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PubMed This is a summary of 83 peer-reviewed journal articles Updated
Pulmonology

What is LAM? Understanding Your Diagnosis

At a Glance

Lymphangioleiomyomatosis (LAM) is a rare lung disease in women where abnormal cells form cysts in the lungs. While there is no cure, modern treatments like sirolimus effectively stabilize lung function. Today, LAM is managed as a chronic condition, allowing patients a fulfilling quality of life.

Receiving a diagnosis of Lymphangioleiomyomatosis (LAM) can feel overwhelming, especially since you may never have heard the name before [1]. It is common to feel a mix of shock, fear, and even a strange sense of relief that your symptoms finally have a name [2]. While LAM is a serious condition, the landscape of the disease has changed dramatically in recent years. Today, LAM is considered a manageable chronic disease rather than the life-threatening emergency it was once thought to be [3][4].

What is LAM?

Lymphangioleiomyomatosis (pronounced lim-fan-jee-o-ly-o-my-o-ma-to-sis) is a rare lung disease that almost exclusively affects women [5]. In LAM, abnormal, muscle-like cells (called LAM cells) begin to grow out of control in certain organs, particularly the lungs [1][6].

Over time, these cells create thin-walled fluid or air-filled sacs called cysts [1]. As these cysts multiply, they can interfere with the lungs’ ability to transfer oxygen into the bloodstream [7]. LAM can also affect the lymphatic system (the network that helps the body fight infection) and the kidneys, where it may cause benign (non-cancerous) growths called angiomyolipomas [8]. To learn more about how this happens, you can read about the Biology of LAM.

Three Stabilizing Facts

If you are searching for information online, you may find outdated statistics that are unnecessarily frightening. Here is what the modern medical consensus says about LAM today:

01

Treating and Managing LAM

Learn about treatment options for Lymphangioleiomyomatosis (LAM). Understand when to start sirolimus, how to manage estrogen, and lung transplant criteria.

02

Living Well with LAM Long-Term

Learn how to manage Lymphangioleiomyomatosis (LAM) long-term. Discover what to expect with routine monitoring, pregnancy risks, pulmonary rehab, and scanxiety.

03

The Path to a Clear Diagnosis

Learn how Lymphangioleiomyomatosis (LAM) is diagnosed using HRCT scans, VEGF-D blood tests, and biopsies. Understand the criteria for a definite diagnosis.

The Challenge of Rarity

LAM is exceptionally rare, affecting approximately 5 to 10 out of every one million women [13]. Because it is so uncommon, many local primary care doctors or general pulmonologists may only see one case in their entire career [1].

This rarity often leads to a “diagnostic odyssey”—a long period where symptoms like shortness of breath or a collapsed lung (pneumothorax) are mistaken for more common conditions like asthma or bronchitis [1][14]. If your doctor seems unfamiliar with the latest LAM protocols, it is not a reflection of your health, but rather a reflection of how rare this condition is. Seeking a specialist at a dedicated LAM clinic is often a vital step in ensuring you receive the most current standard of care [1]. Organizations like The LAM Foundation are excellent resources for finding specialized care teams near you.

What Research Agrees On

  • mTOR Activity: Scientists have identified that LAM is driven by the overactivity of a protein called mTOR, which acts like a “growth switch” stuck in the “on” position [15]. Sirolimus works by turning this switch off [9].
  • Hormonal Link: Because LAM primarily affects women during their childbearing years, researchers agree that the hormone estrogen plays a role in the disease, though the exact mechanism is still being studied [5][16].
  • Management Over Cure: While there is currently no “cure” that makes the cysts disappear, the medical community agrees that LAM can be successfully managed as a chronic condition with regular monitoring of lung function [5][17]. For more on what to watch for, see Symptoms and Warning Signs.

Common questions in this guide

How is LAM disease diagnosed?
LAM is typically diagnosed using a combination of a high-resolution CT (HRCT) scan of the lungs and a specialized blood test that measures VEGF-D levels. This modern approach often allows doctors to confirm the disease definitively without needing an invasive lung biopsy.
Is there a cure for Lymphangioleiomyomatosis?
While there is currently no cure for LAM, it is highly treatable as a manageable chronic disease. Medications like sirolimus can effectively stabilize lung function, slow the progression of cysts, and help patients maintain an active quality of life for decades.
What causes LAM in the lungs?
LAM is caused by an overactivity of a protein called mTOR, which acts like a growth switch stuck in the 'on' position. This causes abnormal, muscle-like cells to multiply and form cysts in the lungs. Estrogen also plays a role, which is why it primarily affects women in their childbearing years.
What should I ask my doctor after being diagnosed with LAM?
It is important to ask your doctor if your diagnosis is definitive based on scans and blood tests, and whether you are a candidate for targeted therapies like sirolimus. Because the disease is so rare, you should also request a referral to a dedicated LAM clinic with specialized experience.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my HRCT scan and VEGF-D levels, is my diagnosis of LAM definitive or do I need further testing?
  2. 2.Is my LAM considered 'sporadic' or associated with Tuberous Sclerosis Complex (TSC)?
  3. 3.Am I a candidate for sirolimus (Rapamune) now, or should we monitor my lung function first?
  4. 4.What are my current FEV1 and DLCO percentages, and how often will we re-test them?
  5. 5.How many other patients with LAM have you or this clinic treated?
  6. 6.Can you provide a referral to a dedicated LAM clinic or a specialist connected with The LAM Foundation?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (17)
  1. 1

    Lung Diseases Unique to Women.

