 264, 508, 508f–509f
electron microscopy of, 263, 264f, 508, 509f
microscopic findings in, 263, 264f, 508, 509f
Warthin-Starry stain for, 263, 488f, 508, 509f
Bacillus anthracis See Anthrax
Bacterial diseases, 252–276
actinomycosis as, 271–272
anthrax as, 260
bacillary angiomatosis as, 263–264
botryomycosis as, 257–258
cat scratch disease as, 263–264
cellulitis as, 255–256
chancroid as, 260–261
coryne-, 259–260
cutaneous manifestations of septicemia as, 256–257
ecthyma as, 253
erysipelas as, 255–256
granuloma inguinale as, 261–262
impetigo as, 252
infectious folliculitis as, 254
malakoplakia as, 258–259
myco-, 264–270
atypical, 266–268
cutaneous tuberculosis as, 264–266
Hansen disease (leprosy) as, 268–270
necrotizing fasciitis as, 253–254
nocardiosis as, 272–273
rhinoscleroma as, 262–263
rickettsiosis (Rocky Mountain spotted fever) as, 270–271
spirochetal, 273–276
borreliosis and Lyme disease as, 275–276
syphilis as, 273–275
staphylococcal scalded skin syndrome as, 252–253
toxic shock syndrome as, 254–255
Balamuthia mandrillaris See Amebiasis
Balanitis, Zoon plasmacellular, vs. erythroplasia of Queyrat, 338
Baldness See Alopecia(s)
Balloon cell melanoma
metastatic, 418–419, 420f–421f
vs. sebaceous carcinoma, 377
Balloon cell nevi, 668–669, 670f
“Bamboo hairs, ”, 235
Barber’s sinus, 208
Bartonella bacilliformis, 263
Bartonella henselae See Bacillary angiomatosis (BA); Cat scratch disease
Bartonella quintana, 263
Basal cell carcinoma (BCC), 344–349
adenoid, 346–347
amyloidosis within, 123, 124f
basosebaceous, 347–348
basosquamous, 348
clear cell, 348–349
clinical features of, 344–345
congenital, 345
dedifferentiated (carcinosarcomatous), 348
differential diagnosis of, 349
vs. basaloid follicular hamartoma, 359
vs. dermatofibroma, 444
vs. pilomatricoma, 365–366
vs. sebaceous adenoma, 374–375
vs. sebaceous carcinoma, 377
vs. squamous cell carcinoma, 341
vs. trichilemmoma, 361
vs. trichoepithelioma, 364
electron microscopy of, 348
fibroepithelioma of Pinkus as, 345–346, 346f
granular cell, 348–349
“horrifying, ”, 345
infiltrative, 347, 347f
infundibulocystic, 347, 347f
vs. basaloid follicular hamartoma, 359
“keratopurpuric, ”, 345
keratotic (pilar), 347–348
metastatic, 345
vs. primary, 434, 434b
metatypical, 348, 348f
micronodular, 347, 347f
microscopic findings in, 345–348
morpheaform, 345, 347
nodulocystic, 345–346, 346f
noduloulcerative lesions in, 345
in non–sun-exposed locations, 345
papulonodular lesions in, 345
with perineural infiltration, 345
pigmentation in, 345
regression of, 345
sclerotic, 345
stains for, 348
superficial, 345–346, 346f
vs. basaloid follicular hamartoma, 359
syndromes featuring, 345
in transplant patients, 345
unusual forms of, 348
Basal cell hyperplasia, dermatofibromas with, 442, 442f
Basal cell nevus, linear, 345
Basal cell nevus syndrome, 345
Basaloid cells, in pilomatricoma, 364–365, 365f
Basaloid follicular hamartoma, 358–359
clinical features of, 358
differential diagnosis of, 359
vs. basal cell carcinoma, 349
microscopic findings in, 358, 358f
Basaloid sebaceous carcinoma, 376–377
vs. basal cell carcinoma, 349
Basaloid squamous cell carcinoma, metastatic, 422–423, 424f
Basidiobolus ranarum, 280
Basosebaceous basal cell carcinoma, 347–348
Basosquamous basal cell carcinoma, 348
Bazex syndrome, 345
BCC See Basal cell carcinoma (BCC)
B-cell chronic lymphocytic leukemia, vs. marginal zone B-cell lymphoma, 622
B-cell lymphoma
follicular, 623–624
large
diffuse, 624–625
clinical features of, 624
differential diagnosis of, 625
microscopic findings in, 624–625, 625f
intravascular, 625–626
clinical features of, 625–626
differential diagnosis of, 626
microscopic findings in, 626, 626f
marginal zone (MALT type), 622–623
