DERMPATH KODACHROMES Flashcards by Sharmaine Lozano

Cornoid lamellae

Porokeratosis

How well did you know this?

Not at all

Perfectly

CORPS RONDS / GRAINS / DYSKERATOSIS

Darier’s Disease

How well did you know this?

Not at all

Perfectly

FESTOONING

-Papillary dermis retains an undulating pattern

Seen in Porphyria Cutanea Tarda

How well did you know this?

Not at all

Perfectly

Flame Figures
- formed by degranulated eosinophils surrounding altered collagen

seen in Well’s syndrome, other eosinophil predominant dermatitis

How well did you know this?

Not at all

Perfectly

Flame Figures
- formed by degranulated eosinophils surrounding altered collagen

seen in Well’s syndrome, other eosinophil predominant dermatitis

How well did you know this?

Not at all

Perfectly

Flame Figures
- formed by degranulated eosinophils surrounding altered collagen

seen in Well’s syndrome, other eosinophil predominant dermatitis

How well did you know this?

Not at all

Perfectly

Eccrine Glands

“-Donut-shaped” tubules -made of one layer of clear and dark cells and an outer thin layer of myoepithelial cells

How well did you know this?

Not at all

Perfectly

Sebaceous Glands

-Several lobules of sebocytes (pale cells with vacuolated fenestrated cytoplasm which contains lipids and stellate central nuclei)

How well did you know this?

Not at all

Perfectly

Apocrine Glands

Clue: Look for decapitation secretion (detachment of the apical portion of the secretory cells into the lumina) as a clue to apocrine differentiation.

How well did you know this?

Not at all

Perfectly

Langhans Giant Cells

How well did you know this?

Not at all

Perfectly

Foreign Body Giant cell

How well did you know this?

Not at all

Perfectly

Touton Giant cell

How well did you know this?

Not at all

Perfectly

Kamino Body

Seen in Spitz Nevus

How well did you know this?

Not at all

Perfectly

identify the cells

Langerhans Cells

How well did you know this?

Not at all

Perfectly

Smooth Muscle

How well did you know this?

Not at all

Perfectly

OTHER NOTES:
- squamous eddies- Circular whorls composed of eosinophilic, flattened squamous cells arranged in an onion-peel fashion (irritated seb ker); irritated seborrheic keratosis (inverted follicular keratosis)

- horn/keratin pearl- Trapped keratin within cystic nests; dense/parakeratin (not loose flaky keratin) and 2. Located in dermis (not epidermis); (eosinophilic parakeratotic keratinization); well or moderately differentiated; WITH DENSE PINK KERATIN; IN THE MIDDLE OF ISLANDS OF ATYPICAL KERATINOCYTES; A LOT OF NUCLEI; IN THE DERMIS; YUNG KERATIN PARANG NATTRAP INSIDE THE NEST OF TUMOR; ENTRAPPED PARAKERATOSIS

- horn cyst - foci of orthokeratosis within the substance of the lesion, loose keratin; In the EPIDERMIS; representfoci of abrupt complete keratinization(with only a very thin surrounding granular cell layer and without retained nuclei); Seb ker; NASA EPIDERMIS TAPOS LOOSE YUNG KERATIN; ORTHOKERATIN (WALANG NUCLEI)

- pseudohorn cyst - Keratin-filled cystic structure that is the result of cutting through invaginations of the stratum corneum; with connection on the surface; in the epidermis; seb ker; OPEN UP TO THE SURFACE

How well did you know this?

Not at all

Perfectly

Identify the site

SCALP

-Numerous follicles that extend down into the panniculus

-Associated sebaceous glands, arrector pili muscles

How well did you know this?

Not at all

Perfectly

Identify the site

FACE

-Thin epidermis

-Hair follicles and sebaceous glands numerous in the dermis

-Eyelid and ear: vellus hair

-Upper dermis of eyelid: skeletal muscle

How well did you know this?

Not at all

Perfectly

Meissner Corpuscle

How well did you know this?

Not at all

Perfectly

Pacinian Corpuscle

How well did you know this?

Not at all

Perfectly

SPONGIFORM PUSTULE OF KOGOJ

Neutrophils in the stratum spinosum, associated with spongiosis at periphery

How well did you know this?

