Scientists at the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) report that women with a rare lung disease known as LAM (lymphangioleiomyomatosis) have a high prevalence of meningiomas, a type of brain tumor.
The study, published in the October 17 issue of the Journal of the American Medical Association, is the first to document the extent of the association between LAM and meningiomas.
"These findings provide important new information on the nature of this disease and have implications for both the diagnosis and treatment of patients with LAM," said NHLBI Director Dr. Claude Lenfant.
The meningiomas were detected in an ongoing study of the natural history of LAM. LAM is associated with a rare genetic neurological disorder called tuberous sclerosis (TS). In an effort to determine whether patients with LAM also showed signs of tuberous sclerosis, NHLBI scientists performed magnetic resonance imaging (MRI) and computed tomography (CT) brain scans on 250 women with the lung disease. They were looking for brain abnormalities called "tubers," one of the criteria for diagnosing TS.
Unexpectedly, MRI scans revealed that 8 patients had meningiomas a rate that far exceeds the 1 in 20,000 expected in the general population.
According to the investigators, it is not clear whether the meningiomas are caused by LAM itself, hormonal treatments for the disease or a combination of the two. They note that the abnormal smooth muscle cells found in the lungs and other tissues of LAM patients produce certain growth factors that are believed to foster meningiomas. However, the possibility that the meningiomas have a hormonal cause has implications for the overall treatment of LAM.
Because LAM occurs primarily in women of childbearing age, it has been thought to be affected by hormonal factors. As a result, it
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Contact: NHLBI Communications Office
301-496-4236
NIH/National Heart, Lung, and Blood Institute
18-Oct-2001