clinical features of, 622
differential diagnosis of, 623
vs. follicular lymphoma, 623–624
vs. lymphocytoma cutis, 622
microscopic findings in, 622–623, 623f
B-cell neoplasms, mature, 622–629
lymphoma as
diffuse large, 624–625
follicular, 623–624
intravascular large, 625–626
marginal zone, 622–623
lymphomatoid granulomatosis as, 626–628
other, 628–629
BCL2 expression, in diffuse large B-cell lymphoma, 624
Becker melanosis, 358
and smooth muscle hamartoma, 581–582, 582f
Becker nevus, 358, 667, 667f
and smooth muscle hamartoma, 581–582, 582f
Bedbugs, 301
Bednar tumor, 460
clinical features of, 460
differential diagnosis of, 460
microscopic findings in, 460, 460f
Behçet syndrome, 80–81
clinical features of, 80
differential diagnosis of, 81
microscopic findings in, 80, 81f
treatment of, 80
Benign cephalic histiocytosis, 597
clinical features of, 597
differential diagnosis of, 597
microscopic findings in, 597
Benign lymphangioendothelioma, vs. atypical hemangioma, 486–489, 488f
Benign triton tumor, 523–550, 555f
Bipolaris spicifera infection, 281
Birt-Hogg-Dube syndrome
acrochordons in, 439–440
trichodiscomas in, 358, 368
Black heel
clinical features of, 179
differential diagnosis of, 182
microscopic findings in, 180, 181f
Blastic plasmacytoid dendritic cell neoplasm (BPDCN), 647–648
clinical features of, 647–648
differential diagnosis of, 647–648
vs. NK/T-cell sinonasal-type lymphoma, 645
microscopic findings in, 648f, 653
Blastomyces dermatitidis, 282, 283f
vs. histoplasmosis, 287
Blastomycosis
keloidal, 283–284
clinical features of, 283–284
differential diagnosis of, 283–284
microscopic findings in, 283, 284f
North American, 282
clinical features of, 282
differential diagnosis of, 282
microscopic findings in, 282, 283f
South American, 282–283
clinical features of, 282–283
differential diagnosis of, 283
microscopic findings in, 282–283
Blastomycosis-like pyoderma
clinical features of, 88
differential diagnosis of, 88–89
vs. pemphigus vegetans, 45
microscopic findings in, 88, 88f
“Bleaching agent, ” ochronosis due to, 134, 135f
Blister(s), traumatic, 59–60
coma, 59–60, 60f
due to cryotherapy, 59–60
due to electrical injury, 59–60
friction, 59–60
suction, 59–60
due to thermal burns, 59–60, 60f
Blister beetles, 301
Blistering diseases, inherited, 54–58
bullous Darier disease as, 55–56
Hailey-Hailey disease as, 54–55
hereditary epidermolysis bullosa as, 56–58
“Blood lakes, ” due to metastatic renal cell carcinoma, 404, 408f, 418
Bloom syndrome, vs. lupus erythematosus, 112–113
Blue nevus, 679–681
cellular, 679–680, 681f
clinical features of, 679–680
common, 679–680, 680f
differential diagnosis of, 680–681
epithelioid, 679–680
hypopigmented, 680, 680f
microscopic findings in, 680, 680f–681f
“Blueberry muffin” lesions, 653
Blunt trauma, panniculitis due to
clinical features of, 99–100
differential diagnosis of, 100–101
microscopic findings in, 100
B-lymphoblastic lymphoma, precursor, 628, 628f
Boil, 254, 254f
Bone tumors, 590–591
calcifying aponeurotic fibroma as, 590–591
fibro-osseous pseudotumor of the digits as, 590
ossifying fibromyxoid tumor as, 590
osteosarcoma as, 585
Borrelia afzelii, 275
Borrelia burgdorferi, 16, 275
Borrelia garinii, 16, 275
Borrelia lonestari, 16
Borreliosis, 275–276
clinical features of, 275
differential diagnosis of, 275–276
microscopic findings in, 275
Botfly, myiasis due to, 300
Botryomycosis, 257–258
clinical features of, 257–258
differential diagnosis of, 257–258
vs. actinomycosis, 271–272
microscopic findings in, 257, 258f
Bowen disease, 335–337
clinical features of, 335–336
differential diagnosis of, 337
vs. actinic keratosis, 334
vs. Paget disease, 337, 394
vs. seborrheic keratosis, 330
human papillomavirus in, 335–336, 336f
