Lymphangioleiomyomatosis: Current understanding and potential treatments

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 、、。.

Lymphangioleiomyomatosis with Tuberous Sclerosis Complex-A Case Study

Lymphangioleiomyomatosis (LAM) is characterized by lung cysts that cause lung deterioration, changes in the lymphatic system, and tumors in the kidneys. It mainly affects women of reproductive age and is a progressive disease. LAM can occur as an isolated disease or coexist with tuberous sclerosis (TSC). The source of LAM cells is unknown. Patients with confirmed LAM should be treated with an mTOR inhibitor, sirolimus, or everolimus. We present a case of LAM with TSC in a patient whose symptoms, including those in the lymph nodes and chyaloperitoneum, mainly concern the abdominal cavity.

Automated Segmentation and Measurements of Pulmonary Cysts in Lymphangioleiomyomatosis across Multiple CT Scanner Platforms over a Period of Two Decades

(1) Background: Lymphangioleiomyomatosis is a genetic disease that affects mostly women of childbearing age. In the lungs, it manifests as the progressive formation of air-filled cysts and is associated with a decline in lung function. With a median survival of 29 years after the onset of symptoms, computed-tomographic monitoring of cystic changes in the lungs is a key part of the management of the disease. However, the current standard method to measure cyst burdens from CT is semi-automatic and requires manual adjustments from trained operators to obtain consistent results due to variabilities in CT technology and imaging conditions over the long course of the disease. This can be impractical for longitudinal studies involving large numbers of scans and is susceptible to subjective biases. (2) Methods: We developed an automated method of pulmonary cyst segmentation for chest CT images incorporating novel graphics processing algorithms. We assessed its performance against the gold-standard semi-automated method performed by experienced operators who were blinded to the results of the automated method. (3) Results: the automated method had the same consistency over time as the gold-standard method, but its cyst scores were more strongly correlated with concurrent pulmonary function results from the physiology laboratory than those of the gold-standard method. (4) Conclusions: The automated cyst segmentation is a competent replacement for the gold-standard semi-automated process. It is a solution for saving time and labor in clinical studies of lymphangioleiomyomatosis that may involve large numbers of chest CT scans from diverse scanner platforms and protocols.

Resection of Extrapulmonary Lymphangiomyoma and Post-Operative Management Considerations

Background: Lymphangiomyomatosis is a rare disease involving the lymph vessels, causing obstruction and cystic formation with an incidence of 3-8 per million women. The disease might be sporadic or inherited. Lymphangiomyomatosis mostly affects the pulmonary system, whereas extrapulmonary Lymphangiomyomatosis may present in various site, occasionally as a localized abdominal mass. The diagnostic process might entail surgical resection to obtain a specimen for pathology that may also help to achieve a long-term control of the disease. Methods: Herein, we present a case of a 45 years old female, who suffered from pulmonary symptoms, and during her workup an abdominal mass was found. The patient underwent exploratory laparotomy with resection of a left retroperitoneal bilobar mass. Results: Histopathological report revealed Lymphangiomyoma. She had a complication of a lymphatic leakage that required a second laparotomy with satisfactory clinical outcome. Conclusions: Surgeons should be aware of the pathological lymphatics and manage post-operative complications by a trial of conservative.

Rapamycin treatment unmasks a sex-specific pattern of scar expansion of the infarcted rat heart: The relationship between mTOR and KATP channel

