Genetic tests in lymphatic vascular malformations and lymphedema

Central conducting lymphatic anomaly: from bench to bedside

Central conducting lymphatic anomaly (CCLA) is a complex lymphatic anomaly characterized by abnormalities of the central lymphatics and may present with nonimmune fetal hydrops, chylothorax, chylous ascites, or lymphedema. CCLA has historically been difficult to diagnose and treat; however, recent advances in imaging, such as dynamic contrast magnetic resonance lymphangiography, and in genomics, such as deep sequencing and utilization of cell-free DNA, have improved diagnosis and refined both genotype and phenotype. Furthermore, in vitro and in vivo models have confirmed genetic causes of CCLA, defined the underlying pathogenesis, and facilitated personalized medicine to improve outcomes. Basic, translational, and clinical science are essential for a bedside-to-bench and back approach for CCLA.

Dietary supplements in lymphedema

Lymphedema is a chronic inflammatory disorder resulting from ineffective fluid uptake by the lymphatic system, and the effects are principally felt in the lower limbs. The condition is said to be primary when caused by genetic mutations and secondary when caused by injuries, infections, or surgery. Lymphedema, a worldwide pathology, does not have an effective therapy so far. Leukotriene B4 has recently been identified as a key molecule in lymphedema pathogenesis. Surgical, nonsurgical, and pharmacological treatments have been proposed; however, they do not cure the disease and only ameliorate the symptoms. Nutrition and nutritional status are extremely important in lymphedema physiopathology. Obesity is a comorbidity that exacerbates the risk for secondary lymphedema and constitutes a negative prognostic factor. Indeed, anti-inflammatory foods and their effects on the inflammatory state and on oxidative stress are now being investigated for their possible therapeutic role in lymphedema. Although no special diet has so far been proven to be very effective, specific dietary tips could help in alleviating the edematous state of patients with lymphedema. A few supplements have been tested for lymphedema treatment. Among them, GARLIVE^® containing hydroxytyrosol, hesperidin, spermidine and vitamin A, exhibited promising effects in the animal model. Hydroxytyrosol, a polyphenol from olives, showed anti-inflammatory effects and reduced leukotriene B4 synthesis, thus holding promise as a potential natural candidate for lymphedema treatment.

Preferred place of death and end-of-life care for adult cancer patients in Iran: A cross-sectional study

Background

More than 50,000 deaths in terms of cancer occur annually in Iranian hospitals. Determining the preferred place of end-of-life care and death for cancer patients in Iran is a quality marker for good end-of-life care and good death. The purpose of this study was to determine the preferred place of end-of-life care and death in cancer patients.

Method

In 2021, the current descriptive cross-sectional investigation was carried out. Using the convenience sample approach, patients were chosen from three Tehran referral hospitals (the capital of Iran). A researcher-made questionnaire with three parts for demographic data, clinical features, and two questions on the choice of the desired location for end-of-life care and the death of cancer patients served as the data collecting instrument. Data were analyzed using SPSS software version 18. The relationship between the two variables preferred place for end-of-life care and death and other variables was investigated using chi-square, Fisher exact test, and multiple logistic regression.

Result

The mean age of patients participating in the study was 50.21 ± 13.91. Three hundred ninety (69.6%) of the patients chose home, and 170 (30.4%) patients chose the hospital as the preferred place of end-of-life care. Choosing the home as a preferred place for end-of-life care had a significant relationship with type of care (OR = .613 [95% CI: 0.383–0.982], P = .042), level of education (OR = 2.61 [95% CI: 1.29–5.24], P = 0.007), type of cancer (OR = 1.70 [1.01–2.89], P = .049), and income level (Mediate: (OR: 3.27 (1.49, 7.14), P = .003) and Low: (OR: 3.38 (1.52–7.52), P = .003). Also, 415 (75.2%) patients chose home and 137 (24.8%) patients chose hospital as their preferred place of death. Choosing the home as a preferred place of death had a significant relationship with marriage (OR = 1.62 [95% CI: 1.02–2.57], P = .039) and time to diagnostic disease less than 6 months (OR = 1.62 [95% CI: 0.265–0.765], P = .002).

