An absence of cilia outer microtubules, an etiology not previously recognized in bilateral mucocele.
Most paranasal sinus mucoceles are unilateral and affect one or at most two contiguous sinuses. We describe the case of a 44-year-old woman with bilateral maxillary sinus mucoceles who presented clinically with left malar pain, right-sided swelling, and proptosis of the right eye. The diagnostic workup included computed tomography and magnetic resonance imaging. In addition, because of the atypical bilateral presentation, we analyzed mucosal sinonasal tissue samples by electron microscopy. Microscopic analysis revealed an absence of one of the microtubule doublets in three of the outer doublets of the axoneme, thereby establishing a diagnosis of isolated ciliary dysfunction. To the best of our knowledge, ciliary dysfunction as a cause of bilateral mucoceles has not been previously reported in the literature. The patient underwent successful surgery for removal of the mucoceles, and she exhibited no evidence of recurrence at the 18-month follow-up. When a diagnosis of bilateral mucocele formation is made, we suggest that ciliary dysfunction be considered in the differential diagnosis and that electron microscopy of the sinonasal mucosa be performed in the workup.
Most paranasal sinus mucoceles are unilateral and affect one or at most two contiguous sinuses. They produce dilation of the involved sinus, as its interior fills with mucus produced by the mucosa. They usually arise as a result of occlusion of the sinus ostium, which can occur secondary to inflammation, scarring, or a neoplasm. (1-3)
Bilateral mucoceles are rarely reported. They can occur secondary to surgery, a papillomatous tumor, or chronic inflammation, and they might be related to mucous abnormalities or primary ciliary dyskinesia. (1-3)
The histologic appearance of mucoceles is remarkable given the intense intralesional pressure. They exhibit strips of flattened ciliated columnar epithelium with bone remodeling and chronic inflammation. (4)
Primary ciliary dyskinesia is a rare, genetically heterogeneous disorder that results in impairment of mucosal ciliary movement. It usually manifests as recurrent and chronic infections of the upper and lower airways. (1) The structure of the ciliary apparatus consists of a microtubule-base-daxoneme, which is a highly ordered structure made up of nine peripheral microtubule doublets that are arranged around a central core. This core might or might not contain two central microtubules (a 9 + 2 axoneme and a 9 + 0 axoneme, respectively). The cilia of the 9 + 2 axoneme usually contain dynein arms that link the microtubule doublets, and the cilia are motile. Most cilia of the 9 + 0 axoneme lack dynein arms, and they are nonmotile. Mutations of two genes--DNA11 and DNAH5--account for about 30 to 50% of all cases of primary ciliary dyskinesia, and they are responsible for the defects in the outer dynein arms. (1,5)
In this article, we describe a case of bilateral maxillary sinus mucoceles that featured an absence of one of the microtubule doublets in three of the outer doublets of the axoneme, thereby establishing a diagnosis of isolated ciliary dysfunction.
A 44-year-old woman presented with a 7-month history of left malar pain, right-sided swelling, and proptosis of the right eye. Previously, her dentist had performed a left upper canine extraction. During that procedure, the dentist had found a bulking lesion in the alveolar canine area that was filled with mucinous fluid.
On physical examination at our institution, we observed preserved vision in both eyes, but with a limitation of downward movement of the right eye. Nasal endoscopy detected swelling in the right lateral nasal wall and a white polypoid mass with smooth edges in the left nasal lateral wall. Both middle meatuses were without purulent discharge. Findings on the remainder of the examination were normal.
The diagnostic workup included computed tomography (CT) and magnetic resonance imaging (MRI), which clearly demonstrated the bilateral masses in the maxillary sinuses (figure 1). Because of the atypical bilateral presentation of the mucocele, we also performed electron microscopy to examine sinonasal mucosa tissue samples. This analysis revealed an absence of one of the microtubule doublets in three of the outer doublets of the axoneme (figure 2). To rule out etiologies such as cystic fibrosis and Kartagener syndrome, we obtained a chest x-ray and performed a chloride-in-sweat test; findings were normal. Our final diagnosis was isolated ciliary dysfunction.
The patient underwent endoscopic sinus surgery with a medial inferior left endoscopic maxillectomy. The mucoceles were drained via a sublabial approach and endoscopic right mucopyocele drainage.
The surgical outcome was satisfactory. Follow-up CT performed 18 months later detected no sinonasal disease.
