Tonsillar Metastasis of Small Cell Lung Cancer in a Patient With Idiopathic Pulmonary Fibrosis: A Case Report

Small cell lung cancer (SCLC) metastasizes widely, but palatine tonsil is an extremely unusual site for metastasis. Idiopathic pulmonary fibrosis (IPF) is associated with increased risk of lung cancer. However, the most common histological findings among patients of lung cancer with IPF are known as non-SCLC such as adenocarcinoma and squamous cell carcinoma. In addition, the majority of them are located in IPF-associated fibrotic peripheral lesions. A 77-year-old man visited for 1-month persistent cough and dyspnea, with inspiratory dry crackles on both lower lung fields and a large oval mass in his throat. Chest computed tomography revealed 2 masses in the left lower lobe, 1 mass in the right upper lobe, and multiple enlarged mediastinal lymph nodes of the lung accompanying with IPF, which were diagnosed as SCLC pathologically. Very interestingly, the tonsillar mass was also confirmed as the metastatic lesion of SCLC. Chemotherapy for SCLC and medical treatment for IPF were applied. However, in following-up, he expired due to respiratory failure by an acute exacerbation of IPF 3 months after the diagnosis. In this current report, we describe, for the first time, a case of tonsillar metastasis of SCLC with IPF detected simultaneously in a 77-year-old man.