Mucinous adenocarcinoma of the temporal region initially diagnosed as temporomandibular disorders: a case report

Adenocarcinoma occurring in the temporal region has not previously been reported. We present a case of mucinous adenocarcinoma of the temporal region. A 62-year-old female patient was diagnosed as having temporomandibular disorders because of severe trismus and joint pain. Although trismus progressively worsened, there were no abnormal findings on diagnostic imaging studies including magnetic resonance imaging (MRI) and bone scintigraphy. As swelling of the temporal region was observed, biopsy was performed. Histologic examination showed chronic inflammation of the striated muscle. Approximately 6 months later, follow-up MRI demonstrated an ill-defined mass lesion in the infratemporal region extending to the intracranium. Histologic diagnosis of the biopsy showed that this mass lesion was moderately differentiated mucinous adenocarcinoma.