Invasive fungal rhinosinusitis: current evidence and research opportunities

PURPOSE OF REVIEW

To summarize the evidence surrounding diagnosis, treatment, prognosis, and surveillance of patients with acute invasive fungal sinusitis (AIFS) and discuss future research needs.

RECENT FINDINGS

New risk factors for AIFS such as COVID have been identified, and a new prognostic staging system has been developed.

SUMMARY

Most patients who develop AIFS are immunocompromised, with the majority having a history of diabetes or a hematologic malignancy. Unfortunately, there are not any highly sensitive and specific diagnostic tools. Therefore, a combination of signs and symptoms, imaging, endoscopy, biopsy, and labs should be used to diagnosis AIFS. Although surgery and systemic antifungals are known to improve outcomes, there is limited data on time to intervention, duration of antifungals, and surveillance patterns. There is also limited information on factors that can predict outcomes in AIFS patients. However, sensory/perceptual changes, prolonged neutropenia duration, and comorbidity burden may be associated with a poor prognosis.

Microvascular Free Flap Outcomes in Maxillectomy Defects from Invasive Fungal Sinusitis

OBJECTIVES

Microvascular free tissue transfer is routinely used for reconstructing midface defects in patients with malignancy, however, studies regarding reconstructive outcomes in invasive fungal sinusitis (IFS) are lacking. We aim to describe outcomes of free flap reconstruction for IFS defects, determine the optimal time to perform reconstruction, and if anti-fungal medications or other risk factors of an immunocompromised patient population affect reconstructive outcomes.

METHODS

Retrospective review of reconstruction for IFS (2010-2022). Age, BMI, hemoglobin A1c, number of surgical debridements, and interval from the last debridement to reconstruction were compared between patients with delayed wound healing versus those without. Predictor variables for delayed wound healing and the effect of time on free flap reconstruction were analyzed.

RESULTS

Twenty-seven patients underwent free flap reconstruction for IFS. Three patients were immunocompromised from leukemia and 21 had diabetes mellitus (DM). Patients underwent an average of four surgical debridements for treatment of IFS. The interval from the last IFS debridement to flap reconstruction was 5.58 months (±5.5). Seven flaps (25.9%) had delayed wound healing. A shorter interval of less than 2 months between the last debridement for IFS and reconstructive free flap procedure was associated with delayed wound healing (Fisher Exact Test p = 0.0062). Other factors including DM, BMI, HgA1c, and bone reconstruction were not associated with delayed wound healing.

CONCLUSION

Patients with maxillectomy defects from IFS can undergo microvascular-free flap reconstruction with good outcomes while on anti-fungal medication. Early reconstruction in the first 2 months after the last IFS debridement is associated with delayed wound healing.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1642-1647, 2024.

[Clinical features and risk factors for invasive fungal sinusitis after allogeneic hematopoietic stem cell transplantation]

Objective: To analyze the clinical characteristics and outcomes of patients with invasive fungal sinusitis (invasive fungal rhinosinusitis, IFR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and explored the risk factors for IFR after allo-HSCT. Methods: Nineteen patients with IFR after allo-HSCT at Peking University People's Hospital from January 2012 to December 2021 were selected as the study group, and 95 patients without IFR after allo-HSCT during this period were randomly selected as the control group (1:5 ratio) . Results: Nineteen patients, including 10 males and 9 females, had IFR after allo-HSCT. The median age was 36 (10-59) years. The median IFR onset time was 68 (9-880) days after allo-HSCT. There were seven patients with acute myeloid leukemia, five with acute lymphoblastic leukemia, two with myelodysplastic syndrome, two with chronic myeloid leukemia, one with acute mixed-cell leukemia, one with multiple myeloma, and one with T-lymphoblastic lymph node tumor. There were 13 confirmed cases and 6 clinically diagnosed cases. The responsible fungus was Mucor in two cases, Rhizopus in four, Aspergillus in four, and Candida in three. Five patients received combined treatment comprising amphotericin B and posaconazole, one patient received combined treatment comprising voriconazole and posaconazole, nine patients received voriconazole, and four patients received amphotericin B. In addition to antifungal treatment, 10 patients underwent surgery. After antifungal treatment and surgery, 15 patients achieved a response, including 13 patients with a complete response and 2 patients with a partial response. Multivariate analysis revealed that neutropenia before transplantation (P=0.021) , hemorrhagic cystitis after transplantation (P=0.012) , delayed platelet engraftment (P=0.008) , and lower transplant mononuclear cell count (P=0.012) were independent risk factors for IFR after allo-HSCT. The 5-year overall survival rates in the IFR and control groups after transplantation were 29.00%±0.12% and 91.00%±0.03%, respectively (P<0.01) . Conclusion: Although IFR is rare, it is associated with poor outcomes in patients undergoing allo-HSCT. The combination of antifungal treatment and surgery might be effective.

