Massive Radicular Cyst Involving the Maxillary Sinus: A Case Report
The radicular cyst is an inflammatory cyst associated with the root apex of a non-vital tooth. Because of the high incidence of pulpal pathology, it is the most common cyst of the oral and maxillofacial region. Most radicular cysts are small, but they can reach a large size. In this case, the cyst may cause displacement of surrounding structures. Such lesions may evoke more aggressive lesions. In the posterior part of the maxilla, a massive radicular cyst can displace the floor of maxillary sinus. In this situation, a careful interpretation of plain radiographs and/or CT images is necessary to differentiate between a lesion originating from the maxillary sinus and those from the maxilla. The purpose of this article was to report the case of a large radicular cyst that had displaced the floor of the maxillary sinus.
Keywords: Maxilla; Maxillary Sinus; Radicular Cyst; Jaw Cysts; Inflammatory Cyst; Massive lesion.
Ahmed Chkoura, Wafae El Wady, Bouchra Taleb. Massive Radicular Cyst Involving the Maxillary Sinus: A Case Report. International Journal of Oral & Maxillofacial Pathology; 2013:4(1):68-71. ©International Journal of Oral and Maxillofacial Pathology. Published by Publishing Division, Celesta Software Private Limited. All Rights Reserved.
Radicular cysts are the most common cystic lesions in the jaws (62% of odontogenic cysts); they arise from the epithelial residues in the periodontal ligament as a result of periapical periodontitis following death and necrosis of the pulp. Cysts arising in this way are found most commonly at the apices of the involved teeth. Quite often a radicular cyst remains behind in the jaws after removal of the offending tooth and this is referred to as a residual cyst.1 Most radicular cysts are small in size ranging from 0.5 to 1.5cm, but they can even exceed five centimeters. In the maxilla, sometimes, a cyst associated with molars or premolars may enlarge to such a point that it encroaches on almost the entire sinus, and the residual sinus space may appear as a thin saddle over the cyst.2 Radicular cyst associated with molars or premolars can reach large dimensions, so that it may extend toward the maxillary sinus and reducing it to a small cavity.1 The purpose of this paper is to report a case of large radicular cyst associated with residual roots of the first molar that has displaced forward the maxillary sinus floor.
A 30-year-old Moroccan male was referred by his dentist to our oral surgery Department, for evaluation and treatment of swelling on the right cheek (Fig 1a) that had started one year ago, according to the patient. Extraoral examination shows painless swelling limited at the top of the cheek below the zygoma, behind the nasolabial fold and in front of the front edge of the masseter. Nerve sensitivity was not altered and no lymphadenopathy was found. Intraoral examination revealed soft and fluctuant well-defined swelling extending from the second upper right premolar to the maxillary tuberosity (Fig 1b). The right upper first premolar was missing, the upper first molar was grossly carious with only root stumps remaining, the second premolar and the other molars were vital. The overlying mucosa was non-ulcerated and unchanged in color. There was no evidence of oro-nasal and oro-antral communication, and the palatal mucosa was intact.
Panoramic radiograph shows a smooth-outlined dome-shaped soft tissue density in right maxillary sinus (Fig 1c). Computed tomography scan demonstrated a large lesion measuring 3 x 2.5cm in dimension occupying most of right maxillary sinus, associated with the roots of the upper first molar. There was expansion and thinning of the sinus floor, which was absent at places, with expanded and destroyed lateral wall of the maxilla (Fig 1d & e). On the basis of the clinical and radiographic findings, the differential diagnosis of radicular cyst, ameloblastoma and odontogenic keratocystic tumor were made. An incisional biopsy was performed and a histological diagnosis of radicular cyst with nonkeratinizing stratified squamous epithelium and fibrous connective tissue was made. The mass was enucleated completely; gross examination revealed a cystic lesion measuring 3 x 2.5 x 1.5cm, the specimen was submitted for histopathological examination which revealed a diagnosis of radicular cyst (Fig 1f). The postoperative course was uneventful and two years later, there were no signs of recurrence.