Inhibition of the mammalian target of rapamycin (mTOR) with the macrolide rapamycin or pharmacological suppression of KATP channel opening translated to scar expansion of the myocardial infarcted (MI) adult female rodent heart. The present study tested the hypotheses that rapamycin-mediated scar expansion was sex-specific and that mTOR signaling directly influenced KATP channel subunit expression/activity. Scar size was significantly larger in post-MI male rats as compared to the previous data reported in post-MI female rats. The reported scar expansion of rapamycin-treated post-MI female rats was not observed following the administration of the macrolide to post-MI male rats. Protein levels of the KATP channel subunits Kir6.2 and SUR2A and phosphorylation of the serine2448 residue of mTOR were similar in the normal heart of adult male and female rats. By contrast, greater tuberin inactivation characterized by the increased phosphorylation of the threonine1462 residue and reduced raptor protein levels were identified in the normal heart of adult female rats. Rapamycin pretreatment of phorbol 12,13-dibutyrate (PDBu)-treated neonatal rat ventricular cardiomyocytes (NNVMs) suppressed hypertrophy, inhibited p70S6K phosphorylation, and attenuated SUR2A protein upregulation. In the presence of low ATP levels, KATP channel activity detected in untreated NNVMs was significantly attenuated in PDBu-induced hypertrophied NNVMs via a rapamycin-independent pathway. Thus, rapamycin administration to post-MI rats unmasked a sex-specific pattern of scar expansion and mTOR signaling in PDBu-induced hypertrophied NNVMs significantly increased SUR2A protein levels. However, the biological advantage associated with SUR2A protein upregulation was partially offset by an mTOR-independent pathway that attenuated KATP channel activity in PDBu-induced hypertrophied NNVMs.

Pulmonary lymphangioleiomyomatosis (LAM): A literature overview and case report

Lymphangioleiomyomatosis is a rare multisystem disease associated with genetic mutations. The disease usually occurs in women of childbearing age and is characterized by infiltration of immature smooth muscle cells into the lungs, airways, and axial lymphatic systems of the chest and abdomen. The disease often destroys lung parenchyma and produces air cysts. Lymphangioleiomyomatosis cell infiltration of the lymphatic axis can affect hilar lymph nodes, mediastinal ganglia, and extrathoracic lymph nodes. The disease can cause lymphatic dilation in the lungs and thoracic ducts, causing chylous effusion into the pleural or abdominal cavities. Invasion of cells into the walls of pulmonary veins can lead to venous obstruction and pulmonary venous hypertension with hemoptysis. Most patients present with cough, dyspnea, pneumothorax, hemoptysis, and abnormal lung function. Definitive diagnosis is usually based on histopathology and immunohistochemistry. We present a case of LAM in a 36-year-old female patient who was confirmed by specimens obtained from pneumothorax surgery and positive immunohistochemical staining with HMB-45.

LINE1 are spliced in non-canonical transcript variants to regulate T cell quiescence and exhaustion

How gene expression is controlled to preserve human T cell quiescence is poorly understood. Here we show that non-canonical splicing variants containing long interspersed nuclear element 1 (LINE1) enforce naive CD4+ T cell quiescence. LINE1-containing transcripts are derived from CD4+ T cell-specific genes upregulated during T cell activation. In naive CD4+ T cells, LINE1-containing transcripts are regulated by the transcription factor IRF4 and kept at chromatin by nucleolin; these transcripts act in cis, hampering levels of histone 3 (H3) lysine 36 trimethyl (H3K36me3) and stalling gene expression. T cell activation induces LINE1-containing transcript downregulation by the splicing suppressor PTBP1 and promotes expression of the corresponding protein-coding genes by the elongating factor GTF2F1 through mTORC1. Dysfunctional T cells, exhausted in vitro or tumor-infiltrating lymphocytes (TILs), accumulate LINE1-containing transcripts at chromatin. Remarkably, depletion of LINE1-containing transcripts restores TIL effector function. Our study identifies a role for LINE1 elements in maintaining T cell quiescence and suggests that an abundance of LINE1-containing transcripts is critical for T cell effector function and exhaustion.

