Lymphangioleiomyomatosis (LAM) is an interstitial lung disease seen virtually only in women of childbearing age. The diagnosis, symptoms, paraclinical investigations including the use of CT and spirometry are reviewed. A hormonal dependency of LAM seems obvious, but the exact mechanism has never been understood. Oestrogen and Progesterone receptors may or may not be present in the myoma tissue in LAM. The receptor status seems to have no influence on the results of treatment with medroxyprogesterone or oophorectomy. In spite of the uncertain results of hormonal treatment a therapeutic trial with medroxyprogesterone 200 mg i.m. weekly is warranted. If no improvement is observed bilateral oophorectomy is recommended. Death due to respiratory insufficiency is common, but prognosis seems better than previously though, survivors for more than 20 years after diagnosis being described.