Updated Prevalence of Lymphangioleiomyomatosis in Europe

Pulmonary lymphangioleiomyomatosis (LAM) having no extra-pulmonary manifestations with chemical and mechanical pleurodesis: A case report and review of literature

Lymphangioleiomyomatosis (LAM) is a rare, progressive lung disease characterized by abnormal smooth muscle proliferation, leading to cystic destruction of the lung parenchyma. We present the case of a female in her early 40s who presented with intermittent chest pain for 1 month. Imaging revealed left hydropneumothorax with multiple bilateral pulmonary parenchymal cysts, and a subsequent lung biopsy confirmed the diagnosis of pulmonary LAM. The patient underwent video-assisted thoracoscopic surgery (VATS) with mechanical and chemical pleurodesis. Given her stable condition, no immediate sirolimus therapy was initiated, and close follow-up with serial imaging was planned. This case highlights the diagnostic challenges of LAM, especially with low VEGF-D levels, and underscores the role of pleurodesis as a management option in select patients. Early recognition and tailored management are essential to optimize patient outcomes.

Increased malignancy risk in patients with lymphangioleiomyomatosis: findings from a Chinese cohort

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare, low-grade neoplasm. Abnormal activation of the mammalian target of rapamycin (mTOR) pathway plays a critical role in LAM pathogenesis by promoting cell proliferation, which may increase susceptibility to malignancies in these patients. However, owing to the rarity of LAM, comprehensive data on the risk of malignancy in this population are limited.

METHODS

We retrospectively analyzed 849 LAM patients who participated in the LAM-China Registry Study at Peking Union Medical College Hospital. We collected medical records of patients with malignant tumors and estimated the incidence of malignancy in the LAM-China cohort.

RESULTS

A total of 849 patients were included in our research, of whom 760 were sporadic LAM and 89 had tuberous sclerosis complex-associated LAM. Thirty-one patients (3.65%) had a history of malignancy. More than 80% of LAM and malignant tumors developed successively within 5 years, with a median time interval of 1.5 years. Eighteen patients who were diagnosed with malignancy after diagnosis of LAM were included in the incidence calculation. The three most prevalent cancers were thyroid cancer (n = 5), breast cancer (n = 4) and ovarian cancer (n = 3). Except for lung cancer, the SIRs for all other cancers mentioned in the present study were significantly increased: thyroid cancer (SIR = 10.87, 95% CI 3.53-25.37), breast cancer (SIR = 5.95, 95% CI 1.62-15.24), and ovarian cancer (SIR = 24.54, 95% CI 5.07-71.86). After standardization by age, the SIR for malignancy in our cohort was 3.20 (95% CI 1.89-5.05, p = 0.00003). However, this elevated risk of malignancy appeared to be confined to younger age groups. Among individuals aged over 50 years, there was no statistically significant difference in the incidence of malignancy between LAM patients and the reference population.

CONCLUSION

The risk of malignant tumors is significantly increased in LAM patients than that in the reference population. Thyroid cancer, breast cancer, and ovarian cancer were the three most prevalent malignancies in our cohort. Each type of cancer that appeared in the cohort presented a relatively high incidence, except for lung cancer.

Iron metabolism disorder and artesunate inhibiting tumor growth by inducing ferroptosis in Lymphangioleiomyomatosis

BACKGROUND

Sirolimus, the therapy choice for lymphangioleiomyomatosis (LAM), displayed cytostatic but not cytocidal action, with disease recurrence after withdrawal. The aim of this study is to identify novel potential biomarkers and therapeutic strategies for LAM patients.

METHODS

TMT-labeling proteomics was utilized for screening the differentially expressed proteins (DEPs) in the plasma of 10 LAM patients and 6 controls. Plasma levels of transferrin (TRF), ferritin (FRT) and beta2-microglobulin (B2M) were validated in a cohort of 30 LAM patients and 20 controls. The diagnostic efficacy of TRF with/without VEGF-D was assessed using ROC curve analysis. The therapeutic effects of a ferroptosis inducer artesunate (ART) were evaluated both in vitro Tsc2 - / - MEFs cells and in xenograft LAM models.

