Copyright © 2017 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited. Rapidly Progressive Maxillary Atelectasis Ahmad Elkhatib, MD,  Kyle McMullen, MD,  Ralph Abi Hachem, MD,  Ricardo L. Carrau, MD, y and Nicholas Mastros, MD z Objective: Report of a patient with rapidly progressive maxillary atelectasis documented by sequential imaging. Clinical Report: A 51-year-old man, presented with left periorbital and retro-orbital pain associated with left nasal obstruction. An initial computed tomographic (CT) scan of the paranasal sinuses failed to reveal any significant abnormality. A subsequent CT scan, indicated for recurrence of symptoms 11 months later, showed significant maxillary atelectasis. An uncinectomy, maxillary antrostomy, and anterior ethmoidectomy resulted in a complete resolution of the symptoms. Conclusion: Chronic maxillary atelectasis is most commonly a consequence of chronic rhinosinusitis. All previous reports have indicated a chronic process but lacked documentation of the course of the disease. This report documents a patient of rapidly progress- ive chronic maxillary atelectasis with CT scans that demonstrate changes in the maxillary sinus (from normal to atelectatic) within 11 months. Key Words: Chronic maxillary atelectasis, chronic rhinosinusitis, complication, imploding antrum syndrome, silent sinus syndrome C hronic maxillary atelectasis (CMA) is an uncommon con- sequence of chronic rhinosinusitis. It is characterized by chronic antral remodeling, as a result of abnormal outflow and ventilation of the sinus. This can cause orbital and midface asym- metry, which frequently is the presenting symptom. In the absence of chronic sinus disease, this is known as silent sinus syndrome. We describe the development of chronic maxillary atelectasis over a relatively short period of time in an adult patient. CLINICAL REPORT A 51-year-old man presented with a 3-month history of mild, slowly progressive dull left periorbital and retro-orbital pain associated with left nasal obstruction, without visual or facial changes. Symp- toms had arisen the previous summer while he was mowing his lawn. Patient denied any history of chronic sinusitis, previous nasal/ sinus surgery, or nasal spray use. Of note, a noncontrasted computed tomographic (CT) of the paranasal sinuses had been obtained 11 months prior for similar symptoms. This scan was deemed unre- markable, and his symptoms resolved shortly thereafter (Fig. 1A). Endoscopic endonasal examination revealed a septal spur impinging upon the superior aspect of the left inferior turbinate and middle meatus with no evidence of acute sinusitis or polyps. A noncontrasted CT scan was obtained due to progression of symp- toms, revealing new bowing of the posterior wall of the left maxillary sinus and moderate thickening of the maxillary sinus mucosa, partial dehiscence and inferior displacement of the floor of the orbit, and lateralization of the uncinate process and middle turbinate (Fig. 1B). Given the interval change in CT imaging, with anterior bowing of the posterior maxillary sinus wall and apparent enlargement of the pterygopalatine fossa, a contrasted magnetic resonance imaging was obtained confirming the antral deformity without an associated lesion in the pterygopalatine or infratemporal fossae. The recurrence of symptoms and imaging findings prompted a recommendation to proceed with endoscopic sinus surgery. Intraoperatively, a large septal spur was noted to be displacing the left middle turbinate and obstructing the osteomeatal complex. An endoscopic removal of the spur gained space for instrumenta- tion and provided access to the middle meatus. Both the middle turbinate and uncinate process were noted to be flaccid and lateralized. An uncinectomy and subsequent middle turbinectomy confirmed that the bone of both structures had been resorbed. After the uncinectomy, the maxillary os was identified at a position that was significantly more inferior than expected (appar- ently the floor of the orbit has descended displacing the os inferiorly). The os was enlarged posteriorly and inferiorly to provide better drainage and to inspect the posterior wall of the antrum. Samples of the thickened mucosa were taken for cultures and sensitivities and for histological analysis. A total ethmoi- dectomy was performed. His lamina papyracea was very thin and medially displaced. The patient was discharged home shortly after the procedure. On the basis of imaging and intraoperative findings, our patient was diagnosed with Stage II chronic maxillary atelectasis. Patho- logic examination of the sinus contents revealed normal respiratory mucosa with suggestion of an inclusion cyst. All symptoms had resolved upon a follow-up visit 4 weeks later. DISCUSSION Chronic maxillary atelectasis is a descriptive term, which refers to the progressive decrease of maxillary sinus volume and inward bowing of its walls. It is an uncommon cause of sinonasal symp- toms; however, its associated bony remodeling (ie, collapse) can lead to midface asymmetry and enophthalmos, which may be the presenting symptomatology. Conversely, asymptomatic atelectasis is termed silent sinus syndrome. Chronic maxillary atelectasis has been categorized into 3 stages according to the degree of deformity as follows. Stage I: membranous deformity only (ie, lateralization of the uncinate process). Stage II: bony deformity identified either radio- graphically or intraoperatively. Stage III: clinical deformity, either of the midface or orbit. 1,2 According to this scheme, Sporakar definition of silent sinus syndrome would be considered stage III. 3 However, silent sinus syndrome is currently recognized as a constellation of a group of clinical and radiological manifestations. Painless enophthalmos and/or hypophthalmos in the absence of sinonasal inflammatory symptoms are the most frequently reported clinical manifestations of this entity. Many reports of chronic maxillary atelectasis and silent sinus syndrome describe obvious mid-facial asymmetry and enophthalmos as the presenting symptoms; however, clinicians must be aware that either disease can occur without evident deformity. 3–8 In this report, the patient had progressive left-sided nasal obstruction and facial/retro-orbital pain. From the  Department of Otolaryngology—Head and Neck Surgery; y Department of Neurological Surgery, The Ohio State University Wex- ner Medical Center, Columbus; and z Trinity Health System, Steuben- ville, OH. Received January 20, 2016; final revision received May 2, 2016. Accepted for publication May 10, 2016. Address correspondence and reprint requests to Nicholas Mastros, MD, Ear, Nose and Throat, Trinity Health System, 2315 Sunsent Blvd, Steubenville, OH 43952; E-mail: Mastros5@yahoo.com The authors report no conflicts of interest. Copyright # 2017 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000002890 BRIEF CLINICAL STUDIES The Journal of Craniofacial Surgery  Volume 00, Number 00, Month 2017 1