Conclusion

The findings of the current research indicate that the majority of cancer patients selected their homes as the preferred location for end-of-life care and final disposition. Researchers advise paying more attention to patients’ wishes near the end of life in light of the findings of the current study. This will be achieved by strengthening the home care system using creating appropriate infrastructure, insurance coverage, designing executive instructions, and integration of palliative care in home care services.

Pediatric Lymphedema: Study of 180 Patients Referred to a Tertiary Lymphedema Clinic

BACKGROUND

Lymphedema is due to dysfunction of the lymphatic system. It can be primary or secondary. Pediatric lymphedema is more often primary and is a chronic disease with a heavy burden on quality of life.

METHODS

Medical records of patients under 18 years of age referred between 1996 and 2021 to the specialized lymphedema clinic at the Sainte-Justine University Hospital Center were reviewed. Demographic data, sex, age at presentation, location of the lymphedema, clinical features, genetic testing, symptoms, complications, investigations, and treatment were collected.

RESULTS

Of 180 referred patients, lymphedema was confirmed in 151, and 137 were primary lymphedema. Median age of apparition of primary lymphedema was 7.00 years and was significantly lower in boys than in girls. Primary congenital lymphedema was more frequent in boys (51.0%, 27.3% in girls, P = .007), and onset of primary lymphedema during adolescence was more frequent in girls (53.4%, 25.0% in boys, P = .001). Lower limbs were the most impacted (88.3%). Sixty patients had genetic testing, and 38 (63.3%) of them were discovered to have a pertinent genetic mutation. The most common mutated gene was the FLT4 gene (in 9 patients). Seven patients (5.1%) had associated extensive/central lymphatic malformation and 24 (17.6%) had a polymalformative syndrome/syndromic lymphedema.

CONCLUSIONS

Pediatric lymphedema is more frequent in girls, usually involves lower limb, and is most often sporadic, but often associated with a genetic mutation, and genetic testing should be performed.

Low Efficacy of Genetic Tests for the Diagnosis of Primary Lymphedema Prompts Novel Insights into the Underlying Molecular Pathways

Lymphedema is a chronic inflammatory disorder caused by ineffective fluid uptake by the lymphatic system, with effects mainly on the lower limbs. Lymphedema is either primary, when caused by genetic mutations, or secondary, when it follows injury, infection, or surgery. In this study, we aim to assess to what extent the current genetic tests detect genetic variants of lymphedema, and to identify the major molecular pathways that underlie this rather unknown disease. We recruited 147 individuals with a clinical diagnosis of primary lymphedema and used established genetic tests on their blood or saliva specimens. Only 11 of these were positive, while other probands were either negative (63) or inconclusive (73). The low efficacy of such tests calls for greater insight into the underlying mechanisms to increase accuracy. For this purpose, we built a molecular pathways diagram based on a literature analysis (OMIM, Kegg, PubMed, Scopus) of candidate and diagnostic genes. The PI3K/AKT and the RAS/MAPK pathways emerged as primary candidates responsible for lymphedema diagnosis, while the Rho/ROCK pathway appeared less critical. The results of this study suggest the most important pathways involved in the pathogenesis of lymphedema, and outline the most promising diagnostic and candidate genes to diagnose this disease.

Retrograde Lymph Flow in the Lymphatic Vessels in Limb Lymphedema

OBJECTIVE

Retrograde movement of lymph due to damaged and/or incompetent valves in the lymphatic vessels has been considered a pathological feature of lymphedema. This study aimed to determine the prevalence of retrograde lymph flow and the characteristics of patients with this condition using indocyanine green (ICG) lymphography.

METHODS

An audit of 679 patients with upper or lower limb swelling who underwent ICG lymphography was undertaken over a 4-year period. Harvey's technique was applied to identify retrograde flow in the lymph collecting vessel during ICG lymphography. The characteristics of patients with retrograde lymph flow were recorded.

