Allergic mucin with and without fungus: a comparative clinicopathologic analysis

The Impact of Climatic, Socioeconomic, and Geographic Factors on the Prevalence of Allergic Fungal Rhinosinusitis: A Worldwide Ecological Study

BACKGROUND

The prevalence of allergic fungal rhinosinusitis (AFRS) and its associated risk factors have been an issue of debate. Some epidemiological factors have been correlated to the disease prevalence.

OBJECTIVES

To observe the prevalence pattern of AFRS worldwide and to investigate the effect of specific epidemiological factors on the disease prevalence.

METHODS

A systematic review was derived from 1983 to December 2018. Data on the prevalence of AFRS were collected from the selected studies. Relevant factors assessing each city's climate, socioeconomics and geography were used to study the association with AFRS prevalence.

RESULTS

35 cities across 5 continents were investigated. The worldwide average rate of AFRS in CRS cases is 7.8% (0.2%-26.7%) in which more than half of the investigated cities (57%) had low AFRS prevalence, while the remaining cities had intermediate (11%) and high (32%) prevalence. Cities with higher temperatures were associated with a higher prevalence of AFRS (p-value 0.002), whereas cities with humid continental climate were significantly associated with a low prevalence of AFRS (p-value 0.032). Humidity and wind speed were lower in the cities with higher AFRS prevalence (p-value 0.018 and 0.008, respectively). There were no significant correlations between AFRS prevalence and economic levels, presence of water bodies, rainfall amounts, altitude, and presence of forests.

CONCLUSION

AFRS has a worldwide distribution pattern with varying prevalence. In this ecological study, we observed a correlation between AFRS prevalence and climatic factors (climate classification, humidity, temperature, and wind speed). Socioeconomic factors should be analyzed on an individual basis for better assessment of the relationship with disease prevalence.

Characteristics of Chronic Rhinosinusitis with Nasal Polyps Based on Allergic Mucin and Fungal Elements in Patients Undergoing Revision Endoscopic Sinus Surgery

This study sought to document the features in chronic rhinosinusitis with nasal polyp (CRSwNP) patients undergoing revision endoscopic sinus surgery (RESS), based on presence or absence of allergic mucin (AM) and fungal elements (F). A retrospective chart review of RESS cases collected Lund Mackay score (LMS), endoscopic, microbiological, histopathological, surgical and follow-up data of these patients. Patients were categorised into AM + F +, AM + F-, AM-F + and AM-F- subgroups based on the presence or absence of AM and F. The total serum IgE was significantly higher (p > 0.001) in the AM + F + subgroup. Other factors analysed including LMS, duration from previous surgery, comorbidities, degree of inflammation and disease recurrence showed no specific predilection among subgroups. Patients with a retained middle turbinate showed lesser (p = 0.04) recurrence on follow-up. Subgroups of recurrent CRSwNP showed similar characteristics and had further disease recurrence which was independent of allergic mucin and fungal elements. The presence of an intact healthy middle turbinate could reduce early disease recurrence following RESS.

Algorithmic Approach to Fibroinflammatory Sinonasal Tract Lesions

Fibroinflammatory lesions of the sinonasal tract are one of the most common head and neck lesions submitted to surgical pathology. When the fibroinflammatory pattern represents the lesion (i.e., not surface reactive ulceration), an algorithmic approach can be useful. Separated into reactive, infectious, and neoplastic, and then further divided based on common to rare, this logical progression through a series of differential considerations allows for many of these lesions to be correctly diagnosed. The reactive lesions include chronic rhinosinusitis and polyps, granulomatosis with polyangiitis, and eosinophilic angiocentric fibrosis. Infectious etiologies include acute invasive fungal rhinosinusitis, rhinoscleroma, and mycobacterial infections. The neoplastic category includes lobular capillary hemangioma, inflammatory myofibroblastic tumor, and NK/T-cell lymphoma, nasal type. Utilizing patterns of growth, dominant cell types, and additional histologic features, selected ancillary studies help to confirm the diagnosis, guiding further clinical management.