Diagnosis, Prognosticators, and Management of Acute Invasive Fungal Rhinosinusitis: Multidisciplinary Consensus Statement and Evidence-Based Review with Recommendations

BACKGROUND

Acute invasive fungal sinusitis (AIFS) is an aggressive disease that requires prompt diagnosis and multidisciplinary treatment given its rapid progression. However, there is currently no consensus on diagnosis, prognosis, and management strategies for AIFS, with multiple modalities routinely employed. The purpose of this multi-institutional and multidisciplinary evidence-based review with recommendations (EBRR) is to thoroughly review the literature on AIFS, summarize the existing evidence, and provide recommendations on the management of AIFS.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from inception through January 2022. Studies evaluating management for orbital, non-sinonasal head and neck, and intracranial manifestations of AIFS were included. An iterative review process was utilized in accordance with EBRR guidelines. Levels of evidence and recommendations on management principles for AIFS were generated.

RESULTS

A review and evaluation of published literature was performed on 12 topics surrounding AIFS (signs and symptoms, laboratory and microbiology diagnostics, endoscopy, imaging, pathology, surgery, medical therapy, management of extrasinus extension, reversing immunosuppression, and outcomes and survival). The aggregate quality of evidence was varied across reviewed domains.

CONCLUSION

Based on the currently available evidence, judicious utilization of a combination of history and physical examination, laboratory and histopathologic techniques, and endoscopy provide the cornerstone for accurate diagnosis of AIFS. In addition, AIFS is optimally managed by a multidisciplinary team via a combination of surgery (including resection whenever possible), antifungal therapy, and correcting sources of immunosuppression. Higher quality (i.e., prospective) studies are needed to better define the roles of each modality and determine diagnosis and treatment algorithms.

Clinical predictors of invasive fungal rhinosinusitis in a tertiary pediatric hospital

OBJECTIVES

Invasive fungal rhinosinusitis (IFRS) is a potentially fatal disease that affects the severely immunocompromised and requires aggressive treatment. The objective of this study is to better describe predictors of biopsy positivity in patients at high risk of IFRS at a pediatric hospital.

METHODS

This was a single-center case-control study of 36 patients (37 total biopsies) ≤ 21 years old with one of five high-risk oncologic/hematologic diagnoses who underwent operative endoscopy for clinical suspicion for IFRS. IFRS positivity was defined histologically. Collected information included patient demographics, primary diagnosis, oncologic relapses, time from diagnosis to biopsy, clinical characteristics, and endoscopic findings. These data were used to create a simple predictive scoring system.

RESULTS

17 patients had biopsy-proven IFRS (IFRS(+)) for an overall incidence of 2.1% in the designated high-risk population. Average time from most recent oncologic development (diagnosis, relapse, or hematopoietic stem-cell transplant) to biopsy in the IFRS(+) group was 2.09 months (SD = 2.26), and 7.28 months in the IFRS(-) group (SD = 9.17) (p = 0.009). Clinical characteristics did not differentiate between IFRS(+) and IFRS(-). Bedside endoscopy performed poorly, as it was interpreted as normal in 42.8% of IFRS(+) and 53.8% of IFRS(-). In contrast, the presence of any positive endoscopic finding intra-operatively was highly specific for IFRS(+) (94%) with moderate sensitivity (70%), and the difference in rate of positivity between groups was statistically significant (p < 0.001).

CONCLUSION

Operative endoscopy with biopsy remains the gold-standard to rule-out IFRS in the setting of high clinical suspicion. Time elapsed from most recent oncologic development to clinical concern for IFRS may influence the likelihood of disease, though this requires further study. Clinical symptoms and bedside endoscopy were not predictive and should be used with caution in decision-making.