RESULTS

Twenty-one patients (3.7%, lower limb: n=19, upper limb: n=2) were identified as having retrograde flow in lymph collecting vessels out of 566 confirmed lymphedema patients (lower limb: n=275, upper limb: n=291). Of the two patients with upper limb lymphedema, one had a short segment of retrograde lymph flow in the forearm. The other patient with upper limb lymphedema and one patient with lower limb lymphedema were previously diagnosed with Lymphedema-Distichiasis Syndrome. Of the remaining 18 patients with lower limb lymphedema and retrograde lymph flow, nine had initiating insect bites with lymphangitis and three had palpable benign enlarged inguinal lymph nodes evident prior to lower limb swelling onset. None had cancer-related lower limb lymphedema.

CONCLUSIONS

Retrograde lymph flow with valve incompetence in the lymph collecting vessels was a rare finding in upper limb lymphedema and a relatively uncommon in lower limb lymphedema, contradicting conventional understanding of pathological changes in lymphedema. ICG lymphography identified anticipated retrograde lymph flow in two patients with Lymphedema-Distichiasis. In the remaining patients, retrograde lymph flow may have resulted from toxic or asymptomatic lymphangitis but no association with secondary cancer-related lymphedema. These findings have implication for conservative management as well as lymphovenous anastomosis surgery where both ends of a transected lymph collecting vessel would be potential targets for anastomoses.

EPHB4 Mutation Suppresses PROX1 Expression and Disrupts Lymphatic Development in Neonatal Hydrops

This case report highlights the importance of screening for mutations in EPHB4 and other genes that regulate lymphatic development in infants with the nonimmune hydrops fetalis.

Lymphatic Collecting Vessels in Health and Disease: A Review of Histopathological Modifications in Lymphedema

Secondary lymphedema of the extremities affects millions of people in the world as a common side effect of oncological treatments with heavy impact on every day life of patients and on the health care system. One of the surgical techniques for lymphedema treatment is the creation of a local connection between lymphatic vessels and veins, facilitating drainage of lymphatic fluid into the circulatory system. Successful results, however, rely on using a functional vessel for the anastomosis, and vessel function, in turn, depends on its structure. The structure of lymphatic collecting vessels changes with the progression of lymphedema. They appear initially dilated by excess interstitial fluid entered at capillary level. The number of lymphatic smooth muscle cells in their media then increases in the attempt to overcome the impaired drainage. When lymphatic muscle cells hyperplasia occurs at the expenses of the lumen, vessel patency decreases hampering lymph flow. Finally, collagen fiber accumulation leads to complete occlusion of the lumen rendering the vessel unfit to conduct lymph. Different types of vessels may coexist in the same patient but usually the distal part of the limb contains less affected vessels that are more likely to perform efficient lymphatic–venular anastomosis. Here we review the structure of the lymphatic collecting vessels in health and in lymphedema, focusing on the histopathological changes of the lymphatic vessel wall based on the observations on segments of the vessels used for lymphatic–venular anastomoses.

CDH5, a Possible New Candidate Gene for Genetic Testing of Lymphedema

Background: Expressed by endothelial cells, CDH5 is a cadherin involved in vascular morphogenesis and in the maintenance of vascular integrity and lymphatic function. The main purpose of our study was to identify distinct variants of the CDH5 gene that could be associated with lymphatic malformations and predisposition for lymphedema. Methods and Results: We performed Next Generation Sequencing of the CDH5 gene in 235 Italian patients diagnosed with lymphedema but who tested negative for variants in known lymphedema genes. We detected six different variants in CDH5 five missense and one nonsense. We also tested available family members of the probands. For family members who carried the same variant as the proband, we performed lymphoscintigraphy to detect any lymphatic system abnormalities. Variants were modeled in silico. The results showed that CDH5 variants may contribute to the onset of lymphedema, although further in vitro studies are needed to confirm this hypothesis. Conclusions: Based on our findings, we propose CDH5 as a new gene that could be screened in patients with lymphedema to gather additional evidence.

