Lymphangioleiomyomatosis: pathogenesis, clinical features, diagnosis, and management

Synergistic effects of mTOR inhibitors with VEGFR3 inhibitors on the interaction between TSC2-mutated cells and lymphatic endothelial cells

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease affecting the lung, kidney, and lymphatic system with a molecular mechanism of tuberous sclerosis complex 2 (TSC2) mutations. Vascular endothelial growth factor D (VEGF-D), a ligand for vascular endothelial growth factor receptor 3 (VEGFR3), is a diagnostic biomarker of LAM and is associated with lymphatic circulation abnormalities. This study explored the interaction between LAM cells and lymphatic endothelial cells (LECs) and the effects of rapamycin on this interaction, which may help to identify new targets for LAM treatment. This study used direct and indirect cocultures of TSC2-null cells and LECs. The xenograft model was applied to explore the therapeutic feasibility. Single-cell sequencing revealed increased LECs in the lungs of LAM patients through activation of pathways involved in lymphangiogenesis. TSC2-null cells attracted LECs and promoted tube formation. VEGF-D/VEGFR3 was a key mediator of the above interaction. Rapamycin can directly inhibit recruitment but not the tube formation of LECs in vitro. The combination of rapamycin with VEGFR3 inhibitors not only enhanced the effect of rapamycin but also inhibited lymphatic related manifestations including the tube formation and the lymphatic metastasis. Our findings demonstrated that LAM cells recruit LECs and promote tube formation via VEGF-D/VEGFR3. Rapamycin only partially blocked this interaction. The synergistic effects of rapamycin and VEGFR3 inhibitors suggest a novel strategy for the treatment of LAM and other TSC2-mutated diseases.

The Bi-steric Inhibitor RMC-5552 Reduces mTORC1 Signaling and Growth in Lymphangioleiomyomatosis

Mutations in the TSC (tuberous sclerosis complex) genes result in the hyperactivation of the mTORC1 (mechanistic/mammalian target of rapamycin 1) growth pathway in mesenchymal pulmonary cells. Rapamycin (sirolimus), a naturally occurring macrolide, is the only therapeutic approved for women with lymphangioleiomyomatosis (LAM), a progressive, destructive lung disease caused by TSC gene mutations and mTORC1 hyperactivation. However, on cessation of the drug, lung function decline continues. We demonstrated here that pulmonary LAM cancer stem-like state (SLS) cells most highly expressed the eIF4E (eukaryotic translation initiation factor 4E)-dependent translation initiation genes. We also showed that the 4E-BP1 (eukaryotic initiation factor 4E-binding protein 1) gene has the lowest expression in these cells, indicating that the 4E-BP1/eIF4E ratio in LAM SLS cells favors unrestrained eIF4E oncogenic mRNA translation. The bi-steric mTORC1-selective compound RMC-5552 prevented growth of LAM-associated fibroblasts and phosphorylation of proteins in the ribosomal protein S6K1/ribosomal protein S6 (S6K1/S6) and 4E-BP1/eIF4E translation mTORC1-driven pathways, whereas rapamycin only blocked the S6K/S6 axis. Rapamycin inhibition of LAM-associated fibroblast growth was rapidly reversed, but RMC-5552 inhibition was more durable. RMC-5552, through its potential to eradicate LAM cancer SLS cells, may have therapeutic benefit in LAM and other diseases with mTORC1 hyperactivity.

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.

Associations of VEGF-D levels with clinical manifestations in lymphangioleiomyomatosis: a cross-sectional analysis of 631 cases

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disorder characterized predominantly by dyspnea, recurrent pneumothorax, chylous effusion and diffuse pulmonary cystic changes in women. Vascular endothelial growth factor-D (VEGF-D) is an important biomarker for LAM.

RESULTS

This study cohort comprised 631 LAM patients and investigated the correlations between serum VEGF-D levels and clinical manifestations of LAM. The median serum level of VEGF-D was 1452pg/ml (820.0-2659pg/ml) among the study population. Patients with highly-elevated VEGF-D levels exhibited younger age, lower BMI, and a higher prevalence of tuberous sclerosis complex (TSC). Elevated VEGF-D levels were associated with a lower prevalence of pneumothorax and angiomyolipomas (AMLs), and a higher risk for retroperitoneal lymphangioleiomyomas and chylous effusion. Elevated VEGF-D levels were associated with increased High-Resolution Computed Tomography (HRCT) LAM grading, reduced forced expiratory volume in one second (FEV1) and diffusion capacity for carbon monoxide (DLco), and decreased arterial oxygen partial pressure. Multiple logistic regression analysis identified age, TSC, AMLs, retroperitoneal lymphangioleiomyomas, chylous effusion, and HRCT grade as independent risk factors for elevated VEGF-D levels. As a diagnostic biomarker for LAM, adding VEGF-D in the diagnostic algorithm enabled the diagnosis of LAM without lung biopsy in 83.5% patients with LAM.

CONCLUSIONS

The findings highlighted the pivotal role of serum VEGF-D in LAM pathophysiology and underscore that age, TSC, retroperitoneal LAM, chylous effusion, AMLs, and high HRCT grade were independent risk factors for increased VEGF-D levels. VEGF-D is a valuable biomarker in evaluation of LAM and improve the efficiency of diagnostic algorithm.

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.

Multicystic Interstitial Lung Disease Due to a Novel Biallelic C-C Chemokine Receptor Type 2 Variant

OBJECTIVE

We are presenting two individuals with biallelic C-C chemokine receptor type 2 (CCR2) deficiency carrying the novel c.644C>T p.L215P variant, who presented with chronic respiratory symptoms during infancy and developed multiple diffuse cystic lesions during childhood.

METHODS

The patients were diagnosed by means of whole exome sequencing and functional validation of the variant was performed in primary patient cells.

RESULTS

While size and extent of the cysts were stable over years, progressive lung function decline was noted in adolescence and adulthood respectively. The CCR2 p.L215P variant was found to be loss-of-expression and patient monocytes displayed a migration defect upon stimulation with the CCR2 ligand C-C motif ligand 2 (CCL2).

CONCLUSION

With a follow-up of up to 25 years, this report expands our understanding of lung disease in CCR2 deficiency and offers another monogenic cause of cystic lung disease. Early genetic diagnosis of affected individuals might allow potentially curative treatment by haematopoietic stem cell transplantation.

[Incidental diagnosis of lymphangioleiomyomatosis in gynecological surgery-a case series]

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare, slow progressing, low-grade neoplasia that primarily effects young women. The disease is well known for its pulmonary involvement with cystic destruction, but extra-pulmonary disease may occur. LAM is associated with mutations in the TSC 1 or TSC 2 genes and may develop sporadically or in the context of hereditary disease tuberous sclerosis complex (TSC). Incident LAM may represent the sentinel finding of the disease.

OBJECTIVE

Raising awareness for rare extrapulmonary LAM lesions in retroperitoneum and pelvic cavity.

METHODS

Data-based research was performed for LAM in gynecological surgical specimens. H&E-stained slides were re-examined, and immunohistochemical stains were re-evaluated. Clinical data were retrieved for the presence pulmonary LAM or TSC.

