Prevalence and clinical characteristics of lymphangioleiomyomatosis (LAM) in patients with tuberous sclerosis complex

The true prevalence of pulmonary lymphangioleiomyomatosis (LAM) in patients with tuberous sclerosis complex (TSC) is unknown. The prevalence of LAM, r adiological features, and lung function in patients with TSC was measured. The presence of LAM, as defined by the presence of cysts by high-resolution chest computed tomography (HRCT) scan, was determined in patients with TSC without prior pulmonary disease (Group 1). To determine the significance o f early detection, severity of disease in screened patients (Group 1) was c ompared with that in patients with TSC with a prior diagnosis of LAM (Group 2). Forty-eight patients with TSC and no prior history of LAM were screene d. Of the 38 females, 13 (34%) had LAM; LAM was absent in males. Lung funct ion was preserved in patients with TSC who were found to have LAM by screen ing. In patients previously known to have LAM, FEV, and DLCO correlated inv ersely with severity of disease as assessed by CT scan. The prevalence of L AM in women with TSC was 34%, similar to 10-fold that previously reported, consistent with a large hitherto unrecognized subclinical population of pat ients at risk for pulmonary complications.