Primary lymphoedema

Lymphoedema is the swelling of one or several parts of the body owing to lymph accumulation in the extracellular space. It is often chronic, worsens if untreated, predisposes to infections and causes an important reduction in quality of life. Primary lymphoedema (PLE) is thought to result from abnormal development and/or functioning of the lymphatic system, can present in isolation or as part of a syndrome, and can be present at birth or develop later in life. Mutations in numerous genes involved in the initial formation of lymphatic vessels (including valves) as well as in the growth and expansion of the lymphatic system and associated pathways have been identified in syndromic and non-syndromic forms of PLE. Thus, the current hypothesis is that most cases of PLE have a genetic origin, although a causative mutation is identified in only about one-third of affected individuals. Diagnosis relies on clinical presentation, imaging of the structure and functionality of the lymphatics, and in genetic analyses. Management aims at reducing or preventing swelling by compression therapy (with manual drainage, exercise and compressive garments) and, in carefully selected cases, by various surgical techniques. Individuals with PLE often have a reduced quality of life owing to the psychosocial and lifelong management burden associated with their chronic condition. Improved understanding of the underlying genetic origins of PLE will translate into more accurate diagnosis and prognosis and personalized treatment.

Primary lymphedema French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins)

Primary lymphedema is a rare chronic pathology associated with constitutional abnormalities of the lymphatic system. The objective of this French National Diagnosis and Care Protocol (Protocole National de Diagnostic et de Soins; PNDS), based on a critical literature review and multidisciplinary expert consensus, is to provide health professionals with an explanation of the optimal management and care of patients with primary lymphedema. This PNDS, written by consultants at the French National Referral Center for Primary Lymphedema, was published in 2019 (https://has-sante.fr/upload/docs/application/pdf/2019-02/pnds_lymphoedeme_primaire_final_has.pdf). Primary lymphedema can be isolated or syndromic (whose manifestations are more complex with a group of symptoms) and mainly affects the lower limbs, or, much more rarely, upper limbs or external genitalia. Women are more frequently affected than men, preferentially young. The diagnosis is clinical, associating mild or non-pitting edema and skin thickening, as confirmed by the Stemmer’s sign (impossibility to pinch the skin on the dorsal side or the base of the second toe), which is pathognomonic of lymphedema. Limb lymphoscintigraphy is useful to confirm the diagnosis. Other causes of swelling or edema of the lower limbs must be ruled out, such as lipedema. The main acute lymphedema complication is cellulitis (erysipelas). Functional and psychological repercussions can be major, deteriorating the patient’s quality of life. Treatment aims to prevent those complications, reduce the volume with low-stretch bandages, then stabilize it over the long term by exercises and wearing a compression garment. Patient education (or parents of a child) is essential to improve observance.

Genetic Determinants of the Effects of Training on Muscle and Adipose Tissue Homeostasis in Obesity Associated with Lymphedema

It is widely accepted that metabolic changes associated with training are influenced by a person's genetic background. In this review, we explore the polymorphisms underlying interindividual variability in response to training of weight loss and muscle mass increase in obese individuals, with or without lymphedema, and in normal-weight subjects. We searched PubMed for articles in English published up to May 2019 using the following keywords: (((physical training[Title/Abstract] OR sport activity[Title/Abstract]) AND predisposition[Title/Abstract]) AND polymorphism [Title/Abstract]). We identified 38 single-nucleotide polymorphisms that may modulate the genetic adaptive response to training. The identification of genetic marker(s) that improve the beneficial effects of training may in perspective make it possible to assess training programs, which in combination with dietary intervention can optimize body weight reduction in obese subjects, with or without lymphedema. This is particularly important for patients with lymphedema because obesity can worsen the clinical status, and therefore, a personalized approach that could reduce obesity would be fundamental in the clinical management of lymphedema.

NOTCH1: Review of its role in lymphatic development and study of seven families with rare pathogenic variants

Background

We developed a Next‐Generation‐Sequencing (NGS) protocol to screen the most frequent genetic variants related to lymphedema and a group of candidate genes. The aim of the study was to find the genetic cause of lymphedema in the analyzed patients.

Methods

We sequenced a cohort of 246 Italian patients with lymphatic malformations. In the first step, we analyzed genes known to be linked to lymphedema: 235 out of 246 patients tested negative for the most frequent variants and underwent testing for variants in a group of candidate genes, including the NOTCH1 gene, selected from the database of mouse models. We also performed in silico analysis to observe molecular interactions between the wild‐type and the variant amino acids and other protein residues.

