The Aspergillus fungus of the Aschomycetes class is widespread in nature. Aspergillus spores are common contaminants of the respiratory tract, making it the most common fungal infection of the paranasal sinuses.(1) Aspergillosis of the sphenoid sinus as an isolated disease in an otherwise healthy person is rare. In 1977, Miglets and Saunders reported two cases of sphenoid sinus aspergillosis.(2) They noted that only four reports of isolated sphenoid sinusitis were known prior to 1977; among those four, three proved fatal. Due to the intimate anatomical relationship between the central nervous system and the ocular organs, isolated sphenoid sinus aspergillosis usually manifests as severe symptoms such as blurred vision, ptosis or meningitis. We recently treated two patients with isolated aspergillosis of the sphenoid sinus that were managed endoscopically with positive outcomes.

CASE REPORTS

Case 1
A 53-year-old woman visited our ear, nose and throat clinic principally complaining of bloody postnasal drip which had persisted for 2 weeks. Her symptoms were more evident in the morning. A sensation of fullness in the right ear was also present. She had no history of fever, chills, recent upper respiratory tract infection or mechanical injury to her nose or sinuses. Physical examination of the ear, nose, and throat showed negative findings. No purulent rhinorrhea, polyps nor underlying systemic disease was noted.
A computer tomography (CT) scan performed under the impression of nasopharyngeal carcinoma or sinus disease revealed a soft tissue density containing calcification in the right sphenoid sinus (Fig. 1), and isolated sphenoid sinusitis caused by fungal infection. Laboratory test results revealed blood glucose of 5.16 mmol/L (fasting) and anti-human immunodeficiency virus antibody test were negative.
We arranged functional endoscopic sinus surgery for this patient. We first resected the inferior third of the middle turbinate. The anterior sphenoid sinus wall was sclerotic, and consequently a posterior ethmoidotomy was performed. Through posterior ethmoidotomy, the natural ostium of the sphenoid sinus was entered. Brownish cheesy materials were found in the antrum. The materials were removed with forceps followed by warm saline irrigation and sent for pathologic examination. The sphenoidotomy was extended with curret and back-bite forceps. The wound was packed with Surgicels and Kaltostat? The packings were removed the next day, and the patient was subsequently discharged.
Histological sections from the specimens demonstrated fungal hyphae. Oral antibiotics (amoxicillin 1 g/day) were administered to prevent bacterial infection for 2 weeks, combined with local nasal treatment. No recurrence took place during the 6-month follow-up period.

Case 2
A 61-year-old woman visited our clinic reporting facial pain on the left side and occipital headaches for 2 months. Purulent rhinorrhea was also found. There was no history of sinus operations or trauma. Physical examination of the ear, nose, and throat only revealed mucopus in the left nasal cavity, and no underlying systemic disease was noted.
A sinus CT was performed which showed soft tissue density with calcification in the left sphenoid sinus (Fig. 2). Isolated sphenoid sinusitis was diagnosed clinically.
We arranged functional endoscopic sinus surgery for her. After resecting the inferior one-third of the middle turbinate, the natural ostium of the sphenoid sinus was accessed. Brownish cheesy materials were found in the sphenoid sinus. The materials were removed, irrigated, and sent for pathologic examination. The sphenoidotomy was extended with curret and back-bite forceps. The wound was packed with Surgicels and Kaltostat? The packings were removed the next day.
Histological sections from the specimens demonstrated fungal hyphae. Typical septate hyphae with acute angulation were confirmatory for aspergillosis (Fig. 3).
No antifungal agent was used either orally or intravenously. Oral antibiotics (amoxicillin 1 g/day) were administered to prevent bacterial infection for 2 weeks along with local nasal treatment. No recurrence took place during the 6-month follow-up period.

