Naturally draining ostium of an agger nasi cell: a case report.

Abstract

We describe the case of a 61-year-old woman who underwent functional endoscopic sinus surgery for chronic hyperplastic rhinosinusitis. During surgery, we were able to visualize the natural ostium of her left agger nasi cell. To our knowledge, such a finding has not been previously documented in the literature.

Introduction

The prevalence of the agger nasi cell in the general population is not known with certainty. Jones et al found evidence of agger nasi cells on computed tomography (CT) in 191 of 200 individuals (95.5%). (1) In their study, 100 patients (50.0%) had evidence of paranasal sinus disease, including 95 who had CT evidence of an agger nasi cell. Of the remaining 100 patients (controls), who did not have sinus disease, 96 exhibited CT evidence of an agger nasi cell. From these findings, it appears that agger nasi cells are very common and their presence or absence is not directly associated with sinus pathology. Other studies have found a lower incidence of agger nasi cells. For example, Lang found agger nasi cells in 45 of 58 cadavers (77.6%). (2)

In this article, we describe our discovery of a naturally draining ostium of an agger nasi cell. It was exposed during functional endoscopic sinus surgery for chronic hyperplastic rhinosinusitis.

Case report

We evaluated a 61-year-old woman for nasal complaints that had persisted for more than 5 years. She reported both facial and ear fullness, a constant nasal drip of clear to yellow mucus, nasal congestion, sneezing, and a decreased sense of smell. A brief course of antibiotics had provided temporary relief in the past.

We prescribed a 4-week course of guaifenesin/pseudoephedrine, a topical nasal steroid, and cefuroxime, but her nasal symptoms returned following the completion of treatment. Post-treatment CT demonstrated thickening in the ethmoid and maxillary sinuses; a single frame from this scan showed the agger nasi cell (figure 1).

[FIGURE 1 OMITTED]

The patient underwent septoplasty, left concha bullosa resection, bilateral anterior and posterior ethmoidectomies, bilateral maxillary antrostomies, and bilateral inferior turbinate outfracture. During endoscopic surgery of her left nasal cavity, we noted an ostium at the location of the left agger nasi cell (figure 2). The ostium was well developed, with smooth mucosa overlying the opening. The left agger nasi cell was opened widely with a microdebrider, and her natural ostium was sacrificed as the floor of the cell was resected.

At follow-up 2.5 years postoperatively, the patient had developed mild polypoid changes and had experienced one acute exacerbation of her nasal symptoms, which required antibiotic treatment.

Discussion

Believed to be a remnant of an additional concha found in lower animals, the agger nasi cell can be observed endoscopically as a bulge in the lateral nasal wall lying anterosuperior to the anterior aspect of the middle turbinate. (3,4) It represents the superior remnant of the first ethmoturbinal concha. The most anterior of the ethmoid cells, the agger nasi cell is also the first to pneumatize in the newborn, and it is quite prominent throughout childhood. Between one and seven cells are present, and they usually drain into the frontal recess. (5)

The agger nasi cell is an important surgical landmark, particularly with respect to the frontal sinus. The roof of this cell forms the floor of the frontal sinus. Therefore, a well-pneumatized agger nasi cell can narrow the frontal sinus outflow tract, which might lead to chronic frontal sinusitis. (6) In such cases, it is often necessary to resect the walls of some or all of these cells.

This case featured an interesting endoscopic finding--that is, a natural ostium of an agger nasi cell. Normally, the upper aspect of the uncinate process is removed in an inferior to superior direction, thus opening the agger nasi cell. The natural ostium is not typically visualized because it lies directly above the upper uncinate process, and the two structures are removed simultaneously. To our knowledge, a natural draining ostium of an agger nasi cell has not previously been documented in the literature. Because the drainage pattern of a normal agger nasi cell is not clearly understood, we could not know whether this ostium was simply an accessory ostium similar to that of a maxillary sinus or whether it represented the true natural ostium of an agger nasi cell. However, based on our understanding of sinonasal anatomy and mucociliary clearance patterns, we believe that our endoscopic examination did indeed identify the natural ostium of an agger nasi cell. Further reports will need to be compiled before we are able to elucidate the role of a naturally occurring ostium of an agger nasi cell.

References

(1.) Jones NS. Strobl A. Holland I. A study of the CT findings in 100 patients with rhinosinusitis and 100 controls. Clin Otolaryngol 1997;22:47-51.

(2.) Lang J. Clinical Anatomy of the Nose, Nasal Cavity, and Paranasal Sinuses. New York: Thieme Medical Publishers, 1989:61.

(3.) Hollinshead WH. Anatomy for Surgeons. Vol. 1: The Head and Neck. 3rd ed. Philadelphia: Harper and Row, 1982:234.

(4.) Terrell JE. Primary sinus surgery. In: Cummings CW, ed. Otolaryngology--Head and Neck Surgery. 3rd ed. St Louis: Mosby, 1998: 1155-6.

(5.) Miller A J, Amedee RJ. Sinus anatomy and function. In: Bailey BJ, ed. Head and Neck Surgery-Otolaryngology. 2nd ed. Philadelphia: Lippincott-Raven, 1998:416.

(6.) Yanagisawa E, Joe JK. The surgical significance of the agger nasi cell. Ear Nose Throat J 1999:78:328-30.

From the School of Medicine, State University of New York at Stony Brook (Mr. Yoo); the Department of Otolaryngology--Head and Neck Surgery, Mayo Clinic, Scottsdale, Ariz. (Dr. Kim); and the Department of Otolaryngology--Head and Neck Surgery, School of Medicine, Case Western Reserve University, Cleveland (Dr. Houser).

Reprint requests: Steven M. Houser, MD, Department of Otolaryngology--Head and Surgery, MetroHealth Medical Center, 2500 MetroHealth Dr., Cleveland, OH 44109. Phone: [phone]; fax: [phone]; e-mail: [e-mail]

This article was prepared independent of any financial support from any external entity and was not presented at any meeting or conference.