invasive carcinoma arising from, 336–337, 337f
microscopic findings in, 336–337
follicular atypia as, 336, 336f
pagetoid configuration as, 336, 336f
“wind-blown” appearance as, 336, 336f
Bowenoid actinic keratoses, 336
Bowenoid papulosis, 338
clinical features of, 338
differential diagnosis of, 338
microscopic findings in, 338, 338f
BPDCN See Blastic plasmacytoid dendritic cell neoplasm (BPDCN)
Branchial cleft cyst, 323, 323f
Brazilian pemphigus, 42
Breast, nevi from, 672
Breast carcinoma, metastatic, 404–429
adenoid cystic, 412–429, 415f
in “crops, ”, 403f
“herald” metastases of, 403f, 404–408
idiosyncratic presentations of
“clown nose” as, 404
thoracic carcinoma en cuirasse (carcinoma erysipelatoides) as, 402–404, 403f
infiltrating lobular, 409–410, 410f
histiocytoid, 409–410, 411f
vs. primary signet-ring cell adenocarcinoma, 410, 412f
with signet-ring cell appearance, 409, 411f
invasive ductal, 408, 409f
admixed with mucinous (“colloid”) adenocarcinoma, 412, 413f
“herald” metastasis of, 403f, 408
inflammatory, 408, 410f
vs. primary ductal eccrine adenocarcinoma, 408, 409f
mucinous (“colloid”), 412
admixed with invasive ductal adenocarcinoma, 412, 413f
“enteric” type of, 412, 414f
labeling of mucin in, 412, 414f
vs. primary mucinous (“colloid”) carcinoma of skin, 412, 413f
papillary, 412–429
vs. ductopapillary apocrine carcinoma, 414, 417f
vs. papillary digital eccrine carcinoma, 412–414, 415f, 417f
vs. papillary ovarian carcinoma, 414, 416f
vs. papillary thyroid carcinoma, 414, 416f, 418f
Broad beta disease, xanthomas due to, 136
Bromoderma
clinical features of, 173
differential diagnosis of, 174
microscopic findings in, 173, 173f
Bronchogenic cyst, 322, 323f
Brooke tumors, 362–363
Brown fat, in hibernomas, 557f, 564, 565f
Brown recluse spider bite, 301–302, 302f
Brunsting-Perry variant, of cicatricial pemphigoid, 48
Buerger disease, 72
Bulla(e), coma, 59–60, 60f
Bullosis diabeticorum, 129–130
Bullous arthropod bite reactions, 301–302, 302f
Bullous congenital ichthyosiform erythroderma, 233–234
clinical features of, 233
differential diagnosis of, 234
microscopic findings in, 233–234, 234f
Bullous Darier disease, 55–56, 55f
Bullous dermatosis of hemodialysis, vs. porphyria, 127–129, 129f
Bullous disorders, 41–61
immuno-, 41–54
inherited blistering diseases as, 54–58
pustular dermatosis(es) as, 58–59
traumatic blisters as, 59–60, 60f
Bullous lupus erythematosus, 50–51
clinical features of, 50
differential diagnosis of, 50–51
immunofluorescence studies of, 50, 51f
microscopic findings in, 50, 50f
Bullous mastocytosis, 610, 611f
Bullous pemphigoid, 45–47
clinical features of, 45
differential diagnosis of, 46–47
vs. epidermolysis bullosa acquisita, 49–50
direct immunofluorescence of, 46, 46f
microscopic findings in, 45–46
eosinophilic spongiosis as, 45–46, 45f
in infiltrate-poor type, 45–46, 45f
in infiltrate-rich type, 45–46, 46f
treatment of, 45
Burkitt lymphoma, 628–629, 629f
Burns
blisters due to, 59–60, 60f
clinical features of, 179
differential diagnosis of, 180–182
first-degree, 179–182
microscopic findings in, 179, 179f
second-degree, 179–182
third-degree, 179–182, 179f
Buruli ulcer
clinical features of, 266–267
differential diagnosis of, 268
microscopic findings in, 267–268
Buschke-Ollendorff syndrome, 440

C

Café-au-lait macules, 666–667
Calcaneal petechiae
clinical features of, 179
differential diagnosis of, 182
microscopic findings in, 180, 181f
Calcific elastosis
papular, 148
perforating, 147–148
clinical features of, 147, 245
differential diagnosis of, 148
microscopic findings in, 147–148, 148f
Calcification
dystrophic, 130–131, 130f
metastatic, 130–131, 131f
in pilomatricoma, 364–365, 365f
Calcified epidermal cyst, 130f
