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A man in his 40s presented with mobility of the anterior mandibular dentition. A consultation with a dentist 1 year prior revealed an impacted mandibular canine (No. 22). He denied any pain, swelling, or paresthesia, and his medical history was unremarkable. Clinical examination revealed fullness on the mentolabial fold but no gross facial asymmetry or mental nerve paresthesia. Intraorally, there was an expansile mass of the left anterior mandible with ill-defined margins, which crossed the midline and obliterated the gingivolabial sulcus.
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C. Clear cell odontogenic carcinoma
This case demonstrates a unique example of an impacted tooth in intimate association with a clear cell odontogenic carcinoma (CCOC), a rare odontogenic malignant tumor. Clinicians usually expect to encounter endodontic infection, displacement of adjacent teeth, cyst development, or a benign tumor growth when investigating a radiolucent lesion in association with an impacted tooth, but malignant tumors are rarely reported.1 Cases of CCOC are often misdiagnosed and may receive insufficient or inappropriate treatment.2,3
Diagnosis of CCOC is challenging because its clinical presentation and radiological features are nonspecific. Clear cell odontogenic carcinoma is most often seen in women in the fifth to eighth decades of life. The most common presentation is swelling of the jaw with loose teeth, often followed by pain and paresthesia.4 Clear cell odontogenic carcinoma may appear as an expansive, ill-defined radiolucency with irregular margins and root resorption on imaging.5 There is no standard protocol for treating patients with CCOC, although wide surgical resection with uninvolved margins is recommended due to the potential for recurrence and metastasis.5,6 Adjuvant radiotherapy has been used on a case-by-case basis.6,7 In a recent literature review of published cases, recurrence was identified in 38 of 88 cases in which the presence or absence of recurrence was reported (over a mean [range] follow-up period of 3.5 years [2 months to 15 years]) with metastases most commonly seen in the regional lymph nodes and lungs.5 Patients should be followed in the long term. In the present case, because incisional biopsy confirmed CCOC, the patient underwent a transoral mandibulectomy and simultaneous reconstruction with a titanium plate and left fibula free flap. Re-resection and reconstruction were necessary due to evidence of graft necrosis and positive margins at the time of initial resection. The patient subsequently received adjuvant radiotherapy.
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Corresponding Author: Karin Miller, MD, Department of Pathology, Johns Hopkins University School of Medicine, Pathology Building, 600 N Wolfe St, Baltimore, MD 21287 (email@example.com).
Published Online: September 17, 2020. doi:10.1001/jamaoto.2020.2589
Conflict of Interest Disclosures: None reported.
Additional Contributions: We thank the patient for granting permission to publish this information. We also thank Lisa Rooper, MD, in the Department of Pathology at Johns Hopkins Hospital, for meeting and discussing the pathological findings, as well as providing our group with the histological sections; and Christine Gourin, MD, MPH, and Zubair Khan, MBBS, MPH, in the Department of Otolaryngology–Head and Neck Surgery at Johns Hopkins Hospital for their thoughtful input and guidance during the production of this article. They were not compensated for their contributions.
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