Not at all

Perfectly

SQUAMOUS EDDIES
- Circular whorls composed of eosinophilic, flattened squamous cells arranged in an onion-peel fashion

Concentric whorls of squamous cells, with gradual keratinization towards the center
seen in irritated seb ker, SCC, keratoacanthoma

- horn/keratin pearl- Trapped keratin within cystic nests; dense/parakeratin (not loose flaky keratin) and 2. Located in dermis (not epidermis); (eosinophilic parakeratotic keratinization); well or moderately differentiated; WITH DENSE PINK KERATIN; IN THE MIDDLE OF ISLANDS OF ATYPICAL KERATINOCYTES; A LOT OF NUCLEI; IN THE DERMIS; YUNG KERATIN PARANG NATTRAP INSIDE THE NEST OF TUMOR; ENTRAPPED PARAKERATOSIS

- horn cyst - foci of orthokeratosis within the substance of the lesion, loose keratin; In the EPIDERMIS; representfoci of abrupt complete keratinization(with only a very thin surrounding granular cell layer and without retained nuclei); Seb ker; NASA EPIDERMIS TAPOS LOOSE YUNG KERATIN; ORTHOKERATIN (WALANG NUCLEI)

- pseudohorn cyst - Keratin-filled cystic structure that is the result of cutting through invaginations of the stratum corneum; with connection on the surface; in the epidermis; seb ker; OPEN UP TO THE SURFACE

How well did you know this?

Not at all

Perfectly

Pityriasis Rubra Pilaris
- alternating ortho and parakeratosis in both vertical and horizontal directions

How well did you know this?

Not at all

Perfectly

Pityriasis Rosea

extravasated erythrocytes in the papillary dermis
MOUNDS of parakeratosis

How well did you know this?

Not at all

Perfectly

Seborrheic Dermatitis - "shoulder parakeratosis" - regular acanthosis and elongation of the rete ridges - mild spongiosis sparse - mononuclear cell infoltrate

What do you call this sign? What condition is this seen

Hair Palm Sign: folliculosebaceous units seen with a thick compact cornified layer (resembles a biopsy taken from the volar skin) LICHEN SIMPLEX CHRONICUS

Nutritional deficiency dermatitis

SMALL PLAQUE PARAPSORIASIS - elongated parakeratosis above a basket-weave cornified layer - scant spongiosis, slight acanthosis

HAILEY HAILEY DISEASE

DARIER DISEASE

Dermatitis herpetiformis - subepidermal vesiculation - accumulation of neutrophils at the tips of dermal papillae - slight fibrin deposition

ERYTHEMA ANNULARE CENTRIFUGUM - FOCAL PARAKERATOSIS - TIGHTLY CUFFED LYMPHOHISTIOCYTIC INFILTRATES INFILTRATES

Inflammatory linear verrucous epidermal nevus (ILVEN) * HORIZONTAL * SLIGHTLY RAISED PARAKERATOTIC AREA * PSORIASIFORM

POROKERATOSIS * CORNOID LAMELLA ⚬ COLUMN OF COMPACT PARAKERATOSIS ON AN AREA OF DEPRESSION OF EPIDERMIS WITH (-) GRANULAR LAYER ⚬ DYSKERATOTIC CELLS

VERRUCA * SPIRES OF PARAKERATOSIS * OVER THE TIPS OF THE PAPILLARY PROJECTIONS * ALTERNATE WITH ORTHOKERATOSIS * OVERLY HYPERGRANULOTIC VALLEYS OF THE EPIDERMIS

LICHEN PLANUS * COMPACT ORTHOKERATOSIS * WEDGE-SHAPED HYPERGRANULOSIS * BAND-LIKE DERMAL LYMPHOCYTIC INFILTRATE

LICHEN PLANUS * CIVATTE BODIES ⚬ NECROTIC KERATINOCYTES IN THE LOWER EPIDERMIS ⚬ HOMOGENOUS, EOSINOPHILIC

Pityriasis lichenoides et varioliformis acuta (PLEVA) * CONFLUENT PARAKERATOSIS * LICHENOID WITH SUPERFICIAL. AND DEEP PERIVASCULAR LYMPHOCYTIC INFILTRATES

