Fungal rhinosinusitis could be acute or chronic. The evolution of this condition implies an inflammatory response or allergic reaction of rhinosinusal mucous membrane due to the presence of fungi at this level. Fungi are ubiquitous organisms that reach the rhinosinusal level by air, generally being saprophytic elements. There is a permanent balance between fungal pathogenesis and the body's ability to defend itself. Fungi are dependent on: the ability to adhere to the epithelium; the secretion of toxins and enzymes that destroy tissues and impair the host's defense barriers; the ability of fungi to adapt to the conditions of the host organism; last but not least the ability to defend and to reduce the aggression produced by the human body on them. Human body fights through complex mechanisms against fungal colonization such as anatomical barriers – rhinosinusal mucosa (mucociliary clearance – which eliminates inhaled particles; epithelial integrity – is a physical barrier; microbial saprophytic flora) but also through the specific and non-specific defense.¹ Therefore, since these fungi are ubiquitous, the only variable that determines the evolution of fungal rhinosinusitis is the immune response of the host organism to fungal aggression. In immunocompromised individuals, invasive fungal sinusitis represents a major treatment difficulty with unknown results while a fungal colonization of an immunocompetent patient determines isolated, often asymptomatic, fungal sinusitis.²

Fungus ball is a form of non-invasive fungal sinusitis in immunocompetent patients, which is usually limited to a single sinus, especially the maxillary and sphenoid. The most common species of fungi found is Aspergillus fumigatus.³ The favorable factors that imply the formation of the fungus ball are sinus hypoventilation that benefits anaerobiosis, dental treatments, climatic conditions, local anatomical variants. Surgical treatment is the only viable option and consists in total removal of the fungi. Any remains may lead to recurrences of the fungus ball. Endoscopic approach consists in: middle antrostomy, ethmoidectomy, sphenoidotomy.

Immunocompromised patients tend to develop invasive sinusitis. The body's response to fungal aggression is minimal, microscopic examination highlighting the intramucosal and intravascular invasion of fungi – causes the appearance of intraluminal thrombi and infarction of the vascular territory. The most common predisposing comorbidities are diabetes and hematological malignancies. Among the fungal species, we mention Mucor and Aspergillus. Treatment consists of extensive surgical debridement of necrotic tissue, systemic antifungal treatment, review of immunosuppressive therapy.²

All forms of fungal sinusitis can produce complications. Erosions of sinus walls can be observed in fungus ball involvement. This can produce an intracranial extension of fungus, orbital complications like temporary diplopia or visual loss, even thrombosis of the cavernous sinus. Invasive forms of fungal sinusitis produce the following complications: rhino-orbito-cerebral, pulmonary, gastrointestinal, cutaneous, renal and disseminated. All these complications are emergency situations that require surgical treatment as soon as possible.

We performed a retrospective study on consecutive patients, hospitalized and treated between 2018 and 2019 for chronic fungal rhinosinusitis in the "Sfânta Maria” ENT&HNS Department, Bucharest, Romania.

The inclusion criteria in the study were: adult patients diagnosed clinically, radiologically and histopathologically with fugal sinusitis (fungus ball and invasive fungal sinusitis), who underwent endoscopic sinus surgery. All patients were evaluated preoperatively by endoscopy and by CT scan imaging. The group of patients was analyzed based on criteria such as invasive or non-invasive fungal sinusitis, the frequency of sinus involvement, gender distribution, the presence of complications, the type of surgery performed. The aim of the study was to determine the type of fungal sinusitis (non-invasive sinusitis – fungus ball – or acute invasive sinusitis), the complications and treatment difficulties.

In the study group, 74 patients were diagnosed with fungal rhinosinusitis: 72 had non-invasive fungal sinusitis – fungus ball type – Aspergillus (Figure 1 A and B) and two patients had invasive fungal sinusitis – Mucor type (Figure 2 A and B).

The age of the patients varied between 18 years and 87 years, with an average of 51.94 years, a median of 53.5 and a standard deviation of 14.97. The most frequent age ranged between 50 to 59 years (Table 1).

The gender distribution of patients was as follows: in the group of patients with fungus ball: 51 females and 21 males respectively; in the group of patients with invasive sinusitis: 2 men.

The location of the fungus ball colonization was as follows: maxillary sinus - 58 patients, sphenoid sinus - 13 patients, ethmoid sinus - one patient (Figure 3).

The patients who presented complications were three from the group of those with fungus ball. These complications consisted of erosion of the sinus walls, cavernous sinus thrombosis, diplopia. A patient with invasive fungal sinusitis that was immunocompromised due to chemotherapy for leukemia had systemic dissemination and multiple organ damage that led to death.

Surgical treatment performed in the case of patients with fungus ball consisted in sinus drainage, removal of the fungal material under endoscopic control. The procedures were middle antrostomy in 78.37% of the cases, sphenoidotomy - 17.56% and ethmoidectomy - 1.35%. Patients who had invasive forms of fungal sinusitis required extensive drainage and rhinosinusal debridement (extended sinus surgery - 2.7%), with one patient requiring orbit exenteration, partial resection of hard palate and approach of the pterygopalatine fossa.

