6/12/2018 1 Infectious Dermatopathology

6/12/2018

Infectious Dermatopathology – What is “bugging” you? Alina G. Bridges, D.O. Associate Professor Program Director, Dermatopathology Fellowship ASDP Alternate Advisor to the AMA-RUC Department of Dermatology, Division of Dermatopathology and Cutaneous Immunopathology Mayo Clinic, Rochester

Disclosures

▪Relevant Financial Relationships ▪None ▪Off Label Usage ▪No

Background

▪ One of the most challenging tasks in medicine is the accurate and timely diagnosis of infectious diseases ▪ Classically, infectious disease diagnosis is under the domain of the microbiology laboratory ▪ Culture ▪ May not be performed due to lack of clinical suspicion ▪ Time consuming ▪ Not possible for some organisms ▪ May fail to grow organism due to prior antibiotic treatment, sampling error

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Background, continued

▪ Infectious diseases has always played a significant role in our specialty ▪ Many infectious diseases have primary skin manifestations ▪ Dermatopathologists offer invaluable information: ▪ Knowledge of inflammatory patterns and other similar appearing non-infectious conditions ▪ Visualize microorganisms and associated cellular background ▪ Colonization versus Invasion

Course Objectives

At the end of this course, participants should be able to: ▪ Identify common and important infectious organisms in dermatopathology specimens based on histopathologic features ▪ Develop an appropriate differential diagnosis based on morphologic features, clinical presentation, exposure history, and corresponding microbiology results ▪ Use an algorithm to differentiate infectious processes from inflammatory processes and morphologic mimickers ▪ Select and interpret appropriate special stains and ancillary tests to facilitate or support the morphologic diagnosis

Histologic patterns of importance in the diagnosis of cutaneous infections

▪ Pattern recognition ▪ Morphology of the organisms ▪ Correlate with culture ▪ Serology ▪ Molecular testing

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Histologic patterns of importance in the diagnosis of cutaneous infections

▪Invisible dermatoses

Invisible Dermatoses

▪Dermatophyte (tinea) infection ▪Tinea versicolor ▪Tinea nigra ▪Pitted keratolysis ▪Erythrasma ▪Erythema migrans

Dermatophyte (tinea) infection Caused by Trichophyton, Epidermophyton, and Microsporum genera

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Clue for dermatophyte infection: “Sandwich” sign

Tinea versicolor Caused by the Malassezia globose > Malassezia furfur

Tinea nigra Superficial mycosis caused by the dematiaceous fungus Hortaea werneckii

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Pitted keratolysis Caused by several bacterial species, including Corynebacteria, Dermatophilus congolensis, Kytococcus sedentarius, Actinomyces and Streptomyces

Erythrasma Superficial infection caused by Gram positive bacillus, Corynebacterium minustissimum

Erythema migrans Caused by tick-borne spirochete B. Burgdorferi

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Histologic patterns of importance in the diagnosis of cutaneous infections

▪Invisible dermatoses ▪Infectious bulla and vesiculopustule

Infectious Bulla Intraepidermal ▪ Acantholytic ▪ Subcorneal – SSSS ▪ Subcorneal pustule – Impetigo ▪ Spongiform pustule – Candidiasis ▪ Spongiotic ▪ Dermatophyte ▪ Eosinophilic spongiosis ▪ Insect bite reaction ▪ Ballooning degeneration ▪ HSV, VZV ▪ Hand-foot-mouth disease

Subcorneal bulla - Staphylococcal scalded skin syndrome (SSSS)

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Subcorneal pustule- Bullous Impetigo

Spongiform pustule - Candidiasis

Candidiasis

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Spongiotic intraepidermal bulla - Dermatophyte (tinea)

Eosinophilic spongiosis -Insect bite reaction

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Ballooning and reticular degeneration - Herpes Virus Infection

Kaposi’s Varicelliform Eruption (Eczema Herpeticum) HSV and Darier’s disease

P. vulgaris and HSV

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Oral biopsy with Oral biopsyBOTH with CMV BOTH & HSV CMV & HSV

