Tuberous Sclerosis Complex and Lymphangioleiomyomatosis: Miles to Go, Promises to Keep

Two articles in this issue (1, 2) reflect important progressin our understanding of the treatment of lymphangio-leiomyomatosis (LAM) and the relationship between LAM and tuberous sclerosis complex (TSC). Lymphangioleio-myomatosis is a progressive, multisystem disorder in which abnormal smooth muscle–like cells (LAM cells) spread dif-fusely through both lungs, leading to cystic destruction of lung tissue and pneumothorax. It almost exclusively affects women for reasons that remain poorly understood. Most women with LAM also have renal angiomyolipomas, which are benign tumors with 3 distinct components: ab-normal smooth muscle cells, enlarged vessels, and fat. Lymphangioleiomyomatosis occurs in a sporadic form and in association with TSC. Tuberous sclerosis complex is a disorder of a tumor-suppressor gene. It is characterized by neurologic condi