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Research Article, J Otol Rhinol Vol: 3 Issue: 6

Maxillary and Sphenoid Sinus Fungus Ball: A Single Belgian Centre's Experience

Eloy P1, Marlair C1, de Dorlodot CL1 and Weynand B2
1HNS & ENT Department, CHU Dinant - Godinne, UCL Namur, Avenue Thérasse,1, 5530, Yvoir, Belgium.
2Department of Histopathology, CHU Dinant - Godinne, UCL Namur, Avenue Thérasse, 1, 5530, Yvoir, Belgium
*Corresponding author :Pr. Eloy Philippe
HNS & ENT Department, CHU Dinant - Godinne, UCL Namur, Avenue Thérasse, 1, 5530, Yvoir, Belgium
Tel: 003281423705; Fax: 003281423703
E-mail: [email protected]
Received: May 15, 2014 Accepted: October 29, 2014 Published: December 05, 2014
Citation: Eloy P, Marlair C, de Dorlodot CL, Weynand B (2014) Maxillary and Sphenoid Sinus Fungus Ball: A Single Belgian Centre's Experience. J Otol Rhinol 3:6. doi:10.4172/2324-8785.1000198


Maxillary and Sphenoid Sinus Fungus Ball: A Single Belgian Centre's Experience

Background: Fungus ball describes the non invasive accumulation of dense fungal concrements in a sinus cavity. Bone, blood vessels, submucosa and sinus mucosa are free of fungal elements. It usually occurs in immunocompetent adults. It can involve the maxillary or the sphenoid sinus.

Methodology: We reviewed the files of 66 patients treated for sinus fungus ball (SFB) in the ENT department of the CHU Dinant - Godinne during the past 15 years. Our cohort of patients was divided in 2 groups. The first group comprised the patients with maxillary fungus ball (MSFB) (n = 50 patients) and the second with sphenoid fungus ball (SSFB) (n = 16 patients). Clinical presentation, imaging and surgical treatment were recorded.

Results: Patients with MSFB complained more frequently of postnasal drip whereas retroocular pain was more common in the group of SSFB. On CT scans, an heterogeneous partial or complete opacity of the affected sinus with sclerosis of the bony walls was present in both groups. Microcalcifications were much more common in the group of MSFB. The definitive diagnosis was made by the pathologist in all the cases. When positive (n = 13/55), Aspergillus fumigatus grew on culture. Fungus balls were treated by surgery (mainly endonasal approach) with a success rate of 91%. It consisted of a complete removal of the fungal hyphae with preservation of the healthy mucosa and restoration of the aeration and drainage of the sinus. Surgery mainly consisted of a middle antrostomy in the first group and a sphenoidotomy performed via the sphenoethmoidal recess in the second one.

Conclusions: The clinicians must be aware of this entity in case of a unilateral symptomatic rhinosinusitis persisting despite appropriate medical treatment. A biopsy of the mucosa adjacent to the fungus ball must be performed to rule out any invasion within the tissues.

Keywords: Fungus ball; Maxillary sinus; Sphenoid sinus; Histology; Diagnosis; Imaging; Functional endoscopic surgery


Fungus ball; Maxillary sinus; Sphenoid sinus; Histology; Diagnosis; Imaging; Functional endoscopic surgery


Fungi are ubiquitous microorganisms producing volatile spores. Their concentration depends on environmental conditions. Humans are in permanent contact with fungal elements but fungal diseases are fairly rare. The entire respiratory system (nose, paranasal sinus cavities, bronchi and lungs) can be involved by fungal disease [1].
Aspergillus species is the most commonly reported cause of fungal sinusitis in Europe followed by dematiaceous fungi [2,3].
The most common classification of fungal rhinosinusitis (FRS) is based upon pathological findings [4]. This classification divides the FRS in two categories: the “invasive” and “non-invasive” FRS [5-7].
Invasive FRS (IFRS) is characterized by the infiltration of the tissues by the fungus. It includes three clinical entities: acute (fulminant) IFRS, granulomatous IFRS and chronic IFRS. Typically, these types of fungal infection affect immunocompromised patients [7].
Non-invasive FRS (NIFRS) is also called extra-mucosal FRS because the fungus develops on the sinus mucosa without invasive or granulomatous changes. NIFRS includes saprophytic fungal infestation, eosinophil related FRS and fungus ball [4-7].
Fungus ball is the most prevalent presentation of NIFRS [8-13]. It describes the non invasive accumulation of dense fungal concrements in a single sinus cavity, usually the maxillary sinus. It affects immunecompetent adults.
The pathogenesis of fungus ball remains unclear. Two ways of entry of the fungus have been suggested: the so-called “aerogenic” pathway, which is the most common and the odontogenic “iatrogenic” pathway [12, 14-18].
The authors report a retrospective study of cases treated for a SFB during the past 15 years (from May 1998 and June 2013) in the ENT department of the CHU Dinant - Godinne.