RESULTS

A total of 13 cases were identified. The age of the patients ranged from 32 to 77 years, and 8/13 were ≤ 55 years. Two women had a history of pulmonary LAM and TSC. Most women underwent surgery for gynecological malignancy. On histological examination, 10/13 patients presented LAM in 1 to 9 lymph nodes with a lesion size of 0.5 to 12.0 mm, mainly located subcapsular or in the nodal parenchyma. Three of the 13 women showed extranodal involvement of the retroperitoneum, myometrium, and the hilum of the ovary. Immunohistochemically LAM was positive for HMB45, desmin, and smooth muscle actin.

CONCLUSION

LAM is a rare systemic disease that mainly involves the lungs. Nevertheless, extra-pulmonary manifestations may occur. It is important to report the incidental finding of even small foci of LAM within the pathology report. Incidental LAM may represent the sentinel lesion for pulmonary LAM and/or TSC.

Enhanced Gαq Signaling in TSC2-Deficient Cells Is Required for Their Neoplastic Behavior

Inherited or sporadic loss of the TSC2 gene can lead to pulmonary lymphangioleiomyomatosis (LAM), a rare cystic lung disease caused by protease-secreting interstitial tumor nodules. The nodules arise by metastasis of cells that exhibit features of neural crest and smooth muscle lineage (LAM cells). Their aberrant growth is attributed to increased activity of mechanistic target of rapamycin complex 1 (mTORC1), an anabolic protein kinase that is normally suppressed by the TSC1-TSC2 protein complex. The mTORC1 inhibitor rapamycin slows the progression of LAM but fails to eradicate disease, indicating a role for mTORC1-independent mechanisms in LAM pathogenesis. Our previous studies revealed G protein-coupled urotensin-II receptor (UT) signaling as a candidate mechanism, but how it promotes oncogenic signaling in TSC2-deficient cells remained unknown. Using a human pluripotent stem cell-derived in vitro model of LAM, we now show hyperactivation of UT, which was required for their enhanced migration and proneoplastic signaling in a rapamycin-insensitive mechanism that required heterotrimeric Gαq/11 (Gαq). Bioluminescence resonance energy transfer assays in HEK 293T cells lacking TSC2 demonstrated selective and enhanced activation of Gαq and its RhoA-associated effectors compared with wild-type control cells. By immunoprecipitation, recombinant UT was physically associated with Gαq and TSC2. The augmented Gαq signaling in TSC2-deleted cells was independent of mTOR activity and associated with increased endosomal targeting of p63RhoGEF, a known RhoA-activating effector of Gαq. These studies identify potential mTORC1-independent proneoplastic mechanisms that can be targeted for prevention or eradication of pulmonary and extrapulmonary LAM tumors.

Pediatric reference values of VEGF-D derived from a German population-based cohort of healthy children

BACKGROUND

Vascular endothelial growth factor D (VEGF-D) is a growth-factor involved in the development of blood vessels and lymphatics in tissues all over the human body. Interestingly, VEGF-D serum levels are increased in certain tumor entities. For tuberous sclerosis complex (TSC), a rare genetic disease associated with (benign) tumor growth, VEGF-D is already implemented as a diagnostic and therapeutic biomarker to monitor onset and progress of lymphangioleiomyomatosis (LAM), one of the noncancerous tumor manifestations in mainly female adult TSC patients. To date only adult VEGF-D serum cut off values are established and used as a diagnostic tool in LAM. Neither cut off nor pediatric reference values for VEGF-D serum levels are known, our study aims to provide reliable pediatric VEGF-D results in samples from healthy children and adolescents.

METHODS

We analyzed 2003 samples provided by healthy children aged 0.25-18 years participating in the prospective longitudinal population-based cohort study "LIFE Child" in Leipzig, Germany. Serum VEGF-D levels were measured by enzyme-linked immunoassay.

RESULTS

VEGF-D levels in healthy children and adolescents show age-and gender specific variations. We showed a significant difference between girls and boys in post pubertal VEGF-D levels. Especially the fact, that girls showed higher VEGF-D levels with advancing stages of puberty is underlining the importance of estrogen metabolism in context of VEGF-D mediated cell proliferation, angiogenesis and associated disease mechanisms.

CONCLUSION

Knowing VEGF-D levels in growing healthy young children and adolescents could help to recognize early disease progression of LAM in individuals at risk especially young women suffering from TSC. Further studies are needed on VEGF-D serum levels in children, especially the impact of estrogen metabolism on VEGF-D should be investigated further.

Surgical management of pleural complications in lymphangioleiomyomatosis

OBJECTIVE

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease occurring primarily in women. Pneumothorax and chylothorax are common pleural complications in LAM. We aim to explore various options in the surgical management of pleural disease in LAM.

METHODS

A retrospective chart review of all patients at the Center for LAM and Rare Lung Diseases at Columbia University was performed, and date, type, and indication for surgical procedure were collected. All patients with any cystic lung disease seen between January 1, 2000, and March 1, 2023, were included in the database.

RESULTS

The charts for 326 patients with possible LAM were reviewed, including 213 with confirmed LAM and 113 women with cystic lung disease consistent suspected to be LAM were reviewed. A total of 40.5% underwent surgical procedures at our institution or at referring hospitals. A total of 15.6% of patients underwent surgical lung biopsies. A total of 16.6% had a history of pneumothoraces, of whom 79.6% underwent chemical and/or mechanical pleurodesis, 14.8% required pleurectomy, and 7.4% were discharged with tunneled indwelling pleural catheters. We found that 5.6% of confirmed LAM patients have history of chylothorax, with thoracic duct ligation, thoracic duct embolization, pleurodesis, and pleurodesis with long-term tunneled indwelling pleural catheter placement all used as treatment strategies.

CONCLUSIONS

Here we demonstrate the significant burden of pleural disease in patients with LAM. It is imperative that thoracic surgeons understand the high incidence of pneumothorax in this patient population. Tunneled indwelling pleural catheters are underutilized but provide long-term options for chylous management with long-term mechanical pleurodesis and a decrease in hospital length of stay.

A challenging convergence of conditions in a patient with thalassemia major presenting with thymoma and lymphangioleiomyomatosis: a case report

BACKGROUND

β-Thalassemia major is a complex, multisystemic condition. Effective transfusion programs, optimal iron chelation therapy, and progresses in magnetic resonance imaging have significantly improved patient survival. Despite these advancements, the fundamental pathophysiology remains unaltered, leading to an increase in comorbidities and cancer diagnoses with advancing age. We report a unique case of coincidentally discovered thymoma and lymphangioleiomyomatosis in a patient with β-thalassemia major.

CASE PRESENTATION

A 56-year-old Italian female patient with β-thalassemia major underwent magnetic resonance imaging to quantify myocardial, hepatic, and pancreatic iron deposition. Her medical history included transfusion-dependent β-thalassemia, splenectomy, and cholecystectomy. At the time of magnetic resonance imaging, she had no significant endocrine, cardiac, or hepatic complications and was on deferasirox, vitamin D, and luspatercept. Magnetic resonance imaging revealed a lobulated mass in the prevascular mediastinum, which showed mild radiotracer uptake on positron emission tomography. Chest computed tomography revealed multiple thin-walled cysts in the lungs, indicating lymphangioleiomyomatosis. Following multidisciplinary evaluation, the patient underwent thoracoscopic thymectomy and lung wedge resection. Histopathology confirmed type B2 thymoma and pulmonary lymphangioleiomyomatosis. Post-surgery, the patient was recommended for adjuvant radiation therapy and sirolimus treatment.