Calcified nodule, subepidermal, 130–131, 131f
Calcifying aponeurotic fibroma, 590–591
clinical features of, 590–591
differential diagnosis of, 591
microscopic findings in, 591, 591f
Calcifying epithelioma of Malherbe See Pilomatricoma
Calcifying tumors, 590–591
Calcinosis cutis, 130–132
clinical features of, 130
differential diagnosis of, 131–132, 132f
with dystrophic calcification, 130–131, 130f
idiopathic scrotal, 130–131, 131f
metastatic calcification (calciphylaxis) as, 130–131, 131f
microscopic findings in, 130–131
in miliary osteomas, 130–131, 131f
staining for, 131–132, 132f
with subepidermal calcified nodule, 130–131, 131f
tumoral, 130–131
Calciphylaxis, 130–131, 131f
with panniculitis, 104
Calcium crystal deposition, with panniculitis, 104
Calcium oxalate deposition, 132–133
clinical features of, 132
differential diagnosis of, 133
microscopic findings in, 132–133, 132f–133f
with panniculitis, 104
primary, 132
secondary, 132
treatment of, 132
Calliphoridae, myiasis due to, 300
Calymmatobacterium granulomatis See Granuloma(s), inguinale
c-ANCA, in Wegener granulomatosis, 75
Candida albicans, 278–279
Candida guilliermondii, 278
Candida krusei, 278
Candida tropicalis, 278
Candidiasis, 278–279
clinical features of, 278–279
differential diagnosis of, 279
vs. contact dermatitis, 3–4
vs. necrolytic migratory erythema, 87
disseminated, 278–279
microscopic findings in, 279, 279f
mucocutaneous
acute, 278
chronic, 278–279
Capillary hemangioma, 478–480
cellular, 480, 480f
clinical features of, 478–480, 479f
lobular, 480–481
vs. bacillary angiomatosis, 264
clinical features of, 480, 481f
intravascular, 481, 482f
metastatic lesions imitating, 404, 406f
microscopic findings in, 480–481, 481f–482f
satellitotic, 481, 483f
microscopic findings in, 480, 480f
Carbuncle, 254
Carcinoid, pellagra due to, 87
Carcinoma
ex cylindroma, 392
erysipelatoides, 402–404, 403f
simplex, of breast, 408
ex spiradenoma, 392, 392f
Carcinosarcoma, 343–344
clinical features of, 343
differential diagnosis of, 344
microscopic findings in, 343–344, 344f
Carcinosarcomatous basal cell carcinoma, 348
Cardiofaciocutaneous syndrome, 206
Carney complex
cutaneous myxomas in, 157–158
epithelioid blue nevus in, 679–680
“Carpet tacking” sign, in discoid lupus erythematosus, 107–109, 109f
Carrion disease, 263
Cartilaginous tumors, 587–589
chondrosarcoma as, 589
extraskeletal chondroma as, 587–588
parachordoma as, 588–589
subungual osteochondroma and exostosis as, 588
Carvajal syndrome, 236
Casal necklace, 87
Castleman disease, 615–616
clinical features of, 615
differential diagnosis of, 616
microscopic findings in, 615–616, 616f
Cat hookworm, larva migrans due to, 298–299, 299f
Cat scratch disease, 263–264
clinical features of, 263–264
differential diagnosis of, 263–264
microscopic findings in, 263, 263f
Catagen follicles, 210, 210f
Caterpillar bodies, in porphyria cutanea tarda, 128–129, 128f
Catharsis, 143
Cavernous hemangioma, 478–480, 479f–480f
CCLE (chronic cutaneous lupus erythematosus), 98, 99f
CD4+ small/medium-sized pleomorphic T-cell lymphoma
clinical features of, 642
differential diagnosis of, 644
microscopic findings in, 643, 643f
CD4+/CD56+ hematodermic neoplasm See Blastic plasmacytoid dendritic cell neoplasm (BPDCN)
CD7, in mycosis fungoides, 632–633
CD8, in mycosis fungoides, 633, 633f
CD30+ T-cell lymphoproliferative disorders, 637–640
lymphomatoid papulosis as, 637–639
primary cutaneous and secondary anaplastic large-cell lymphoma as, 639–640
Cellular angiolipoma, 558f, 560, 562f
Cellular blue nevus, 679–680, 681f
Cellular capillary hemangioma, 480, 480f
Cellular dermatofibromas, 442–443
Cellular digital fibroma, 446–447
clinical features of, 446
differential diagnosis of, 447
