Acute invasive fungal rhinosinusitis (AIFRS) - A histopathological analysis of expanding spectrum of fungal infections in backdrop of COVID-19 pandemic

Context

Acute invasive fungal rhinosinusitis (AIFRS) is an aggressive infection affecting immunocompromised patients and carries a high morbidity and mortality. It is commonly seen in immunocompromised patients, mainly in uncontrolled diabetes, malignancy, acquired immunodeficiency syndrome, and so on. However, there has been an exponential increase in the incidence of AIFRS in relation to recent coronavirus disease 2019 (COVID-19) infection.

Aims

We present this study to assess histomorphological features of fungal infections in the background of COVID-19 era.

Materials and Methods

The study includes interpretation of 34 biopsies of suspected AIFRS in post COVID-19 patients. The demographic details like patients age, sex, diabetic status, COVID-19 status, and history of steroid intake were collected. All specimens were stained with hematoxylin and eosin and PAS stain. Detailed microscopic examination including the presence of fungal hyphae in the tissue, characterization of inflammatory response, presence of tissue invasion, angioinvasion, and necrosis was noted for each case.

Results

Thirty-four biopsy specimens from various sites - nasal cavity, maxillary sinus, ethmoid sinus, and so on - were studied. The mean age of the patients with AIFRS was 52.68 years. The dominant fungi were Mucorales in 31 (91.3%), Aspergillus and Mucorales in 1 (2.9%), a combination of Mucorales and Candida identified in 1 (2.9%) case, and Candida alone in 1 case (2.9%). Bony invasion and perineural invasion were observed in 5 cases (14.7%) and 1 (2.9%) case, respectively.

Conclusion

Histopathological examination plays an essential role in the diagnosis and appropriate management of the patients. Histopathological features including characterization of fungi, angioinvasion, and bone invasion may provide information on rare dreaded infections in post-COVID-19 patients for possible prognostic characteristics on histology.

Neurosarcoidosis - A diagnostic challenge?

Background: Sarcoidosis is an inflammatory granulomatous multisystem disease with an unknown etiology. Neurosarcoidosis is a cryptogenic neuroinflammatory manifestation of sarcoidosis. Objective: This article aims at better understanding of one of the rarer diseases whose diagnosis may be difficult leading to delay in definitive management of the patient. Method: We describe a case of neurosarcoidosis with initial presentation similar to acute invasive fungal rhinosinusitis, whose diagnosis was challenging and delayed owing to the presenting symptoms. Conclusion: The diagnosis of neurosarcoidosis becomes challenging when it presents as isolated clinical neurological symptoms. We want to highlight the variable nature of neurosarcoidosis and its consideration as diagnosis after excluding other common infectious and inflammatory conditions.

Magnetic Resonance Imaging Prognostic Findings for Visual and Mortality Outcomes in Acute Invasive Fungal Rhinosinusitis

PURPOSE

To identify initial, preintervention magnetic resonance imaging (MRI) findings that are predictive of visual and mortality outcomes in acute invasive fungal rhinosinusitis (AIFRS).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients with histopathologically or microbiologically confirmed AIFRS cared for at a single, tertiary academic institution between January 2000 and February 2020.

METHODS

A retrospective review of MRI scans and clinical records of patients with confirmed diagnosis of AIFRS was performed. For each radiologic characteristic, a modified Poisson regression with robust standard errors was used to estimate the risk ratio for blindness. A multivariate Cox proportional hazards model was used to study AIFRS-specific risk factors associated with mortality.

MAIN OUTCOME MEASURE

Identification of initial, preintervention MRI findings associated with visual and mortality outcomes.

RESULTS

The study comprised 78 patients (93 orbits, 63 with unilateral disease and 15 with bilateral disease) with AIFRS. The leading causes of immunosuppression were hematologic malignancy (38%) and diabetes mellitus (36%). Mucormycota constituted 56% of infections, and Ascomycota constituted 37%. The overall death rate resulting from infection was 38%. Risk factors for poor visual acuity outcomes on initial MRI included involvement of the orbital apex (relative risk [RR], 2.0; 95% confidence interval [CI], 1.1-3.8; P = 0.026) and cerebral arteries (RR, 1.8; 95% CI, 1.3-2.5; P < 0.001). Increased mortality was associated with involvement of the facial soft tissues (hazard ratio [HR], 4.9; 95% CI, 1.3-18.2; P = 0.017), nasolacrimal drainage apparatus (HR, 5.0; 95% CI, 1.5-16.1; P = 0.008), and intracranial space (HR, 3.5; 95% CI, 1.4-8.6; P = 0.006). Orbital soft tissue involvement was associated with decreased mortality (HR, 0.3; 95% CI, 0.1-0.6; P = 0.001).

CONCLUSIONS

Extrasinonasal involvement in AIFRS typically signals advanced infection with the facial soft tissues most commonly affected. The initial, preintervention MRI is prognostic for a poor visual acuity outcome when orbital apex or cerebral arterial involvement, or both, are present. Facial soft tissues, nasolacrimal drainage apparatus, intracranial involvement, or a combination thereof is associated with increased mortality risk, whereas orbital soft tissue involvement is correlated with a reduced risk of mortality.

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.

Pathology of Fungal Rhinosinusitis: A Review

Fungal rhinosinusitis (FRS) comprises a spectrum of disease processes that vary in clinical presentation, histologic appearances, and biological significance. FRS can be acute or chronic and is most commonly classified as non-invasive or invasive based on whether fungi have invaded into tissue. This manuscript will review the pathologic classification of FRS.