We report a case of lymphangioleiomyomatosis (LAM) in a 33-year-old woman. Left pneumothorax was noted during a physical checkup at a local clinic. Multiple bullae in the bilateral lungs were also seen on chest computed tomography. Therefore, she underwent surgery for diagnosis and therapy. A large number of cysts of various sizes were seen in the left pleural cavity, and a cyst located at the lingular region was resected. Histopathological examination of the cyst walls showed a thin rim of abnormal muscle consisting of spindle-shaped cells resembling smooth muscle cells as well as thick, eccentric, or concentric proliferation. The examination described above confirmed the diagnosis of LAM. The patient is currently being followed up on an outpatient basis.