A second hit somatic (p.R905W) and a novel germline intron-mutation of TSC2 gene is found in intestinal lymphangioleiomyomatosis: a case report with literature review

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by hamartomas in multiple organs associated with germline mutations in TSC1 and TSC2, including exonic, intronic, or mosaic mutations. Gastrointestinal (GI) tract Lymphangioleiomyomatosis (LAM) is an extremely rare manifestation of TSC, with few reported cases. Herein, we aimed to determine the driver mutation, pathogenesis, and relationship of germline and somatic mutations of LAM through whole-genome sequencing (WGS) of the tumor and blood samples and whole transcriptome sequencing (WTS) analysis.

CASE PRESENTATION

A nine-year-old girl with a full-blown TSC presented with abdominal masses detected during a routine check-up. Resected intestinal masses were diagnosed as LAM by thorough pathological examination. Interestingly, the LAM presented a somatic TSC2 gene mutation in exon 24 (p.R905W, c.C2713T), and the patient had intron retention by a novel germline mutation in the intron region of TSC2 (chr16:2126489, C > G).

CONCLUSION

Our case suggests that intron retention by a single nucleotide intronic mutation of TSC2 is sufficient to develop severe manifestations of TSC, but the development of LAM requires an additional somatic oncogenic mutation of TSC2.

A Systematic Review of Lymphangioleiomyomatosis on Diagnosis and Molecular Mechanism

Objective

Lymphangioleiomyomatosis (LAM) is a rare low-grade metastatic tumor; however, LAM patients were always found in young age with difficulty for diagnosis. Our study is aimed at observing the clinical characteristics of patients with lymphangiomatosis, including the clinical manifestations, imaging findings, histopathological features, and immunophenotype.

Methods

We did a systematic review on LAM/PLAM cases, especially on male cases, and collected the clinical features and molecular mechanisms of PLAM based on previous findings.

Results

Diagnosis criteria were summarized by combining CT scans, MRI, immunohistochemistry results, and gene sequencing results for effectively distinguishing between PLAM and similar diseases. Moreover, our study illustrated the molecular mechanism of PLAM as well as the signaling pathway involved in the disease initials. In addition, a male case was reported with differential diagnosis on the clinical manifestations, microscopic features, immunophenotypes, and genotypes.

Conclusion

Our review will definitely improve the understanding of diagnosis and treatment in PLAM cases.

Ultra-Small Lung Cysts Impair Diffusion Without Obstructing Air Flow in Lymphangioleiomyomatosis

Background

Lymphangioleiomyomatosis (LAM) is a rare lung disease found primarily in women of childbearing age, characterized by the formation of air-filled cysts, which may be associated with reductions in lung function. An experimental, regional ultra-high resolution CT scan identified an additional volume of cysts relative to standard chest CT imaging, which consisted primarily of ultra-small cysts.

Research Question

What is the impact of these ultra-small cysts on the pulmonary function of patients with LAM?

Study Design and Methods

A group of 103 patients with LAM received pulmonary function tests and a CT examination in the same visit. Cyst score, the percentage lung volume occupied by cysts, was measured by using commercial software approved by the US Food and Drug Administration. The association between cyst scores and pulmonary function tests of diffusing capacity of the lungs for carbon monoxide (Dlco) (% predicted), FEV₁ (% predicted), and FEV₁/FVC (% predicted) was assessed with statistical analysis adjusted for demographic variables. The distributions of average cyst size and ultra-small cyst fraction among the patients were evaluated.

Results

The additional cyst volume identified by the experimental, higher resolution scan consisted of cysts of 2.2 ± 0.8 mm diameter on average and are thus labeled the “ultra-small cyst fraction.” It accounted for 27.9 ± 19.0% of the total cyst volume among the patients. The resulting adjusted, whole-lung cyst scores better explained the variance of Dlco (P < .001 adjusted for multiple comparisons) but not FEV₁ and FEV₁/FVC (P = 1.00). The ultra-small cyst fraction contributed to the reduction in Dlco (P < .001) but not to FEV₁ and FEV₁/FVC (P = .760 and .575, respectively). The ultra-small cyst fraction and average cyst size were correlated with cyst burden, FEV₁, and FEV₁/FVC but less with Dlco.