Utilizing CT soft-tissue markers as a screening tool for acute invasive fungal sinusitis

OBJECTIVES

Acute invasive fungal sinusitis (AIFS) is a rapidly progressive disease, whose delayed identification results in poor outcomes, especially in immunocompromised individuals. A surge in of AIFS in the wake of the COVID-19 pandemic has lent additional morbidity and mortality to an already precarious clinical scenario. Early detection of AIFS in individuals who are symptomatic/ at risk can allow early therapy, enabling better patient outcomes. Our study aims to determine optimal soft-tissue markers on CT for the early detection of AIFS.

METHODS

In this case-control study, 142 patients with equal distribution of subjects were chosen based on histopathological diagnosis of AIFS; and their non-contrast CT scans were retrospectively assessed to determine the diagnostic utility of specific soft-tissue markers that would enable diagnosis of AIFS.

RESULTS

A total of nine markers with adequate sensitivity and specificity were identified, including pterygopalatine and sphenopalatine fossae, inferior orbital fissure and nasolacrimal duct involvement, premaxillary thickening, retro-antral and orbital stranding, and infratemporal muscle oedema. It was determined that the combined occurrence of any three out of nine markers was 91.5% sensitive and 95.9% specific for diagnosis of AIFS (p < 0.005).

CONCLUSION

Early, accurate detection of AIFS in predisposed individuals is possible with identification of soft-tissue markers on NECT, enabling early intervention.

ADVANCES IN KNOWLEDGE

Being the aggressive disease that it is, AIFS may be managed early if the index of suspicion is held high via CT imaging; which our diagnostic checklist aims at enabling.

Development and Validation of Ultra-Rapid Periodic Acid-Schiff Stain for Use in Identifying Fungus on Frozen Section

CONTEXT.—

There is no standardized process for utilization of periodic acid-Schiff during intraoperative frozen sections to identify fungal organisms.

OBJECTIVE.—

To develop a rapid staining process for fresh tissue with periodic acid-Schiff during intraoperative consultation and develop an appropriate control block.

DESIGN.—

Muscle tissue was inoculated with 2 species of fungus (Aspergillus fumigatus and Paecilomyces spp) and grown at 3 different temperatures for 72 hours. Inoculated tissue was embedded in optimal cutting temperature compound, cut, and stained using a modified periodic acid-Schiff stain. The optimal control was determined for future use as the standard control. Multiple control slides were cut and stained, using successively shorter time intervals for each step. The staining process that provided accurate results in the shortest amount of time was deemed ultra-rapid periodic acid-Schiff. This method was validated by carryover studies and clinical specimens.

RESULTS.—

Paecilomyces spp incubated at 30°C for 72 hours was the most optimal positive control with numerous yeast and hyphal forms. The fastest staining process involved 2 minutes of periodic acid and Schiff reagent and 10 dips of light green solution. Tap water was as effective as distilled water. Validation was successfully achieved. Clinical cases all stained identical to formalin-fixed, paraffin-embedded tissue stained with hematoxylin-eosin and periodic acid-Schiff.

CONCLUSIONS.—

Ultra-rapid periodic acid-Schiff provides fast and reliable identification of fungal organisms on fresh tissue. Development of a concurrent positive control allows for quality control and validation.

Accuracy of Intraoperative Frozen Section in Detection of Acute Invasive Fungal Rhinosinusitis

CONTEXT.—

Acute invasive fungal rhinosinusitis (AIFRS) is an aggressive form of fungal sinusitis, which remains a significant cause of morbidity and mortality. Early diagnosis and intervention are keys to improving patient outcomes. Intraoperative consultation has shown promise in facilitating early surgical intervention, but the accuracy of frozen section has not been clarified in this setting.

OBJECTIVES.—

To assess the accuracy of frozen-section diagnosis in patients with clinically suspected AIFRS.

DESIGN.—

All cases of clinically suspected AIFRS during a 10-year period (2009-2019) were retrospectively reviewed. The frozen-section results were compared with the final permanent sections as well as the tissue fungal culture results, following which the accuracy of frozen section was determined.