Materials and Methods

This study includes a cohort of 66 patients. They were divided in two groups: the first one was treated for a fungus ball involving the maxillary sinus (MSFB) and the second one for a fungus ball in the sphenoid sinus (SSFB). The mean follow-up was 27 months (range: 1-126 months).
All the patients had a detailed medical history taking, a flexible nasal endoscopy and a sinus CT scan. In some cases a MRI completed the assessment.
The definitive diagnosis was made by the pathologist.
Culture was performed in 55 out of 66 patients.


The first group (MSFB) included 50 patients. There were 28 females and 22 males. The sex ratio (F/M) was 4/3 and the average age was 54 years (range: 26-89). All were immune-competent.
49 patients had symptoms and signs mimicking chronic rhinosinusitis without polyp. Indeed 36 patients complained with purulent rhinorrhea, 26 with facial pain, 20 with nasal obstruction and 6 patients had cacosmia (Figure 1). These four symptoms were frequently associated at varying degrees.
Figure 1: Comparison between symptomatology and radiology.
In one case the diagnosis was suggested incidentally by CT scan performed in a context of brain trauma.
Nasal endoscopy was normal in 12 patients and showed black concretions in 7 patients.
In the other cases endoscopic findings consisted of either an inflammation of the mucosa of the middle meatus or purulent secretions.
On CT scans, the disease was unilateral in 48 out of 50 cases and microcalcifications were demonstrated in 80% of patients (Figure 1). The opacity of the maxillary sinus was heterogeneous and complete in 15 patients and partial in 35 patients. A dental origin was found in 11 patients who underwent an endodontic treatment in the past with overfilling of the dental root canal with zinc oxide.
Two patients underwent a MRI to rule out a tumoral aetiology.
The surgical treatment consisted of a middle antrostomy in all patients (Figure 2A & 2B). In 19 patients an inferior antrostomy was also performed. A limited approach through the canine fossa was required in 6 patients.
Figure 2: (A) Coronal CT-maxillary fungus ball - right maxillary sinus with microcalcification - preoperative view; (B) Coronal CT - postoperative view - middle antrostomy; (C) Axial CT - sphenoid fungus ball -preoperative view; (D) Axial cut - postoperative view – sphenoidotomy.
The operative samples were analyzed by the pathologist. They did not show any sign of allergic mucin, fungal invasion, granulomatous reaction or malignancy.
Mycological studies were performed on 41 samples. The fungal culture was positive only in 10 of them. Aspergillus fumigatus was the causative agent.
Until now, 6 recurrences were diagnosed, requiring revision surgery. The latter was performed endonasally. It consisted of a middle antrostomy in 4 cases, associated with an inferior antrostomy in 2 other cases.
The second group (SSFB) included 16 immunocompetent adults. There were 10 females and 6 males. The sex ratio (F/M) was 2/1. The average age was 63 years old (range: 37-81).
The major clinical symptoms were retro- or periorbital pain associated with postnasal dripping. Other symptoms such as nasal obstruction (n=5) and cacosmia (n=1) were also reported. 2 patients had diplopia due to a 6th cranial nerve palsy (Figure 1).
Nasal endoscopy detected abnormalities (edema, polyp or secretion) in the sphenoethmoidal recess (SER) in 6 patients. On CT scans, the disease was unilateral in 11 cases with complete sinus opacity in 10 patients. Sclerosis or thickening of the bony walls was visualized in 12 cases, while microcalcifications were quite rare (n = 4) (Figure 1). Six patients underwent an MRI which was of some help in the differential diagnosis.
In 10 out of 16 cases, the surgical treatment consisted of a pure endonasal sphenoidotomy performed through the sphenoethmoidal recess (Figure 2C & 2D). In 2 patients, a posterior ethmoidectomy was carried out in addition to the sphenoidotomy. Four patients underwent a paraseptal sphenoidotomy with resection of the posterior part of the nasal septum and drilling of the anterior walls of both sphenoid sinuses.
Mycological analysis was performed on 14 samples. The culture was positive for Aspergillus fumigatus in 3 of them. No revision surgery was required in this group of patients.
Table 1: Differential diagnosis of fungal Rhinosinusitis.