Interpretation

The ultra-small cysts primarily contributed to the reduction in Dlco, with minimal effects on FEV₁ and FEV₁/FVC. Patients with lower cyst burden and better FEV₁ and FEV₁/FVC tended to have smaller average cyst size and higher ultra-small cyst fraction.

Clinical Trial Registration

ClinicalTrials.gov; No.: NCT00001465; URL: www.clinicaltrials.gov

Usefulness of 99mTc-ASC lymphoscintigraphy and SPECT/CT in the evaluation of rare lymphatic disorders: Gorham-Stout disease, lymphangioma, and lymphangioleiomyomatosis

The purpose of this study was to investigate the role of Tc-antimony sulfide colloid (ASC) lymphoscintigraphy and single photon emission computed tomography/computed tomography (SPECT/CT) in the evaluation of rare lymphatic disorders, including Gorham--Stout disease (GSD), lymphangioma, and lymphangioleiomyomatosis (LAM).Nine patients suspected to have rare lymphatic disorders were included in this retrospective study. All patients underwent Tc-ASC lymphoscintigraphy and SPECT/CT to evaluate the lesions. The lymphoscintigraphy results were compared with the clinical and immunopathological findings.Tc-ASC lymphoscintigraphy and SPECT/CT could provide lymphatic draining and anatomical information for rare lymphatic disorders. Among the 9 patients, 3 were diagnosed with GSD (1 female, 2 males; aged 15-34 years, range 27.0 ± 10.4 years), 3 with lymphangioma (1 female, 2 males; aged 17-42 years, range 32.0 ± 13.2 years), and 3 patients were diagnosed with LAM (3 females; aged 33-50 years, range 43.7 ± 9.3 years]. GSD is characterized by multiple bone destruction, including spine, ribs, ilium, pubis, ischium, and femur. The tracer uptake of involved bones and soft tissue around bone is increased, accompanied by chylothorax, chylopericardium, and chylous leakage in abdominal and pelvic cavity. Lymphangiomas present as multiple cystic lesions with increased tracer uptake in the peripancreatic, retroperitoneal, and iliac areas, and in the abdominopelvic cavity. LAM presents as multiple thin-walled cysts in the bilateral lungs and multiple retroperitoneal enlarged lymph nodes with increased tracer uptake.Tc-ASC lymphoscintigraphy and SPECT/CT could comprehensively and specifically detect some rare lymphatic disorders, namely, GSD, lymphangioma, and LAM. This technique is useful for the evaluation of GSD, lymphangioma, and LAM.

Possible Novel Therapeutic Targets in Lymphangioleiomyomatosis Treatment

Lymphangioleiomyomatosis (LAM) is a rare systemic neoplastic disease that exclusively happens in women. Studies focusing on LAM and tuberous sclerosis complex (TSC) have made great progress in understanding the pathogenesis and searching for treatment. The inactive mutation of TSC1 or TSC2 is found in patients with LAM to activate the crucial mammalian target of rapamycin (mTOR) signaling pathway and result in enhanced cell proliferation and migration. However, it does not explain every step of tumorigenesis in LAM. Because cessation of rapamycin would break the stabilization of lung function or improved quality of life and lead to disease recurrent, continued studies on the pathogenesis of LAM are necessary to identify novel targets and new treatment. Researchers have found several aberrant regulations that affect the mTOR pathway such as its upstream or downstream molecules and compensatory pathways in LAM. Some therapeutic targets have been under study in clinical trials. New methods like genome-wide association studies have located a novel gene related to LAM. Herein, we review the current knowledge regarding pathogenesis and treatment of LAM and summarize novel targets of therapeutic potential recently.

