A case of malignant melanoma discovered as a result of metastatic disease of the temporomandibular joint

We report the case of a patient with malignant melanoma discovered upon her experiencing pain when opening her mouth. In 2009, a 42-year-old female patient was referred to the Sakai Municipal Hospital because of preauricular pain when opening her mouth. We suspected a malignant tumor because a simple X-ray showed a radiolucent lesion in the mandibular condyle, and this was confirmed after computed tomographic (CT) and magnetic resonance imaging (MRI) scans. We also detected fluorine-18-deoxyglucose accumulation in the left mandibular condyle, right inferior lobe of lung, and lymph nodes throughout the body during a positron emission tomography PET-CT scan. We performed a biopsy on the bronchoscopic tissue and malignant melanoma was confirmed by histopathology. The patient was subsequently treated at another hospital with systemic chemotherapy along with radiotherapy applied to the left mandibular condyle, but the lymph node tumor enlarged. Accordingly, palliative therapy was given, and the patient died from the tumor 10 months after her first consultation. We could find the malignant melanoma by identifying the radiolucent lesion in the TMJ on panoramic X-ray. Hence, it is crucial not to overlook images indicating bone destruction in the mandibular condyle if there is a malignant tumor in the TMJ.