Radicular cysts are the most common inflammatory cysts; they develop following pulpal necrosis caused by caries or traumatic insult, which stimulate the epithelial rest cells of Malassez in the periodontal ligament to proliferate.2 Radicular and residual cysts are by far the most common cystic lesions in the jaws, comprising 52.2% of jaw cysts and 62% of odontogenic cysts. In the Sheffield series 51.5% were in men and 48.5% in women, but this gender difference was not significant. 1 They occur in all tooth-bearing areas of the jaws, although about 60% are found in the maxilla and 40% in the mandible. There is a particularly high frequency in the maxillary anterior region.1
Figure 1: The clinical photograph showing swelling extraorally on the right cheek region (a) and intraorally obliterating the vestibule (b). The radiograph of the panoramic view showing a smooth-outlined dome-shaped soft tissue density in right maxillary sinus (c), coronal bone-window CT image shows lesion encroaching on a large volume of the maxillary sinus cavity (d) and sagittal bone-window CT image shows expansive process associated with the apices of the maxillary first molar (e). The photomicrograph of hematoxylin and eosin stained sections shows a stratified squamous epithelial lining with prominent rete ridges and underlying dense, chronic inflammatory infiltrate invading the epithelium.
The radicular cyst is the model pathogenesis of an inflammation‐stimulated cyst and has been extensively studied. The origin of the cyst epithelium lies with rests of Malassez, which are epithelial remnants of Hertwig epithelial root sheath that lie dormant within the periodontal ligament. The products of pulpal infection and necrosis spill out into the periapical tissues, inciting an inflammatory response. The inflammatory cells secrete a host of lymphokines to neutralize, immobilize, and degrade bacteria. They also induce bone resorption through the elaboration of interleukin‐1 and osteoclast‐activating factors. These same cells are thought to elaborate many other factors that either directly or indirectly act as epithelial growth factors, stimulating the proliferation of the rests of Malassez in the periapical granuloma. As the epithelial cell mass enlarges, the central cells become distant from their blood supply and break down, thereby forming a cyst. The cyst continues to enlarge by epithelial proliferation in the lining and by hydrostatic pressure generated in the cyst lumen from the hyperosmolarity created by cellular breakdown and sloughing of cells into the lumen. Therefore, the osmotic gradient favors transudation of fluid into the lumen, which maintains its hydrostatic pressure and causes further resorption of the surrounding bone.2
Many radicular cysts are symptomless and are discovered when periapical radiographs are taken of teeth with nonvital pulps. Overall, however, radicular cysts are probably the most common cause of swelling of the jaws and patients usually complain of slowly enlarging swellings. At first the enlargement is bony hard but as the cyst increases in size, the covering bone becomes very thin despite subperiosteal bone deposition and the swelling then exhibits ‘springiness’ or ‘egg shell crackling’. Only when the cyst has completely eroded the bone will the lesion be fluctuant.1 The roots of the maxillary premolar and molar teeth are situated below the sinus floor. The second molars roots are the closest to the floor, followed by the roots of the first molar, third molar, second premolar, first premolar, and canine. In contrast, the roots of the central and lateral incisors are not close to the maxillary sinus. The apex of the maxillary second molar root is the closest to the sinus floor (mean distance of 1.97 mm), and the apex of the buccal root of the maxillary first premolar is the furthest from the sinus floor (mean distance of 7.5 mm). These short distances explain the easy extension of a large radicular cyst from these teeth to the maxillary sinus.3
Expansion of the cyst causes erosion of the floor of the maxillary sinus. As soon as it enters the maxillary antrum the expansion starts to occur a little faster because there is space available for expansion. Tapping the affected teeth will cause shooting pain. This is virtually diagnostic of pulpal infection. A sine qua non for the diagnosis of a radicular cyst is the related presence of a tooth with a non-vital pulp. Occasionally, a sinus may lead from the cyst cavity to the oral mucosa. The classic description of the radiological appearance of radicular cysts is that they are round or ovoid radiolucencies surrounded by a narrow radiopaque margin which extends from the lamina dura of the involved tooth. In infected or rapidly enlarging cysts, the radiopaque margin may not be present.1 For the cyst developed near the maxillary sinus, the lesion may displace the floor of the antrum. The internal structure of the cyst is homogeneous and radiopaque relative to the sinus cavity.