Th2 Immunological Inflammation in Allergic Fungal Sinusitis, Nonallergic Eosinophilic Fungal Sinusitis, and Chronic Rhinosinusitis

Background

Noninvasive fungal sinusitis is a heterogenous group of conditions including allergic fungal sinusitis (AFS) and nonallergic eosinophilic fungal sinusitis (NEFS). Th2-mediated cascades have been postulated to be the major inflammatory response in patients with AFS although other mechanisms also may be involved. The detailed mucosal Th2 cytological status of NEFS still has not been studied in great depth.

Methods

Using a meticulous patient selection algorithm over a 2-year period, infundibular mucosal tissue from patients with AFS, NEFS, chronic rhinosinusitis (CRS), and normal controls was studied (n = 59). Immunohistochemistry for mast cells, eosinophils, and immunoglobulin E (IgE) cells was performed and cell counts per unit area were measured.

Results

Mast cell, eosinophil, and IgE+ cell numbers were significantly raised in patients with AFS, NEFS, and CRS when compared with controls. There was no significant difference between cell numbers in patients with AFS and NEFS.

Conclusion

Patients with AFS exhibit a classic Th2 inflammatory response in nasal mucosal tissue with NEFS and CRS patients showing evidence of a similar Th2 cascade, including the presence of IgE+ cells.

Revisiting the Utility of Histopathological Examination of Biopsy: A Necessity in Microbiology

INTRODUCTION

Culture is the gold standard, while potassium hydroxide mount is simplest technique used for diagnosis of fungal pathogens. Histopathological examination is the only definitive means to identify certain uncultivable fungi.

AIM

To analyse role of histopathological examination and potassium hydroxide (KOH) mount for diagnosing fungal infections by correlating them with culture.

MATERIALS AND METHODS

In this nine year retrospective study, all biopsy specimens submitted for microbiological examination were included. Histopathological examination of biopsies of cases with positive microbiological findings on either KOH mount or culture was carried out. Any discrepancy between histopathology interpretation and microbiology KOH or culture results, taking culture as the gold standard, were noted.

STATISTICAL ANALYSIS

Open Epi software was used for statistical analysis. Comparisons between groups were made by using the chi-square test. A p-value < 0.05 was considered statistically significant. Cohen's Kappa coefficient (κ) was calculated as a measure of agreement between different variables.

RESULTS

Concurrent pathology specimen could be obtained in 70 samples positive for fungal elements in either KOH or culture. Thirty-two cases were positive for fungi in culture, of which 16 were correctly identified by histopathological examination. Histopathological examination was strongly associated with culture result. KOH mount was in good agreement with positive culture result for yeast. Eleven culture negative but KOH and histopathology positive cases included seven samples with hyphae suggestive of zygomycosis, and two cases of rhinosporidiosis. Allergic mucin was strongly associated with Aspergillus species. KOH mount and detection of allergic mucin on histopathological examination were found to be excellent complementary tools for diagnosing Aspergillus species. Necrosis was highly specific for fungal growth in culture and had good positive predictive value.

CONCLUSION

We advocate using histopathology, culture and KOH examination in an integral manner to avoid potential lapses in patient management.

Categorization and clinicopathological features of chronic rhinosinusitis with eosinophilic mucin in a korean population

Objectives

Chronic rhinosinusitis (CRS) with eosinophilic mucin is relatively rare in Korea. We categorized CRS patients with characteristic eosinophilic mucin into several groups and compared the groups based on their clinicopathological features.

Methods

In total, 52 CRS patients with eosinophilic mucin were enrolled. Based on the presence or absence of an allergy (A) to a fungus or fungal element (F) in the mucin, the patients were divided into four groups: allergic fungal rhinosinusitis (AFRS, A+F+), AFRS-like sinusitis (A+F-), eosinophilic fungal rhinosinusitis (EFRS, A-F+), and eosinophilic mucin rhinosinusitis (EMRS, A-F-). Clinical and immunological variables were compared between the groups.

