Lung involvement is more common in women with TSC than men. The average age of onset is during the childbearing years, although lung involvement can occasionally occur in teenagers with TSC, as well as in postmenopausal women.
This suggests that lung involvement in TSC could be estrogen related. However, a very small number of men with lung disease have been reported.
What are the lung features of TSC?
Two forms of lung involvement in TSC have been described:
- Lymphangioleiomyomatosis (LAM)/pulmonary cysts
- Multifocal micronodular pneumocyte hyperplasia (MMPH)
Lymphangioleiomyomatosis (LAM)
Many women who have lung involvement due to TSC have lymphangioleiomyomatosis (LAM), a degenerative cystic disease of the lungs. The first symptoms of lung involvement in an individual with TSC may be shortness of breath after mild exercise, cough, or spontaneous pneumothorax (a collection of air or gas in the chest causing the lung to collapse).
Multifocal micronodular pneumocyte hyperplasia (MMPH)
Multifocal micronodular pneumocyte hyperplasia (MMPH) consists of overgrowth (hyperplasia) of the pneumocytes (a specific type of cell found in the lining of the air sacs in the lung) into small nodules. An individual with TSC who has MMPH may have a few or many nodules in their lungs. This condition occurs with equal frequency in men and women with TSC and does not usually produce clinical symptoms. It is important to be aware of this entity, however, since doctors may otherwise wonder whether these small nodules are due to a variety of other possible causes.
TSC and LAM research protocols
Several clinical trials are underway at TSC and LAM clinic sites. Some women and men with TSC and LAM may be eligible to participate in clinical studies at the Clinical Center at the National Institutes of Health in Bethesda, MD. The LAM Foundation can be contacted for up-to-date information about LAM research studies and trials.