In some cases the cyst may enlarge to the point that it has encroached on almost the entire sinus and the residual sinus space may appear as a thin saddle over the cyst.4,5,7 The cyst cortex and the sinus wall may be indistinguishable from one another, and thus as the cyst enlarges, the sinus decreases in size. The result is a radiopaque line between the cyst and the air space of the sinus; dividing the contents of the cyst from the internal aspect of the sinus. This appearance is in contrast to a retention pseudocyst, which, being inside the sinus, does not have a cortex around its periphery. If the odontogenic cyst were to become infected, the cortex may be lost. At this point it may become difficult to determine whether the lesion arises from outside or from within the sinus. However, in most cases careful study of the radiographic image of the lesion will reveal some remaining cyst cortex. Also, the relationship to neighboring teeth may help to make this decision. Very large cysts may completely efface the sinus cavity.4,6 When this occurs, no radiographic evidence may exist of the air space left, and it may appear as if the cyst is the sinus. In this case, because of the radiopacity of the cyst, the appearance may resemble sinusitis with radiopacification of the sinus. A cyst that occupies the entire sinus usually causes expansion of the medial wall (middle meatus) of the sinus and will alter the sigmoid contour of the posterior-lateral wall of the sinus as viewed in axial CT images.4
Grossly, the contents of radicular cysts are usually a soft brown material, often with glistening, oily, yellow flecks. Nodules of opaque yellow material, representing cholesterol, may be seen protruding into the lumen or within the wall. The radicular cyst is typically lined by a nonkeratinizing stratified squamous epithelium of varying thickness. As an inflammatory‐based cyst, its wall usually contains a dense, mixed inflammatory infiltrate, rich in plasma cells and lymphocytes. The wall itself, in addition to its inflammatory component, is fibrous and will often contain numerous capillaries, particularly in areas adjacent to the epithelial lining.2 With regard to the relationship between the tooth and the cyst lining; there is some evidence for two distinct types of radicular cyst. The first had cavities completely enclosed by epithelium and were termed apical true cysts, whereas in the second type the cyst lumen was open to the root canal and these were termed apical pocket cysts.1 Because a radicular cyst is derived from the stimulated epithelium of a periapical granuloma, the treatment implications are the same.
Treatment is then dictated mostly by the restorability of the tooth. Treatment for non-restorable teeth involves tooth removal and surgical curettage of the apical area. The Caldwell Luc approach is indicated for large cysts that displace the floor of the sinus. Restorable teeth are treated with endodontic therapy followed by full occlusal coverage restorations. Radicular cysts are definitively resolved if the tooth and the apical lesion are removed. If the tooth is removed and the cyst is not, most cysts will involute because of the removal of the inflammatory focus. A few rare cases will retain their cystic stimulation independent of the tooth, probably by ongoing inflammation in the wall of the cyst. This is termed a residual cyst. Endodontically treated teeth will resolve radicular cysts as they do periapical granulomas as long as they have a successful pulp canal debridement and fill.2,8,9 In cases of endodontic failure due to incomplete fills or other pulpal leakage, the apical radiolucency will darken and enlarge, indicating a continuation of the granuloma‐radicular cyst spectrum. In such cases, performing endodontic therapy again, often with assisted magnification techniques, will enable the treatment of accessory untreated canals. These accessory canals must be instrumented and filled and the previously treated canals re‐treated to larger sizes and filled. Apicoectomies with a retrofill of the apical area and curettage of the residual lesion or tooth removal is indicated if this re‐treatment fails.2
Generally small, radicular cyst may reach great dimensions; In this case, the differential diagnosis with other radiolucent lesions of jaws is not easy. A good examination of clinical, radiological information and histological data is necessary to make the correct diagnosis.
1.Dr.Ahmed Chkoura, Specialist of Oral Surgery, 2.Dr.Wafae El Wady, Professor and Head, 3.Dr.Bouchra Taleb, Professor, Department of Oral Surgery, Faculty of Dentistry, University Mohammed V Souissi, Rabat, Morocco.
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Dr. Ahmed Chkoura,
Department of Oral Surgery,
Faculty of Dentistry,
Source of Support: Nil, Conflict of Interest: None Declared.
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