Results

There were 13 patients in the AFRS group, 13 in the EFRS group, and 26 in the EMRS group. No patient was assigned to the AFRS-like sinusitis group. The AFRS group showed a significantly higher association with allergic rhinitis than did the EFRS and EMRS groups. The mean total serum IgE level in the AFRS patients was significantly higher than in the EFRS and EMRS patients. While 7.7% of the patients with AFRS and EFRS were asthmatic, 65.4% of the patients with EMRS had bronchial asthma. In the AFRS and EFRS groups, 31% had bilateral disease, in contrast to 100% of EMRS patients with bilateral disease. The prevalence of high attenuation areas by computed tomography was significantly higher in the AFRS group than in the EMRS group, and the mean Hounsfield unit values of the areas of high attenuation in the AFRS patients were significantly greater than those in the EMRS patients.

Conclusion

AFRS is believed to be an allergic response to colonizing fungi in atopic individuals. In EFRS, local allergies to fungi may play a role in the pathogenesis of the disease. EMRS is thought to be unconnected with fungal allergies.

Efficacy of a marine bacterial nuclease against biofilm forming microorganisms isolated from chronic rhinosinusitis

Background

The persistent colonization of paranasal sinus mucosa by microbial biofilms is a major factor in the pathogenesis of chronic rhinosinusitis (CRS). Control of microorganisms within biofilms is hampered by the presence of viscous extracellular polymers of host or microbial origin, including nucleic acids. The aim of this study was to investigate the role of extracellular DNA in biofilm formation by bacteria associated with CRS.

Methods/Principal Findings

Obstructive mucin was collected from patients during functional endoscopic sinus surgery. Examination of the mucous by transmission electron microscopy revealed an acellular matrix punctuated occasionally with host cells in varying states of degradation. Bacteria were observed in biofilms on mucosal biopsies, and between two and six different species were isolated from each of 20 different patient samples. In total, 16 different bacterial genera were isolated, of which the most commonly identified organisms were coagulase-negative staphylococci, Staphylococcus aureus and α-haemolytic streptococci. Twenty-four fresh clinical isolates were selected for investigation of biofilm formation in vitro using a microplate model system. Biofilms formed by 14 strains, including all 9 extracellular nuclease-producing bacteria, were significantly disrupted by treatment with a novel bacterial deoxyribonuclease, NucB, isolated from a marine strain of Bacillus licheniformis. Extracellular biofilm matrix was observed in untreated samples but not in those treated with NucB and extracellular DNA was purified from in vitro biofilms.

Conclusion/Significance

Our data demonstrate that bacteria associated with CRS form robust biofilms which can be reduced by treatment with matrix-degrading enzymes such as NucB. The dispersal of bacterial biofilms with NucB may offer an additional therapeutic target for CRS sufferers.

Rhinosinusitis in children

Rhinosinusitis is the inflammation of the mucous membranes of nose and paranasal sinus(es). 5-13% of upper respiratory tract infections in children complicate into acute rhinosinusitis. Though not life threatening, it profoundly affects child's school performance and sleep pattern. If untreated, it could progress to chronic rhinosinusitis (CRS). The pathogens involved in perpetuation of CRS consist of multidrug-resistant mixed microflora. CRS is challenging to manage and could further extend to cause eye or intracranial complications. In children, CRS diagnosis is often either missed or incomprehensive. Due to this, morbidity and strain on healthcare budget are tremendous. Flexible fiberoptic endoscopy has revolutionized management of CRS. Its utility in children is being increasingly recognized. Optimal management entails specific appropriate antimicrobials as well as treatment of underlying causes. The aim is to normalize sinus anatomy and physiology and regain normal mucociliary function and clearance.

Fungus: a role in pathophysiology of chronic rhinosinusitis, disease modifier, a treatment target, or no role at all?

