Downloaded 137 times
Uploaded byMargie Morgan
Fungal Pathology in Tissue
This document provides a summary of important fungal infections seen in tissue samples under the microscope. It describes key characteristics of common molds and yeasts that cause infection, including Aspergillus, Mucor, Fusarium, Blastomyces, Coccidioides, Histoplasma, Cryptococcus, and Candida. For each fungus, the document outlines features visible in tissue, such as hyphal morphology, budding patterns, and staining properties. It also provides images comparing fungal structures and growth patterns on culture. The goal is to enable pathologists to accurately identify fungal pathogens in clinical specimens.
More Related Content
Similar to Fungal Pathology in Tissue
Fungal Pathology in Tissue
- 1. Fungus in Tissue BriefReview Margie Morgan, PhD D(ABMM) 1
- 2. Important Infections withMolds and Yeast • Hyaline septate molds Yeast • Aspergillus species Candida • Pseudallescheria (Scedosporium) complex Cryptococcus • Fusarium species • Hyaline aseptate molds (mucormycetes) • Dimorphic fungi • Histoplasma capsulatum • Coccidioides immitis and C. posadasii • Blastomyces dermatitidis • Sporothrix schenckii complex • Penicillium (Talaromyces) marneffei • Dematiacious molds • Mycetoma • Chromoblastomycosis • Phaeohyphomycosis 2
- 3.
- 4. Aspergillus Species intissue Dichotomous = branching into two pieces Higher magnification 4
- 5. Aspergillus compared toMucormycete fungi (Mucor) Broad hyphae rare/no septations Broader hyphae than Aspergillus Branching more irregular/some at 90* angle Thinner hyphae than Mucormycete Regular septations, 45* angle branching referred to as dichotomous branching 5
- 6. Aspergillus and Pseudallescheria(Scedosporium) Aspergillus hyphaeis usually broader than Scedosporium species Both show dichotomous branching, invade vessels, and have similar infections. 6
- 7. Aspergillus fumigatus Fungus ball Culture 30*C /4 days Scotch Tape Prep A. fumigatus is the most common Aspergillus species to cause pulmonary or disseminated infection 7
- 8. Aspergillus fumigatus Aspergilloma formationin the lung fungus ball Invasion of blood vessels 8
- 9. Aspergillus niger Unusual tocause pulmonary infection, most often associated with ear infections 9
- 10. Aspergillus terreus Note: Intrinsic resistance to amphotericin Candisseminate and cause disease much like Aspergillus fumigatus 10
- 11. Aspergillus flavus Can cause infection muchlike Aspergillus fumigatus 11
- 12. Fusarium species Random branching ofhyphae / no characteristic pattern Hyaline septate with banana shaped conidia 12
- 13. Mucormycetes – Mucor andRhizopus Broad ribbon like hyphae without septations – can appear faintly staining Rhizopus Mucor 13
- 14.
- 15. Blastomyces dermatitidis No color(negative) on Mucicarmine stain stain S lung lung Skin is a primary site of dissemination GMS PAS Dermis 15
- 16. Blastomyces dermatitidis Culture Scotchtape prep Growth 30* C In @ 2-3 weeks 16
- 17. Coccidioides immitis and C.posadasii Spherule formation in human tissue/ NO yeast forms Spherules 17
- 18. Coccidioides species Mold growthin 3-5 days at 30*C Alternating barreled arthroconidia Scotch tape preparation 18
- 19. Histoplasma capsulatum Bonemarrow lung Yeast are usually intracellular within macrophages, 2-4 um in size 19
- 20. Histoplasma capsulatum In fixed tissue,P. brasiliensis forms multiple buds on the primary yeast cell, appears similar to macroconidia of Histoplasma H. capsulatum adhesive tape prep Tuberuculate macroconidia microconidia **Do not confuse Histoplasma mold phase with the yeast of Paracoccidioides brasiliensis complex in fixed tissue Growth in culture 30* C for 2 weeks Yeast of P. brasiliensis in fixed tissue 20
- 21. Sporothrix schenckii Dermis inflammation Yeast cells variablein shaper some Cigar shaped Asteroid body commonly the only structure observed Progression up lymphatics Adhesive tape preparation /spores form daisy head arrangement Culture at 30* C 21
- 22. Penicillium (Talaromyces) marneffei Skin –yeast like cells Bone marrow 30*C culture/ note red diffusible pigment surrounding green colony Adhesive prep of mold Skin lesions 22
- 23.
- 24. Subcutaneous fungal infections •Infection with dematiaceous (black) molds • Chromoblastomycosis • Phaeohyphomycoses • Infection with dematiaceous (black) molds or higher bacteria (Nocardia) • Mycetoma 24
- 25. Chromoblastomycosis Cauliflower (raised) skin lesions Naturallybrown colored copper penny or sclerotic body identified in tissue 25
- 26. Phaeohyphomycosis GMS H & Estain Naturally brown colored hyphae in tissue Nodular skin lesions 26
- 27. Mycetoma Sulfur granule Actinomycotic Mycetoma EumycoticMycetoma Nocardia species Black (dematiacious) molds Sulfur granule formed in tissue Sulfur granule formed in tissue with thin filamentous bacteria with thick dark hyphae Swollen extremity 27
- 28. Candida species GI tissue C.Albicans pseudophyphae extensions growing out from colony 28
- 29. Cryptococcus species Yeast areround and variable in size (2-20um) with capsule. Capsule stains dark pink on mucicarmine stain 29