Bilateral transversely clefted middle turbinates.

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A 53-year-old woman presented with a history of sinusitis for more than 2 years despite treatment with multiple rounds of antibiotics, twice-daily sinus rinses, and treatment with azelastine nasal spray. She had symptoms of throat drainage, congestion, and maxillary and intercanthal pressure. Allergy testing in the past had been negative.

Anterior rhinoscopy revealed patent nares and a midline septum. On nasal endoscopy with a 0[degrees] scope, the nasal mucosa appeared healthy and without significant edema or erythema. The inferior turbinates demonstrated normal anatomy. However, both middle turbinates exhibited an uncommon bilobed configuration. The anterior lobe was separated from the more laterally located posterior lobe with a transverse cleft (figure 1). Palpation of the lobes confirmed that they indeed were firm turbinate tissue, not nasal polyps.

Computed tomography (CT) of the paranasal sinuses demonstrated the anatomic relationship of the two lobes of the middle turbinates (figures 2 and 3). The anterior lobe of the left middle turbinate was partially pneumatized. The posterior lobe more closely crowded the uncinate process and potentially narrowed the ostiomeatal complex. Mild mucosal inflammation was seen in the anterior ethmoid and maxillary sinuses, as well as at the ostiomeatal complex. An accessory ostium in the posterior fontanel was present bilaterally.

Many variations of the middle turbinate exist, some of which are theorized to cause disease as they obstruct nasal outflow. Joe et al cataloged nasal anatomic variations in 119 consecutive patients at the time of sinonasal surgery. (1) Normal middle turbinate anatomy was seen in 63%; a sagittal cleft--appearing as a groove along the inferior border of the middle turbinate running parallel to the floor of the nose--was noted in 6%; and a transverse cleft--as seen in our patient-was found in only 0.5%. (1)

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Clefting of the middle turbinate may result from an interruption in its development, as bilobed middle turbinates are seen more commonly in fetuses than in adults. (2) Clefted middle turbinates theoretically can lead to ostiomeatal unit obstruction, but they likely also exist asymptomatically. Familiarity with this anatomic variation, which can otherwise masquerade as a polyp or a tumor, is helpful in improving the safety and efficacy of sinus surgery.

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References

(1.) Joe JK, Ho SY, Yanagisawa E. Documentation of variations in sinonasal anatomy by intraoperative nasal endoscopy. Laryngoscope 2000; 110(2 Pt 1):229-35.

(2.) Rossiter JL. Sagittally-clefted middle turbinate: An endoscopic view. Ear Nose Throat J 1995;74(7):452-3.

Laura M. Dooley, MD; C.W. David Chang, MD