VITILIGO

What do you call this sign? What condition is this seen

Dermatophytosis * COMPACT ORTHOKERATOSIS * SANDWICH SIGN: HYPHAE SANDWICHED BETWEEN 2 ZONES OF CORNIFIED CELLS * NEUTROPHILS IN THE SC

PITYRIASIS VERSICOLOR * MALASSEZIA FUNGAL FORMS LOCATED IN THE SC * " SPAGHETTI/ZITI AND MEATBALLS"

SCABIES * SCALE-CRUST WITH NEUTROPHILS * MILDLY HYPERPLASTIC EPIDERMIS * PATCHY LYMPHOID INFILTRATE * PIGTAILS ⚬ CURLED PINK STRUCTURES ⚬ REMNANTS OF EGGS OR CASINGS LEFT BEHIND AFTER HATCHING

SCABIES * ADULT FEMALE MITE

TOXIC EPIDERMAL NECROLYSIS * NORMAL STRATUM CORNEUM * NECROTIC KERATINOCYTES AT ALL LEVELS OF THE EPIDERMIS * BLISTER ROOF- DUE TO CONFLUENCE * INTERFACE DERMATITIS

Diagnosis? Pattern?

POLYARTERITIS NODOSA SEPTAL PANNICULITIS WITH VASCULITIS - Neutrophilic LCV involving medium arteries of the subcutaneous septa - Neutrophils, leukocytoclastic nuclear dust, extravasated erythrocytes, and fibrin aggregate within and around the affected artery.

ERYTHEMA NODOSUM

IDENTIFY. WHAT CONDITION IS THIS SEEN?

MIESCHER RADIAL GRANULOMA: Collection of nonenlarged histiocytes forming a central radial or slitlike extracellular cleft ERYTHEMA NODOSUM

NECROBIOSIS LIPOIDICA

RHEUMATOID NODULE

A. Pattern? B. Diagnosis C. Give 2 differentials

A. Lobular panniculitis B. SC fat necrosis of the newborn C. sclerema neonoatrum, poststeroid pannicuitis

GRANULOMA ANNULARE * Zone of degenerated collagen and mucin is surrounded by a rim of palisading histiocytes * Multinucleated histiocytes often present, but usually subtle * Eosinophils in half of the cases

NECROBIOSIS LIPOIDICA * Entire thickness of the dermis (or lower 2/3) * Horizontal, acellular, pale, degenerated collagen between layers of granuloma -likened to TIERED CAKE * Rectangular punch due to sclerosis

RHEUMATOID NODULE * Several areas of fibrinoid degeneration of collagen -> homogenously red * Mucin is always minimal or absent * Foreign-body giant cells - 50% of biopsies

NECROBIOTIC XANTHOGRANULOMA * X-shaped red zones of necrosis within granulomatous nodule (X-shaped necrosis in NXG) * Characteristic finding: lymphoid follicles or aggregates * Cholesterol clefts are common

GOUT * Palisaded granuloma surrounding amorphous, gray blue material with feathery appearance * Granuloma- infiltrate with many foreign-body giant cells

ASTEROID BODY Eosinophilic, star-burst inclusion within a giant cell Sarcoidosis, Sporotrichosis ## Footnote Stellate inclusion bodies composed of crystalline inclusions (lipoproteins, calcium, phosporus, etc) seen in granulomatous diseases like sarcoidosis, sporotrichosis, etc

SCHAUMANN BODY Cytoplasmic, laminated calcifications Sarcoidosis

JUVENILE XANTHOGRANULOMA

Identify the cells

LANGERHANS CELL

A. LOCATION? B. DIAGNOSIS?

EYELID, PERIORBITAL AREA XANTHELASMA * Characterized by foamy cells (macrophages that have engulfed lipid droplets)

LICHEN PLANUS PROTOTYPE OF LICHENOID INTERFACE DERMATITIS

COLLOID, CYTOID, OR CIVATTE BODIES LICHEN PLANUS

MAX JOSEPH SPACE: DUE TO EXTENSIVE DAMAGE TO BASAL CELLS LICHEN PLANUS

PAUTRIER MICROABSCESS: PROMINENT CLUSTERS OF ATYPICAL LYMPHOCYTES WITHIN THE EPIDERMIS - EPIDERMOTROPISM OF LARGE, ATYPICAL LYMPHOCYTES WITH LITTLE SPONGIOSIS - LYMPHOCYTES HYPERCHROMATIC AND SURROUNDED BY WHITE SPACE (LUMP OF COAL ON A PILLOW) - LYMPHOCYTES TEND TO LINE UP ALONG THE DEJ MYCOSIS FUNGOIDES