CMV HSV

The Many Faces of The Many Faces of Human Herpesviridae

EBV ISH

Summary: Clinically important herpesviruses

Name HHV-1 Herpes simplex virus 1 HHV-2 Herpes simplex virus 2 HHV-3 Varicella zoster virus HHV-4 Epstein-Barr virus HHV-5 Cytomegalovirus HHV-6A&B Roseoloviruses HHV-7 HHV-8 Kaposi-sarcoma-associated herpesvirus

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HHV-6 and HHV-7 associated diseases

▪ Pityriasis rosea • Graft-versus-host disease • Gianotti-Crosti syndrome ▪ DRESS • Exanthem subitem- roseola ▪ Lichen planus • Increased susceptibility to BCC

Acantholytic SCC vs. Herpetic infection

Bullous Grover Disease vs. Herpetic infection

▪ Avoid pitfall by: ▪ Absence of true cytopathic effect ▪ Recognition of dyskeratosis ▪ Focality of process

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Ballooning degeneration - Hand-Foot-Mouth Disease, Coxsackie A16

Molluscum Contagiosum, Pox virus

HPV - Verruca

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HPV-Epidermodysplasia verruciformis

Histologic patterns of importance in the diagnosis of cutaneous infections

▪Invisible dermatoses ▪Infectious bulla and vesiculopustule ▪Infectious suppurative folliculitis

Suppurative Folliculitis Pseudomonas folliculitis (necrosis, abscess, neutrophils)

▪ Infectious ▪ Bacterial ▪ Viral – Herpes ▪ Fungal ▪ Dermatophyte ▪ Pityrosporum

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Bacterial folliculitis

Erysipelas – Group A Streptococci

Deep abscess

Cellulitis Actinomycosis

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HSV Folliculitis

Polyoma Virus-associated Trichodysplasia Spinulosa

Majocchi’s granuloma

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Pityrosporum folliculitis

Histologic patterns of importance in the diagnosis of cutaneous infections

▪Invisible dermatoses ▪Infectious bulla and vesiculopustules ▪Infectious suppurative folliculitis ▪Lichenoid +/- granulomatous inflammation

Lichenoid interface dermatitis Syphilis

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Lichenoid and granulomatous dermatitis

Diagnosis: Histoplasma capsulatum

▪Distinguishing Features: ▪ Differential diagnosis of ▪ 2-4 µm yeast parasitized histiocytes ▪ Single narrow-based ▪ Leishmaniasis budding ▪ Rhinoscleroma ▪ Often inside histiocytes ▪ Granuloma inguinale ▪ Virtually invisible on ▪ Penicillium marneffei H&E ▪ Lepromatous leprosy

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Leishmaniasis – History helpful; parasitized histiocytes with 2-4 m nonencapsulated round/oval bodies containing a nucleus & paranucleus (kinetoplast); stain with Giemsa

Rhinoscleroma - 2-3 m Gram-negative bacilli (Frisch bacilli; Klebsiella rhinoscleromatis) in Mikulicz cells (larger than the other parasitized histiocytes); plasma cells & Russell bodies prominent

Granuloma inguinale - Parasitized histiocytes with 1-2 m encapsulated Gram-negative bacilli (Donovan bodies; Klebsiella granulomatis); stain with Giemsa

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Penicillium marneffei - Parasitized histiocytes with 1-8 m pleomorphic round to sausage shaped yeast; unlike histoplasmosis, divides by binary fission not by budding

Lepromatous Leprosy

Histologic patterns of importance in the diagnosis of cutaneous infections

▪Invisible dermatoses ▪Infectious bulla and vesiculopustules ▪Infectious suppurative folliculitis ▪Lichenoid +/- granulomatous inflammation ▪Pseudoepitheliomatous hyperplasia with intraepithelial microabscesses

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Pseudoepitheliomatous hyperplasia with intraepithelial microabscesses

▪ Deep fungal infections ▪Halogenoderma ▪ Blastomycosis-like ▪Pemphigus vegetans pyoderma ▪Pyostomatitis ▪ Atypical mycobacterial vegetans infections ▪ Protothecosis ▪ Leishmaniasis

Blastomycosis dermatitidis • Cryptococcus neoformans ▪ Broad-based budding ▪ Narrow-based budding ▪ Uniform large (8-15 ▪ Variable size (4 - 20 µm) micron) diameter ▪ Polysaccharide capsule (large halo on H&E) ▪ Always a yeast, not dimorphic

