Abstract
Odontogenic myxoma is an uncommon, benign neoplasm that tends to recur because it locally invades or is trapped among the bony trabeculae. It is thought to arise from mesenchymal tissue associated with teeth and periodontium, as it develops in the tooth-bearing area of the jawbones, often in proximity to an unerupted tooth. Occasionally it may displace teeth. Those occurring in the maxilla often invade the maxillary sinuses. We report here a rare case of an odontogenic myxoma of the maxillary sinus associated with an ectopic tooth which was impinging on the nasal mucosa and accordingly was extracted through the nose.
Highlights
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An odontogenic myxoma developed in the maxillary sinus.
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It was next to an ectopic tooth that impinged on the nasal cavity.
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The tooth was in the same position five or more years before onset of symptoms.
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The tooth was extracted through the nose.
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The tumor was excised though the mouth.
1
Introduction
Odontogenic myxomas (OM) are benign, locally invasive tumors of the jaws composed of round and stellate cells in a stroma rich in mucopolysaccharides [ ]. They arise in the tooth-bearing areas of the mandible and maxilla, often in close approximation to teeth, and closely resemble the mesenchymal portion of a developing tooth histologically. Epithelial rests are frequently encountered in the stroma but are not necessary for the diagnosis. Radiographically, they usually appear as unilocular or multilocular radiolucencies that can displace teeth and erode borders [ ].
Although OM is the second most common odontogenic tumor, overall, it is rare, accounting for 3.3–15.7 % of all odontogenic tumors [ ]. Approximately a third of OMs occur in the maxilla and 22 % of these invade the maxillary sinuses [ ]. A survey of cases of OM of the maxillary sinuses in PubMed and Medline using search terms “OM, maxillary sinus, ectopic tooth” yielded 36 reports in which 6 OMs were and 18 were not associated with an impacted or unerupted tooth (not cited), two in which teeth had been displaced by the tumor [ , ], and two that were associated with an ectopic tooth [ , ].
From the foregoing it is clear that an OM in the maxillary sinus associated with an ectopic tooth is exceedingly rare. We report here a case of an OM of the maxillary sinus associated with an ectopic third molar.
1.1
Case report
A man 44 years of age presented to the Medical Clinic of the Washington, DC Department of Veterans Affairs Medical Center with a complaint of left nasal and maxillary sinus congestion. He noted progressive purulent, foul-smelling nasal and oral discharge, relieved temporarily with antibiotic and ibuprofen medication. Four months previously, magnetic resonance imaging (MRI) by a private physician was interpreted as “a large cyst into the left maxillary antrum accompanied by an unerupted tooth which extended into the nasal cavity.” Though he reported a four-year history of nasal and sinus congestion, his military medical records revealed only an acute onset of a nasal discharge and congestion diagnosed as a viral infection four years previously. He was referred to the Dental Clinic where a panoramic dental radiograph (PAN) revealed a radiopaque object ( Fig. 1 A) in the roof of the left maxillary sinus and that the left maxillary third molar was missing. On oral examination he was found to have a probing depth greater than 12 mm with draining purulence distal to the maxillary second molar consistent with an antral-oral fistula.
Subsequently, in non-contrast computed topography (CT) scans ( Fig. 2 ), there was a “large cyst invaginating into the left maxillary antrum and extending into the left nasal cavity in the middle meatus. The size of the cyst is approximately 3.6 cm in craniocaudal, 2.7 cm in anteroposterior and 2.1 cm in transverse dimensions. There is a dehiscence and absence of the wall along the posterior inferior corner at its junction with the maxilla. The unerupted tooth in the left middle meatus narrows the nasal passage.” Interestingly, a PAN taken on entry to miliary duty almost ten years previously ( Fig. 1 B) and at least five years before the onset of symptoms shows an almost identical object in the same location in the sinus and that there is no tooth distal to the second molar. We surmised that this object was the third molar that was partly obscured by a radiopaque reflection artifact in both PAN radiographs. Based on these findings the differential diagnosis included ameloblastoma, odontogenic keratocyst and dentigerous cyst. Further examination of the CT scans found that the left maxillary sinus was filled with homogeneous, moderately radiopaque material and that the radiolucent pericoronal sac around the tooth was not enlarged, suggesting that the sinus harbored a solid tumor, not a dentigerous cyst,
After the sinus infection was controlled with oral Amoxicillin and Clindamycin, under general anesthesia, the patient underwent nasal endoscopy using a 0° endoscope. The tooth was revealed by peeling back the overlying nasal mucosa ( Fig. 3 A) and extracted with forceps. The surrounding inflamed nasal mucosa and granulation tissue were removed with a combination of cold steel instrumentation and microdebrider ( Fig. 3 B). Some of the cystic contents were removed through the widened maxillary antrostomy using endoscopic graspers. Further surgical exploration that would require an intra-oral approach was postponed pending biopsy results.