Fungal spores, due to their ubiquitous nature, are continuously inhaled and deposited on the airway mucosa. This article focuses on the potential role of fungi in chronic rhinosinusitis (CRS). Five forms of fungal disease affecting the nose and paranasal sinuses have been recognized: (1) acute invasive fungal rhinosinusitis (including rhinocerebral mucormycosis), (2) chronic invasive fungal rhinosinusitis, (3) granulomatous invasive fungal rhinosinusitis, (4) fungal ball (mycetoma), and (5) noninvasive (allergic) fungal rhinosinusitis. There are several potential deficits in the innate and potentially also acquired immunity of CRS patients that might reduce or change their ability to react to fungi. There are not many arguments to suggest a causative role for fungi in CRS with or without nasal polyps. However, due to the intrinsic or induced change in immunity of CRS patients, fungi might have a disease-modifying role.

Allergic fungal sinusitis: pathophysiology, diagnosis and management

Allergic fungal sinusitis (AFS) is a noninvasive form of fungal rhinosinusitis with an incidence of between 6 and 9% of all rhinosinusitis requiring surgery. Regional variation in incidence has been reported, with the southern and southwestern US particularly endemic. Patients with AFS commonly present with chronic rhinosinusitis with nasal polyps, inhalant atopy, elevated total serum immunoglobulin E (IgE), and sinus-obstructing inspissates of a characteristic extramucosal 'peanut buttery' visco-elastic eosinophil-rich material called 'allergic mucin' that contains sparse numbers of fungal hyphae. Sinus CT is always abnormal, showing findings of chronic rhinosinusitis that often include central areas of increased contrast ('hyperattenuation') within abnormal paranasal sinuses that represent the presence of fungal-containing allergic mucin. AFS has been found to be analogous in several ways to allergic bronchopulmonary aspergillosis (ABPA). Both are chronic inflammatory respiratory tract disorders that are driven by hypersensitivity responses to the presence of small numbers of extramucosal fungi found growing within airway-impacting allergic mucin. AFS allergic mucin typically cultures positive for either dematiaceous fungi such as Bipolaris spicifera or Curvularia lunata, or Aspergillus species such as A. fumigatus, A. flavus or A. niger. As with ABPA, patients have type I immediate hypersensitivity to the etiologic mold in AFS. Further, both AFS and ABPA have been found to have association with specific class II major histocompatibility alleles. Proper diagnosis of AFS and differentiation from the other forms of both noninvasive and invasive fungal rhinosinusitis requires strict adherence to published diagnostic criteria. Medical treatment of AFS has been modeled to an extent after treatment approaches for ABPA that includes the use of postoperative oral corticosteroids and aggressive antiallergic inflammation therapy. The use of follow-up measurements of total serum IgE during treatment of both AFS and ABPA patients can help to monitor disease activity. Future AFS research will lead to further insights into pathogenesis, improved treatments, and ultimately decreases in surgical recurrence rates for this highly recurrent hypertrophic rhinosinusitis disorder.

Allergic fungal sinusitis

Many common chronic inflammatory rhinosinusitis conditions (hypertrophic sinus disease [HSD]) have the histopathological profile of allergic or asthmatic inflammation. Allergic fungal sinusitis (AFS) is both a type of noninvasive fungal rhinosinusitis and a type of HSD. AFS has clinicopathological features that make it similar, but not identical, to allergic bronchopulmonary aspergillosis (ABPA). Allergic mucin is a defined pathological entity occurring in ABPA, AFS, and in the HSD "eosinophilic mucin rhinosinusitis (EMRS)." Diagnosis of AFS requires a careful review of surgical reports, histopathology, and culture results. Treatment includes surgery and aggressive postoperative medical management of allergic inflammatory disease. Prognosis is good with integrated medical-surgical follow-up, but recurrence remains problematic. The association of ABPA, AFS, and HSD with class II genes of the major histocompatibility complex places the initiation of these inflammatory diseases within the context of antigen presentation and the acquired immune response. Pathological immunomanipulation of this response by local microbial superantigens may be a common mechanism for disease pathogenesis. Future research into the molecular biology of these related conditions may offer insight into the pathogenesis of other chronic inflammatory diseases.

