後発頸部リンパ節転移および多発肺転移を認めたstage Ⅰ粘表皮癌の1例

抄録

We report a case of stage Ⅰ mucoepidermoid carcinoma with late metastasis to the cervical lymph node and lung, although it was an early-stage cancer. The patient was a man in his 60s who visited our department because of an ill-fitting maxillary denture. A mass was found in the right soft palate, and CT showed a nodular lesion behind the right maxillary tuberosity. Surgery was performed on clinical diagnosis of malignant tumor of the right soft palate, and the lesion was histopathologically diagnosed as mucoepidermoid carcinoma. Since the margin was negative, the patient was regularly followed up after the surgery, but late metastasis to the cervical lymph node occurred at 1 year and 7 months after the surgery. Furthermore, lung metastasis occurred at 3 years and 8 months after the first surgery.
It is challenging to evaluate the prognostic factors in salivary gland carcinomas because of their various histological types. Clinical stage is an important prognostic factor in minor salivary gland carcinomas. However, occult nodal disease may be recognized even in the clinical diagnosis of N0. The utility of FDG-PET has also been reported in the diagnosis of cervical lymph node metastasis. Currently, there is no standard guideline for conducting elective neck dissection in minor salivary gland tumors. As metastasis may occurs after a long period of time, careful follow-up in such cases is crucial.