Lymphangiomyomatosis is a rare disease of unknown etiology characterized by hamartomatous proliferation of smooth muscle in the pulmonary lymphatics, blood vessels and airways. The disease occurs exclusively in women of reproductive age. Although the clinical course and radiographic findings may strongly suggest lymphangiomyomatosis, definitive diagnosis is made by obtaining open-lung biopsy. The clinical course of lymphangiomyomatosis is progressive, leading to pulmonary insufficiency and death within 10 years. Treatment with hormonal manipulation and/or oophorectomy has resulted in temporary improvement or stabilization of the disease process.