microscopic findings in, 446–447, 447f
Cellulitis, 255–256
clinical features of, 255
differential diagnosis of, 255–256
eosinophilic, 17–18
clinical features of, 17
differential diagnosis of, 17–18
microscopic findings in, 17, 18f
microscopic findings in, 255, 255f
Cenicientos, los, 32–33
clinical features of, 32–33
differential diagnosis of, 33
microscopic findings in, 33, 33f
Central/centrifugal scarring alopecia, 214–216
clinical features of, 214–215
differential diagnosis of, 215–216
microscopic findings in, 215, 215f–216f
Cephalic histiocytosis, benign, 597
clinical features of, 597
differential diagnosis of, 597
microscopic findings in, 597
Cerebrotendinous xanthomatosis, 136
Cetuximab, reactions to, 168t
CGH (cutaneous glial heterotopia), 552–553, 553f–554f
Chancre, 273
Chancroid, 260–261
clinical features of, 260–261
differential diagnosis of, 261
microscopic findings in, 261, 261f
Chédiak-Higashi syndrome, pigmentation disorders in, 226
clinical features of, 226
differential diagnosis of, 226
microscopic findings in, 226, 226f
Cheilitis
actinic, vs. lichen planus, 28
granulomatosa, 197
clinical features of, 197
differential diagnosis of, 197
microscopic findings in, 197, 197f
Chemical leukoderma, 224
Chemotherapeutic agents
anagen effluvium due to, 212
reactions to, 167–169
clinical features of, 167–168, 168t
differential diagnosis of, 168–169
microscopic findings in, 168, 168f–169f
Chilblain lupus, 74, 196
Chloracne, 204–205
clinical features of, 204
differential diagnosis of, 205
microscopic findings in, 204, 204f
Cholesterol embolus, 66–67, 67f
Cholinergic urticaria, 13
Chondrodermatitis nodularis chronica helicis, 152–153
clinical features of, 152
differential diagnosis of, 152–153
microscopic findings in, 152, 153f
Chondroid lipoma, 556f, 562, 563f
Chondroid syringoma, 387–388
clinical features of, 387
differential diagnosis of, 388
microscopic features of, 387–388, 388f
Chondroma
extraskeletal, 587–588
clinical features of, 587
differential diagnosis of, 588
microscopic findings in, 587–588, 588f
periosteal, 587
Chondrosarcoma, 589
clinical features of, 589
differential diagnosis of, 589
microscopic findings in, 589, 589f
myxoid, 589, 589f
Chordoma, vs. parachordoma, 589
CHP See Cytophagic histiocytic panniculitis (CHP)
Christ-Siemens-Touraine syndrome, 240
Chromoblastomycosis See Chromomycosis
Chromomycosis, 281–282
clinical features of, 281
differential diagnosis of, 281–282
microscopic findings in, 281, 282f
Chronic actinic dermatitis
clinical features of, 177
differential diagnosis of, 179
microscopic findings in, 178, 178f
Chronic cutaneous lupus erythematosus (CCLE), 98, 99f
Chronic lymphocytic leukemia, 650–652, 651f
vs. marginal zone B-cell lymphoma, 622
Chronic superficial dermatitis, 9–10
clinical features of, 9–10
differential diagnosis of, 10
microscopic findings in, 10, 10f
and mycosis fungoides, 629
Chrysiasis
clinical features of, 174
differential diagnosis of, 175
microscopic findings in, 174–175
Churg-Strauss syndrome, 76
clinical features of, 76
differential diagnosis of, 76
microscopic findings in, 76, 76f
Cicatricial pemphigoid, 48–49
Brunsting-Perry variant of, 48
clinical features of, 48
differential diagnosis of, 48–49
vs. bullous pemphigoid, 46
vs. lichen planus, 28–29, 49
immunofluorescence studies of, 48, 49f
microscopic findings in, 48, 48f
“Cigar bodies, ” in sporotrichosis, 287–288
Ciliated cysts, 321–323
branchial cleft, 323
bronchogenic, 322
cutaneous, 322
in endometriosis, 321
in endosalpingiosis, 322
mucinous and ciliated vulvar, 322
thymic, 323
thyroglossal duct, 323
Circumscribed acral hypokeratosis, 237–238
clinical features of, 237
differential diagnosis of, 238
microscopic findings in, 237–238, 237f
