To the Editor: Lymphangioleiomyomatosis is a rare, progressive, frequently fatal cystic lung disease that affects women almost exclusively.¹,² It occurs in up to 40% of women with the tuberous sclerosis complex, a tumor-suppressor syndrome associated with seizures, cognitive impairment, and hamartomas in multiple organs, and can also occur in a nonheritable sporadic form that involves only the lung, lymphatics, and kidney.³ The presence of the tuberous sclerosis complex or fat-containing renal hamartomas called angiomyolipomatas in a woman with characteristic cystic changes on a high-resolution computed tomographic (CT) scan of the chest is considered to be diagnostic of lymphangioleiomyomatosis. However, . . .