Lymphangioleiomyomatosis

Abstract

Lymphangioleiomyomatosis (LAM) is a rare disease that is characterized by proliferation of abnormal smooth muscle-like cells (LAM cells), which leads to the formation of lung cysts, fluid-filled cystic structures in the axial lymphatics, and abdominal tumors. It primarily affects women. The authors present a review of large series, registries, and protocols to highlight the prevalence, pathology, clinical features, diagnosis, and treatment options for patients with LAM. LAM commonly presents with progressive breathlessness or with recurrent pneumothorax, chylothorax, or sudden abdominal hemorrhage. Computed tomography (CT) scans show numerous thin-walled cysts throughout the lungs, abdominal angiomyolipomas, and lymphangioleiomyomas. Pulmonary function tests show decreased forced expiratory volume in 1 second (FEV₁) and diffusion capacity for carbon monoxide (Dlco). Exercise testing shows gas-exchange abnormalities, ventilatory limitation, and hypoxemia that may occur with near-normal lung function. No effective treatment currently exists for this progressive disorder. However, recent progress in cancer and smooth muscle cell biology and a better understanding of the factors regulating angiogenesis and lymphangiogenesis may provide a foundation for the development of new therapeutic strategies.