Characterizing Lymphangiogenesis and Concurrent Inflammation in Adipose Tissue in Response to VEGF-D

The metabolic consequences of obesity arise from local inflammation within expanding adipose tissue. In pre-clinical studies targeting various inflammatory factors, systemic metabolism can be improved through reduced adipose inflammation. Lymphatic vessels are a critical regulator of inflammation through roles in fluid and macromolecule transport and immune cell trafficking and immunomodulation. Lymphangiogenesis, the expansion of the lymphatic network, is often a necessary step in restoring tissue homeostasis. Using Adipo-VD mice, a model of adipocyte-specific, inducible overexpression of the potent lymphangiogenic factor vascular endothelial growth factor-D (VEGF-D), we previously identified that dense de novo adipose lymphatics reduced immune accumulation and improved glucose homeostasis in obesity. On chow diet, however, Adipo-VD mice demonstrated increased adipose tissue immune cells, fibrosis, and inflammation. Here, we characterize the time course of resident macrophage accumulation and lymphangiogenesis in male and female Adipo-VD mice fed chow and high fat diets, examining multiple adipose depots over 4 months. We find that macrophage infiltration occurs early, but resolves with concurrent lymphatic expansion that begins robustly after 1 month of VEGF-D overexpression in white adipose tissue. In obesity, female Adipo-VD mice exhibit reduced lymphangiogenesis and maintain a more glycolytic metabolism compared to Adipo-VD males and their littermates. Adipose lymphatic structures appear to expand by a lymphvasculogenic mechanism involving lymphatic endothelial cell proliferation and organization with a cell source we that failed to identify; hematopoietic cells afford minimal structural contribution. While a net positive effect occurs in Adipo-VD mice, adipose tissue lymphangiogenesis demonstrates a dichotomous, and time-dependent, inflammatory tissue remodeling response.

Clinical CT underestimation of the percentage volume occupied by cysts in patients with lymphangioleiomyomatosis

PURPOSE

To evaluate the accuracy of cyst score measurements by standard high-resolution helical volume chest CT (HRCT) in patients with lymphangioleiomyomatosis (LAM), using a short z-length ultra-high resolution re-scan (UH re-scan) as the reference. In cystic lung diseases, cyst score is derived from CT scans and defined as the percentage of the total lung parenchymal volume occupied by cysts, a biomarker which measures the severity of the disease.

METHODS

In a prospective study of 73 LAM patients, each patient received the standard HRCT chest scan and a short z-length UH re-scan. Cyst scores were acquired from both scans using a standard FDA-approved scoring software on the CT scanner.

RESULTS

The limited UH re-scan resolved small cysts that were not resolved in the HRCT. The HRCT-derived cyst scores were on average 59.6% of the reference values from the UH re-scan (p = 4.7e-25). The amount of under-estimation by HRCT varied from patient to patient, with an inter-quartile range of 29.8% and standard deviation of 20.7%. The overall trend was more pronounced underestimation for patients with lower cyst scores. For patients whose reference cyst scores were below 15 (n = 29), the HRCT cyst scores were 46.9 ± 21.6% of reference values (p = 7.4e-12), while for the rest of the patients (n = 44) the HRCT cyst scores were 68.0 ± 15.3% of reference values (p = 1.2E-19). Reconstructing the HRCT images to the resolution of the UH re-scan further widened the spread of the discrepancy between HRCT and reference values due to increased image noise, and did not provide accurate cyst scores.

CONCLUSION

Cyst scores derived from standard high-resolution helical volume chest CT significantly underestimates the percentage lung volume occupied by cysts. This inaccuracy needs to be taken into consideration when cyst score is used as part of the CT assessment of the patient's condition.

