We report a rare case of cystic lymph node metastasis originating from mucoepidermoid carcinoma of the sublingual gland. A 64-year-old male was referred to our hospital for the further examination and treatment of cystic cervical lesion and lung metastatic lesions. He had undergone excision of right sublingual primary mucoepidermoid carcinoma 5 years earlier and removal of a recurrent lesion 2 years earlier. At one month before his first visit, image examinations indicated right cystic cervical lesion and left lung metastatic lesions; the maximum standardized uptake value （SUVmax） of FDG-PET/CT was significantly high in the lung lesions, but not in the cervical lesion. We re-examined the cervical lesion by imaging examinations and fine-needle aspiration cytology （FNAC）. Although SUVmax of FDG-PET/CT and FNAC were not positive for malignancy, enlargement and ring enhancement of cystic lymph node were observed. We performed modified radical neck dissection under a clinical diagnosis of cervical lymph node metastasis, then respiratory surgeons carried out endoscopic surgery of lung lesions. The histopathological diagnosis of both lesions was metastatic mucoepidermoid carcinoma.