Fungal sinusitis is a special group of sinusitis with an increasing incidence in recent decades. Although endoscopic and radiologic examination may suggest the presence of fungi, the definitive diagnoses will be established at histopathological examination. Fungal rhinosinusitis can be found in 6-12% of patients with chronic rhinosinusitis.⁴ The vast majority of fungal sinusitis are non-invasive forms and affect immunocompetent individuals. According to our study, the most affected people are those aged 50 to 59 years, with an average age of 51.94 years. This is confirmed by other studies such as those published by Jung et al. and Yoon et al. - 55 years and 58.3 years respectively.^5,6 Women tend to be more affected by fungal sinusitis - in the present study, the ratio is higher compared to data found in the literature (2.42:1 women vs. men compared to a ratio between 1.5 - 1.9:1 women vs. men).³ Non-invasive fungal sinusitis is found in isolated form mainly in the maxillary sinus (80.56%) and sometimes in the sphenoid sinus (18.06%); the locations at the level of the frontal and ethmoid sinuses are exceptional.^7,8 Given that the most common location of the fungus ball is in the maxillary sinus, some authors have conducted studies and demonstrated the link between the colonization of dental material penetrated into the sinus (Figure 4).⁹

In the case of fungus ball, patients may be asymptomatic or may present specific symptoms of unilateral sinusitis such as nasal obstruction, rhinorrhea, pressure sensation, etc. In the case of patients with acute invasive fungal sinusitis, they may experience rapidly evolving symptoms such as fever, facial pain, nasal congestion, epistaxis.¹⁰

The surgical treatment of non-invasive isolated fungal sinusitis is eminently surgical – middle antrostomy, sphenoidotomy, ethmoidectomy under endoscopic visualization, depending on the location of the fungus ball. Even if the treatment of fungus balls is not a challenge, the complications of this condition, especially for the sphenoid sinus involvement, can endanger the patient's life. Not infrequently, damage to the sinus walls (Figure 5) and invasion of adjacent structures can be noticed despite the fact that it is not an invasive form. An explanation could be the fact that bacterial infection could occur concomitant and this leads to bone erosion. Patients may present with diplopia or even decreased visual acuity.¹¹ Also, cavernous sinus thrombosis or intracranial penetration of these conglomerates requires prompt surgical treatment.

In our study, two patients had acute invasive rhinosinusitis with Mucor species. They required emergency surgical treatment which consisted of extensive debridement of devitalized structures. They were also given systemic antifungal adjuvant therapy. One of the patients had a medical history of type II diabetes mellitus, cirrhosis, chronic hepatitis B and D virus and liver transplantation in recent medical records. The other one had myeloid leukemia and was treated with chemotherapy and allotransplantation of stem cells.¹² Despite all the efforts, one of the patients died due to systemic dissemination of fungi. As other authors mention, the mechanism of local spread of the fungus infection is through angioinvasion, resulting in devitalized mucosa, local ischemia and necrosis with rapid onset of one of these forms: rhino-orbito-cerebral, pulmonary, gastrointestinal, cutaneous, renal and disseminated.^12,13

The most frequent form of fungal sinusitis was the non-invasive one (fungus ball) while invasive sinusitis was a rare condition. Women are more often affected than men. Surgical treatment is the only reasonable option. Although the incidence of complications is low, when they occur they may be life-threatening. Extended endoscopic sinus surgery is required in order to remove all the necrotic tissue in aggressive forms. As other authors stated, immunocompromising conditions like type II diabetes and hematological malignancies are the most common causes that predispose to fungal colonization. In these patients, we must pay close attention to the signs and symptoms of sinusitis and adopt the right treatment as soon as possible.

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https://doi.org/10.2500/ajr.2008.22.3228

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https://doi.org/10.4193/Rhin20.600

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https://doi.org/10.7162/S1809-48722012000200020

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https://doi.org/10.1002/alr.22007

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https://doi.org/10.1016/j.anl.2012.07.008

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https://doi.org/10.1053/hn.1999.v120.a89436

8. Mensi M, Piccioni M, Marsili F, Nicolai P, Sapelli PL, Latronico N. Risk of maxillary fungus ball in patients with endodontic treatment on maxillary teeth: a case-control study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007;103:433-6.

https://doi.org/10.1016/j.tripleo.2006.08.014

9. Legent F, Billet J, Beauvillain C, Bonnet J, Miegeville M. The role of dental canal fillings in the development of Aspergillus sinusitis: a report of 85 cases. Arch Otorhinolaryngol. 1989;246:318-20.

https://doi.org/10.1007/BF00463584

10. Aribandi M, McCoy VA, Bazan C 3rd. Imaging features of invasive and noninvasive fungal sinusitis: a review. Radiographics. 2007;27:1283-96.

https://doi.org/10.1148/rg.275065189

11. Marza A, Manea C. Abducens nerve palsy on a patient with sphenoid fungal rhinosinusitis and cavernous sinus meningioma - case report. Rom J Rhinol. 2018;8:193-6.

https://doi.org/10.2478/rjr-2018-0022

12. Badea C, Sarafoleanu C, Marza A. Rhinosinusal mucormycosis: literature review and some particular cases. Rom J Rhinol. 2019;9:129-37.

https://doi.org/10.2478/rjr-2019-0015

13. Taylor AM, Vasan K, Wong EH, et al. Black turbinate sign: MRI finding in acute invasive fungal sinusitis. Otolaryngol Case Rep. 2020;17:100222.

https://doi.org/10.1016/j.xocr.2020.100222