Fungus ball is defined as the sequestration of a fungus within a solitary paranasal sinus cavity. The maxillary sinus is by far the most commonly involved followed by the sphenoid and the ethmoid sinuses [10-13].
The disease affects immunocompetent older adults (mean age between 50 and 60) with a female predominance as we have noticed in this study.
Fungal rhinosinusitis is encountered in about 10% of the patients requiring surgery for the nose and the sinuses [10,12,13,19,20] . Particularly, the prevalence of maxillary SFB in patients undergoing maxillary sinus surgery was 13% and 28,5% in 2 different studies [19,20]. Isolated sphenoid disease accounts for 1% and 2.7% of all sinus diseases [21,22] and the incidence of sphenoid SFB amongst these isolated sphenoid diseases varies from 4.5% to 26.8% [22-26].
In the majority of the cases fungal contamination comes from an aerogenic pathway. High quantity of fungal spores penetrates in the sinus through the natural ostium and finds favourable conditions to their growth and subsequent sequestration such as hyperplasia of the mucosa, decreased mucociliary clearance and obstruction of the main ostium [10-13].
In some cases of maxillary sinus fungus ball an odontogenic pathway has been suggested and was likely in 6 of our cases [14-18,27,28]. The first author to point out the relationship between teeth and fungal infection was Pr Legent in France in 1989 [14]. Since then there have been more and more literature demonstrating that root canal treated teeth with overextension of the root canal sealer or solid materials such as gutta-percha or silver cones into the sinus might be the main etiological factor for aspergillosis of the maxillary sinus in healthy patients. Root-filling materials based zinc oxide-eugenol is considered to be a growth factor for aspergillus. Zinc can play a role of foreign body when it is present in the lumen of the sinus [27]. It also produces an inflammatory reaction, decreases the mucociliairy clearance and promotes the growth of Aspergillus.
The symptoms associated to a sinus fungus ball are nonspecific [1,4,10-13,24-26,30-33]. They are usually of long duration (months or years). They mimic signs of chronic rhinosinusitis without polyp. Maxillary SFB causes postnasal dripping associated with facial pain, nasal congestion, rhinorhea and cacosmia [2-4,10-13,19,20,29-33]. Headache and postnasal dripping are more common complaints in case of sphenoid SFB. The pain often occurs during the night, is perior retro-orbital or localized at the vertex and is described as deep, intermittent, exacerbated by standing, walking and coughing [1,24,34-39]. In practice, the persistence of unilateral complaints of rhinosinusitis despite a well-conducted medical treatment must draw the clinician's attention to such a disease [1].
Without any treatment, SFB can lead to different complications particularly in case of sphenoid sinus infection [1,24,34,36,37,39]. The sphenoid SFB can cause orbital and intracranial complications. Compression of the optic nerve leads to blindness. None of our patients had such a complication but 2 patients had diplopia due to compression of the 6th cranial nerve. Fortunately the diplopia resolved after the surgery. The proximity of sphenoid sinus with meningoencephalic structures may explain the development of other complications such as meningitis or brain abscess.
Fungus ball can be asymptomatic. The detection of SFB is then incidental, during an imaging of brain or sinuses as it was the case for one of our patients. In the literature the prevalence of asymptomatic FB varies from 10 to 20% of cases [10,11,30-33].
Diagnosis is based on physical examination, imaging, and biopsy.
Nasal endoscopy reveals mild to no mucosal inflammation with 10% of patients having polyps [40]. Black concretions are pathognomonic of a SFB but this finding is quiet rare. We had 7 patients with fungus mass in the middle meatus.
The most common imaging modality utilized is computed tomography [1,11,12,30-33,37,40,41]. On CT scans, the disease involves a single sinus in 59-94% of cases with complete or subtotal opacification of the involved paranasal sinus cavity, bony sclerosis and microcalcifications. Complete opacification is more common in the sphenoid sinus (63%) than in the maxillary sinus (30%). Sclerosis of sphenoid and maxillary bony walls was found in respectively 75% and 70% of cases. However bony destruction can be seen, in 3.6-17% of cases [30]. Pseudotumoral aspect of the disease was found in 12% of our patients. Microcalcifications are much more common in MSFB (80%) than in SSFB (25%) [1,10-14,24,31,32,35,36].
In case of pseudotumoral aspect or when doubt exists, a MRI can be helpful to make the differential diagnosis with a tumor. The MRI shows the SFB as a nodular and heterogenous iso- or hypointensity on T1-weighted images, and a marked hypointensity on T2-weighted images which does not enhance after injection of gadolinium, in contrast to an enhancement of the inflammatory adjacent sinus mucosa [1,24,30,32,36,37,40,41].