Molecular Targeting of Immunosuppressants Using a Bifunctional Elastin-Like Polypeptide

Elastin-Like Polypeptides (ELP) are environmentally responsive protein polymers which are easy to engineer and biocompatible, making them ideal candidates as drug carriers. Our team has recently utilized ELPs fused to FKBP12 to carry Rapamycin (Rapa), a potent immunosuppressant. Through high affinity binding to Rapa, FKBP carriers can yield beneficial therapeutic effects and reduce the off-site toxicity of Rapa. Since ICAM-1 is significantly elevated at sites of inflammation in diverse diseases, we hypothesized that a molecularly targeted ELP carrier capable of binding ICAM-1 might have advantageous properties. Here we report on the design, characterization, pharmacokinetics, and biodistribution of a new ICAM-1-targeted ELP Rapa carrier (IBPAF) and its preliminary characterization in a murine model exhibiting elevated ICAM-1. Lacrimal glands (LG) of male NOD mice, a disease model recapitulating the autoimmune dacryoadenitis seen in Sjögren's Syndrome patients, were analyzed to confirm that ICAM-1 was significantly elevated in the LG relative to control male BALB/c mice (3.5-fold, p < 0.05, n = 6). In vitro studies showed that IBPAF had significantly higher binding to TNF-α-stimulated bEnd.3 cells which overexpress surface ICAM-1, relative to nontargeted control ELP (AF)(4.0-fold, p < 0.05). A pharmacokinetics study in male NOD mice showed no significant differences between AF and IBPAF for plasma half-life, clearance, and volume of distribution. However, both constructs maintained a higher level of Rapa in systemic circulation compared to free Rapa. Interestingly, in the male NOD mouse, the accumulation of IBPAF was significantly higher in homogenized LG extracts compared to AF at 2 h (8.6 ± 6.6% versus 1.3 ± 1.3%, respectively, n = 5, p < 0.05). This accumulation was transient with no differences detected at 8 or 24 h. This study describes the first ICAM-1 targeted protein-polymer carrier for Rapa that specifically binds to ICAM-1 in vitro and accumulates in ICAM-1 overexpressing tissue in vivo, which may be useful for molecular targeting in diverse inflammatory diseases where ICAM-1 is elevated.

Role of thoracic imaging in the management of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare diffuse lung cystic disease (DLCD) that occurs sporadically or in association with Tuberous Sclerosis Complex (TSC). The diagnostic pathway is tracked on the identification of the disease hallmarks on chest High-Resolution Computed Tomography (HRCT). Aim of this review is to discuss the thoracic HRCT pathognomonic features, essential to rule out other DLCD. It also examines the new evidences emerging from Computed Tomography (CT) quantitative studies that, by demonstrating a specific cysts distribution and a pathological aspect of the parenchyma near the cysts, could improve our understanding of this rare disorder and supply pulmonologists with a new tool for a more appropriate long-term management. Finally, the contribution of other image techniques as low dose chest CT, Magnetic Resonance Imaging (MRI) and Ultrasound (US) is discussed.

Tuberous sclerosis complex: new insights into clinical and therapeutic approach

Tuberous sclerosis complex (TSC) is a complex disease with many different clinical manifestations. Despite the common opinion that TSC is a rare condition, with a mean incidence of 1/6000 live births and a prevalence of 1/20,000, it is increasingly evident that in reality this is not true. Its clinical sequelae span a range of multiple organ systems, in particular the central nervous system, kidneys, skin and lungs. The management of TSC patients is heavily burdensome in terms of time and healthcare costs both for the families and for the healthcare system. Management options include conservative approaches, surgery, pharmacotherapy with mammalian target of rapamycin inhibitors and recently proposed options such as therapy with anti-EGFR antibody and ultrasound-guided percutaneous microwaves. So far, however, no systematically accepted strategy has been found that is both clinically and economically efficient. Thus, decisions are tailored to patients' characteristics, resource availability and clinical and technical expertise of each single center. This paper reviews the pathophysiology and the clinical (diagnostic-therapeutic) management of TSC.