Identify the pointed structure. What sign is this

BARE UNDERBELLY SIGN: TENDENCY FOR THE SUPERFICIAL PERIVASCULAR LYMPHOID INFILTRATE TO PREDOMINATE ABOVE THE VESSEL MYCOSIS FUNGOIDES

Pityriasis lichenoides et varioliformis acuta (PLEVA) - COMPACT STRATUM CORNEUM WITH OR WITHOUT ULCERATION - DENSE BANDLIKE LYMPHOCYTIC INFILTRATE - EXTENDS INTO THE RETICULAR DERMIS IN A WEDGE-SHAPED PATTERN

ERYTHEMA MULTIFORME: PROTOTYPE OF VACUOLAR INTERFACE DERMATITIS - KERATINOCYTE NECROSIS WITHIN AND ABOVE BASAL LAYER

SJS/ TEN - FULL-THICKNESS NECROSIS - FOLLICULAR INVOLVEMENT- BASAL LAYER DEGENERATION

FIXED DRUG ERUPTION - HYDROPIC DEGENERATION OF THE BASAL LAYER LEADS TO PIGMENTARY INCONTINENCE

fixed drug eruption

A. PREDOMINANT CELL IN FULLY DEVELOPED LESION? B. DIAGNOSIS?

HISTIOCYTE LICHEN NITIDUS

DIAGNOSIS? ETIOLOGY?

A. ERYTHEMA MULTIFORME B.HSV, MYCOPLASMA

PLASMA CELL WARTHIN STARRY, STEINER SYPHILIS

WHAT TYPE OF GRANULOMA

TUBERCULOID GRANULOMA

LICHEN SCLEROSUS ET ATROPHICUS a) hyperkeratosis b) atrophy of the s malpighii c) edema & homogenization of collagen in the upper dermis d) inflammatory infiltrate in the mid-dermis

ELASTOSIS PERFORANS SERPIGINOSA * Channel ⚬ Coarse elastic fibers ⚬ Granular basophilic debris

REACTIVE PERFORATING COLLAGENOSIS * Channel lined by acanthotic epithelium * Base- attenuated layer of keratinocytes * Vertically oriented collagen

SCAR * Vertically-aligned vessels * East to west orientation of fibroblasts * Parallel bundles of cellular collagen

KELOID * Hypocellular zones of thickened glassy collagen bundles in haphazard array, in contrast to normal collagen

OCHRONOSIS * Free pigment in the tissue, endothelial cells, basement membrane, secretory cells of the sweat glands, within macrophages * OCHRONOTIC PIGMENT WITHIN COLLAGEN BUNDLES ⚬ fractured, pointed ends

A. Diagnosis? B. Close differential

A. Keloid B. Hypertrophic scar

A. Diagnosis? B. Stain?

A. Elastosis perforans serpiginosa (EPS) B. Verhoeff Van Gieson

A. Morphea B. Eccrine trapping

Donovan Body Intracytoplasmic collections of bacteria seen in granuloma inguinale

Angiolipoma ## Footnote A, Narrow and dilated, thin-walled capillaries are admixed with mature adipocytic tissue. B, The adipocytic component can predominate.

1. diagnosis? 2. this is a benign neoplasm of what tissue? 3. common site affected 4. stain that will highlight tumor cells

1. Hibernoma 2. Brown fat 3. thigh 4. S100 and uncoupling protein ## Footnote * Typical hibernomas are composed of large, polygonal, brown fat cells with multivacuolation, granular cytoplasm, and a small, centrally located nucleus admixed with mature white fat cells * Immunohistochemically, tumor cells stain positively for S-100 protein and for **uncoupling protein, **a protein unique to brown adipocyte mitochondria

junctional nevus

intradermal nevus

1. diagnosis 2. mutation present 3. variant with elevated risk for development of melanoma 4. related lesions 5. areas of predilection 6. positive stains

