Palatine Tonsillar Metastasis of Small-Cell Neuroendocrine Carcinoma from the Lung Detected by FDG-PET/CT After Tonsillectomy: A Case Report

Metastasis from a malignant tumor to the palatine tonsils is rare, accounting for only 0.8% of all tonsillar tumors, with only 100 cases reported in the English-language literature. Various malignant lung carcinomas may metastasize to the tonsils. A few cases of tonsillar metastasis from neuroendocrine lung carcinoma have been reported. A 67-year-old female underwent a right tonsillectomy because of a sore throat and an enlarged right tonsil. The postoperative pathology showed right tonsillar small cell neuroendocrine carcinoma (SCNC). Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) demonstrated metabolic activity in the lower lobe of the right lung. In addition, hypermetabolic foci were noted in the lymph nodes of the right neck and mediastinum. A needle biopsy of the pulmonary mass showed SCNC. The patient received chemotherapy and died of multiple distant metastases after 6 months. This is the first report using PET/CT to evaluate tonsillar metastasis from lung SCNC.