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Histologic patterns of importance in the diagnosis of cutaneous infections

Suppurative granuloma

▪ Deep fungal infections ▪ Atypical mycobacterial infections ▪ Sporotrichosis ▪ Tularemia ▪ Cat-scratch disease

Suppurative granulomas: Chromomycosis

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Suppurative granulomas: Chromomycosis

▪ Small, 6-12 m, round, ▪ Chronic verrucous disease thick-walled, brown spores caused by several (Medlar bodies, copper dematiaceous fungi pennies, sclerotic bodies) ▪ Fonsecaea pedrosoi – within giant cells or free in most common ▪ dermis Fonsecaea compacta ▪ Phialophora verrucosa ▪ Cladosporium carrionii

Suppurative granulomas: Atypical Mycobacterial Infections

QUIZ

▪59 yo woman admitted with 1 yr. history of expanding leg ulcers ▪On prednisone, cyclosporine and azathioprine for presumed diagnosis of pyoderma gangrenosum ▪No biopsy

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What is your diagnosis?

A. Pyoderma gangrenosum B. Lymphoma C. Infection D. Occlusive vasculopathy E. Calciphylaxis

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Sporotrichosis Yeast form: round (6 - 8 um) or cigar-shaped (diagnostic of sporotrichosis)

Sporotrichosis

Admission 4 months 1 year

Paracoccidiomycosis

Yeast: 4 to 60 μm Clear space around fungus Usually found inside multinucleated giant cells

Pilot wheel: Pathognomonic -Multiple buds surrounding the parent cell

Not all yeasts show buds around the entire circumference -May be confused with sporothrix or crypto

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Histologic patterns of importance in the diagnosis of cutaneous infections

▪ Invisible dermatoses ▪ Infectious bulla – intraepidermal ▪ Suppurative folliculitis ▪ Lichenoid +/- granulomatous inflammation ▪ Pseudoepitheliomatous hyperplasia with intraepithelial microabscesses ▪ Suppurative granuloma ▪ Tuberculoid granuloma

Tuberculoid granuloma: Tuberculosis; Lupus vulgaris

Histologic patterns of importance in the diagnosis of cutaneous infections

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Sarcoidal granuloma: Tertiary Syphilis

Sarcoidal granuloma: Tuberculoid Leprosy

Coccidioidomycosis

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Rhinosporidiosis Coccidioidiomycosis

Large sporangia 100-400 um Hundreds to thousands of endospores Sporangia - 10 to 80 um up to 7 um in diameter

Histologic patterns of importance in the diagnosis of cutaneous infections

Infectious Vasculitis

Immunologic or Infectious or Septic Occlusive Allergic

Type II Reactional Leprosy- ENL – Type III VZV > HSV Bacteria Fungal Rickettsial Intraluminal IC or serum-sickness- like reaction (LCV)

Fibrin

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Erythema nodosum leprosum (ENL)

Herpes Vasculitis (VZV>HSV)

Infectious Vasculitis Meningococcemia

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Infectious Vasculitis Histologic Features

▪Involvement of deeper vessels ▪Prominent thrombosis ▪Usually cell-poor infiltrate ▪Organisms may be visualized in & around blood vessel walls in acute but not chronic septic vasculitis

Infectious Vasculitis Histologic Features

Septic vasculitis: Ecthyma gangrenosum GNR surrounding a necrotic blood vessel

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Infectious Vasculitis Aspergillus

• Nonpigmented, narrow, regularly septate hyphae • Can’t be differentiated by morphology alone

QUIZ

▪ 45 year old male ▪ Hodgkin lymphoma ▪ Treated with multiple chemotherapeutic regimens ▪ Poor response to treatment ▪ Pneumonia with abscess and chest wall cellulitis ▪ Over the next few days, he developed a black necrotic bulla in the center of the lesion ▪ Rapidly progressive increasing size of the erythema

Skin punch biopsy

H&E 20x

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H&E 40x

H&E 100x

How would you sign this case out?

A. Mucor B. Aspergillus C. Rhizopus D. Zygomycetes E. Mucormycosis

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Culture

▪Rhizopus spp.