Results

Seven out of 235 probands, five with sporadic and two with familial lymphedema, were found to carry rare missense variants in the NOTCH1 gene.

Conclusions

Our results propose that NOTCH1 could be a novel candidate for genetic predisposition to lymphedema.

Factors influencing quality of life in children with low-flow vascular malformations: a qualitative study using focus groups

BACKGROUND

Very few studies have evaluated the quality of life (QoL) of children suffering from low-flow vascular malformations. This is the first study investigating the influencing factors.

OBJECTIVES

To identify the factors influencing QoL in children with low-flow vascular malformations.

METHODS

We conducted a qualitative study employing focus group interviews (Clinical Trials Number: NCT03440827). The study was a prospective, interventional, non-comparative, multicentre study performed in four expert centres for vascular anomalies. Qualitative data about personal experiences, feelings, difficulties, needs and various factors influencing behaviours were collected. Theme-based content analysis (manual and specialist textural software guided) were used to analyse the verbatim transcripts of all focus group sessions. Manual qualitative discourse analysis was performed to identify the different themes and categories. Informatics' analyses were subsequently performed for each individual category.

RESULTS

Ten focus groups (26 individuals including 10 children aged 11 to 15 years) were conducted until saturation. Influencing factors were related to 4 categories: medical care, self-image, social impact on daily activities and challenging social relationships. These factors were responsible for intrafamily upheavals and may lead to future identity-building problems.

CONCLUSIONS

This study provides an essential framework from which physicians can develop strategies to improve patient care and quality of life. These data may also be useful to develop specific age-sensitive QoL questionnaires.

Segregation Analysis of Rare NRP1 and NRP2 Variants in Families with Lymphedema

Neuropilins are transmembrane coreceptors expressed by endothelial cells and neurons. NRP1 and NRP2 bind a variety of ligands, by which they trigger cell signaling, and are important in the development of lymphatic valves and lymphatic capillaries, respectively. This study focuses on identifying rare variants in the NRP1 and NRP2 genes that could be linked to the development of lymphatic malformations in patients diagnosed with lymphedema. Two hundred and thirty-five Italian lymphedema patients, who tested negative for variants in known lymphedema genes, were screened for variants in NRP1 and NRP2. Two probands carried variants in NRP1 and four in NRP2. The variants of both genes segregated with lymphedema in familial cases. Although further functional and biochemical studies are needed to clarify their involvement with lymphedema and to associate NRP1 and NRP2 with lymphedema, we suggest that it is worthwhile also screening lymphedema patients for these two new candidate genes.

Possible Role of the RORC Gene in Primary and Secondary Lymphedema: Review of the Literature and Genetic Study of Two Rare Causative Variants

Background: RAR-related Orphan Receptor C (RORC) is a DNA-binding transcription factor and the key transcription factor responsible for differentiation of T helper 17 cells. The RORC gene plays a role in lymphoid organogenesis, thymopoiesis, and lymph node organogenesis. The aim of our study was to determine the possible role of RORC in the development of lymphatic system malformations by combining data from the scientific literature and next-generation sequencing of RORC in lymphedema patients negative for known causative genes. Methods and Results: We sequenced RORC in 235 lymphedema patients negative for known lymphedema-associated genes. We found two probands carrying nonsense RORC variants. Conclusions: We show that RORC is important for normal function of the lymphatic system and that a rare variant with a possible causative effect may imply predisposition for lymphedema.

TIE1 as a Candidate Gene for Lymphatic Malformations with or without Lymphedema

TIE1 is a cell surface protein expressed in endothelial cells. Involved in angiogenesis and lymphangiogenesis, including morphogenesis of lymphatic valves, TIE1 is important for lymphatic system functional integrity. The main purpose of this study was to identify different variants in the TIE1 gene that could be associated with lymphatic malformations or dysfunction and predisposition for lymphedema. In a cohort of 235 Italian lymphedema patients, who tested negative for variants in known lymphedema genes, we performed a further test for new candidate genes, including TIE1. Three probands carried different variants in TIE1. Two of these segregated with lymphedema or lymphatic dysfunction in familial cases. Variants in TIE1 could contribute to the onset of lymphedema. On the basis of our findings, we propose TIE1 as a candidate gene for comprehensive genetic testing of lymphedema.