RESULTS.—

Forty-eight patients with 133 frozen-section evaluations for AIFRS were included in the study. Thirty of 48 patients and 61 of 133 specimens were positive for AIFRS on final pathology. Of 30 positive patients, 27 (90%) had at least 1 specimen diagnosed as positive during intraoperative consultation; among the 61 positive specimens, 54 (88.5%) were diagnosed as positive during intraoperative consultation. Of 72 negative specimens, all were interpreted as negative on frozen section. Thus, frozen sections had a sensitivity of 88.5% (95% CI, 0.78-0.97), specificity of 100% (95% CI, 0.94-1), positive predictive value of 100% (95% CI, 0.92-1), and negative predictive value of 90.6% (95% CI, 0.82-0.97).

CONCLUSIONS.—

This study represents the largest series assessing the diagnostic accuracy of frozen section analysis in AIFRS. These findings are useful in frozen section-informed intraoperative decision making.

Acute invasive fungal rhinosinusitis: Molecular identification and update in management of frozen section biopsy

The clinical diagnosis of Acute Invasive Fungal Rhinosinusitis (AIFRS) is technically difficult because it presents with non-exclusive and nonspecific clinical symptoms. Laboratory confirmation (usually via histopathologic techniques such as formalin-fixed paraffin-embedded (FFPE)) is necessary but it is time-consuming, despite the urgent need for timely diagnosis of AIFRS for effective management. This study aimed to investigate the sensitivity and specificity of the GMS frozen-section biopsy in the diagnosis of AIFRS and compare the same with that of different tissue staining methods to provide valid decision-grounds that may guide clinicians in prompt diagnosis of acute fungal invasive rhinosinusitis. A cross-sectional study was conducted in the Medical Mycology Laboratory, Faculty of Medicine, Iran University of Medical Sciences between 2018 and 2020 on 200 patients with suspected AIFRS referred to Baqiyatallah and Imam Khomeini Hospital, Tehran. All patients were subjected to diagnostic nasal endoscopy and computed tomography (CT) scan of paranasal sinuses. Magnetic resonance imaging (MRI) was done in cases of suspected intracranial extension. After screening by routine mycological examination, the diagnosis was confirmed using complementary molecular methods. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the frozen-section biopsy were also compared with FFPE. Of the 200 suspect patients, 47 cases (23.5%) met the criteria for AIFRS. Species of the genus Aspergillus were the predominant 27 (57.4%) followed by Mucorales species 10 (21.3%), and Fusarium spp 3 (6.4%). Also, 3 cases (6.4%) of co-infection due to Aspergillus/Rhizopus were reported. The accuracy, sensitivity, specificity, PPV, and NPV of frozen section assessments were 99.5%, 97.9%, 100%, 100% and 99.3%, respectively. For GMS frozen-section alone, sensitivity, specificity, NPV, and PPV was 100%. Overall, the calculated accuracy of FFPE was 98.5%, sensitivity was 94%, specificity was 100%, PPV was 100%, and NPV was 98.1%. Examination of the frozen-section biopsy is a highly predictive tool for a rapid and effective diagnosis of patients with suspected AIFRS. We observed that GMS frozen-section is a fast and reliable exam to confirm the diagnosis of fungal invasion, with good accuracy, sensitivity, and specificity compared to the gold-standard FFPE biopsy.

Usefulness of intraoperative frozen section for diagnosing acute invasive fungal rhinosinusitis: A systematic review and meta-analysis

BACKGROUND

The accuracy of diagnoses of acute invasive fungal rhinosinusitis (AIFRS) based on frozen sections has been questioned.

METHODS

PubMed, the Cochrane Central Register of Controlled Trials, Embase, Web of Science, SCOPUS, and Google Scholar were used for data sources. True-positive, true-negative, false-positive, and false-negative data were extracted for each study. Methodological quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) Tool.

RESULTS

Nine prospective and retrospective studies were included. The diagnostic odds ratio of intraoperative frozen section in AIFRS was 124.4717 (95% confidence interval [CI], 75.5168-205.1623). The area under the summary receiver operating characteristic curve was 0.906. The sensitivity, specificity, and positive predictive value were 0.8337 (95% CI, 0.7962-0.8655), 0.9858 (95% CI, 0.9330-0.9971), and 0.9822 (95% CI, 0.8905-0.9973), respectively. The correlation between sensitivity and the false-positive rate was 0.437, indicating a lack of heterogeneity. In subgroup analysis, the "per patient" subgroup tended to show higher diagnostic accuracy than the "per specimen" subgroup. Regarding fungal species, the frozen biopsy of aspergillus showed higher sensitivity than that of mucor (0.8103 vs. 0.7544).