CONCLUSION

This is the first reported case of the coincidental discovery of thymoma and lymphangioleiomyomatosis in a patient with β-thalassemia major. This case emphasizes the importance of thorough radiologic evaluations in patients with β-thalassemia to detect potential neoplastic conditions early. Enhanced awareness among clinicians and radiologists is crucial for the timely diagnosis and management of these patients.

Lung Transplantation Outcomes and Peritransplant Sirolimus Use in Lymphangioleiomyomatosis

Background

With the introduction of sirolimus as medical therapy for lymphangioleiomyomatosis (LAM), an updated evaluation of LAM lung transplant (LT) outcomes and characterization of peritransplant sirolimus use is needed.

Methods

We identified adult LT recipients from 2005-2021 using the Scientific Registry of Transplant Recipients database and stratified by diagnosis (LAM vs other). Multivariable Cox regression was performed to calculate the adjusted hazard ratio for LAM vs other diagnoses. A pharmacy claims database was linked to provide sirolimus prescription information, and a subgroup analysis comparing outcomes with pre- vs posttransplant sirolimus use was performed.

Results

Of 32,337 recipients identified, 156 (0.5%) were diagnosed with LAM. Operative complications, including airway dehiscence, did not significantly differ between groups. After adjusting for donor and recipient characteristics, LAM diagnosis was associated with 45% lower mortality than other diagnoses. Among recipients with pharmacy data, 32% were prescribed sirolimus at any point. Compared with only post-LT use only, recipients with pre-LT sirolimus use had increased mortality (log-rank P = .003).

Conclusions

This study supports lung transplant as a treatment for severe pulmonary LAM and identifies increased mortality associated with pre-LT sirolimus, though this may be due to uncharacterized baseline differences.

Illness cognition, illness perception and related factors in patients with lymphangioleiomyomatosis

PURPOSE

To explore the self-perceived illness cognition and perception status, as well as the relevant factors among lymphangioleiomyomatosis (LAM) patients.

METHODS

A web-based questionnaire survey was conducted in September 2023. A total of 121 LAM patients participated (including 16 patients with TSC-LAM), and the survey collected general demographic information, responses to a disease cognition questionnaire, and a simplified disease perception questionnaire.

RESULTS

LAM patients have a higher level of negative illness cognition and a lower level of positive illness cognition, specifically characterized by helplessness (15.74 ± 4.68 points), acceptance (16.00 ± 3.28 points), and perceived benefits (16.92 ± 3.86 points). Single-factor analysis of variance found significant correlations between cultural level, age, family average monthly income, use of rapamycin, use of home oxygen therapy, hospitalization frequency, disease duration, severity of respiratory distress, activity limitation, and the helplessness score of LAM patients (p ≤ 0.05); the number of children was significantly associated with acceptance scores of LAM patients (p ≤ 0.05); and whether surgery had been performed was significantly associated with acceptance and perceived benefits scores of LAM patients (p ≤ 0.05). Disease duration and activity limitation entered the regression equation for helplessness dimension, while whether surgery had been performed entered the regression equation for perceived benefits dimension, but no factor entered the regression equation for acceptance dimension. Applying the same analysis to disease perception, we found that the average score of the Illness Perception Questionnaire was 45.43 ± 8.97, with lower scores in the reverse-scored items of individual control, treatment, and understanding.

CONCLUSIONS

LAM patients exhibit higher levels of helplessness, particularly among those with longer disease duration and greater activity limitations, leading to a more negative perception of the disease. Additionally, patients who have undergone surgical procedures tend to perceive fewer benefits. Furthermore, there is a significant correlation between illness perception and factors such as rapamycin usage, home oxygen therapy, disease duration and activity limitations caused by LAM. This indicates that clinical healthcare providers should pay more attention to LAM patients and their associated groups, providing both informational and psychological support.

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.

Beyond the Graft: Recurrence of Interstitial Lung Diseases Post Transplant

Interstitial lung diseases (ILDs) represent a heterogenous group of lung disorders marked by inflammation and/or fibrosis of the lung parenchyma, often leading to progressive shortness of breath and end-stage respiratory failure. In the U.S., ILDs affect approximately 650,000 individuals and cause approximately 25,000-30,000 deaths annually. Lung transplantation (LTx) offers definitive treatment for advanced ILD, with improved survival attributed to advancements in immunosuppression, organ preservation, surgical techniques, and postoperative care. However, disease recurrence in transplanted lungs remains a significant concern. Understanding the risk factors and mechanisms underlying recurrence is critical for refining recipient selection and improving outcomes. This review examines ILD recurrence post LTx and its implications for lung transplantation success.

Diffuse Cystic Lung Disease: A Clinical Guide to Recognition and Management

TOPIC IMPORTANCE

Diffuse cystic lung diseases (DCLDs) represent a group of pathophysiologically heterogeneous entities that share a common radiologic phenotype of multiple thin-walled pulmonary cysts. DCLDs differ from the typical fibroinflammatory interstitial lung diseases in their epidemiology, clinical presentation, molecular pathogenesis, and therapeutic approaches, making them worthy of a distinct classification. The importance of timely and accurate identification of DCLDs is heightened by the impact on patient management including recent discoveries of targeted therapeutic approaches for some disorders.

REVIEW FINDINGS

This article offers a practical framework for evaluating patients with DCLD, indicating the most appropriate and current diagnostic and management approaches. We focus on the DCLDs that are most likely to be encountered by practicing pulmonologists: lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, and lymphoid interstitial pneumonia. Chest CT scan is the most informative noninvasive diagnostic modality to identify DCLDs. Thereafter, instituting a structured approach to high-yield associated factors (eg, medical, social, and family history; renal and dermatologic findings) increases the likelihood of identifying DCLDs and achieving a diagnosis.

SUMMARY

Although the individual diseases that comprise the DCLD family are rare, taken together, DCLDs can be encountered more frequently in clinical practice than commonly perceived. An increased eagerness among general pulmonary physicians to recognize these entities, coupled with a practical and systematic clinical approach to examinations and investigations, is required to improve case findings, allow earlier intervention, and reduce morbidity and mortality.

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.

Characteristics and outcomes of patients with LAM receiving sirolimus in France based on real-life data

LAM is a rare multi-cystic lung disease for which treatment with sirolimus is indicated in cases of moderate or severe lung disease or declining lung function. The aim of this study was to describe patients treated with sirolimus for LAM and their outcomes. This retrospective observational study was based on data from the French national health insurance data system (SNDS). All adult women receiving sirolimus were identified in France between 2014 and 2021. In the absence of a specific LAM code in the system, an algorithm was developed to identify patients treated for possible LAM exclusion of other sirolimus indications (transplantation, graft-versus-host disease), or probable LAM (among possible LAM, patients hospitalized for pneumothorax, pleural drainage, pleurisy, ascites, chronic respiratory failure, lung transplantation, or angiomyolipoma). Over the entire study period, 638 patients were considered as treated with sirolimus for possible LAM, including 208 patients treated for "probable" LAM and 33 patients for TSC-LAM. Median [Q1; Q3] age at index date was 45.0 years [34.0; 58.5] for patients with probable LAM and 40.0 years [28.0; 56.0] for patients with TSC-LAM. Overall, the number of incident patients varied from 28 to 96 each year for possible LAM, from 11 to 33 each year for probable LAM and from 1 to 4 patients each year for TSC-LAM patients. In 2021, the incidence rate of patients treated with sirolimus for probable LAM in France was estimated at 0.9 per 1,000,000 French adult women and the prevalence rate at 6.3 per 1,000,000 French adult women. The 5-year survival after sirolimus initiation was 84% (95% CI: 76%; 90%) for probable LAM patients, and 77% (95% CI: 48%; 91%) for TSC-LAM patients. This study provides an updated epidemiological estimate of LAM patients treated with sirolimus in France between 2014 and 2021. Even though some of the results should be interpreted cautiously in the light of limitations related to the use of claims database, evolution of the disease and missing safety data, the information retrieved in this study is very valuable, as few studies provide real-world information on LAM populations.