    Criner RN, Al-Abcha A, Lambert AA, Han MK

    Clinics in chest medicine 2021; (42(3)):507-516 doi:10.1016/j.ccm.2021.04.014.

    PMID: 34353455
  2. 2

    Clinical and Functional Outcomes Associated with Quality of Life in Patients with Lymphangioleiomyomatosis: A Cross-Sectional Study.

    Queiroz DS, da Silva CCBM, Oliveira MR, et al.

    Lung 2024; (202(6)):757-765 doi:10.1007/s00408-024-00751-w.

    PMID: 39402376
  3. 3

    Cystic Lung Disease in Genetic Syndromes with Deficient Tumor Suppressor Gene Function.

    Daccord C, Nicod LP, Lazor R

    Respiration; international review of thoracic diseases 2017; (94(6)):467-485 doi:10.1159/000485106.

    PMID: 29169151
  4. 4

    Determinants of Progression and Mortality in Lymphangioleiomyomatosis.

    Xu W, Yang C, Cheng C, et al.

    Chest 2023; (164(1)):137-148 doi:10.1016/j.chest.2023.02.026.

    PMID: 36801466
  5. 5

    CrossTORC and WNTegration in Disease: Focus on Lymphangioleiomyomatosis.

    Evans JF, Obraztsova K, Lin SM, Krymskaya VP

    International journal of molecular sciences 2021; (22(5)) doi:10.3390/ijms22052233.

    PMID: 33668092
  6. 6

    mTORC1 upregulates B7-H3/CD276 to inhibit antitumor T cells and drive tumor immune evasion.

    Liu HJ, Du H, Khabibullin D, et al.

    Nature communications 2023; (14(1)):1214 doi:10.1038/s41467-023-36881-7.

    PMID: 36869048
  7. 7

    Long-term clinical course and progression of lymphangioleiomyomatosis in a single lung transplant referral centre in Korea.

    Chang S, Choi JS, Leem AY, et al.

    Scientific reports 2022; (12(1)):8260 doi:10.1038/s41598-022-12314-1.

    PMID: 35585116
  8. 8

    Giant Renal Angiomyolipomas and Pulmonary Lymphangioleiomyomatosis: Follow-up Report after More than a Decade.

    Nasir K, Ahmad A

    Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia 2023; (34(6)):671-675 doi:10.4103/sjkdt.sjkdt_324_21.

    PMID: 38725217
  9. 9

    The efficacy and safety of pharmacological treatments for lymphangioleiomyomatosis.

    Wang Q, Luo M, Xiang B, et al.

    Respiratory research 2020; (21(1)):55 doi:10.1186/s12931-020-1316-3.

    PMID: 32059669
  10. 10

    Efficacy and Safety of Long-Term Sirolimus Therapy for Asian Patients with Lymphangioleiomyomatosis.

    Takada T, Mikami A, Kitamura N, et al.

    Annals of the American Thoracic Society 2016; (13(11)):1912-1922 doi:10.1513/AnnalsATS.201605-335OC.

    PMID: 27513278
  11. 11

    Brazilian Thoracic Association recommendations for the management of lymphangioleiomyomatosis.

    Baldi BG, Feitosa PHR, Rubin AS, et al.

    Jornal brasileiro de pneumologia : publicacao oficial da Sociedade Brasileira de Pneumologia e Tisilogia 2025; (51(1)):e20240378 doi:10.36416/1806-3756/e20240378.

    PMID: 39936727
  12. 12

    Emerging biomarkers of lymphangioleiomyomatosis.

    Nijmeh J, El-Chemaly S, Henske EP

    Expert review of respiratory medicine 2018; (12(2)):95-102 doi:10.1080/17476348.2018.1409622.

    PMID: 29171770
  13. 13

    Epidemiology of patients with lymphangioleiomyomatosis: A descriptive study using the national database of health insurance claims and specific health checkups of Japan.

    Kimura Y, Jo T, Hashimoto Y, et al.

    Respiratory investigation 2024; (62(3)):494-502 doi:10.1016/j.resinv.2024.03.010.

    PMID: 38583226
  14. 14

    Complications of lymphangioleiomyomatosis in pregnancy: a case report and review of the literature.

    Wang-Koehler E, Kern-Goldberger AR, Srinivas SK

    AJOG global reports 2024; (4(1)):100309 doi:10.1016/j.xagr.2024.100309.

    PMID: 38327672
  15. 15

    Lung-selective mRNA delivery of synthetic lipid nanoparticles for the treatment of pulmonary lymphangioleiomyomatosis.

    Qiu M, Tang Y, Chen J, et al.

    Proceedings of the National Academy of Sciences of the United States of America 2022; (119(8)) doi:10.1073/pnas.2116271119.

    PMID: 35173043
  16. 16

    Long-term efficacy and safety of sirolimus therapy in patients with lymphangioleiomyomatosis.

    Hu S, Wu X, Xu W, et al.

    Orphanet journal of rare diseases 2019; (14(1)):206 doi:10.1186/s13023-019-1178-2.

    PMID: 31429781
  17. 17

    Functional improvements in patients with lymphangioleiomyomatosis after sirolimus: an observational study.

    Zhan Y, Shen L, Xu W, et al.

    Orphanet journal of rare diseases 2018; (13(1)):34 doi:10.1186/s13023-018-0775-9.

    PMID: 29458386

This page provides general educational information about Lymphangioleiomyomatosis (LAM). It is not a substitute for professional medical advice, diagnosis, or treatment from a qualified pulmonologist or LAM specialist.

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