Lung adenocarcinoma presenting with intrapulmonary metastases through air spaces concomitant with silicosis: a case report and literature review.

Herein, we reported a rare case of bilateral intrapulmonary metastases spread through air spaces (STAS) and silicosis to advance understanding and knowledge of this disease. A middle-aged man was diagnosed with a left upper lung nodule with bilateral silicosis by preoperative imaging. Local pleural indentation and extensive metastases spread in the visceral pleura were observed during the operation. Pathological examination showed multiple metastases of lung adenocarcinoma, and STAS positive. Genetic testing indicated EGFR mutation, and ektinib was administered. STAS can promote lung cancer, leading to multiple pulmonary metastases, and silicosis can contribute to the carcinogenesis of lung cancer. This case provided valuable clinical lessons. More studies are warranted to elucidate the role and underlying mechanism of silicosis and STAS in the development of lung cancer. More accurate imaging methods and radiographic criteria should be formulated for different diffuse nodules and STAS grades, and the exploration of optimal therapeutic regimens to treat these concomitant patients is urgently needed to improve diagnostic rates and formulate more optimal therapies.