PATHOLOGYPATHOLOGY CLINIC CLINIC

Allergic fungal sinusitis

Lester D.R. Th ompson, MD

Figure 1. Th e alternating tide-line appearance is quite characteristic Figure 2. Th e mucinous material serves as a background for the of allergic fungal sinusitis. Th e degenerated mucinous material degenerating infl ammatory cells. Note the numerous eosinophilic stains lighter than the cellular components. Charcot-Leyden crystals, a breakdown product from eosinophils

Allergic fungal sinusitis, also known as allergic mu- Approximately 10% of patients with chronic rhi- cin and eosinophilic fungal rhinosinusitis, is an allergic nosinusitis or nasal polyposis have concurrent aller- response in the sinonasal tract mucosa to aerosolized gic fungal sinusitis. Th is rate is higher in patients with fungal allergens, amplifi ed and perpetuated by eosino- asthma, allergies (atopic), and allergic bronchopulmo- phils. Th e class II genes in the major histocompat- nary aspergillosis. It is interesting that the incidence of ibility complex are involved in antigen presentation allergic fungal sinusitis is higher in warmer climates. and immune response (modulation), and an allergic Either sex will present between the third and seventh reaction develops to inhaled fungal elements in im- decades of life with chronic, unrelenting rhinosinusitis munocompetent people. Aspergillus species are the or a mass lesion. Within the sinonasal tract, the maxil- most common agents (widespread in soil, wood, and lary and ethmoid sinuses are most commonly aff ected. decomposing plant material), but Alternaria, Bipolaris, Atopy is frequently present, along with discharge, rhi- Curvularia, Exserohilum, and Phialophora species have norrhea, and headaches, while facial dysmorphia and also been reported. proptosis are also reported. Patients frequently dem- Th e atopic host is exposed to fi nely dispersed fungi onstrate peripheral eosinophilia and an elevated fun- and develops an infl ammatory response mediated by gus-specifi c IgE level. Cultures will frequently identify IgE. Th is results in tissue edema with sinus obstruc- the etiologic fungal agent, but the results are used only tion and stasis. Th e fungus proliferates and increases to conduct desensitization treatments. antigenic exposure, creating a self-perpetuating cycle Th e consistency of the polypoid fragments is like producing allergic mucin and possibly polyps. that of putty, grease, mud, or crunchy peanut butter,

From the Department of Pathology, Woodland Hills Medical Center, Southern California Permanente Medical Group, Woodland Hills, Calif.

106 ■ www.entjournal.com ENT-Ear, Nose & Throat Journal ■ March 2011 PATHOLOGY CLINIC and they usually have a foul odor. “Mucinous” material completely diff erent management approach; cultures is free-fl oating, unattached to the surrounding respira- are of value in determining antimicrobial sensitivities. tory tissues. Th e most characteristic fi ndings are the In general, management of allergic fungal sinusitis “tide lines,” “tree rings,” waves, or ripples created by an requires a combination of surgery and medical therapy alternating pattern of mucin material and infl amma- to achieve the best long-term clinical outcome. Exten- tory debris, which appears as blue and pink (fi gure 1). sive debridement and complete evacuation of impacted Th e degenerated material is composed of neutro- mucin is the mainstay of therapy. Postoperative anti- phils, eosinophils, and mucinous debris. Ghost out- infl ammatory therapy and oral corticosteroids usu- lines of cells are common, along with nuclear debris. ally yield the best results. Although a good outcome Charcot-Leyden crystals (degenerated eosinophils) are generally can be achieved with integrated medical and present as long, needle-shaped, or bipyramidal eosino- surgical approaches, recurrences develop with fair fre- philic crystals (fi gure 2). In general, fungal elements quency and must be diligently treated. are uncommon, and even when they are present, they are oft en diffi cult to detect. Th erefore, the diagnosis is Suggested reading usually rendered without ancillary techniques to con- Ferguson BJ. Defi nitions of fungal rhinosinusitis. Otolaryngol Clin North Am 2000;33(2):227-35. fi rm the presence of fungal elements. If necessary, the Heff ner DK. Allergic fungal sinusitis is a histopathologic diagnosis; hyphae can be seen with Gomori methenamine silver paranasal mucocele is not. Ann Diagn Pathol 2004;8(5):316-23. or a PAS light-green staining. It is important for the Ryan MW, Marple BF. Allergic fungal rhinosinusitis: Diagnosis and management. Curr Opin Otolaryngol Head Neck Surg 2007;15(1): histologic examination to exclude invasive fungal si- 18-22. nusitis, in which fungal hyphae are identifi ed within Schubert MS. Allergic fungal sinusitis. Clin Allergy Immunol 2007;20: vessel walls or vascular spaces and which requires a 263-71.

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