CONCLUSION

Positive frozen sections are reliable and facilitate early intervention in AIFRS. Collecting multiple specimens during surgery will decrease the rate of false-negative results.

A Case of Invasive Aspergillus Rhinosinusitis Presenting with Unilateral Visual Loss and Subsequently Associated with Meningitis, Subarachnoid Hemorrhage, and Cerebral Infarction

Visual impairment can occur because of several mechanisms, including optic nerve disease and occasionally fungal sinusitis. An 87-year-old man presented with the loss of right visual acuity; he was diagnosed with optic neuritis. Steroid pulse therapy was not effective. One month later, he became unconscious because of meningitis, following which treatment with ceftriaxone and acyclovir was initiated. However, his consciousness deteriorated because of a subarachnoid hemorrhage caused by a ruptured aneurysm. Meningitis and vascular invasion caused by fungal rhinosinusitis were suspected, and the sinus mucosa was biopsied. He was pathologically diagnosed with invasive Aspergillus rhinosinusitis. Despite continuous liposomal amphotericin B administration, he died of cerebral infarction, following a right internal carotid artery occlusion. It is important to consider the possibility of Aspergillus as an etiological agent, especially when cerebrovascular events are associated with visual impairment.

An internally validated diagnostic tool for acute invasive fungal sinusitis

BACKGROUND

Acute invasive fungal sinusitis (AIFS) is a potentially life-threatening diagnosis in immunocompromised patients. Identifying patients who could benefit from evaluation and intervention can be challenging for referring providers and otolaryngologists alike. We aimed to develop and validate an accessible diagnostic tool to estimate the probability of AIFS.

METHODS

Retrospective chart review from 1999 to 2017 identified all patients evaluated for possible AIFS at a tertiary care center. AIFS was diagnosed by pathologic confirmation of fungal tissue angioinvasion. Stepwise selection and univariate logistic regression were used to screen risk factors for a multivariable predictive model. Model performance was assessed using Tukey's goodness-of-fit test and the area under the receiver operator characteristic curve (AUC). Model coefficients were internally validated using bootstrapping with 1000 iterations.

RESULTS

A total of 283 patients (244 negative controls, 39 with AIFS) were included. Risk factors in our final diagnostic model included: fever ≥38°C (log-odds ratio [LOR] 1.72; 95% CI, 0.53 to 2.90), unilateral facial swelling, pain, or erythema (LOR 2.84; 95% CI, 1.46 to 4.23), involvement of the orbit or pterygopalatine fossa on imaging (LOR 3.02; 95% CI, 1.78 to 4.26), and mucosal necrosis seen on endoscopy (LOR 5.52; 95% CI, 3.81 to 7.24), with p < 0.01 for all factors. The model had adequate goodness of fit (p > 0.05) and discrimination (AUC = 0.96).

CONCLUSION

We present an internally validated diagnostic tool to stratify the risk for AIFS. The estimated risk may help determine which patients can be observed with serial nasal endoscopy, which ones could be biopsied, and which ones would benefit from immediate surgical intervention.

Invasive and Non-Invasive Fungal Rhinosinusitis-A Review and Update of the Evidence

Fungal infections are a subset of infectious processes that an otolaryngologist is required to be familiar with. They can be encountered in otology, rhinology and head and neck surgery. The presence of fungal rhinosinusitis is well recognised by otolaryngologists, but the classifications and appropriate management are not so well understood. The prevalence of fungal sinus disease is thought to be have been increasing in recent decades There is speculation that this may be due to increased awareness, antibiotic overuse and increased use of immunosuppressant medications. Added to this, there has been a large amount published on the role of fungi as a causative organism in chronic rhinosinusitis. Given the importance of fungal rhinosinusitis in clinical practice, we aim to review the classification and current management strategies based on up-to-date literature.

Impact of early detection of acute invasive fungal rhinosinusitis in immunocompromised patients

Background

Early diagnosis of acute invasive fungal rhinosinusitis (AIFRS) is vital to improving outcomes in immunocompromised patients. This study evaluated the impact of a systematic protocol with nasal endoscopy and biopsies to early detect AIFRS in immunocompromised patients. Additionally, we compared the accuracy of frozen-section biopsy and culture with formalin-fixed paraffin-embedded (FFPE) biopsy.