Allergic fungal sinusitis

Many common chronic inflammatory rhinosinusitis conditions (hypertrophic sinus disease [HSD]) have the histopathological profile of allergic or asthmatic inflammation. Allergic fungal sinusitis (AFS) is both a type of noninvasive fungal rhinosinusitis and a type of HSD. AFS has clinicopathological features that make it similar, but not identical, to allergic bronchopulmonary aspergillosis (ABPA). Allergic mucin is a defined pathological entity occurring in ABPA, AFS, and in the HSD "eosinophilic mucin rhinosinusitis (EMRS)." Diagnosis of AFS requires a careful review of surgical reports, histopathology, and culture results. Treatment includes surgery and aggressive postoperative medical management of allergic inflammatory disease. Prognosis is good with integrated medical-surgical follow-up, but recurrence remains problematic. The association of ABPA, AFS, and HSD with class II genes of the major histocompatibility complex places the initiation of these inflammatory diseases within the context of antigen presentation and the acquired immune response. Pathological immunomanipulation of this response by local microbial superantigens may be a common mechanism for disease pathogenesis. Future research into the molecular biology of these related conditions may offer insight into the pathogenesis of other chronic inflammatory diseases.

Allergic fungal sinusitis is a histopathologic diagnosis; paranasal mucocele is not

Allergic fungal sinusitis has been known to pathologists for two decades. During this time, multiple articles have stressed that the condition continues to be underdiagnosed. This is true, but it can also be overdiagnosed. This means that series of cases used for clinical studies usually are "contaminated" with cases that are misdiagnosed. Because the condition is often quite problematic to control, determination of the best treatment regimens is important. This will be dependent on clinical studies including only correctly diagnosed cases for study. This article discusses the steps toward making the correct diagnosis.

Fungus culture and PCR in nasal lavage samples of patients with chronic rhinosinusitis

Chronic rhinosinusitis (CRS) affects approximately 15 % of the adult population in industrialized countries. Fungi have been recognized as important pathogens in CRS in the immunocompromised host. Recently, fungi have been detected in more than 90 % of nasal lavages (NLs) in immunocompetent patients with CRS. Employing NLs of immunocompetent patients with CRS in the present study, the detection rates for fungi by culture techniques were compared with the results of different fungus-specific PCR assays. Standard fungal cultures were performed on NLs from 77 patients with CRS. NLs were also tested for the presence of fungal DNA by a panfungal assay with and without specific probes for Candida spp. and Aspergillus spp./Penicillium spp., and an Aspergillus-specific nested PCR assay. Nineteen of the 77 samples (25 %) grew fungi. Fungus-specific DNA was detected in 34 of 77 NLs (44 %). Twelve samples were positive for both culture and panfungal PCR, whereas seven specimens grew fungi in culture, but were negative in panfungal PCR, and an additional seven samples were positive in panfungal PCR, but negative in culture. The combination of culture and all employed PCR assays detected fungi in 39 patients (50 %). This study demonstrated that PCR and conventional culture techniques could be complementary diagnostic techniques to detect fungi in nasal specimens from CRS patients.

HLA-DQB1 *03 in allergic fungal sinusitis and other chronic hypertrophic rhinosinusitis disorders

BACKGROUND

Many common chronic inflammatory disorders have strong HLA gene associations, particularly with MHC class II. Allergic fungal rhinosinusitis (AFS) and hypertrophic sinus disease (HSD) are chronic sinonasal mucosal inflammatory disorders. Allergic bronchopulmonary aspergillosis, a disorder analogous to AFS, was recently reported to have HLA-MHC class II associations.

OBJECTIVE

We sought to determine whether MHC class II is also associated with AFS and HSD.

METHODS

HLA DNA genotyping was obtained on 44 patients with AFS and 30 patients with HSD (of which 21 were atopic).