The presence of mucoceles in both maxillary sinuses is a rare presentation, accounting for only 4% of all reported cases of mucocele. (2,3) When bilateral cases do occur, most are bilaterally symmetrical; asymmetrical sinus involvement with or without orbital complications has rarely been reported. (2,3) Maxillary sinus involvement is also uncommon, accounting for less than 10% of all mucocele cases. (2,3)
Many bilateral mucoceles are pseudomucoceles that arise as a result of mucus abnormalities or primary ciliary dysfunction, as is the case with cystic fibrosis or Kartagener syndrome; this presentation is commonly associated with a rhinobronchial syndrome. (2,3) Our patient presented without chronic rhinosinusitis symptoms. Because of her atypical presentation, we suspected ciliary dysfunction. Analysis of the sinus mucosa under electron microscopy found alterations of the cilia, which explained the underlying pathophysiology of the mucocele formation. (5) To the best of our knowledge, such a cause of bilateral maxillary mucoceles has not been previously described in the literature.
As far as we know, only 1 case of mucocele secondary to primary ciliary dyskinesiahas been reported. (1) In that case, a 12-month-old boy who presented with such a mucocele and ipsilateral proptosis was found to have an absence of the inner dynein arms linking the microtubule doublets. Our case involved alterations of the outer microtubules. The variations of the ciliary alterations may explain the different clinical presentations in these two cases.
We suggest that in addition to endoscopy and imaging studies, otolaryngologists should consider performing electron microscopy and measuring levels of chloride in sweat in cases of bilateral or atypical mucocele formation (figure 3).
Javier E. Spinola-Hernandez, MD; Andres E. Castell-Rodriguez, MD; Hector M. Prado-Calleros, MD; Gerardo A. Bravo-Escobar, MD; Andres Sadek-Gonzalez, MD
From the Division of Otolaryngology-Head and Neck Surgery, General Hospital "Dr. Manuel Gea Gonzalez," Mexico City (Dr. Spinola-Hernandez, Dr. Prado-Calleros, Dr. Bravo-Escobar, and Dr. Sadek-Gonzalez); and the Department of Cell Biology and Tissue, National Autonomous University of Mexico, Mexico City (Dr. Castell-Rodriguez). The case described in this article occurred at General Hospital "Dr. Manuel Gea Gonzalez."
Corresponding author: Hector M. Prado-Calleros, MD, Division of Otolaryngology-Head and Neck Surgery, General Hospital "Dr. Manuel Gea Gonzalez," Calzada de Tlalpan 4800, Colonia Seccion XVI, Delegacion Tlalpan, 14080 Mexico City, Mexico. Email: firstname.lastname@example.org
(1.) Berlucchi M, Maroldi R, Aga A, et al. Ethmoid mucocele: A new feature of primary ciliary dyskinesia. Pediatr Pulmonol 2010;45(2):197-201.
(2.) Varghese L, John M, Kurien M. Bilateral asymmetric mucoceles of the paranasal sinuses: A first case report. Ear Nose Throat J 2004;83(12):834-5.
(3.) Chong AW, Prepageran N, Rahmat O, et al. Bilateral asymmetrical mucoceles of the paranasal sinuses with unilateral orbital complications. Ear Nose Throat J 2011;90(2):E13.
(4.) Thompson LD. Paranasal sinus mucocele. Ear Nose Throat J 2012;91(7):276-8.
(5.) Bisgrove BW, Yost HJ. The roles of cilia in developmental disorders and disease. Development 2006; 133(21):4131-43.
Caption: Figure 1. A: Coronal CT shows the homogeneous isodense soft-tissue mass occupying both maxillary sinuses with bone remodeling of their walls, including the orbital floor. B: Axial T2-weighted MRI demonstrates the hyperintense cystic masses in both maxillary sinuses and the expansion of the orbital floor.
Caption: Figure 2. Electron microscopy demonstrates the absence of an outer microtubule in three of the nine external doublets of the cilia (one of them is highlighted).
Caption: Figure 3. Flow chart shows our suggestion for the diagnosis of ciliary dysfunction.
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|Title Annotation:||ORIGINAL ARTICLE|
|Author:||Spinola-Hernandez, Javier E.; Castell-Rodriguez, Andres E.; Prado-Calleros, Hector M.; Bravo-Escobar|
|Publication:||Ear, Nose and Throat Journal|
|Date:||Apr 1, 2018|
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