[Investigation and Analysis of Primary Lung Cancer with Endotracheal and Endobronchial Metastases].

Background: Endotracheal and endobronchial metastases (EEM) is a rare manifestation in primary lung cancer. It has not yet been reported in Chinese literatures. The aim of this study was to summarize and analyze the clinical feature of lung cancer with EEM.
Methods: We retrospectively reviewed 6 patients who presented with EEM of lung cancer from Peking University Third Hospital from January 2015 to December 2018. With "endotracheal metastases, endobronchial metastases, lung cancer" as the keywords, 13 cases were retrieved from PubMed database until February 2020. The clinical, radiologic and bronchoscopic data were collected.
Results: Six patients were selected from 967 patients with lung cancer, and all were diagnosed with lung cancer and EEM simultaneously. There were 4 cases of squamous cell carcinoma, 1 case of adenocarcinoma, and 1 case of small cell lung cancer. One patient had stage IIIb and 5 patients had stage IV. There were 5 cases of central lung cancer and 1 case of peripheral lung cancer. EEM on bronchoscope examination presented as endoluminal nodular or polypoid lesion in 5 patients, and abnormal white bulge in 1 patient. 5 cases metastasized to the contralateral bronchus, 1 case to the ipsilateral bronchus and 1 case to the trachea. The median overall survival was 7.5 months. Totally 13 cases of lung cancer with EEM were retrieved from PubMed database. 12 cases were diagnosed during the follow up after lung cancer resection. There were 8 cases of squamous cell carcinoma and 9 cases of central type. Endotracheal or endobronchial nodules showed in 10 cases and eccentric wall thickening in 2 cases were seen on chest computed tomography (CT), which corresponding to the nodular or polypoid lesion bronchoscopically. 5 cases metastasized to the contralateral bronchus, 10 cases to the trachea and 1 case to the ipsilateral bronchus.
Conclusions: EEM is a rare metastasis of lung cancer, which can occur at the initial diagnosis of lung cancer or after surgical resection. It is often seen in the patients of squamous cell carcinoma with central type in advanced stage. The prognosis is poor.