1. blue nevus 2. GNAQ/GNA11 3. cellular blue nevus 4. nevus of Ota/Ito, Mongolian spot, dermal dendritic hamartoma 5. dorsal hands and feet, scalp, and buttocks or sacral skin 6. S100, Mart-1, HMB-45 ## Footnote * All types of blue nevus have components that include some of the following: **deeply pigmented dendritic melanocytes, spindled and less pigmented melanocytes, oval melanocytes, melanophages, and fibrotic stroma ** * Nevus cells may show perivascular or periadnexal accentuation. * Almost all blue nevi **lack a junctional component.**

1. diagnosis 2. identify the eosinophilic globules 3. age group where this is commonly seen 4. associated mutation

1. spitz nevus 2. kamino bodies 3. children 4. HRAS ## Footnote * Spitz nevi are characterized by melanocytic cells with large epithelioid nuclei, often with prominent nucleoli and surrounded by a rim of eosinophilic cytoplasm with “ground-glass” appearance * Small intraepidermal eosinophilic globules (Kamino bodies), which are positive for periodic acid–Schiff and diastase resistant (resembling colloid bodies), may be seen.

Dysplastic nevus. A, Compound dysplastic nevus with architecturally disordered junctional nests extending well beyond the dermal component (100× magnification). B, Junctional melanocytic nests are situated along the tips and sides of rete and display random cytologic atypia. There is underlying papillary dermal fibroplasia, lymphocytic infiltrate, and pigment incontinence (200× magnification).

Dysplastic nevus

Dysplastic nevus Lamellar fibroplasia and bridging of the melanocytic nests. Upward migration of the nevomelanocytes is present.

foam cells seen in xanthoma

etiologic agent?

Histoplasma capsulatum

etiologic agent?

Histoplasma capsulatum

The fungus can be found in KOH mounts of pus, skin scrapings, or sputum as thick-walled, rounded, refractile, spherical cells with** broad-based buds** What is the diagnosis?

Blastomycosis

**spore-containing spherules **can be seen in what condition?

Coccidioidomycosis

mycosis fungoides

**Patch stage of mycosis fungoides. ** A, Single atypical mononuclear cells in epidermis with sparse superficial perivascular infiltrate in the papillary dermis. (Hematoxylin and eosin-stained section.) B, High-power view of atypical cells in epidermis of same section.

Indeterminate leprosy histopathology. Up to 70% of the indeterminate cases may have an unspecific histopathology. In 30% it is possible to observe a perineural infiltrate with nerve delamination (A and B, arrows), as demonstrated here, and if extensively searched, sometimes it is possible to find an acid-fast bacilli (C, arrow).

**Tuberculoid leprosy** histopathology. Presence of deep and superficial well-developed granuloma, that touch the epidermis (A), associated with lymphocyte infiltration surrounding or invading and destroying skin appendages, like nerves, erector pili muscle (B), or sweat gland (C).

**Borderline-tuberculoid leprosy **histopathology. Deep and superficial tuberculoid granuloma (A) that does not touch the epidermis (B). The tuberculoid granuloma may be seen invading the nerves (C), and acid-fast bacilli can be found (D, 100×).

Borderline-borderline leprosy histopathology. Deep and superficial tuberculoid granuloma that does not touch the epidermis, starting to form a grenz zone (A). Inflammatory cells are invading cutaneous annexes and nerves, that are degenerated (B), and acid-fast bacilli can be found more easily, some forming globi (C).

Borderline-lepromatous leprosy histopathology. There is a mixed macrophage lymphocytic inflammatory infiltrate (macrophage granuloma) on superficial and deep dermis (A). The mixed infiltrate does not touch the epidermis and may be seen surrounding or invading nerve bundles (B). A large number of acid-fast bacilli is seen (C).

1. Diagnosis 2. Causative agent

1. Paracoccidioidomycosis 2. Paracoccidioides brasiliensis

compound nevus

congenital nevomelanocytic nevus

Hidradenoma ## Footnote * B, The tumor is a circumscribed, nonencapsulated, solid and cystic dermal neoplasm. * C, Hidradenoma is composed of clear cells and cells with ductal and glandular differentiation. * Large nodule * +/- cysts * cuboidal cells with pink ample cytoplasm * CLEAR CELLS * Cuticle lined ducts * POROID CELLS + LARGE DERMAL NODULE + CYSTS = HIDRADENOMA

Poroma ## Footnote * connects with epidermis * cuboidal cells with ample cytoplasm * cuticle-lined ducts * intracytoplasmic lumina * POROID CELLS + EPIDERMAL ATTACHMENT = POROMA

FIBROEPITHELIOMA OF PINKUS ## Footnote In FEP, long strands of interwoven basiloma cells are embedded in fibrous stroma with abundant collagen.

