TSC1 and TSC2 mutations in patients with lymphangioleiomyomatosis and tuberous sclerosis complex

BACKGROUND: Lymphangioleiomyomatosis (LAM) is a prominent finding in the setting of tuberous sclerosis complex (TSC). OBJECTIVE: The present study was designed to compare cystic lung changes consistent with LAM in patients with a TSC1 disease-causing mutation, TSC2 disease-causing mutation, or no mutation identified (NMI). METHODS AND RESULTS: We conducted a retrospective review of the chest computed tomography (CT) of 45 female and 20 male patients with TSC and found cysts consistent with LAM in 22 (49%) women and two (10%) men. In the female population, changes consistent with LAM were observed in six of 15 (40%) patients with TSC1, 11 of 23 (48%) with TSC2, and five of seven (71%) with NMI. While the predominant size of cysts did not differ across these three groups, TSC2 women with LAM had a significantly greater number of cysts than did TSC1 patients (p = 0.010). CONCLUSIONS: These findings suggest a higher rate of LAM in TSC1 than previously recognised, as well as a fundamental difference in CT presentation between TSC1 and TSC2.