A Case of Lung Squamous Cell Carcinoma Mimicking Benign Solitary Cyst

Lung cancer with cyst formation is a rare entity. We report a 63-year-old man who underwent surgical treatment of primary lung cancer, which mimics benign solitary cyst. We incidentally found his pulmonary cyst by a low dose chest tomography and followed up for 2 years. Rapid growth of cyst and focal wall thickening evoke us to have a suspicion of its malignancy. Left lower lobectomy via video-assisted thoracoscopic surgery was performed without any preoperative pathologic confirmation. The postoperative pathological finding revealed squamous cell carcinoma with carcinoma in situ on the cyst wall. We emphasize the need for physicians to be aware of the potential of lung cancer in patients with growing pulmonary cyst.