Civatte bodies, in lichen planus, 27
Cladophialophora carrionii infection, 281
Cladosporium werneckii infection, 278
Clear cell acanthoma, 331
clinical features of, 331
differential diagnosis of, 331
microscopic findings in, 331, 331f
Clear cell basal cell carcinoma, 348–349
Clear cell eccrine carcinoma, 392–393
vs. metastatic carcinoma, 418–419, 421f
Clear cell hidradenoma, 385
Clear cell metastatic tumors, 414–422, 418b
vs. “balloon cell” melanoma, 418–419, 420f–421f
vs. clear cell eccrine carcinoma (“hidradenocarcinoma”), 418–419, 419f, 421f
vs. clear cell sarcoma (“melanoma of soft parts”), 419–422, 422f–423f
vs. epithelioid angiomyolipoma (perivascular epithelioid cell tumor [PEComa]), 419–422, 423f
of müllerian-tract origin, 418, 420f
vs. myoepithelioma, 419, 422f
from renal cell carcinoma, 418
vs. sebaceous carcinoma, 418, 419f
vs. squamous cell carcinoma, 418–419, 418f
vs. trichilemmal carcinoma, 418–419, 419f, 421f
Clear cell papulosis, 331
clinical features of, 331
differential diagnosis of, 331
microscopic findings in, 331, 332f
Clear cell sarcoma (CSS), vs. metastatic tumors, 419–422, 422f–423f
Clofazimine, pigmentary changes due to
clinical features of, 171
differential diagnosis of, 173
microscopic findings in, 172–173
“Clonal” nevi, 674, 675f
“Clonal” seborrheic keratosis, 328–330, 329f
Clouston syndrome, 240
“Clown nose, ”, 404, 405f
CMV See Cytomegalovirus (CMV) infection
Coagulation, disseminated intravascular, 64, 65f
Coagulopathies, 64–66
antiphospholipid syndrome as, 64–65, 65f
clinical features of, 64–65
cryoglobulinemia as, 64–65, 65f
differential diagnosis of, 66
factor V Leiden as, 64
microscopic findings in, 65–66
protein C and S deficiency as, 64–65, 65f
Sneddon syndrome as, 64–66
thrombotic thrombocytopenic purpura as, 64–65
Coccidioides immitis infection See Coccidioidomycosis
Coccidioidomycosis, 284
clinical features of, 284
differential diagnosis of, 284
microscopic findings in, 284, 285f
Cockayne-Touraine type, of epidermolysis bullosa, 56
Cold panniculitis
clinical features of, 99–100
differential diagnosis of, 100–101
equestrian, 74, 99–100
microscopic findings in, 100
Colitis, ulcerative, 88–89
clinical features of, 88
differential diagnosis of, 88–89
microscopic findings in, 88, 88f
Collagen entrapment, in dermatofibroma, 442
Collagenoma perforans verruciforme, 145
Collagenosis, reactive perforating, 145–146
clinical features of, 145
differential diagnosis of, 146
vs. perforating folliculitis and Kyrle disease, 144–145
microscopic findings in, 145–146, 146f
Collagenous fibroma, 449
clinical features of, 449
differential diagnosis of, 449
microscopic findings in, 449
Collodion baby, 232–233
“Colloid” adenocarcinoma
of breast, metastatic, 412
admixed with invasive ductal adenocarcinoma, 412, 413f
labeling of mucin in, 412, 414f
vs. primary mucinous (“colloid”) carcinoma of skin, 412, 413f
of skin, 412, 413f
“Colloid bodies, ” in porphyria cutanea tarda, 128–129
Colloid milium, 126
adult
clinical features of, 126, 148
differential diagnosis of, 126, 127f, 150
microscopic findings in, 148–149
clinical features of, 126
differential diagnosis of, 126, 127f
vs. amyloidosis, 126
juvenile
clinical features of, 126
differential diagnosis of, 126, 127f
microscopic findings in, 126, 127f
microscopic findings in, 126, 127f
Colonic adenocarcinoma, Sister Mary Joseph nodules due to metastatic, 404f
Coma blisters, 59–60, 60f
Combined nevi, 674, 675f
Comedones
in acne vulgaris, 202, 202f
nodular elastosis with
clinical features of, 148
differential diagnosis of, 150
microscopic findings in, 148–149, 149f
Common blue nevus, 679–680, 680f
Common warts, 295–296, 295f
Composite hemangioendothelioma, 496
Compound nevi, 668–669, 668f