Mutations in the ARAP3 Gene in Three Families with Primary Lymphedema Negative for Mutations in Known Lymphedema-Associated Genes

Background

ARAP3 is a small GTPase-activating protein regulator, which has important functions in lymphatic vessel organogenesis and modulation of cell adhesion and migration. Mutations in the ARAP3 gene are associated with impaired lymphatic vessel formation.

Objective

The aim of our study was to determine the genotypes of lymphedema patients in relation to variants in the ARAP3 gene in order to explore its role in the development of lymphedema.

Methods and Results

We applied next-generation sequencing to DNA samples of a cohort of 246 Italian patients with lymphatic malformations. When we tested probands for known lymphedema genes, 235 out of 246 were negative. Retrospectively, we tested the DNA of these 235 patients for new candidate lymphedema-associated genes, including ARAP3. Three out of 235 probands proved to carry rare missense heterozygous variants in ARAP3. In the case of two families, other family members were also tested and proved negative for the ARAP3 variant, besides being unaffected by lymphedema. According to in silico analysis, alterations due to these variants have a significant impact on the overall structure and stability of the resulting proteins.

Conclusions

Based on our results, we propose that variants in ARAP3 could be included in genetic testing for lymphedema.

The Role of Interventional Radiologists in the Treatment of Congenital Lymphatic Malformations

Lymphatic malformations are low-flow vascular malformations that are typically apparent in the pediatric population and can cause significant functional limitations and effects on quality of life. While surgical resection has historically been the mainstay of therapy, percutaneous sclerotherapy has garnered increasing popularity due to its efficacy and low complication rates. The role of interventional radiology in the multidisciplinary management of these often complex malformations requires thorough understanding of the disease process. This article will review the pathophysiology, clinical presentation, imaging workup, and management options of lymphatic malformations. Special attention will be devoted to available sclerosants, the mammalian target of rapamycin inhibitor sirolimus, and complex lymphatic anomalies.

Two rare PROX1 variants in patients with lymphedema

Background

The PROX1 gene is specifically expressed in a subpopulation of endothelial cells that, by budding and sprouting, give rise to the lymphatic system. It also plays a critical role in neurogenesis and during development of many organs, such as the eye lens, liver, and pancreas.

Methods

We used next‐generation sequencing (NGS) to sequence the DNA of a cohort of 246 Italian patients with lymphatic malformations. We first investigated 29 known disease‐causing genes: 235 of 246 patients tested negative and were then retested for a group of candidate genes, including PROX1, selected from a database of mouse models. The aim of the study was to define these patients’ genotypes and explore the role of the candidate gene PROX1 in lymphedema.

Results

Two of 235 probands were found to carry rare heterozygous missense variants in PROX1. In silico analysis of these variants—p.(Leu590His) and p.(Gly106Asp)—indicates that the overall protein structure was altered by changes in interactions between nearby residues, leading to functional protein defects.

Conclusions

Our results suggest that PROX1 is a new candidate gene for predisposition to lymphedema.

Dysfunction of dermal initial lymphatics of the arm and upper body quadrant causes congenital arm lymphedema

OBJECTIVE

The objective of this study was to explore the pathologic process underlying primary lymphedema.

METHODS

Twenty-seven patients with unilateral congenital arm lymphedema who visited our clinic from January 1, 2014, to May 30, 2019, were enrolled. The patients' clinical signs and the findings of indocyanine green (ICG) lymphography, skin tissue immunohistochemical staining, and whole exome sequencing of tissue and blood were evaluated.