DISCUSSION

Aspergillosis is the most common fungal infection of the paranasal sinuses. The first clinical report of sinus mycosis was reported by Hernu and Plaingaud in 1791.(3) Arnico first described aspergillosis of the maxillary sinus in 1890.(4) The pathogenesis of a fungal infection of the paranasal sinuses is unclear, although, in general, mycotic spores are inhaled and most commonly seeded to the ethmoid and maxillary sinuses. Some authors indicated that the fungi became pathogenic under anaerobic conditions when the affected sinus ostium was occluded.(5)
After reviewing the available reports in the English literature, we found elderly women were the most common victims of isolated sphenoid aspergillosis. Lavelle et al.(6) presented a 60-year-old woman with isolated left sphenoid aspergillosis. Miglets(2) presented two patients, one 69-year-old man and the other a 57-year-old woman. Yiotakis et al.(7) presented four patients, and all of them were elderly women (45, 43, 55 and 77 years old, respectively). Both patients reported in this article were elderly women (50 and 61 years old, respectively). None of these patients were immunocompromised. After reviewing the medical histories of our patients, we found both were postmenopausal without regular hormone supplementation. Since endocrine changes may have certain effects on nasal mucosa, although not definitely clarified in the literature, we speculated that the predilection of an Aspergillus infection of the sinus in these patients might be a result of hormone changes due to aging.
As previously reported, isolated sphenoid sinus inflammatory diseases most frequently manifest as headaches (from 50% to up to 98%) and a retro-orbital pain.(8) In these patients, the predominant symptoms were quite diverse including blood-tinged sputum, facial pain, and headaches. Alertness of physicians in clinical practice is of the essence for efficient diagnosis and treatment of such sphenoid lesions.
On the CT scans of both patients, central dense areas were detected within the sphenoid sinus. These are usually found in aspergillosis of the paranasal sinuses and are due to calcium phosphate and, to a lesser degree, calcium sulphate accumulation in necrotic areas, towards the center of the fungal mass.(9,10) This sign is almost pathognomic for Aspergillus sinus infections. The use of magnetic resonance imaging was suggested by Lawson et al.(8) and Mukherji et al.(11) as an adjunct for differential diagnosis of sphenoid sinus fungal infection, as well as granulomatous and chronic invasive fungal sinusitis. In our experience, fungal infection caused by Aspergillus should first be considered when detecting this sign on CT scans.
For isolated sphenoid sinusitis, functional endoscopic sinus surgery has become the most commonly performed procedure, and it has been proven effective. In most cases, a sphenoidotomy was done after resection of the inferior third of the middle turbinate. However in some, the anterior walls of the sphenoid sinuses were sclerotic on CT scans, and markedly thickened intraoperatively. Consequently, the trans-posterior ethmoid approach would be a feasible alternative when sphenoidotomy is difficult.(12,13)
Fungal sinusitis has been classified into invasive and noninvasive forms. The noninvasive form has further been divided into aspergilloma and allergic fungal sinusitis.(7) The cases presented here are examples of aspergilloma. For aspergilloma, as experienced in these two patients, treatment with endoscopic sphenoidotomy and the establishment of adequate sinus drainage were sufficient. No residual disease or symptoms reappeared during the 6-month follow-up period. No post-operative antifungal agents were used. Systemic antifungal agents are only recommended when there are signs of invasion, such as mucosal involvement, extension to posterior ethmoidal cells, and involvement of orbit and meninges.

REFERENCES

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From the Department of Otolaryngology, Chang Gung Memorial Hospital, Taipei; Chang Gung University, Taoyuan.
Received: Jun. 7, 2001; Accepted: Dec. 3, 2001
Address for reprints: Dr. Ta-Jen Lee, Department of Otolaryngology, Chang Gung Memorial Hospital. 5 Fu-Shin Street, Kweishan, Taoyuan 333, Taiwan, R.O.C. Tel.: 886-3-3281200 ext. 3967; Fax: 886-3-3979361; E-mail: bigmac@cgmh.org.tw