Condylomata
acuminata, 295–296, 296f
lata, 273
Confluent and reticulated papillomatosis, 239
clinical features of, 239
differential diagnosis of, 239
microscopic findings in, 239, 239f
Congenital ichthyosiform erythroderma, 232–233
bullous, 233–234
clinical features of, 233
differential diagnosis of, 234
microscopic findings in, 233–234, 234f
clinical features of, 232–233
differential diagnosis of, 233
microscopic features of, 233, 233f
Congenital midline hamartoma, 585
clinical features of, 585
differential diagnosis of, 585
microscopic findings in, 585, 586f
Congenital nevus, 682–684
clinical features of, 682–683
differential diagnosis of, 684
giant, 682–684, 684f
intermediate, 682–684
microscopic findings in, 683–684, 684f–685f
small, 682–684, 685f
Congenital self-healing reticulohistiocytosis, 604
clinical features of, 604
differential diagnosis of, 604
microscopic findings in, 604, 605f
Congenital telangiectatic erythema, vs. lupus erythematosus, 112–113
Congenital vellus hamartomas, 358
clinical features of, 358
differential diagnosis of, 358
microscopic findings in, 358
Congo floor maggot, myiasis due to, 300
Conidiobolus coronatus, 280
Conjunctival nevi, 672, 673f
Connective tissue disorders, 107–122, 244–247
cutis laxa as, 247
dermatomyositis as, 113–115
Ehlers-Danlos syndrome as, 246–247
focal dermal hypoplasia (Goltz syndrome) as, 244–247
lipoid proteinosis as, 246
lupus erythematosus as, 107–113
mixed, 108, 111
pseudoxanthoma elasticum as, 245–246
rheumatoid arthritis as, 120
sclerosing conditions of skin as, 115–120
atrophoderma of Pasini and Pierini as, 117
eosinophilic fasciitis as, 117–118
morphea and scleroderma as, 115–117
nephrogenic systemic sclerosis as, 119–120
Connective tissue nevus, 440–441
clinical features of, 440
differential diagnosis of, 441
microscopic findings in, 440–441, 440f–441f
“Constipated melanocyte, ”, 328–329, 330f
Contact dermatitis, 1–4
allergic, 1–2, 2f–3f
clinical features of, 1–2
dermal, 18–19, 19f
differential diagnosis of, 3–4, 4f
irritant, 2–3, 3f
microscopic findings in, 2–3, 2f–3f
subacute, 3
Contact urticaria, 13
“Copper pennies, ”, 281
Coproporphyria, hereditary, 128
Corynebacterial infections, 259–260
clinical features of, 259
differential diagnosis of, 260
microscopic findings in, 259–260, 259f–260f
Cradle cap, 4–5
Cranial fasciitis, 456
Creeping eruption, 298–299
clinical features of, 298
microscopic findings in, 298–299, 299f
CREST syndrome, 115
Crohn disease, 88
clinical features of, 88
differential diagnosis of, 88
vs. sarcoidosis, 197
microscopic findings in, 88, 88f
“Crops, ” metastatic carcinoma in, 402, 403f
Crusted scabies, 297–298, 299f
Cryoglobulinemia, 64–65, 65f
Cryotherapy, blisters due to, 59–60
Cryptococcosis, 284–286
clinical features of, 284
differential diagnosis of, 285–286
microscopic findings in, 285, 286f
Cryptococcus neoformans infection See Cryptococcosis
Crystal deposition diseases, associated with panniculitis, 104
CSS (clear cell sarcoma), vs. metastatic tumors, 419–422, 422f–423f
CTCL See Cutaneous T-cell lymphoma (CTCL)
Cunninghamella infection, 280
“Curlicue” configuration, in dermatofibroma, 441, 442f
Cutaneous angiomyolipoma, 515, 584
clinical features of, 584
differential diagnosis of, 584
microscopic findings in, 584, 584f
Cutaneous ciliated cyst, 322, 322f
Cutaneous erythropoiesis, 653
Cutaneous fibrous histiocytoma See Dermatofibroma
Cutaneous glial heterotopia (CGH), 552–553, 553f–554f
Cutaneous horn formation, actinic keratosis with, 332–333, 333f
Cutaneous keratocyst, 317–318
clinical features of, 317
microscopic findings in, 317–318, 318f
Cutaneous lymphoid hyperplasia, 620–622
clinical features of, 620
differential diagnosis of, 621–622