RESULTS

Proteomics analysis revealed 132 DEPs between LAM patients and controls, which primarily enriched in the regulation of iron ion transport. LAM patients had decreased TRF, elevated FRT and B2M levels compared with controls in the confirmation cohort (p = 0.0386, p = 0.0327 and p = 0.0155, respectively) which independent with VEGF-D level or rapamycin therapy. TRF positively correlated with both FEV1% predicted (r = 0.4486, p = 0.0251) and DLCO% predicted (r = 0.4018, p = 0.0516) of LAM patients. The combination of TRF and VEGF-D showed superior diagnostic value compared to individual indicator. ART induced the ferroptosis and inhibited the growth in Tsc2 - / - MEFs cells. In LAM animal models, ART exerted anti-tumor effects without obvious adverse effect.

CONCLUSIONS

LAM patients exhibit abnormal iron metabolism independent of VEGF-D level. Ferroptosis inducer ART holds promise as a therapeutic novel approach for treating LAM.

mTOR pathway diseases: challenges and opportunities from bench to bedside and the mTOR node

Mechanistic target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that regulates key cellular processes including cell growth, autophagy and metabolism. Hyperactivation of the mTOR pathway causes a group of rare and ultrarare genetic diseases. mTOR pathway diseases have diverse clinical manifestations that are managed by distinct medical disciplines but share a common underlying molecular basis. There is a now a deep understanding of the molecular underpinning that regulates the mTOR pathway but effective treatments for most mTOR pathway diseases are lacking. Translating scientific knowledge into clinical applications to benefit the unmet clinical needs of patients is a major challenge common to many rare diseases. In this article we expound how mTOR pathway diseases provide an opportunity to coordinate basic and translational disease research across the group, together with industry, medical research foundations, charities and patient groups, by pooling expertise and driving progress to benefit patients. We outline the germline and somatic mutations in the mTOR pathway that cause rare diseases and summarise the prevalence, genetic basis, clinical manifestations, pathophysiology and current treatments for each disease in this group. We describe the challenges and opportunities for progress in elucidating the underlying mechanisms, improving diagnosis and prognosis, as well as the development and approval of new therapies for mTOR pathway diseases. We illustrate the crucial role of patient public involvement and engagement in rare disease and mTOR pathway disease research. Finally, we explain how the mTOR Pathway Diseases node, part of the Research Disease Research UK Platform, will address these challenges to improve the understanding, diagnosis and treatment of mTOR pathway diseases.

Mechanisms of exercise limitation and pulmonary rehabilitation in patients with cystic lung diseases

INTRODUCTION

The main diffuse cystic lung diseases (DCLD) include lymphangioleiomyomatosis (LAM), pulmonary Langerhans cell histiocytosis (PLCH), Birt-Hogg-Dubé syndrome, and lymphocytic interstitial pneumonia. Exercise limitation is frequent and secondary to multiple mechanisms in DCLD. Some studies addressed mechanisms for exercise limitation, field tests, and pulmonary rehabilitation (PR) in DCLD.

AREAS COVERED

This review aims to present the main mechanisms that determine exercise limitation, the responses of patients in field tests, and the details regarding the safety and efficacy of PR in DCLD, with emphasis on LAM and PLCH. A search on the issue was performed in the MEDLINE and SciELO databases between 27 November 2024 and 20 February 2025. Manuscripts were reviewed and important topics were included in this review.

EXPERT OPINION

Reduced exercise capacity is common and multifactorial, including ventilatory, cardiocirculatory, and peripheral limitations, pulmonary hypertension (PH), and impaired gas exchange in LAM and PLCH. Variables from field tests are correlated with pulmonary function tests, and PR is safe and beneficial in LAM. Further studies are necessary to evaluate exercise in other DCLDs, the impact of other therapeutic modalities on DH, hypoxemia, and exercise-induced PH in LAM and PLCH, and the safety and benefits of PR mostly in PLCH.

Brazilian Thoracic Association recommendations for the management of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare disease, characterized as a low-grade neoplasm with metastatic potential that mainly affects women of reproductive age, in which there is proliferation of atypical smooth muscle cells (LAM cells) and formation of diffuse pulmonary cysts. It can occur in a sporadic form or in combination with tuberous sclerosis complex. In recent decades, a number of advances have been made in the understanding of the pathophysiology and management of LAM, leading to improvements in its prognosis: identification of the main genetic aspects and the role of the mechanistic target of rapamycin (mTOR) pathway; relationship with hormonal factors, mainly estrogen; characterization of pulmonary and extrapulmonary manifestations in imaging studies; identification and importance in the diagnosis of VEGF-D; a systematic diagnostic approach, often without the need for lung biopsy; use of and indications for the use of mTOR inhibitors, mainly sirolimus, for pulmonary and extrapulmonary manifestations; pulmonary rehabilitation and the management of complications such as pneumothorax and chylothorax; and the role of and indications for lung transplantation. To date, no Brazilian recommendations for a comprehensive approach to the disease have been published. This document is the result of a non-systematic review of the literature, carried out by 12 pulmonologists, a radiologist, and a pathologist, which aims to provide an update of the most important topics related to LAM, mainly to its diagnosis, treatment, and follow-up, including practical and multidisciplinary aspects of its management.