RESULTS

Sixty-six percent of patients with AFS carried at least one HLA-DQB1 *03 allele; DQB1 *0301 and DQB1 *0302 were the most frequent allelic variants (odds ratio [OR] vs healthy subjects = 8.22; 95% CI, 4.30-15.73; P < .001; OR vs all patients with HSD = 1.93; 95% CI, 1.09-3.41; P < .01; OR vs atopic patients with HSD = 2.57; 95% CI, 1.46-4.53; P < .001). Of the 31 patients with AFS and positive Bipolaris spicifera cultures, 68% had DQB1 *03, with DQB1 *0301 and DQB1 *0302 being most frequent (OR vs healthy subjects = 8.93; 95% CI, 4.65-17.15; P < .001; OR vs patients with HSD = 2.10; 95% CI, 1.18-3.73; P < .001). Of the 30 patients with HSD, 50% carried DQB1 *03 (OR vs healthy subjects = 4.25; 95% CI, 2.25-8.02; P < .001) but differed in frequencies of DQB1 *03 allelic variants compared with patients with AFS ( P = .0004). For HSD, nonatopic subjects had the highest DQB1 *03 association (OR vs healthy subjects = 8.63; 95% CI, 4.50-16.54; P < .001). DQB1 *03 allelic variants did not correlate with allergy skin test results, atopic status, total serum IgE levels, culture results, asthma, or aspirin-nonsteroidal anti-inflammatory drug hypersensitivity.

CONCLUSION

Patients with AFS and HSD have HLA-DQB1 *03 alleles as a risk factor for disease, with AFS having the highest association. However, they differ in DQB1 *03 allelic variant frequencies, suggesting several potential roles for MHC class II in their immunopathogenesis.

Allergic fungal sinusitis

AFS is an increasingly recognized form of HSD, now reported throughout the world. It is probably the most frequently occurring fungal rhinosinusitis disorder. The term fungal sinusitis is no longer appropriate because the five categories of fungal rhinosinusitis can now be differentiated. Each category of fungal rhinosinusitis disorder carries different treatment approaches and prognosis. Diagnostic error can be minimized by adhering to strict diagnostic criteria. The analogy (but not identity) of AFS to ABPA has been supported by histopathology, immunopathology, and the clinical response to OCS treatment. AFS represents a true medical surgical disorder in which both surgery and postoperative medical treatment, if properly coordinated between medical and surgical specialists, leads to the best patient outcomes. Continued advances in the understanding of the immunogenetics and immunopathogenesis of AFS may provide fundamental insights into molecular mechanisms operant in other chronic inflammatory disorders, including other chronic eosinophilic-lymphocytic respiratory mucosal disorders such as common forms of HSD and chronic severe asthma.

Role of Local Immunoglobulin E Production in the Pathophysiology of Noninvasive Fungal Sinusitis

OBJECTIVES/HYPOTHESIS

Immunoglobulin (Ig)E-mediated hypersensitivity to fungi has been postulated to explain allergic fungal sinusitis (AFS). Not all patients suspected to have AFS demonstrate systemic evidence of allergy. Locally produced IgE might explain those patients with no systemic evidence of allergy but clinical features of AFS. The aim was to determine whether fungal-specific IgE could be demonstrated in sinus mucin in patients with eosinophilic mucin rhino-sinusitis.

STUDY DESIGN

A prospective study was undertaken in a tertiary rhinology practice in Adelaide, South Australia.

METHODS

: Eighty-six consecutive patients with nasal polyposis and thick, colored macroscopically "fungal-like" sinus mucin at time of surgery for chronic sinusitis were entered in the study. The sinus mucin was liquefied and underwent testing for fungal-specific IgE (Pharmacia UniCAP) and fungal culture. Serum fungal-specific and total IgE, eosinophil count, C-reactive protein (CRP), and eosinophilic cationic protein (ECP) were measured.

RESULTS

Fifty-six (65%) patients were fungal culture positive, and 37% had a detectable fungal-specific IgE in sinus mucin. Data were available to classify 81 patients: AFS = 24 (30%), AFS-like = 6 (7%), nonallergic eosinophilic fungal sinusitis = 32 (40%), nonallergic, nonfungal eosinophilic sinusitis = 19 (23%). Patients with AFS were significantly more likely to have fungal-specific IgE in sinus mucin (17/24, 71%, P =.02). In all fungal culture-positive patients, positive mucin fungal-specific IgE was significantly associated with systemic fungal allergy (P =.005), but a raised total serum IgE was not. Six (19%) of the 32 patients with positive fungal cultures but negative serum fungal-specific IgE had a positive mucin fungal-specific IgE, suggesting that they may be reclassified as AFS. The mean ECP and total IgE were raised most significantly in the AFS subgroup.