Abdominal lymphangioleiomyomatosis in a man presenting with gastrointestinal hemorrhage as the first manifestation: a case report

Lymphangioleiomyomatosis (LAM) is a rare, low-grade malignant condition that typically affects women of childbearing age and primarily involves the lungs. While cases involving males and affecting the gastrointestinal tract are exceedingly uncommon. This report discusses an unusual case of abdominal LAM in a male patient with gastrointestinal hemorrhage. The patient, a 70-year-old man, had been experiencing recurrent abdominal pain, occasional black stools, dizziness, and fatigue for over a month before being admitted to the hospital. Diagnostic electronic gastroscopy identified ulcers in the gastric and duodenal bulb with hemorrhage. An abdominal CT scan revealed multiple cystic foci in the retroperitoneum and mesentery, but no masses were found. Despite receiving medical treatment, the patient continued to have black stools and eventually underwent laparoscopic distal subtotal gastrectomy. The pathological results of the excised distal gastric specimens showed LAM-like lesions in the submucosal layer of the pylorus, mesentery of the side of the lesser curvature of the stomach, and small intestine, leading to a diagnosis of abdominal LAM. However, even after the surgery, the patient still experienced recurrent black stools and developed new symptoms of chest tightness and shortness of breath. A follow-up chest CT revealed bilateral pleural effusion and multiple lung cysts, indicating a worsening condition. The patient was then prescribed oral Sirolimus, which resulted in an improvement in symptoms, including black stool, chest tightness, and shortness of breath. This case report provides a detailed account of the progression of an unusual gastrointestinal LAM case and suggests that a combination of surgery and Sirolimus may be effective in managing the condition.

Pulmonary tuberculosis related diffuse cystic lung disease with recurrent pneumothorax mimicking pulmonary lymphangioleomyomatosis in Ethiopia: A review and case report

Millions of individuals worldwide are afflicted by the fatal infectious disease tuberculosis, which accounts for thousands of avoidable deaths. The literature has provided a good description of the clinical manifestation and radiologic features of pulmonary tuberculosis. However, the parenchymal complication of pulmonary tuberculosis presenting as cystic lung disease, has not been widely documented in the literature and is one of the incredibly uncommon causes of diffuse cystic lung disease. It is very uncommon to have a patient with possible pulmonary lymphangioleomyomatosis to be superinfected with bacteriologically confirmed tuberculosis. This report describes a young female patient who was admitted to the hospital, had repeated chest tube insertions and drainage of recurrent spontaneous pneumothoraxes secondary to likely diffuse cystic lung disease related to pulmonary tuberculosis. First, it was thought that the most likely diagnosis was pulmonary lymphangioleomyomatosis. The patient ultimately diagnosed with diffuse cystic lung disease associated with pulmonary tuberculosis as the most likely cause of her clinical presentation considering the high index of suspicion and her sputum gene xpert results. For drug-susceptible tuberculosis, the patient was finally started on anti-tuberculosis medication. She had both clinical and radiological improvement after completion of her anti tuberculosis treatment. Thus, it is reasonable to conclude that tuberculosis may contribute to diffuse cystic lung disease (DCLD) in tuberculosis endemic settings such as Ethiopia, and that appropriate diagnostic efforts should be undertaken to make the diagnosis. A high index of clinical suspicion is crucial to prevent delays in the diagnosis of diffuse cystic lung disease associated with pulmonary tuberculosis.

Nintedanib for patients with lymphangioleiomyomatosis: a phase 2, open-label, single-arm study

BACKGROUND

Lymphangioleiomyomatosis is an ultra-rare disease mainly affecting women of childbearing age. The MILES trial showed the efficacy of sirolimus, an mTOR inhibitor, in stabilising lung function in patients with lymphangioleiomyomatosis. Drug toxicity and development of resistance are potential limitations of therapy with sirolimus. Nintedanib is a multikinase inhibitor that inhibits PDGFR, which is active in human and murine lymphangioleiomyomatosis lesions. We aimed to investigate the activity and safety of nintedanib in patients with lymphangioleiomyomatosis.

METHODS

This phase 2, open-label, single-arm study was conducted at MultiMedica IRCCS, a national referral university centre for rare pulmonary diseases in Milan, Italy. Eligible participants were aged 18 years and older and had sporadic or tuberous sclerosis complex-associated lymphangioleiomyomatosis with progressive pulmonary function decline in the past year despite treatment with sirolimus or treatment naive. Patients received nintedanib 150 mg orally twice per day, with a possible reduction to 100 mg twice per day in case of side-effects or hepatoxicity, for 12 months, followed by a period of 12 additional months without study treatment. The primary endpoint was the change in FEV1 (FEV1 slope in L) over 12 months. This study is registered with ClinicalTrials.gov, NCT03062943.

FINDINGS

From Oct 14, 2016, to Dec 13, 2019, 35 female patients (mean age 50 years [SD 11]) entered the study, 30 of whom were eligible and received nintedanib. After 12 months, 22 patients completed the treatment, 19 of whom also completed the 12 months of follow-up. FEV1 remained stable after one year of treatment (predicted mean difference 0·001 L [95% CI -0·063 to 0·066]; p=0·97). During the 12 months off treatment, a slight decline in FEV1 was observed (predicted mean difference -0·076 L [95% CI -0·149 to -0·004]; p=0·040). The most frequent adverse events were nausea (15 [50%] patients), diarrhoea (eight [26%]), and abdominal pain (two [7%]). No serious adverse events were observed during the treatment period.

INTERPRETATION

Our findings suggest that nintedanib did not improve FEV1, but that the treatment was generally well tolerated. These results might support nintedanib as a second-line therapy in patients not controlled by standard treatment with mTOR inhibitors. Further investigation, such as a non-inferiority trial comparing nintedanib and sirolimus could help to better clarify the role of this drug as a potential alternative treatment.

FUNDING

Boehringer-Ingelheim.

The development for emerging biomarkers of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare, slowly progressing, low-grade metastatic tumor primarily affecting women. Currently, vascular endothelial growth factor-D (VEGF-D) is the only validated diagnostic biomarker, enabling diagnosis of LAM without the need for lung biopsy in appropriate clinical settings. However, VEGF-D concentrations are normal in about 30% of patients, rendering it insufficient for diagnosing all cases of LAM. There remains a need to identify more non-invasive, safe, sensitive, and specific biomarkers associated with LAM. Therefore, it is imperative to explore novel non-invasive, safe, and specific diagnostic methods for LAM. This article aims to review biomarkers associated with LAM, including potential biomarkers newly discovered or showing advancements in classical biomarkers widely used in LAM, and discuss their application in LAM diagnosis, assessment of disease severity, prediction of treatment response, and prognosis. （LAM） 、，。，-D （VEGF-D） ， LAM。， 30% VEGF-D ， LAM 。 LAM 、、。，、 LAM 。 LAM ， LAM ， LAM 、、。.