Emerging biomarkers of lymphangioleiomyomatosis

INTRODUCTION

Lymphangioleiomyomatosis (LAM) is a destructive lung disease affecting primarily women. LAM is caused by inactivating mutations in the tuberous sclerosis complex (TSC) genes, resulting in hyperactivation of mechanistic/mammalian target of rapamycin complex 1 (mTORC1). Over the past five years, there have been remarkable advances in the diagnosis and therapy of LAM, including the identification of vascular endothelial growth factor D (VEGF-D) as a diagnostic biomarker and the US Food and Drug Administration approval of sirolimus as therapy for LAM. In appropriate clinical situations VEGF-D testing can make lung biopsy unnecessary to diagnose LAM. However, there remains an urgent unmet need for additional biomarkers of disease activity and/or response to therapy. Areas covered: This work reviews VEGF-D, an established LAM biomarker, and discusses emerging biomarkers, including circulating LAM cells, imaging, lipid, and metabolite biomarkers, focusing on those with the highest potential impact for LAM patients. Expert commentary: Ongoing research priorities include the development of validated biomarkers to 1) noninvasively diagnose LAM in women whose VEGF-D levels are not diagnostic, 2) accurately predict the likelihood of disease progression and 3) quantitatively measure disease activity and LAM cell burden. These biomarkers would enable personalized, precision clinical care and fast-track clinical trial implementation, with high clinical impact.

Lymph node stromal and vascular proliferations

The recognition and reporting of stromal and vascular lesions of the lymph node is rife with difficulties including relative rarity, a lack of familiarity with lesions and the challenges of using ancillary studies appropriately. In this manuscript, we highlight a range of benign stromal and vascular abnormalities that can be identified in nodal specimens.

An extrapulmonary manifestation of lymphangioleiomyomatosis: A rare case report

Lymphangioleiomyomatosis (LAM) is a rare and fatal disease which occurs almost exclusively in young women. The disease often affects lungs and most of the patients die from respiratory failure. It is often initially misdiagnosed as asthma or chronic obstructive pulmonary disease. The most common presentations of pulmonary LAM (P-LAM) include dyspnea and coughing. Chylothorax and spontaneous pneumothorax may be seen in advanced cases. Although rare, it may present with extrapulmonary LAM (E-LAM). Renal angiomyolipomas and abdominal lymphadenopathies (LAPs) are common in E-LAM cases. Pelvic retroperitoneal masses are very rare and often require exploratory laparotomy. Herein, we report a 36-year-old female case of a rare extrapulmonary manifestation of LAM who was treated with abdominal and thoracic surgery, radiotherapy and finally sirolimus.

Genomic rearrangements in sporadic lymphangioleiomyomatosis: an evolving genetic story

Sporadic lymphangioleiomyomatosis is a progressive pulmonary cystic disease resulting from the infiltration of smooth muscle-like lymphangioleiomyomatosis cells into the lung. The migratory/metastasizing properties of the lymphangioleiomyomatosis cell together with the presence of somatic mutations, primarily in the tuberous sclerosis complex gene (TSC2), lead many to consider this a low-grade malignancy. As malignant tumors characteristically accumulate somatic structural variations, which have not been well studied in sporadic lymphangioleiomyomatosis, we utilized mate pair sequencing to define structural variations within laser capture microdissected enriched lymphangioleiomyomatosis cell populations from five sporadic lymphangioleiomyomatosis patients. Lymphangioleiomyomatosis cells were confirmed in each tissue by hematoxylin eosin stain review and by HMB-45 immunohistochemistry in four cases. A mutation panel demonstrated characteristic TSC2 driver mutations in three cases. Genomic profiles demonstrated normal diploid coverage across all chromosomes, with no aneuploidy or detectable gains/losses of whole chromosomal arms typical of neoplastic diseases. However, somatic rearrangements and smaller deletions were validated in the two cases which lacked TSC2 driver mutations. Most significantly, one of these sporadic lymphangioleiomyomatosis cases contained two different size deletions encompassing the entire TSC1 locus. The detection of a homozygous deletion of TSC1 driving a predicted case of sporadic lymphangioleiomyomatosis, consistent with the common two-hit TSC2 mutation model, has never been reported for sporadic lymphangioleiomyomatosis. However, while no evidence of the hereditary tuberous sclerosis complex disease was reported for this patient, the potential for mosaicism and sub-clinical phenotype cannot be ruled out. Nevertheless, this study demonstrates that somatic structural rearrangements are present in lymphangioleiomyomatosis disease and provides a novel method of genomic characterization of sporadic lymphangioleiomyomatosis cells, aiding in defining cases with no detected mutations by conventional methodologies. These structural rearrangements could represent additional pathogenic mechanisms in sporadic lymphangioleiomyomatosis disease, potentially affecting response to therapy and adding to the complex genetic story of this rare disease.

