Lymphangioleiomyomatosis : A Clinical Update

Lymphangioleiomyomatosis (LAM) is a rare, cystic lung disease that is associated with mutations in tuberous sclerosis genes, renal angiomyolipomas, lymphatic spread, and remarkable female gender restriction. The clinical course of LAM is characterized by progressive dyspnea on exertion, recurrent pneumothorax, and chylous fluid collections. Lung function declines at approximately twofold to threefold times the rate of healthy subjects, based on an annual drop in FEV1 of 75 to 120 mL in reported series. The diagnosis of pulmonary LAM can be made on high-resolution CT (HRCT) scan with reasonable certainty by expert radiologists, but generally requires a lung biopsy in cases in which tuberous sclerosis complex, angiomyolipomata, or chylous effusions are absent. The currently available treatment strategies are based on the antagonism of estrogen action, and are empiric and unproven. A trial of bronchodilators is warranted in patients with reversible airflow obstruction seen on pulmonary function testing. Pleurodesis should be performed with the initial pneumothorax, because the rate of recurrence is high. Angiomyolipomas that exceed 4 cm in size are more likely to bleed and should be evaluated for embolization. Air travel is well-tolerated by most patients with LAM. Lung transplantation is an important option for LAM patients, and can be safely performed by experienced surgeons despite prior unilateral or bilateral pleurodesis in most patients. Women with unexplained recurrent pneumothorax, tuberous sclerosis, or a diagnosis of primary spontaneous pneumothorax or emphysema in the setting of limited or absent tobacco use should undergo HRCT scan screening for LAM. Multicenter clinical trials based on several well-defined molecular targets are currently underway in the United States and Europe.