1. Diagnosis 2. Associated syndromes 3. This may be a side effect of what medication?

1. Keratoacanthoma 2. Muir-Torre Syndrome/ Ferguson-Smith Syndrome 3. BRAF inhibitors (sorafinib, vemurafenib, dabrafenib)

**Merkel cell carcinoma** A, Hematoxylin and eosin. There is diffuse dermal as well as intraepidermal involvement with Merkel cell carcinoma. This case was seen in consultation, with an initial diagnosis of cutaneous T-cell lymphoma. B, **Cytokeratin-20.** Showing the pathognomonic **“perinuclear pattern” **of cytokeratins (CAM5.2). Classic histologic features of MCC * **sheets of small basophilic cells with scant cytoplasm, fine chromatin, and no nucleoli. ** * There are **numerous mitotic figures** and occasional individual necrotic cells. * **Lymphovascular invasion** is a very common feature

1. Diagnosis 2. Stains that can highlight the cells 3. sensitive cytokeratin stains

1. Paget's disease 2. (+) periodic acid-Schiff, mucicarmine, Alcian blue, and colloidal iron; diastase resistant 3. cytokeratin 7 (CK7) and anticytokeratin (CAM 5.2): sensitive markers for both MPD and EMPD

Kaposi Sarcoma

1. Diagnosis 2. Identify the collection of cells

1. Mycosis Fungoides

Identify

Apocrine glands

Eccrine glands

1. Identify 2. Function

1. Meissner corpuscle 2. Mediate sense of touch

1. Identify the structure below 2. function

1. Vater - Pacini Corpuscles/ Pacinian Corpuscle 2. Mediate sense of PRESSURE

Identify the site

Scalp ## Footnote * Dermis and Subcutis are broad * Dermis: upper parts of abundant hair follicles * Subcutis: hair bulbs * Fibrous tissue layer deep to the subcutis (galea)

Identify the site

Face ## Footnote * Increased sebaceous glands * Vellus hair follicles * +/- solar elastosis/sun damage * Epidermis may be thinned and rete ridges may be flattened

Identify the site

Axilla ## Footnote * Large dilated Apocrine glands beside smaller eccrine glands * Undulating epidermis *May also have similar appearance with groin

Identify the site

Back ## Footnote * Thickened Collagen * Hair follicles are decreased compared to other sites

Identify the site

Palms/Soles ## Footnote * Compact Orthokeratosis * Thickened granular layer * Lamina lucida or stratum lucidum * Eccrine coils * NO HAIR FOLLICLES! * Pacinian corpuscle * Meisnner’s corpuscle **If you see a slide that looks like acral skin, but with hair follicles, think of lichenified processes such as LSC/ Prurigo nodularis = HAIR PALM SIGN

Identify the site

Eyelid and Ear ## Footnote * Thin epidermis * Vellus hair follicles

Identify the cells

Langerhans cells ## Footnote Dendritic cells in the skin and bone marrow with immune response function

Identify the cells

Foam cells / Xanthomatous cells ## Footnote Lipid-laden macrophages

Identify

Necrobiosis ## Footnote Degeneration of collagen; blurring and loss of definition of collagen bundles possibly due to mucin, fibrin, lipids etc

Identify the cells

A. Xanthomatous cells B. Langhans type giant cells C. Foreign Body giant cells D. Touton giant cells

1. Identify 2. Where is this seen?

1. Asteroid Body 2. granulomatous diseases like sarcoidosis, sporotrichosis, etc ## Footnote Stellate inclusion bodies composed of crystalline inclusions (lipoproteins, calcium, phosporus, etc) seen in granulomatous diseases like sarcoidosis, sporotrichosis, etc

Identify

Nerve ## Footnote *wavy appearance

Identify

Smooth muscle ## Footnote *cigar-shaped nuclei

Identify

collagen ## Footnote *fibroblasts have spindle and stellate shaped nuclei

lichen planus ## Footnote A, The characteristic findings of lichen planus with compact orthohyperkeratosis, wedgeshaped hypergranulosis, sawtoothed rete ridges, and a lichenoid infiltrate. B, Dense, lichenoid lymphocytic infiltrate with scattered apoptotic keratinocytes and pigment incontinence. A small Max-Joseph space is noted centrally. (H&E × 200.)