Berunda Polypeptides: Multi-Headed Fusion Proteins Promote Subcutaneous Administration of Rapamycin to Breast Cancer In Vivo

Recombinant Elastin-Like Polypeptides (ELPs) serve as attractive scaffolds for nanoformulations because they can be charge-neutral, water soluble, high molecular weight, monodisperse, biodegradable, and decorated with functional proteins. We recently reported that fusion of the FK-506 binding protein 12 (FKBP) to an ELP nanoparticle (FSI) reduces rapamycin (Rapa) toxicity and enables intravenous (IV) therapy in both a xenograft breast cancer model and a murine autoimmune disease model. Rapa has poor solubility, which leads to variable oral bioavailability or drug precipitation following parenteral administration. While IV administration is routine during chemotherapy, cytostatic molecules like Rapa would require repeat administrations in clinical settings. To optimize FKBP/Rapa for subcutaneous (SC) administration, this manuscript expands upon first-generation FSI nanoparticles (R_h ~ 25 nm) and compares them with two second-generation carriers (FA and FAF) that: i) do not self-assemble; ii) retain a hydrodynamic radius (R_h ~ 7 nm) above the renal filtration cutoff; iii) increase tumor accumulation; and iv) have either one (FA) or two (FAF) drug-binding FKBP domains per ELP protein. Methods: The carriers were compared and evaluated for temperature-concentration phase behavior by UV-Vis spectrophotometry; equilibrium binding and thermodynamics by Isothermal Titration Calorimetry; drug retention and formulation stability by Dialysis and Dynamic Light Scattering; in vitro efficacy using a cell proliferation assay; in vivo efficacy in human MDA-MB-468 orthotopic breast cancer xenografts; downstream target inhibition using western blot; tissue histopathology; and bio-distribution via optical imaging in the orthotopic xenograft mouse model. Results: Named after the two-headed bird in Hindu mythology, the 'Berunda polypeptide' FAF with molecular weight of 97 kDa and particle size, R_h ~ 7 nm demonstrated polypeptide conformation of a soluble hydrated coiled polymer, retained formulation stability for one month post Rapa loading, eliminated toxicity observed with free Rapa after SC administration, suppressed tumor growth, decreased phosphorylation of a downstream target, and increased tumor accumulation in orthotopic breast tumor xenografts. Conclusion: This comprehensive manuscript demonstrates the versatility of recombinant protein-polymers to investigate drug carrier architectures. Furthermore, their facilitation of SC administration of poorly soluble drugs, like Rapa, may enable chronic self-administration in patients.

Diagnosis and treatment of cystic lung disease

Cystic lung disease (CLD) is a group of lung disorders characterized by the presence of multiple cysts, defined as air-filled lucencies or low-attenuating areas, bordered by a thin wall (usually < 2 mm). The recognition of CLDs has increased with the widespread use of computed tomography. This article addresses the mechanisms of cyst formation and the diagnostic approaches to CLDs. A number of assessment methods that can be used to confirm CLDs are discussed, including high-resolution computed tomography, pathologic approaches, and genetic/ serologic markers, together with treatment modalities, including new therapeutic drugs currently being evaluated. The CLDs covered by this review are lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, Birt-Hogg-Dube syndrome, lymphocytic interstitial pneumonia/follicular bronchiolitis, and amyloidosis.