Pericardial Effusion as a Presentation of Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare, systemic neoplastic disease that primarily affects women of childbearing age. The disease can arise sporadically or in association with tuberous sclerosis. It is characterized by the proliferation of abnormal smooth muscle-like cells, leading to cystic lung destruction, accumulation of chylous fluid, and development of abdominal tumors. The main clinical presentations are pneumothorax and progressive dyspnea on exertion. In some patients, the onset of symptoms occurs while on estrogen replacement therapy or during pregnancy. Since most patients present with common lung symptoms, such as fatigue and dyspnea, LAM is often the last diagnosis to consider. Worsening symptoms with the menstrual cycle can help raise this suspicion. This report describes a case of LAM in which the lack of awareness about this rare disease led to a significant diagnostic delay. A 34-year-old Caucasian woman presented with symptoms of dyspnea and fatigue that began during her second pregnancy, which were initially misinterpreted as obstructive lung disease for three years. As the disease evolved, the development of a pericardial effusion, a rare manifestation of the disease, led to the need to perform computed tomography, revealing multiple thin-walled intrapulmonary cysts with diffuse distribution suggestive of LAM, mediastinal lymphadenopathy, and lymphangioma. Serum vascular endothelial growth factor A levels were normal, and spirometry testing revealed severe airflow obstruction. Based on clinical and imaging findings, a diagnosis of LAM was made. With this article, we intend to raise awareness for the manifestations of this disease and its relation to hormonal changes and review treatment options.

Unsupervised Exercise in Interstitial Lung Disease: A Delphi Study to Develop a Consensus Preparticipation Screening Tool for Lymphangioleiomyomatosis

BACKGROUND

Little research is available to provide practical guidance to health care providers for exercise preparticipation screening and referral of patients with interstitial lung diseases (ILDs), including lymphangioleiomyomatosis (LAM), to participate in remote, unsupervised exercise programs.

RESEARCH QUESTION

What exercise preparticipation screening steps are essential to determine whether a patient with LAM is medically appropriate to participate in a remote, unsupervised exercise program?

STUDY DESIGN AND METHODS

Sixteen experts in LAM and ILD participated in a two-round modified Delphi study, ranking their level of agreement for 10 statements related to unsupervised exercise training in LAM, with an a priori definition of consensus. Additionally, 60 patients with LAM completed a survey of the perceived risks and benefits of remote exercise training in LAM.

RESULTS

Seven of the 10 statements reached consensus among experts. Experts agreed that an in-person clinical exercise test is indicated to screen for exercise-induced hypoxemia and prescribe supplemental oxygen therapy as indicated prior to initiating a remote exercise program. Patients with recent pneumothorax should wait to start an exercise program for at least 4 weeks until after resolution of pneumothorax and clearance by a physician. Patients with high cardiovascular risk for event during exercise, severe resting pulmonary hypertension, or risk for falls may be more appropriate for referral to a rehabilitation center. A LAM-specific remote exercise preparticipation screening tool was developed from the consensus statements and agreed upon by the panelists.

INTERPRETATION

A modified Delphi study approach was useful to develop disease-specific recommendations for safety and preparticipation screening prior to unsupervised, remotely administered exercise in LAM. The primary product of this study is a clinical decision aid for providers to use when medically screening patients prior to participation in the newly launched LAMFit remote exercise program.

Perivascular Epithelioid Cell-Family Tumors in Children, Adolescents, and Young Adults: Clinicopathologic Features in 70 Cases

CONTEXT.—

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors of uncertain histogenesis expressing smooth muscle and melanocytic markers. The clinicopathologic spectrum in young patients is not well documented.

OBJECTIVE.—

To describe a multi-institutional series of PEComas in children, adolescents, and young adults.

DESIGN.—

PEComas, not otherwise specified (NOS); angiomyolipomas (AMLs); lymphangioleiomyomatosis; and clear cell sugar tumors were retrospectively identified from 6 institutions and the authors' files.

RESULTS.—

Seventy PEComas in 64 patients (median age, 15 years) were identified. They were more common in females (45 of 64 patients), occurring predominantly in the kidney (53 of 70), followed by the liver (6 of 70). Thirty-four patients had confirmed tuberous sclerosis complex (TSC), 3 suspected TSC mosaicism, 2 Li-Fraumeni syndrome (LFS) and 1 neurofibromatosis type 1. Most common variants were classic (49 of 70) and epithelioid (8 of 70) AML. Among patients with AMLs, most (34 of 47) had TSC, and more TSC patients had multiple AMLs (15 of 36) than non-TSC patients (2 of 13). Two TSC patients developed malignant transformation of classic AMLs: 1 angiosarcomatous and 1 malignant epithelioid. Lymphangioleiomyomatosis (5 of 70) occurred in females only, usually in the TSC context (4 of 5). PEComas-NOS (6 of 70) occurred exclusively in non-TSC patients, 2 of whom had LFS (2 of 6). Three were malignant, 1 had uncertain malignant potential, and 2 were benign. All 4 PEComas-NOS in non-LFS patients had TFE3 rearrangements.

CONCLUSIONS.—

Compared to the general population, TSC was more prevalent in our cohort; PEComas-NOS showed more frequent TFE3 rearrangements and possible association with LFS. This series expands the spectrum of PEComas in young patients and demonstrates molecular features and germline contexts that set them apart from older patients.

[Highlights 57th SEPAR Congress]

The Spanish Society of Pneumology and Thoracic Surgery (SEPAR) has held its 57th Congress in Valencia from 6 to 8 of June 2024. The SEPAR Congress is the leading meeting for the entire respiratory scientific community, which allows learning about the main scientific advances in this area and provides the ideal situation to create and strengthen ties. This year, under the title "Respiratory Health for everybody", the SEPAR Congress stressed the importance of raising awareness about the importance of caring for and protecting our respiratory system. In this review, we offer a summary of some notable issues addressed in six selected areas of interest: chronic obstructive pulmonary disease (COPD), asthma, interstitial lung diseases (ILDs), pulmonary vascular diseases, sleep and breathing disorders and respiratory physiotherapy.

Repurposing Nitazoxanide for Potential Treatment of Rare Disease Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare genetic lung disease. Unfortunately, treatment with the mTORC1 inhibitor Rapamycin only slows disease progression, and incomplete responses are common. Thus, there remains an urgent need to identify new targets for the development of curative LAM treatments. Nitazoxanide (NTZ) is an orally bioavailable antiprotozoal small molecule drug approved for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum in children and adults, with a demonstrated mTORC1 inhibitory effect in several human cell lines. NTZ's excellent safety profile characterized by its more than 20 years of clinical use makes it a promising candidate for repurposing. Our rationale for this study was to further investigate NTZ's effect using in vitro and in vivo LAM models and to elucidate the underlying molecular mechanism beyond mTORC1 inhibition. For this purpose, we investigated cell proliferation, cell viability, and changes in protein phosphorylation and expression in primary human cell cultures derived from LAM lung samples before translating our results into a syngeneic mouse model utilizing Tsc2-null cells. NTZ reduced cell growth for all tested cell lines at a dose of about 30 µM. Lower doses than that had no effect on cell viability, but doses above 45 µM lowered the viability by about 10 to 15% compared to control. Interestingly, our western blot revealed no inhibition of mTORC1 and only a mild effect on active ß-Catenin. Instead, NTZ had a pronounced effect on reducing pAkt. In the mouse model, prophylactic NTZ treatment via the intraperitoneal and oral routes had some effects on reducing lung lesions and improving body weight retention, but the results remain inconclusive.