Epidermal Necrolysis ## Footnote Eosinophilic necrosis of the epidermis in the peak stage, with little inflammatory response in the dermis. Note cleavage in the junction zone

Identify the site

Scalp ## Footnote Numerous hair follicles (HF) extend down into the panniculus

Identify the site

Eyelids * Many vellus HF * Skeletal muscle bundles in the upper dermis * Conjunctival surface: Absent s. corneum and HF, (+) Goblet cells

Identify the site

Nose ## Footnote * Vellus HF * Prominent SG

Identify the site

Face ## Footnote * Thin epidermis * Numerous HF and sebaceous glands (SG) in the dermis * +/- Demodex mites

Identify the site

Ear ## Footnote * Many vellus hairs * Cartilage

Identify the site

Skin from the outer aspect of the LIP ## Footnote * Keratinized stratified squamous epithelium * Skeletal muscle fibers in the dermis

Identify the site

Mucosal aspect of the lip ## Footnote * No granular layer * Keratinocytes are large and pale (filled with glycogen) * Dilated vessels * +/- Minor salivary glands

Identify the site

Areola

Identify the site

PENIS (Foreskin)

PITYRIASIS RUBRA PILARIS ## Footnote * Alternating VERTICAL AND HORIZONTAL orthokeraeratosis and parakeratosis (Checkerboard) * Acanthosis – regular or irregular * Parakeratosis adjacent to follicles (Follicular plugging) * Occasional spongiosis * Occasional acantholysis * Usually not much inflammation

1. Diagnosis 2. DDx

Acute spongiotic dermatitis

1. Diagnosis 2. Give DDx

Eosinophilic spongiosis SHAAPPIE * Scabies * Herpes gestationis * Arthropod bite * Allergic contact dermatitis * Pemphigus * Pemphigoid * Incontinentia pigmenti * Erythema toxicum neonatorum

Stasis dermatitis * Cannonball-like angioplasia in the superficial dermis * Hemosiderin - Perls' stain

Erythema multiforme ## Footnote * Acute basketwoven stratum corneum * Vacuolar interface with necrotic keratinocytes * Cell death out of proportion to lymphocytes * Can have confluent epidermal necrosis

Lupus ## Footnote * Lichenoid/vacuolar interface changes * Follicular plugging * Thickening of the BMZ * Superficial and deep perivasc and periadnexal of lymphocytes * Dermal mucin

Lichen Planus ## Footnote * compact orthokeratosis * Sawtooth rete ridges * If lichenoid drug eruption → eosinophils and parakeratosis

PLEVA/PLC ## Footnote * Parakeratosis * Lichenoid infiltrate * Extravasated RBC * V-shaped (wedge) infiltrate * Acute epidermal changes (spongiosis +/ulcerations) * PLC – more subtle findings

Lichen Nitidus ## Footnote * expanded dermal papilla filled with lymphocytes and histiocytes enclosed by claws (ball and claw) * focal parakeratosis * hypogranulosis * thinned suprapapillary plate

IMPETIGO: subcorneal cleft with neutrophil-rich infiltrate and cocci

ERYTHEMA NODOSUM LEPROSUM * Predominantly lobular panniculitis with vasculitis * Superficial and deep, nodular and diffuse infiltrates * ✓ Diffuse infiltrates of neutrophils

1. Diagnosis 2. Identify the pointed structures 3. Etiologic agent 4. Hallmark of the disease 5. Preferred treatment strategy

1. Monkeypox 2. Guarnieri Bodies - eosinophilic cytoplasmic inclusion bodies 3. Monkeypox virus; Genus: orthopoxvirus 4. Lymphadenopathy 5. Postexposure prophylaxis with vaccinia virus

What are the clues to a fungla infection

1. Diagnosis 2. MC etiologic agent

1. MAJOCCHI’S GRANULOMA 2. Trichophyton rubrum, Trichophyton interdigitale, Microsporum canis

1. diagnosis 2. Identify the brown structures on the right photo 3. causative organism 3. Treatment options