CONCLUSIONS

This is the first study to show that fungal-specific IgE may be demonstrated in sinus mucin. It was significantly associated with systemic fungal allergy and may play a role in a minority of fungal sinusitis patients in the absence of systemic fungal allergy.

Allergic fungal sinusitis: pathogenesis and management strategies

Allergic fungal sinusitis (AFS) is a noninvasive form of highly recurrent chronic allergic hypertrophic rhinosinusitis that can be distinguished clinically, histopathologically and prognostically from the other forms of chronic fungal rhinosinusitis. There are three invasive (acute necrotising, chronic invasive and granulomatous invasive) and two noninvasive (fungal ball and allergic fungal) forms of fungal rhinosinusitis currently recognised. Confusion in differentiating between the various forms of fungal rhinosinusitis and between other forms of chronic hypertrophic sinus disease (HSD) can be eliminated by adhering to strict diagnostic criteria. Although there are characteristic presenting clinical history and physical examination findings, laboratory test results, including elevated total serum IgE and positive inhalant allergy skin tests, and sinus computed tomography scans showing chronic rhinosinusitis (often with the presence of hyperattenuating sinus contents) diagnosis of AFS is essentially based on histopathology obtained from sinus surgery. Histopathology shows the presence of eosinophilic-lymphocytic sinus mucosal inflammation, extramucosal allergic mucin (that is also seen grossly at surgery as a characteristic 'peanut-buttery' material), and scattered silver stain positive fungal hyphae within the allergic mucin but not in the mucosa. Treatment and follow up of AFS has been based on its immunopathological analogy to allergic bronchopulmonary aspergillosis, a similar noninvasive fungal hypersensitivity disorder of the lung, and its clinical and pathophysiological relationship to other forms of HSD and asthma. Treatment involves aggressive sinus surgery followed by medical management that includes allergen immunotherapy, topical and systemic corticosteroids, antihistamines and antileukotrienes. Total serum IgE levels should be followed postoperatively as they can be prognostic for recurrent disease. Close follow up and coordination of treatment by both medical and surgical physicians as a team leads to the best clinical outcomes. Ongoing studies are being directed at furthering our understanding of the pathophysiological relationships and treatment options for AFS, and other common forms of chronic hypertrophic rhinosinusitis disorders.

Fungal sinusitis: histologic spectrum and correlation with culture

Fungi are important etiologic agents of sinusitis. However, features of fungal sinusitis including the histologic spectrum, diagnostic mishaps, incidence, and fungal types have not been systematically studied. From 1996 through 2001, a total of 788 surgical pathology sinus specimens from 384 cases was retrieved. Fungal sinusitis was diagnosed in 58 specimens (7%) from 47 cases (12%). Four histologic categories of fungal sinusitis were identified: (1) allergic fungal sinusitis in 34 cases (copious mucin, abundant eosinophils, Charcot-Leyden crystals (so-called allergic mucin), with rare noninvasive fungal hyphae); (2) mycetoma/fungus ball in 11 cases (tightly packed fungal hyphae without allergic mucin or tissue invasion); (3) chronic invasive fungal sinusitis in 1 case (tissue granulomas with fungal hyphae); and (4) acute fulminant fungal sinusitis in 1 case (fungal vascular invasion). The diagnosis was initially missed in 16/34 (47%) cases of allergic fungal sinusitis despite typical features; incorrect classification was noted in 47% of cases. Sixty-seven percent of cases had positive fungal cultures, dematiaceous fungi being the most common. Allergic fungal sinusitis accounted for the majority of fungal sinusitis. Although misdiagnosis or incorrect classification is rather frequent for fungal sinusitis, awareness of the distinctive morphologic features of this entity may prevent these errors.