microscopic findings in, 620–621, 621f
Cutaneous myxomas, vs. focal mucinosis, 157–158, 158f
Cutaneous pseudosarcomatous polyp, vs. pleomorphic fibroma, 448, 448f
Cutaneous reactive angiomatoses, 512
Cutaneous T-cell lymphoma (CTCL)
vs. adult T-cell leukemia/lymphoma, 646
granulomatous slack skin as, 635
vs. Langerhans cell histiocytosis, 604
vs. lymphocytoma cutis, 622
mycosis fungoides as, 629–634
pagetoid reticulosis as, 634–635
peripheral, 642–644
vs. pigmented purpuric eruptions, 74
pseudo-, 643–644
Sézary syndrome as, 635–637
Cutis laxa, 247
clinical features of, 247
differential diagnosis of, 247
microscopic findings in, 247, 247f
Cylindroma, 380–381
carcinoma ex, 392
clinical features of, 380–381
differential diagnosis of, 381
vs. trichoepithelioma, 364
microscopic findings in, 381
Cyst(s)
branchial cleft, 323, 323f
bronchogenic, 322, 323f
ciliated, 321–323
branchial cleft, 323
bronchogenic, 322
cutaneous, 322
in endometriosis, 321
in endosalpingiosis, 322
mucinous and ciliated vulvar, 322
thymic, 323
thyroglossal duct, 323
dermoid, 320
clinical features of, 320
differential diagnosis of, 320
epibulbar, 358
microscopic findings in, 320, 320f
digital mucinous, 159
clinical features of, 159
differential diagnosis of, 159
ganglion type, 159, 159f
microscopic findings in, 159, 159f
superficial type, 159, 159f
epidermal (infundibular), 315–316
calcified, 130f
clinical features of, 315–316
differential diagnosis of, 316
microscopic findings in, 316, 316f
proliferating, 317
clinical features of, 317
microscopic findings in, 317, 317f
ruptured, 315–316, 316f
epithelial, 315–324
ciliated, 321–323
cutaneous keratocyst as, 317–318
dermoid, 320
epidermal (infundibular), 315–316
eruptive vellus hair, 320–321
in Gardner syndrome, 318
clinical features of, 318
microscopic findings in, 318, 318f
human papillomavirus–associated (“verrucous”), 316
median raphe, 324
metaplastic synovial, 323–324
omphalomesenteric duct polyp as, 324
pigmented follicular, 317
in steatocystoma, 319–320
trichilemmal (pilar, isthmus-catagen), 318–319
proliferating, 319
eruptive vellus hair, 320–321
clinical features of, 320
differential diagnosis of, 321
microscopic findings in, 320–321, 321f
human papillomavirus–associated (“verrucous”), 316
clinical features of, 316
microscopic findings in, 316, 317f
median raphe, 324, 324f
metaplastic synovial, 323–324, 324f
of Moll gland, 378
mucinous and ciliated vulvar, 322, 322f
nodular elastosis with
clinical features of, 148
differential diagnosis of, 150
microscopic findings in, 148–149, 149f
pigmented follicular, 317
clinical features of, 317
microscopic findings in, 317, 317f
thymic, 323, 323f
thyroglossal duct, 323, 323f
trichilemmal (pilar, isthmus-catagen), 318–319
clinical features of, 318
microscopic findings in, 318–319, 318f
proliferating, 319
clinical features of, 319
differential diagnosis of, 319
microscopic findings in, 319, 319f
rupture of, 318–319, 319f
Cystadenoma, apocrine, 378–379
clinical features of, 378
differential diagnosis of, 379
microscopic findings in, 378–379, 379f
Cystic hamartoma, follliculosebaceous, 373
clinical features of, 373
differential diagnosis of, 373
vs. dermoid cyst, 320
microscopic findings in, 373, 373f
Cystic hygroma, 478
Cytokines, reactions to recombinant, 170, 170f
Cytomegalovirus (CMV) infection, 292
clinical features of, 292
differential diagnosis of, 292
in Kaposi sarcoma, 498–500
microscopic findings in, 292, 293f
Cytophagic histiocytic panniculitis (CHP), 102–103
clinical features of, 102–103
differential diagnosis of, 103
microscopic findings in, 103, 103f
with subcutaneous panniculitis-like T-cell lymphoma
clinical features of, 102, 640
microscopic findings with, 103, 103f
treatment of, 102