Lymphangioleiomyomatosis and Pregnancy-Do We Have All the Answers for a Woman Who Desires to Conceive?-Literature Review

Lymphangioleiomyomatosis (LAM) is a rare, progressive, and poor-prognosis systemic disorder that primarily affects women of reproductive age, with a higher prevalence among individuals of Caucasian origin. However, there are limited reliable data on the prevalence of LAM during pregnancy. The fulminant respiratory clinical presentation that often includes progressive dyspnea on exertion, cough, or hemoptysis, frequently complicated by pneumothorax, and the increased risk of spontaneous abortion due to increased estrogen and progesterone production during gestation, are arguments that most often make the diagnosed woman avoid pregnancy. Elevated levels of vascular endothelial growth factor D (VEGF-D), decline in respiratory function, and radiological findings are sufficient arguments in favor of the diagnosis in the pregnant woman. Sirolimus, an mTOR inhibitor, has demonstrated effectiveness in slowing the decline of lung function. Although sirolimus treatment is often recommended to be discontinued before conception due to the increased risk of fetal growth restriction, maintaining a dose level of <5 pcg/mL, with serum drug levels of 3-5 pcg/L, has been considered safe. Given the potential risks, individualized decisions about pregnancy are advised for patients with LAM. For those who choose to proceed, close monitoring by a multidisciplinary team is essential to manage complications effectively. Ongoing research aims to provide clearer guidance to optimize outcomes for both mother and child.

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

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare (twenty-one per million female inhabitants) neoplastic cystic lung disease that impairs health-related quality of life (HRQoL). However, the factors associated with impaired quality of life in patients with LAM are poorly understood.

OBJECTIVE

To assess the clinical, psychosocial, and functional characteristics associated with impaired quality of life in patients with LAM.

METHODS

This was a cross-sectional study performed on two nonconsecutive days. HRQoL (SF-36 and CRQ), lung function tests, anxiety and depression symptoms (HADS), maximal (CPET and ISWT), and submaximal exercise capacity (6MWT) were assessed. Linear associations among outcomes were assessed using Pearson's correlation and multivariate tests.

RESULTS

Forty-five women with LAM (46 ± 10.years; FEV1,74%pred) were evaluated. The lowest SF-36 scores were observed for general health and vitality and the highest for the physical and social domains. The lowest CRQ scores were observed for dyspnea and fatigue, and the highest were for the emotional function and self-control domains. Sixteen (35%) women had anxiety, and 8 (17%) had depression symptoms. Most of the SF-36 and CRQ domains were associated with anxiety and depression symptoms (from r = 0.4 to r = 0.7; p < 0.05) and exercise capacity (from r = 0.3 to r = 0.5; p < 0.05). Lung function parameters were weakly or not associated with quality of life domains. After multiple linear regression, HRQoL was independently associated with depression symptoms and physical capacity but not with lung function.

CONCLUSION

Our results show that aerobic capacity and depression symptoms are the main factors, rather than lung function, related to quality of life in patients with LAM.

Genetic background of pulmonary (vascular) diseases - how much is written in the codes?

PURPOSE OF REVIEW

To provide a comprehensive overview of the underlying genetic defects of pulmonary (vascular) diseases and novel treatment avenues.

RECENT FINDINGS

Pulmonary arterial hypertension (PAH) is the prime example of a pulmonary vascular disease, which can be caused by genetic mutations in some patients. Germline mutations in the BMPR2 gene and further genes lead to vessel remodelling, increase of pulmonary vascular resistance and onset of heritable PAH. The PAH genes with the highest evidence and strategies for genetic testing and counselling have been assessed and evaluated in 2023 by international expert consortia. Moreover, first treatment options have just arisen targeting the molecular basis of PAH.

SUMMARY

Apart from PAH, this review touches on the underlying genetic causes of further lung diseases including alpha 1 antitrypsin deficiency, cystic fibrosis, familial pulmonary fibrosis and lymphangioleiomyomatosis. We point out the main disease genes, the underlying pathomechanisms and novel therapies trying not only to relieve symptoms but to treat the molecular causes of the diseases.