Fungal sinusitis: a spectrum of disease

Invasive fungal sinusitis: A comparison of pediatric versus adult cases

BACKGROUND

Invasive fungal sinusitis (IFS) is a rare infection with high mortality, mainly impacting immunocompromised patients. Given its significant mortality, timely recognition and treatment is crucial. This study aims to highlight the differences in presentation of IFS between pediatric and adult patients to aid in prompt diagnosis and treatment of this condition.

METHODS

A comprehensive literature search of PubMed, EMBASE, Web of Science, Global Index Medicus, Global Health (EBSCO) and Cochrane Database of Systematic Reviews was conducted to identify articles relating to IFS. Patient demographics, comorbidities, presentation, disease characteristics, treatments and outcomes were extracted from the studies, and statistical analyses were conducted to compare these variables between pediatric and adult patients.

RESULTS

111 studies identified 22 pediatric and 132 adult patients worldwide. Children were more likely to have hematologic malignancies compared to adults (59.1 % vs. 15.2 %, p < 0.001). Facial symptoms such as pain, edema, and numbness were the most common symptoms for both age groups. In the pediatric population, fever and nasal or oral mucosal lesions were more common presenting symptoms (both p < 0.001). Pediatric patients were more likely to present without disease extension beyond the sinuses (p < 0.001). There was no significant difference in either medication treatment or mortality between the two cohorts.

CONCLUSION

IFS often presents with non-specific symptoms and a unique presentation in pediatric and adult populations. Clinical awareness of the varying presentations in both populations is important to treat in a timely manner given the rapid progression and high mortality rates of IFS.

RNA Sequencing and Gene Ontology Analysis in Acute Invasive Fungal Sinusitis

Background

Acute invasive fungal sinusitis (AIFS) is an aggressive and dangerous disease of the paranasal sinuses with high morbidity and mortality. The immune response at the level of the nasal mucosa, the site of entry, has not been previously evaluated.

Objective

To evaluate differential gene expression in the sinonasal mucosa of AIFS patients as compared to control patients using RNA sequencing.

Methods

Sinonasal tissue samples were prospectively obtained from consenting patients undergoing surgery between November, 2020 and November, 2021. RNA extraction and sequencing were performed and differential expression was analyzed to detect transcriptional differences between patient groups.

Results

Tissue samples were collected from 4 patients with active AIFS diagnoses, 2 patients with recovered AIFS, 1 patient with a diagnosis of non-invasive fungal ball, and 4 healthy controls. 255 genes were differentially expressed in AIFS patients as compared to control patients. Specific Gene Ontology (GO) biological processes that were identified as differentially expressed in AIFS patients as compared to controls included the following: 1. GO:0007155 (cell adhesion), 2. GO:0030199 (collagen fibril organization) and 3. GO:0001525 (angiogenesis).

Conclusion

Transcriptional differences were noted between AIFS and control patients in sinonasal tissue samples. Future work is necessary to determine causes of the differential gene expressions between AIFS and control patients, specifically those who are immunosuppressed, or with preexisting non-invasive forms of fungal sinusitis, to guide treatment and prevention strategies.

Intermediate Invasive Fungal Sinusitis, a Distinct Entity From Acute Fulminant and Chronic Invasive Fungal Sinusitis

BACKGROUND

The current classification system of invasive fungal sinusitis (IFS) includes acute (aIFS) and chronic (cIFS) phenotypes. Both phenotypes display histopathologic evidence of tissue necrosis, but differ by presence of angioinvasion, extent of necrosis, and disease progression. aIFS is defined by a rapid onset of symptoms, while cIFS slowly progresses over ≥12 weeks. However, a subset of IFS patients do not fit into the clinical presentation and histopathologic characteristics of either aIFS or cIFS.

OBJECTIVES

To investigate the demographic, clinical, and histopathologic characteristics of a distinct subset of IFS.

METHODS

Retrospective review of patients with IFS from a single tertiary-care institution (2010-2020). Patients with symptoms for ≤4 weeks were classified as aIFS if they displayed endoscopic evidence of mucosal necrosis or fungal angioinvasion on pathology. Patients with slowly progressive IFS for ≥12 weeks were classified as cIFS. Patients with symptom duration between 4 and 12 weeks with evidence of invasive fungal disease were classified as a new entity and were further investigated.

RESULTS

Of the 8 patients identified, 50% were immunosuppressed at presentation. The mean symptom duration prior to presentation was 50.5 days (SD 16.8), and common symptoms included facial pain (100%), vision change (87.5%), and blindness (37.5%). Two patients (25%) died of their disease. Sites of fungal involvement confirmed by histopathology included sphenoid (62.5%) and ethmoid sinuses (12.5%), orbital apex (25%), optic nerve (12.5%), pterygopalatine fossa (12.5%), and clivus (12.5%). Fungal elements but without obvious angioinvasion, were identified in all specimens, and fungus balls (50%), granulomas (37.5%), and giant cells (25%) were also observed on histopathology. CT and MRI radiographic imaging showed findings consistent with orbital, intracranial, or skull base involvement in all patients.

CONCLUSION

We propose intermediate IFS as a new subgroup of patients with IFS who do not fit into the standard classification of aIFS or cIFS.