Zygomycetes

▪ Class = Zygomycetes ▪ Order = Mucorales ▪ Comprises multiple genera: ▪ Mucor spp. ▪ Rhizopus spp. ▪ Absidia ▪ Found widely in the environment ▪ Disease: zygomycosis (aka. Mucormycosis) ▪ Life threatening, medical emergency ▪ Need to differentiate broad irregular ribbon like hyphae from narrow, regularly septate hyphae

Zygomycetes

• Vascular invasive; Broad, irregular, ribbon-like, hyaline, rarely septate hyphae • Mucor spp, Rhizopus spp, Absidia spp

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Zygomycetes Aspergillus-like

Aspergillus spp.

GMS 100x

Differential Diagnosis: Other Filamentous Fungi Narrow hyphae: ▪ Aspergillus spp. ▪ **A. flavus has broad hyphae ▪ Fusarium spp. ▪ Dematiaceous (pigmented) fungi ▪ Candida spp. ▪ Spherules of Coccidioides immitis

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How would you sign out this case?

Suggested Diagnostic Comments: Zygomycetes ▪ “Broad irregular hyphae consistent with a Zygomycetes. Correlation with culture is recommended.” OR Aspergillus-Like ▪ “Non-pigmented septate hyphae with parallel walls. Differential diagnosis includes Aspergillus spp. and other filamentous fungi. Correlation with culture is recommended.”

Main points

▪ Zygomycetes may not stain well with GMS or PAS ▪ Narrow septated hyphae cannot be differentiated by morphology alone ▪ Culture is required for identification ▪ Mucor is not the most common isolate among zygomycetes ▪ Aspergillus spp are most common in clinical isolates but not the only ones ▪ Aspergillus-like organisms can have similar appearing hyphae ▪ Fusarium ▪ Dematiaceous fungi, Pseudallescheria boydii ▪ Candida spp ▪ Hyphae (spherules) of Coccidioides immitus

Histologic patterns of importance in the diagnosis of cutaneous infections

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Infectious Panniculitis

▪Mostly seen in immunocompromised patients ▪Bacteria & fungi involved (Staph aureus, Strep pyogenes, Pseudomonas spp, Klebsiella spp, Norcardia spp, typical and atypical Mycobacterium, Candida spp, Fusarium spp, Histoplasma, Cryptococcus, Actinomyces israeli, Sporothrix schenckii, Aspergillus fumigatus, Alternaria & Chromomycosis) ▪Acute & granulomatous lobular inflammation

Cutaneous and Subcutaneous Alternariosis

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Infections Associated with Cutaneous Tumors Kaposi sarcoma – HHV-8

HHV-8

EBV-related lymphoproliferative disorders

CD20

EBV ISH

EBV-associated CD20+ diffuse large B-cell lymphoma

CD20

EBV ISH

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SCCIS – HPV 16,18

▪ 26-year old man ▪ Four years prior: ▪ Infectious mononucleosis (splenomegaly, transaminitis) ▪ Two years prior: ▪ Presumed mosquito bite on forearm with intense reaction ▪ Recurrent skin ulcerations with eschar formation, with Staph superinfection

EBV-associated hydroa vacciniforme-like cytotoxic lymphoma TIA-1 CD3

EBV-ISH

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Angioimmunoblastic T-cell lymphoma

CD3

CD279

EBV ISH

CD3-positive infiltrate; CD279 positive; CD4>>CD8; CD30 negative

Merkel Cell Carcinoma – Merkel cell polyoma virus

Merkel Cell & SCC

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Lymph Node with Merkel cell & Mantle cell Merkel cell KR20

Mantle cell CyclinD1

Pearls & Pitfalls

▪ Unspecified invisible or inflammatory dermatitis ▪ Pseudoepitheliomatous hyperplasia maybe reactive and could be from an underlying infection ▪ Look for clues, remember patterns that can be associated with a cutaneous infection ▪ THINK about the possibility of an underlying infection, then order special stains

▪ History helpful, risk factors, travel history, exposure history or history of immunosuppression ▪ Special stains may be negative in some cases on routine histology or if you can’t differentiate an organism on morphology, then correlation with tissue culture is necessary ▪ Unusual clinical question (POX, etc) ->CDC as resource ▪ Bottom line – high index of suspicion and stains!!!

THANKThank you! YOU!

[email protected]

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Comments/questions?