Surgical Management of Solitary Extrapulmonary Lymphangioleiomyomatosis in the Mesentery: A Case Report

Pulmonary lymphangioleiomyomatosis (LAM) is a rare condition characterised by infiltration of the lungs with abnormal smooth muscles and cystic lesions. A rarer form of the condition is extrapulmonary LAM (E-LAM) where the same cystic lesions are found in various organs throughout the body resulting in a variety of symptoms. Given the rarity of E-LAM and the difficulty in diagnosing it, there is little evidence to guide its management both surgically and medically. We describe a case of a 22-year-old female with a nine-month history of abdominal pain found to have a large mesenteric mass during laparoscopy for suspected ovarian torsion. She underwent a laparotomy to exteriorise the mass and dissect it off the mesentery. The mass was removed without compromise to the bowel or mesentery. The patient recovered well without symptoms and was discharged without complications. Histopathology of the mass revealed it to be E-LAM. This case is the first to our knowledge that demonstrates the successful removal of a solitary E-LAM from the mesentery with minimal adverse outcomes and symptomatic relief.

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.

Machine Learning Model for Predicting Axillary Lymph Node Metastasis in Clinically Node Positive Breast Cancer Based on Peritumoral Ultrasound Radiomics and SHAP Feature Analysis

OBJECTIVE

This study seeks to construct a machine learning model that merges clinical characteristics with ultrasound radiomic analysis-encompassing both the intratumoral and peritumoral-to predict the status of axillary lymph nodes in patients with early-stage breast cancer.

METHODS

The study employed retrospective methods, collecting clinical information, ultrasound data, and postoperative pathological results from 321 breast cancer patients (including 224 in the training group and 97 in the validation group). Through correlation analysis, univariate analysis, and Lasso regression analysis, independent risk factors related to axillary lymph node metastasis in breast cancer were identified from conventional ultrasound and immunohistochemical indicators, and a clinical feature model was constructed. Additionally, features were extracted from ultrasound images of the intratumoral and its 1-5 mm peritumoral to establish a radiomics feature formula. Furthermore, by combining clinical features and ultrasound radiomics features, six machine learning models (Logistic Regression, Decision Tree, Support Vector Machine, Extreme Gradient Boosting, Random Forest, and K-Nearest Neighbors) were compared for diagnostic efficacy, and constructing a joint prediction model based on the optimal ML algorithm. The use of Shapley Additive Explanations (SHAP) enhanced the visualization and interpretability of the model during the diagnostic process.

RESULTS

Among the 321 breast cancer patients, 121 had axillary lymph node metastasis, and 200 did not. The clinical feature model had an AUC of 0.779 and 0.777 in the training and validation groups, respectively. Radiomics model analysis showed that the model including the Intratumor +3 mm peritumor area had the best diagnostic performance, with AUCs of 0.847 and 0.844 in the training and validation groups, respectively. The joint prediction model based on the XGBoost algorithm reached AUCs of 0.917 and 0.905 in the training and validation groups, respectively. SHAP analysis indicated that the Rad Score had the highest weight in the prediction model, playing a significant role in predicting axillary lymph node metastasis in breast cancer.

CONCLUSION

The predictive model, which integrates clinical features and radiomic characteristics using the XGBoost algorithm, demonstrates significant diagnostic value for axillary lymph node metastasis in breast cancer. This model can provide significant references for preoperative surgical strategy selection and prognosis evaluation for breast cancer patients, helping to reduce postoperative complications and improve long-term survival rates. Additionally, the utilization of SHAP enhancing the global and local interpretability of the model.

Immunology and targeted therapy in Castleman disease

INTRODUCTION

Castleman disease (CD) is a benign lymphoproliferative disease causing severe systemic inflammation. Interleukin-6 (IL-6) is a major pathogenesis of multicentric CD (MCD), but only 30-60% of patients respond to IL-6 inhibitors. Novel agents for IL-6 inhibitor-refractory cases are needed. Clinical data and samples are being collected on a large scale and the clinical, pathological, and pathogenetic aspects are being elucidated.

AREAS COVERED

The pathological and clinical classification of CD is outlined. Focusing on idiopathic MCD (iMCD), this review identifies therapeutic targets and summarizes currently recommended drugs and promising therapeutic candidates.

EXPERT OPINION

The pathogenesis of MCD has been implicated in the activation of the Janus kinase (JAK)-transcriptional signaling activator (STAT) 3 pathway and the phosphatidylinositol 3-kinase (PI3K)/Akt/mechanical target of rapamycin (mTOR) signaling pathway. iMCD-TAFRO (thrombocytopenia, anasarca, fever/elevated CRP, reticulin myelofibrosis/renal dysfunction, organ enlargement) is resistant to IL-6 inhibitors, and cyclosporine and mTOR inhibitors are sometimes effective. JAK inhibitors and mTOR inhibitors may be therapeutic agents for iMCD. Recently, we have shown that peripheral helper T (Tph) cell abnormalities are at the core of iMCD pathogenesis. Therapies targeting chemokine (C-X-C motif) ligand 13 (CXCL13) produced by Tph cells and blocking the Tph-CXCL13-B cell pathway may satisfy unmet need in refractory cases.

Ultra-low dose chest CT with silver filter and deep learning reconstruction significantly reduces radiation dose and retains quantitative information in the investigation and monitoring of lymphangioleiomyomatosis (LAM)

PURPOSE

Frequent CT scans to quantify lung involvement in cystic lung disease increases radiation exposure. Beam shaping energy filters can optimize imaging properties at lower radiation dosages. The aim of this study is to investigate whether use of SilverBeam filter and deep learning reconstruction algorithm allows for reduced radiation dose chest CT scanning in patients with lymphangioleiomyomatosis (LAM).

MATERIAL AND METHODS

In a single-center prospective study, 60 consecutive patients with LAM underwent chest CT at standard and ultra-low radiation doses. Standard dose scan was performed with standard copper filter and ultra-low dose scan was performed with SilverBeam filter. Scans were reconstructed using a soft tissue kernel with deep learning reconstruction (AiCE) technique and using a soft tissue kernel with hybrid iterative reconstruction (AIDR3D). Cyst scores were quantified by semi-automated software. Signal-to-noise ratio (SNR) was calculated for each reconstruction. Data were analyzed by linear correlation, paired t-test, and Bland-Altman plots.

RESULTS

Patients averaged 49.4 years and 100% were female with mean BMI 26.6 ± 6.1 kg/m2. Cyst score measured by AiCE reconstruction with SilverBeam filter correlated well with that of AIDR3D reconstruction with standard filter, with a 1.5% difference, and allowed for an 85.5% median radiation dosage reduction (0.33 mSv vs. 2.27 mSv, respectively, p < 0.001). Compared to standard filter with AIDR3D, SNR for SilverBeam AiCE images was slightly lower (3.2 vs. 3.1, respectively, p = 0.005).