1. Chromoblastomycosis (chromomycosis) 2. Medlar bodies/ sclerotic bodies (“copper pennies”) 3. Fosecaea pedrosoi, Cladophialophora carrionii - MC causes 4. Tretment options: * Itraconazole 200 mg once daily or * Terbinaﬁne 250 mg once daily or * IV amphotericin B (up to 1 mg/kg/day) * Treatment continued for several months, until clinical resolution

1. Identify the phenomenon 2. Name a condition where this may be observed

1. Splendore-hoeppli phenomenon 2. Eumycetoma

1. Diagnosis 2. Causative agent

1. CRYPTOCOCCOSIS 2. Cryptococcus neoformans

PARACOCCIDIOMYCOSIS LARGE NARROW-BASED BUDDING YEAST ‘marine-wheel’

BLASTOMYCOSIS BROAD-BASED BUDDING YEAST

COCCIDIOIDOMYCOSIS SPHERULES/SPORANGIUM WITH ENDOSPORES/SPORANGIOSPORES

HISTOPLASMOSIS OVOID YEAST WITH CLEAR HALO

1. Diagnosis 2. Pattern? 3. Stain used to highlight organism 4. What do you call Histiocytes with amastigotes?

1. Leishmaniasis 2. Granulomatous 3. Giemsa stain 4. Leishman-Donovan/ Leishmania bodies

TALAROMYCES OVOID YEAST WITH CLEAR HALO + TRANSVERSE SEPTUM

Pigmented Purpuric Dermatosis

Urticaria

Arthropod Bite Hypersensitivity

Urticaria Pigmentosa

stains for mast cell

Toluidine Blue Giemsa Leder Stain Tryptase CD117 (c-kit)

Pyoderma Gangrenosum

Wells Syndrome

Acne Vulgaris

Rosacea

Alopecia Areata

Androgenetic Alopecia

Trichotillomania

1. Identify 2. Seen in what condition?

1. trichomalacia: distorted narrow hair shaft with irregular pigmentation 2. Trichotillomania

1. Identify 2. Seen in what condition?

1. pigment casts 2. trichotillomania

1. Hamburger sign: longitudinally fractured shafts containing hemorrhage 2. trichotillomania

Lichen Planopilaris

tumid lupus erythematosus - perifollicular lymphocytic infiltrate with mucin deposition

Rosacea - perivascular and perifollicular lymphocytic infiltrate with dilated vessels and demodex mites in the follicular infundibulum

Diffuse dermal infiltrates of eosinophils + flame figures + papillary dermal edema = **Wells syndrome/ Eosinophilic cellulitis**

Scarring or Nonscarring?

Preserved sebaceous glands, peribulbar lymphocytic infiltrate = Nonscarring alopecia; alopecia areata

loss of sebaceous glands in some of the follicular units, perifollicular fibrosis and infiltrates at the level of isthmus = **scarring alopecia; lichen planopilaris**

What are the CD4 and CD8 predominant MF?

1. Diagnosis 2. What additional stain can you request to differentiate if from another close differential?

1. MYCOSIS FUNGOIDES: Plaque Stage 2. CD25

MYCOSIS FUNGOIDES: Folliculotropic

Publishing; 2004. MYCOSIS FUNGOIDES: Granulomatous

LYMPHOMATOID PAPULOSIS: TYPE A

stain for PRIMARY CUTANEOUS MARGINAL ZONE LYMPHOMA (pcMZL)

Bcl2

stain for PRIMARY CUTANEOUS FOLLICLE CENTER LYMPHOMA (pcFCL)

Bcl6

Stain that will provide distinction between pcMZL and PRIMARY CUTANEOUS DIFFUSE LARGE B-CELL LYMPHOMA (pcDLBCL)

MUM-1

Leukemia cutis

1. Diagnosis 2. MC benign neoplasm associated with it 3. MC malignant neoplasm associated with it 4. more than 90% harbor this mutation 5. Syndromes associated with it

1. Nevus Sebaceous (other sources: Nevus sebaceus) 2. Trichoblastoma and syringocystadenoma papilliferum 3. Basal cell carcinoma 4. HRAS mutation 5. Schimmelpenning syndrome and phakomatosis pigmentokeratotica