RESULTS

Among the 27 patients, 11 were diagnosed with stage II and 16 were diagnosed with stage III lymphedema. No lymphatic vessels were visualized in the affected arm in 25 of 27 (93%) patients who underwent ICG lymphography; likewise, no lymphatics were found in the territories of axillary lymph node drainage in the trunk, irrespective of any anomalies of the axillary lymph nodes. In only two (7%) patients, an unclear lymphatic trunk gradually appeared in the dorsum of the affected hand. The number of initial lymphatics was increased in the skin specimens of all nine patients in whom lymphatics were not demonstrated by ICG lymphography. Among 14 tested patients, we found compound heterozygote variants in the PIEZO1 gene in only one (7%) patient. Two missense variants, c.4072C>T; p.Arg1358Cys and c.5033C>T; p. Ala1678Val, were identified and found to have been inherited from the father and mother, respectively. No other pathogenic or likely pathogenic variants of currently known lymphedema-related genes were identified in the remaining 13 patients. No genetic difference was found between the lymphedematous and nonedematous healthy skin tissue of the same person.

CONCLUSIONS

Segmental or regional dysfunction of the dermal initial lymphatics causes congenital arm lymphedema and may have implications for clinical treatment.

Molecular pathways involved in lymphedema: Hydroxytyrosol as a candidate natural compound for treating the effects of lymph accumulation

Lymphedema is a chronic accumulation of interstitial fluid due to inefficient lymph drainage. Major causes of lymphedema are malformations of lymphatic vessels, trauma, toxic damage and surgery. The swelling typically affects the limbs. Lymphedema may be primary, caused by genetic mutations and relatively rare, or secondary (acquired), due to external causes such as infections or surgery. Fluid accumulation induces pathological changes: activation of the inflammatory cascade, immune cell infiltration, tissue fibrosis, adipose accumulation. We focused on the inflammatory phenotype mediated by leukotriene B4, a lipid mediator of the inflammatory pathway, and the potential therapeutic effect of hydroxytyrosol. We conducted an electronic search in PubMed using "lymphedema", "lymphedema pathway", "hydroxytyrosol" as keywords. We found that lymphedema deregulates at least six molecular pathways and that hydroxytyrosol, a compound with antioxidant activity, can improve endothelial dysfunction, hemostatic and lipid profiles, and decrease oxidative stress and inflammation through inhibition of leukotriene B4 activity. This review is the first to highlight the possibility of using hydroxytyrosol to treat the secondary effects of lymphedema, especially inflammation. The possible effects of hydroxytyrosol on lymphedema should be tested in vitro and in vivo to find the best way to treat patients with lymphedema in order to improve their health status.

[Differential diagnostics of lipedema and lymphedema : A practical guideline]

Lipedema is a symmetrical disorder of the subcutaneous adipose tissue that affects almost exclusively women in postpubescent age. The trinity of disfiguring hyperplastic adipose tissue of the proximal extremities, increasing pain over time and bruising is characteristic. Lymphedema can occur in both sexes and is differentiated into primary and secondary subtypes. Symmetry is not a prerequisite for diagnosis. Characteristic for lymphedema is the disproportion between lymphatic fluid and the capacity of lymphatic vessels. The most distal body parts are always more severely affected than proximal parts. In the initial phases lymphedema is painless but in advanced stages tension pain can occur. The combination of both disorders has been described; however, lipedema is not responsible for subsequent lymphedema in contrast to central obesity, which significantly increases the risk of lymphedema. The differential diagnosis is of utmost importance for a meaningful management.

[Differential diagnostics of lipedema and lymphedema : A practical guideline]

Lipedema is a symmetrical disorder of the subcutaneous adipose tissue that affects almost exclusively women in postpubescent age. The trinity of disfiguring hyperplastic adipose tissue of the proximal extremities, increasing pain over time and bruising is characteristic. Lymphedema can occur in both sexes and is differentiated into primary and secondary subtypes. Symmetry is not a prerequisite for diagnosis. Characteristic for lymphedema is the disproportion between lymphatic fluid and the capacity of lymphatic vessels. The most distal body parts are always more severely affected than proximal parts. In the initial phases lymphedema is painless but in advanced stages tension pain can occur. The combination of both disorders has been described; however, lipedema is not responsible for subsequent lymphedema in contrast to central obesity, which significantly increases the risk of lymphedema. The differential diagnosis is of utmost importance for a meaningful management.