CONCLUSION

SilverBeam filter with deep learning reconstruction reduces radiation dosage of chest CT, while maintaining accuracy of cyst quantification as well as image quality in cystic lung disease.

CLINICAL RELEVANCE STATEMENT

Radiation dosage from chest CT can be significantly reduced without sacrificing image quality by using silver filter in combination with a deep learning reconstructive algorithm.

KEY POINTS

• Deep learning reconstruction in chest CT had no significant effect on cyst quantification when compared to conventional hybrid iterative reconstruction. • SilverBeam filter reduced radiation dosage by 85.5% compared to standard dose chest CT. • SilverBeam filter in coordination with deep learning reconstruction maintained image quality and diagnostic accuracy for cyst quantification when compared to standard dose CT with hybrid iterative reconstruction.

Multinodal Cervical Angiomyomatous Hamartoma

Angiomyomatous hamartoma (AMH) is a rare benign lesion of the lymph nodes. Angiomyomatous hamartoma tends to be found in inguinal lymph nodes, and usually in a single lymph node. We present a rare care case of a 53-year-old presenting with a neck lump, found to be AMH involving multiple lymph nodes in her neck. To our knowledge, this is the first case presenting with multiple nodes in this location. There are a limited number of case reports describing magnetic resonance imaging (MRI) features of AMH lesions located in inguinal and head and neck regions. Our MRI findings revealed the mass had intermediate T1 enhancement, high T2 signal enhancement, and high post-gadolinium enhancement and fat saturation of the lesion. Angiomyomatous hamartoma is a histological diagnosis, distinguished from other similar nodal vascular lesions by a number of key features: including the presence of central nodal distribution, muscular blood vessel walls, adipose tissue, and HMB45 negative staining. Early recognition of this benign lesion may have implications for a patient's clinical course and surgical requirements.

[Differential diagnosis of cystic and nodular lung diseases]

BACKGROUND

Cystic and nodular lung diseases encompass a broad spectrum of diseases with different etiologies and clinicoradiological presentations. Their differentiation is crucial for patient management but can be complex due to diseases with features of both categories and overlapping radiological patterns.

OBJECTIVE

This study aims to describe the imaging features of cystic and nodular lung diseases in high-resolution computed tomography (CT) in detail-primarily based on their etiology-in order to allow a more accurate differential diagnosis of these diseases.

MATERIALS AND METHODS

A narrative review based on current literature on the topic was conducted from a clinicoradiological perspective.

RESULTS

This paper systematically categorizes the differential diagnosis of cystic and nodular lung disease and provides insights into their radiological patterns and etiologies. It highlights the role of CT in the diagnosis of these diseases and emphasizes the importance of multidisciplinary panels combining expertise from radiology, pulmonology, rheumatology, and pathology.

CONCLUSION

Reliable differential diagnosis of cystic and nodular lung diseases, particularly based on their radiological features alone, remains difficult due to their overlapping and dynamic nature. Multidisciplinary boards should be the clinical standard for accurate work-up of these diseases, as they combine the medical history, symptoms, radiological findings, and, if necessary, histopathological examinations, thus providing a more robust framework for diagnosis and management.

Circulating biomarkers of kidney angiomyolipoma and cysts in tuberous sclerosis complex patients

Patients with tuberous sclerosis complex (TSC) develop multi-organ disease manifestations, with kidney angiomyolipomas (AML) and cysts being one of the most common and deadly. Early and regular AML/cyst detection and monitoring are vital to lower TSC patient morbidity and mortality. However, the current standard of care involves imaging-based methods that are not designed for rapid screening, posing challenges for early detection. To identify potential diagnostic screening biomarkers of AML/cysts, we performed global untargeted metabolomics in blood samples from 283 kidney AML/cyst-positive or -negative TSC patients using mass spectrometry. We identified 7 highly sensitive chemical features, including octanoic acid, that predict kidney AML/cysts in TSC patients. Patients with elevated octanoic acid have lower levels of very long-chain fatty acids (VLCFAs), suggesting that dysregulated peroxisome activity leads to overproduction of octanoic acid via VLCFA oxidation. These data highlight AML/cysts blood biomarkers for TSC patients and offers valuable metabolic insights into the disease.

Clinical Trial Validation of Automated Segmentation and Scoring of Pulmonary Cysts in Thoracic CT Scans

In cystic lung diseases such as lymphangioleiomyomatosis (LAM), a CT-based cyst score that measures the percentage of the lung volume occupied by cysts is a common index of the cyst burden in the lungs. Although the current semi-automatic measurement of the cyst score is well established, it is susceptible to human operator variabilities. We recently developed a fully automatic method incorporating adaptive features in place of manual adjustments. In this clinical study, the automatic method is validated against the standard method in several aspects. These include the agreement between the cyst scores of the two methods, the agreement of each method with independent tests of pulmonary function, and the temporal consistency of the measurements in the consecutive visits of the same patients. We found that the automatic method agreed with the standard method as well as the agreement between two trained operators running the same standard method; both methods obtained the same level of correlation with laboratory pulmonary function tests; the automated method had better temporal consistency than the standard method (p < 0.0001). The study indicates that the automatic method could replace the standard method and provide better consistency in assessing the extent of cystic changes in the lungs of patients.

Effect of mTOR inhibitors on the mortality and safety of patients with lymphangioleiomyomatosis on the lung transplantation waitlist: A retrospective cohort study

BACKGROUND

Although lung transplantation (LTx) is the last resort for patients with end-stage lymphangioleiomyomatosis (LAM), the high waitlist mortality is a source of concern in Japan. Discontinuation of mechanistic target of rapamycin (mTOR) inhibitors prior to LTx is recommended due to the incidence of severe adverse events. Therefore, we hypothesized that mTOR inhibitors may affect the mortality of patients with LAM on the LTx waitlist.

METHODS

We retrospectively compared the characteristics of consecutive patients with LAM on the LTx waitlist who were and were not receiving mTOR inhibitors.

RESULTS

Twenty-nine consecutive patients with LAM who listed our center between January 2004 and December 2021 were selected from the database and enrolled in the present study. Seventeen patients (58.6%) were receiving a mTOR inhibitor, sirolimus (treatment group). During a median listing period of 1277 days, 12 patients (41.4%) were hospitalized, six patients (20.7%) died from disease before LTx, and 15 patients underwent LTx. Among the deceased patients, four patients (66.6%) had pneumothoraces. The waitlist mortality in the treatment group was significantly lower than that in the non-treatment group (p = 0.03). Among the six patients who discontinued sirolimus in the treatment group, four patients (66.6%) were hospitalized with respiratory complications after the discontinuation of sirolimus. No mTOR inhibitor-related complications arose in the treatment group undergoing LTx (n = 7), including those on a reduced sirolimus dose.

CONCLUSIONS

Administration of an mTOR inhibitor until LTx may decrease waitlist mortality. Due to life-threatening events after discontinuing sirolimus pre-LTx, a reduced dose until LTx is permissible.

