Study of the Disease Process of Lymphangioleiomyomatosis

* INCLUSION CRITERIA: General admission criteria for patients include one or both of the following: Findings on lung biopsy diagnostic of LAM; Findings on chest x-ray and/or chest computed axial tomography consistent with LAM. Patients with TSC and pulmonary LAM will be included in the study. Normal non-smokers in the control group are defined as individuals who have not smoked for greater than or equal to 1 year and have no systemic or pulmonary disease. Normal smokers defined as individuals with no systemic or pulmonary disease, who have smoked for greater than or equal to 1 year and have normal chest x-ray and normal pulmonary function tests may be included if needed as controls for a similar population of patients with LAM. Pregnant and or nursing women including pregnant minors may be included in accordance with Federal Regulations at Subpart B of 45 CFR 46. Subjects who are pregnant and or nursing will be excluded from procedures during their pregnancy that are greater than minimal risk, until they are no longer pregnant and/or nursing. A minor participant with a positive pregnancy test result will be informed promptly. The result will be discussed in a sensitive and developmentally appropriate manner with the minor, including explanation of the result, assessment of safety, and referral for appropriate follow-up care. The participant will be informed of the limits of confidentiality. The study team will encourage involvement of a parent or legal guardian when appropriate and safe. If there is concern for abuse, coercion, exploitation, or danger, the study team will follow applicable mandatory reporting laws and institutional policies, including notification of appropriate authorities and/or a parent or guardian when required to protect the participant or as otherwise required. Procedures that will not be completed while the subject is pregnant and/or nursing include: Arterial Blood Gases (ABG), HIV testing, treadmill test, lung biopsy, thoracentesis, bronchoscopy, and measurements with imaging modalities requiring contrast or with radiation exposure such as Chest x-ray, CT scan, MRI with or without contrast, lung scan, bone densitometry (DEXA). Allowing subjects to be included in the study may glean important information about individuals with uncommon pulmonary disease during and post pregnancy. Rationale for inclusion of children (16 to \< 18 years of age): LAM is a rare progressive disease that can manifest during adolescence, particularly in individuals with TSCassociated disease. Participation is expected to provide clinically meaningful evaluation and/or contribute important information about the natural history and presentation of LAM in younger patients. At age 16, the participant is generally capable of providing meaningful consent, understanding study procedures, and participating in discussions about risks, burdens, and potential benefits. EXCLUSION CRITERIA: Exclusion criteria for patients include: Age less than 16. Advanced stage of a pulmonary or a systemic illness in which the risk of the study is judged to be significant even in the absence of a clear contraindication to the procedures. Exclusion criteria for patients for the formal exercise study and the stress echocardiogram include patients on continuous oxygen. Patients may perform an exercise test that will assess the patient's exercise capacity with activities of daily living.