The definitive diagnosis of fungus ball is made by histological analysis of the surgical samples [1,8-11,20,30,32,41,42]. It has been performed in all patients of the study. Morphologically, Aspergillus species are usually described as thin, septated, acute-angle (45°) or dichotomous branching hyphae. The pathologist can confuse them with Mucorales that produce wide, thin-walled hyphae with few septations and right-angle branching. The microscopic appearance of SFB is described as matted, dense conglomerations of hyphae separated from, but adjacent to the respiratory mucosa of the sinus without invasion or granulomatous reaction. The haematoxylin-eosin staining confirms the absence of an allergic mucin. The sinus mucosa is free of hyphae even at the the Gomori-methenamine-silver stain. However acute or chronic inflammatory infiltrate with lymphocytes, plasma cells, mast cells and eosinophils without an eosinophil predominance or a granulomatous responses may be present in adjacent mucosa [41,42].
The sensitivity and specificity of the histopathological analysis are significantly higher than those of the mycological analysis performed on a routine basis on Sabouraud dextrose agar. Aspergillus sp . was the sole fungus that grew on culture. This was the case in only 13 out of 55 samples (24%). The literature reports values around 30% [1,24,30-32,37,41-43]. Some explanations for this is the poor viability, slow growth and special nutritional requirements of certain fungi. More sophisticated methods of identification are available nowadays such as PCR or hybridization but there are not used on a routine basis.
The treatment of a SFB is exclusively surgical [1,10-13,20,24-26,30-32,36,37,40,41,43,44] and consists of a complete extirpation of the fungal mass, with preservation of the healthy mucosa and re-establishing the drainage from the affected sinus. Irrigation of the affected sinus with saline at high pressure and use of angled forceps and endoscopes are recommended to facilitate the procedure.
A symptomatic patient with opacification of the sinus and bone erosion merits surgical evacuation, however the same line of management in a patient who is asymptomatic is controversial.
Intraoperatively the gross appearance of the fungus is cheesy and clay-like, breaking-up into fragments, the color of which ranges from brown to black to green or yellow.
Concerning maxillary SFB, all our patients underwent a middle antrostomy. In 19 patients, an inferior antrostomy was associated to the middle antrostomy. We recommend this association in case of a SFB close to the anterior wall or the floor of the maxillary sinus. The use of 30°, 45° and 70° rigid endoscopes is recommended to inspect all the recesses of the maxillary sinus for any residual fungal debris [25,32].
When the fungal mass cannot be completely removed via an endonasal approach a limited approach through the canine fossa can be recommended [12,45,46]. That is what we did in only 6 patients.
Concerning the sphenoid SFB, 63% of our patients underwent a pure unilateral sphenoidotomy consisting of a widening of the natural ostium, performed through the sphenoethmoidal recess. Intraoperative irrigations must be performed at low pressure as the bony canal of the optic nerve and carotid artery can be dehiscent. In case of lateral position of the concretions or if the sinus is well pneumatised, it was preferable to associate the sphenoidotomy with a posterior ethmoidectomy (12% of our patients). Finally, we recommend a paraseptal approach with drilling of the anterior walls of both sphenoid sinus and resection of the posterior part of the nasal septum when sphenoid sinuses are small and their walls highly sclerotic (25% of our patients). This approach is also recommended for revision surgery.
In all cases, a biopsy of the mucosa adjacent to the fungus ball is mandatory to rule out any invasion within the tissue. The removal of all the sinus mucosa is performed only in case of significant hyperplasia [2,4,13,20 25,31,32,37,40].
Sinus surgery is associated with a high success rate in the literature [1,11,13,25,26,36,37,40,43,44] and recurrences typically occur when fungal debris remain in the sinus cavity [44]. We experienced 6 revision surgeries in the group of maxillary fungus ball; the overall success rate was 91% in our institution.
Antifungal therapy is not required unless the patient is at high risk for invasive disease or in case of pseudotumoral form of sphenoid sinus FB. In this cohort of patients we did not use it.


Sinus fungus ball is a disease that affects mainly older immunocompetent adults. The maxillary sinus is the first location followed by the sphenoid sinus. The diagnosis is suggested by persistence of symptoms and signs of rhinosinusitis despite a wellconducted medical treatment. The maxillary SFB is more frequently associated with chronic postnasal dripping while sphenoid fungus ball is associated with retro-orbital pain. On CT scans the disease is suspected in case of partial or complete heterogeneous opacification of the sinus, sclerosis of the bony walls and microcalcifications. These hyperdensities are much more common in case of maxillary SFB than in sphenoid SFB. The treatment is surgical. Endoscopic sinus surgery is the treatment of choice today. It consists in a complete removal of the fungal concretions with preservation of the healthy mucosa and restoration of the drainage pathway of the sinus. The erstwhile external approaches should be reserved to some specific and exceptional cases. Biopsy of the mucosa adjacent to the fungus ball is mandatory to rule out any invasion within the tissues. Pathological examination is also required to determine the fungal species because standard mycological studies are frequently negative.


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