Lymphangioleiomyomatosis and pregnancy: a mini-review

Lymphangioleiomyomatosis(LAM) is a slow progressive, rare cystic lung disease in women of reproductive age, associated with infiltration of the lung by atypical smooth muscle like cells, leading to the cystic destruction of the lung parenchyma. As LAM exclusively affects women of childbearing age, it can arise or exacerbate during pregnancy. Many patients with LAM are discouraged from pregnancy, although there is not much objective evidence effect on fertility. Patients diagnosed with LAM during pregnancy experience worse outcomes, so the safety of pregnancy is a vexing problem. What was worse, treatment strategies are limited on the effects of LAM on pregnancy outcomes. Pregnancy could be considered in LAM patients. Successful delivery in women with LAM depends on the condition of the LAM, which is in turn dependent on obstetricians and respiratory physicians. In this review, we describe the epidemiology, pathogenesis, diagnosis, clinical features and the treatment strategies of LAM during pregnancy.

Influence of intersignaling crosstalk on the intracellular localization of YAP/TAZ in lung cells

A cell is a dynamic system in which various processes occur simultaneously. In particular, intra- and intercellular signaling pathway crosstalk has a significant impact on a cell's life cycle, differentiation, proliferation, growth, regeneration, and, consequently, on the normal functioning of an entire organ. Hippo signaling and YAP/TAZ nucleocytoplasmic shuttling play a pivotal role in normal development, homeostasis, and tissue regeneration, particularly in lung cells. Intersignaling communication has a significant impact on the core components of the Hippo pathway and on YAP/TAZ localization. This review describes the crosstalk between Hippo signaling and key lung signaling pathways (WNT, SHH, TGFβ, Notch, Rho, and mTOR) using lung cells as an example and highlights the remaining unanswered questions.

A Case Report of Malignant Perivascular Epithelioid Cell Tumors of the Uterus and Literature Review

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors originating from perivascular epithelioid cells. In gynecological system, the uterus is one of the most common sites affected by PEComas. Most PEComas are benign, and patients usually have a good prognosis. However, malignant uterus PEComa is rare, and better comprehensive epidemiological investigations are needed. To date, there are a few reported cases of uterus PEComa. We herein report a rare case of malignant PEComa occurred in the uterine corpus and cervix, possibly accompanied by pulmonary lymphangioleiomyomatosis (PLAM). In addition, 55 cases of malignant uterus PEComa were picked out and collected in the data base of PubMed and Medline. On the one hand, the age of onset, population distribution, clinical manifestations, metastatic sites and routes of metastasis were analysed. On the other hand, a summary of the epidemiology, pathogenesis, diagnosis, and treatments of uterus PEComa was given.

Tuberous sclerosis complex associated lymphangioleiomyomatosis caused by de novo mutation of TSC2 gene in Vietnam: A case report

Lymphangioleiomyomatosis (LAM) represents a rare, insidiously progressive disease of the pulmonary system, marked by cystic degradation of lung tissues leading to respiratory compromise. Pulmonary LAM has been identified as being associated with tuberous sclerosis complex (TSC) in its pulmonary manifestation (TSC-LAM), a multisystem genetic disorder resulting from mutations in either the TSC1 or TSC2 genes. Herein, we describe an early 20s female admitted to the hospital with dyspnea, chest pain, hypopigmented macules, and facial fibroadenomas. She has a medical history of renal angiomyolipomas (ALMs) and pneumothoraces. Diagnosis with LAM was confirmed through high-resolution computed tomography (HRCT) scan and histopathology of lung biopsy. Whole exome sequencing analysis identified a frameshift mutation c.4504del (p.L1502Cfs*74) in the patient's TSC2 gene. This variant was de novo due to its absence in the patient's parents. This is the first report on the clinical and genetic etiology of TSC-LAM in Vietnam.

A 24-year-Old woman with recurrent pneumothoraces

Lymphangioleiomyomatosis (LAM) is an abnormal proliferation of smooth muscle-like cells and may occur sporadically or in association with tuberous sclerosis complex. Patients are typically female, nonsmoking and may have cystic lung disease with pneumothorax. Diagnosis can be made by compatible imaging findings with a history of tuberous sclerosis complex, or in conjunction with vascular endothelial growth factor-D 800 pg/ml or greater, a highly specific finding. Sirolimus is first line treatment for LAM.

Diagnosis of cystic lung diseases: a position statement from the UK Cystic Lung Disease Rare Disease Collaborative Network

BACKGROUND

Rare cystic lung diseases are increasingly recognised due the wider application of CT scanning making cystic lung disease management a growing part of respiratory care. Cystic lung diseases tend to have extrapulmonary features that can both be diagnostic but also require surveillance and treatment in their own right. As some of these diseases now have specific treatments, making a precise diagnosis is crucial. While Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, lymphoid interstitial pneumonia and lymphangioleiomyomatosis are becoming relatively well-known diseases to respiratory physicians, a targeted and thorough workup improves diagnostic accuracy and may suggest other ultrarare diseases such as light chain deposition disease, cystic pulmonary amyloidosis, low-grade metastatic neoplasms or infections. In many cases, diagnostic information is overlooked leaving uncertainty over the disease course and treatments.

AIMS

This position statement from the Rare Disease Collaborative Network for cystic lung diseases will review how clinical, radiological and physiological features can be used to differentiate between these diseases.

NARRATIVE

We highlight that in many cases a multidisciplinary diagnosis can be made without the need for lung biopsy and discuss where tissue sampling is necessary when non-invasive methods leave diagnostic doubt. We suggest an initial workup focusing on points in the history which identify key disease features, underlying systemic and familial diseases and a clinical examination to search for connective tissue disease and features of genetic causes of lung cysts. All patients should have a CT of the thorax and abdomen to characterise the pattern and burden of lung cysts and extrapulmonary features and also spirometry, gas transfer and a 6 min walk test. Discussion with a rare cystic lung disease centre is suggested before a surgical biopsy is undertaken.

CONCLUSIONS

We suggest that this focused workup should be performed in all people with multiple lung cysts and would streamline referral pathways, help guide early treatment, management decisions, improve patient experience and reduce overall care costs. It could also potentially catalyse a national research database to describe these less well-understood and unidentified diseases, categorise disease phenotypes and outcomes, potentially leading to better prognostic data and generating a stronger platform to understand specific disease biology.

Familial pulmonary cysts: A clue to diagnose Birt-Hogg-Dubé syndrome: A case report and literature review

Birt-Hogg-Dubé syndrome (BHD) is an inherited autosomal dominant condition caused by germline mutations in the FLCN gene, mapped to chromosome 17p11.2. Typical manifestations include pulmonary cysts, spontaneous pneumothorax, fibrofolliculomas, and kidney neoplasms. This report details the case of a 56-year-old female non-smoker diagnosed with multiple pulmonary cysts, presenting with a history of recurrent spontaneous pneumothorax. A computed tomography (CT) scan of her daughter revealed similar pulmonary cysts, raising suspicion of BHD. Further abdominal enhanced CT revealed a left renal tumour and cutaneous fibrofolliculomas on her daughter's neck. Consequently, whole-exome sequencing confirmed an FLCN germline mutation in the patient and three relatives, establishing a diagnosis of BHD. This case highlights the importance of familial pulmonary cysts as a clue for diagnosing BHD, providing crucial insights into comparable clinical presentations.