Sporadic lymphangioleiomyomatosis

**Definition:** This is a rare lung disease that results in a proliferation of disorderly smooth muscle growth (leiomyoma) throughout the lungs, in the bronchioles, alveolar septa, perivascular spaces, and lymphatics, resulting in the obstruction of small airways (leading to pulmonary cyst formation and pneumothorax) and lymphatics (leading to chylous pleural effusion). LAM occurs in a sporadic form, which affects only females, usually of childbearing age; LAM also occurs in patients who have tuberous sclerosis.