Methods

Retrospective cohort in a Tertiary Referral Hospital. Patients with the suspected diagnosis of AIFRS were evaluated following a standardized protocol, including serial nasal endoscopies and biopsies when necessary. The sensitivity and specificity of frozen-section biopsy and culture were also compared with FFPE.

Results

The mortality rate related to AIFRS of this standardized cohort (13/43) was 30.2%. Better outcomes were observed in patients with disease limited to the turbinates and in those with higher peripheral neutrophils count. Frozen-section biopsy positivity correlated with FFPE findings for fungi detection (p-value < 0.0001), with a sensitivity of 90.6%, specificity of 72.7%, and accuracy of 86.0%.

Conclusion

Implementation of this standardized protocol was related to a considerably low mortality rate among patients with suspected AIFRS at our Institution. Frozen-section biopsy revealed high accuracy to diagnose AIFRS. The current protocol including frozen-tissue biopsy improved the evaluation and survival rates of immunocompromised patients with presumed AIFRS.

Acute Invasive Fungal Rhinosinusitis: Frozen Section Histomorphology and Diagnosis with PAS Stain

Acute invasive fungal rhinosinusitis (AIFRS) is a fulminant infection in immunocompromised patients requiring rapid diagnosis (DX), frequently made on frozen section (FS) of sinonasal biopsies, followed by prompt surgical debridement. However, FS interpretation is often difficult and DX sometimes not possible. In this study we sought to characterize reasons for misinterpretation and methods to improve diagnostic accuracy. The FS slides from 271 biopsies of suspected AIFRS in a 16-year period were reviewed and the morphologic features evaluated for their utility in DX. Recurring specific patterns of necrosis were identified, which to our knowledge have not been described in the literature. Although they provide strong evidence for AIFRS, identifying fungus consistently in necrotic tissue is essential for DX. Clues to identifying fungus and pitfalls in misidentification were identified, but even with expert knowledge of these, a gap in accurate DX remained. The key to FS DX of AIFRS is to improve fungus identification in necrotic tissues. Methods had been sought in the past to stain fungus at FS without consistent success. The Periodic Acid Schiff's Reaction for Fungi was modified by our histopathology department for use on frozen tissue (PASF-fs) resulting in effective staining of the fungus. It stained fungus on all 62 positive slides when applied retrospectively over hematoxylin and eosin (H&E) stained FSs and used prospectively at FS for DX. Although knowledge of histologic morphology on FS is important, the crucial value of this study is the novel use of PASF-fs to identify fungus in the DX of AIFRS.

Frozen Section as a Rapid and Accurate Method for Diagnosing Acute Invasive Fungal Rhinosinusitis

Objective

Identify methods to improve the frozen-section diagnosis of acute invasive fungal rhinosinusitis.

Study Design

Biopsies with frozen section for suspected acute invasive fungal rhinosinusitis were reviewed to identify causes for missed diagnoses and evaluate methods for potential improvement.

Setting

All aspects of the study were performed at the Penn State Milton S. Hershey Medical Center.

Subjects and Methods

All frozen sections performed for suspected acute invasive fungal rhinosinusitis between 2006 through 2017 were reviewed with their diagnoses compared to the final diagnoses. Sensitivity and specificity were determined for each biopsy specimen to evaluate the diagnostic method and for each patient for its effectiveness on outcome. Causes for frozen-section failures in diagnosis were identified. A periodic acid–Schiff stain for fungus (PASF) was modified for use on frozen tissue (PASF-fs) and applied both retrospectively and prospectively to frozen sections to determine its ability to identify undetected fungus and improve diagnostic sensitivity.

Results

Of 63 biopsies positive for acute invasive fungal rhinosinusitis, 51 were diagnosed on frozen section, while 61 were identified by including the novel PASF-fs stain, reducing the failure rate from 19% to 3%. Of 41 cases that were positive, 34 were diagnosed on frozen section. Of the 7 that were not, 5 were identified by including the PASF-fs, reducing the failure rate from 17% to 5%.

Conclusions

Frozen section interpretation of biopsies for suspected acute invasive fungal rhinosinusitis using a PASF-fs stain should enable a rapid and accurate diagnosis with improved outcomes by shortening the time to surgery.