Update June 2022

Button-like junctions are discontinuous contacts at the border of oak-leaf-shaped endothelial cells of initial lymphatic vessels. These junctions are distinctively different from continuous zipper-like junctions that create the endothelial barrier in collecting lymphatics and blood vessels. Button junctions are point contacts, spaced about 3 microm apart, that border valve-like openings where fluid and immune cells enter lymphatics. In intestinal villi, openings between button junctions in lacteals also serve as entry routes for chylomicrons. Like zipper junctions that join endothelial cells, buttons consist of adherens junction proteins (VE-cadherin) and tight junction proteins (claudin-5, occludin, and others). Buttons in lymphatics form from zipper junctions during embryonic development, can convert into zippers in disease or after experimental genetic or pharmacological manipulation, and can revert back to buttons with treatment. Multiple signaling pathways and local microenvironmental factors have been found to contribute to button junction plasticity and could serve as therapeutic targets in pathological conditions ranging from pulmonary edema to obesity.

Tertiary lymphoid structures (TLS) are lymph node-like immune cell clusters that emerge during chronic inflammation in non-lymphoid organs like the kidney, but their origin remains not well understood. Here we show, using conditional deletion strategies of the canonical Notch signaling mediator Rbpj, that loss of endothelial Notch signaling in adult mice induces the spontaneous formation of bona fide TLS in the kidney, liver and lung, based on molecular, cellular and structural criteria. These TLS form in a stereotypical manner around parenchymal arteries, while secondary lymphoid structures remained largely unchanged. This effect is mediated by endothelium of blood vessels, but not lymphatics, since a lymphatic endothelial-specific targeting strategy did not result in TLS formation, and involves loss of arterial specification and concomitant acquisition of a high endothelial cell phenotype, as shown by transcriptional analysis of kidney endothelial cells. This indicates a so far unrecognized role for vascular endothelial cells and Notch signaling in TLS initiation.

Administration of Piper retrofractum extract (PRE) has been reported to alleviate edema, but the mechanism underlying this effect is unknown. Promotion of lymphangiogenesis is known to improve lymphedema, but the effect of PRE on lymphangiogenesis remains unclear. In the present study, we investigated whether PRE and specifically, piperine, the main component of PRE, can induce lymphangiogenesis. Treatments with PRE and piperine significantly promoted the proliferation, migration, and tube formation in human dermal lymphatic microvascular endothelial cells (HDLECs) but had no effect on the expression of lymphangiogenic factors. Furthermore, PRE and piperine significantly promoted the phosphorylation of the AKT and ERK proteins in HDLECs, and pretreatment with AKT and ERK inhibitors significantly attenuated the PRE- and piperine-induced lymphangiogenesis. These results indicate that PRE and piperine promote lymphangiogenesis via an AKT- and ERK-dependent mechanism. PRACTICAL APPLICATIONS: The lymphatic system plays various roles such as maintaining tissue fluid homeostasis, immune defense, and metabolism. Disruption of the lymphatic system results in insufficient fluid drainage, which causes edema. Currently, there are no effective treatments for lymphedema; therefore, the development of novel treatment strategies is desirable. In this study, we showed that PRE and its main component piperine promote lymphangiogenesis in lymphatic endothelial cells. Therefore, PRE has the potential to be used as a novel functional food for relieving lymphedema.

In mice, embryonic dermal lymphatic development is well understood and used to study gene functions in lymphangiogenesis. Notch signaling is an evolutionarily conserved pathway that modulates cell fate decisions, which has been shown to both inhibit and promote dermal lymphangiogenesis. Here, we demonstrate distinct roles for Notch4 signaling versus canonical Notch signaling in embryonic dermal lymphangiogenesis. Actively growing embryonic dermal lymphatics expressed NOTCH1, NOTCH4, and DLL4 which correlated with Notch activity. In lymphatic endothelial cells (LECs), DLL4 activation of Notch induced a subset of Notch effectors and lymphatic genes, which were distinctly regulated by Notch1 and Notch4 activation. Treatment of LECs with VEGF-A or VEGF-C upregulated Dll4 transcripts and differentially and temporally regulated the expression of Notch1 and Hes/Hey genes. Mice nullizygous for Notch4 had an increase in the closure of the lymphangiogenic fronts which correlated with reduced vessel caliber in the maturing lymphatic plexus at E14.5 and reduced branching at E16.5. Activation of Notch4 suppressed LEC migration in a wounding assay significantly more than Notch1, suggesting a dominant role for Notch4 in regulating LEC migration. Unlike Notch4 nulls, inhibition of canonical Notch signaling by expressing a dominant negative form of MAML1 (DNMAML) in Prox1+ LECs led to increased lymphatic density consistent with an increase in LEC proliferation, described for the loss of LEC Notch1. Moreover, loss of Notch4 did not affect LEC canonical Notch signaling. Thus, we propose that Notch4 signaling and canonical Notch signaling have distinct functions in the coordination of embryonic dermal lymphangiogenesis.

The formation of new blood and lymphatic vessels is essential for both the development of multicellular organisms and (patho)physiological processes like wound repair and tumor growth. In the 1990s, circulating blood platelets were first postulated to regulate tumor angiogenesis by interacting with the endothelium and releasing angiogenic regulators from specialized alpha granules. Since then, many studies have validated the contributions of platelets to tumor angiogenesis, while uncovering novel roles for platelets in other angiogenic processes like wound resolution and retinal vascular disease. Although the majority of (lymph)angiogenesis occurs during development, platelets appear necessary for lymphatic but not vascular growth, implying their particular importance in pathological cases of adult angiogenesis. Future work is required to determine whether drugs targeting platelet production or function offer a clinically relevant tool to limit detrimental angiogenesis.

Background: Despite the lymphatic system being so important and extensive, the field of lymphatic diseases, research is still very young. Lymphedema is a progressively debilitating condition with no known “cure.” Specific pathologies that could benefit from improved lymphatic drainage by advanced super surgical techniques or engineered tissue transfer are being sought. Microsurgical techniques like lymphovenous bypass and anastomosis have spurred interest as they tend to physiologically restore the damaged lymphatic channels and may be a key to permanent cure. The latest in the field is vascularized lymph node transfer (VLNT), indicated in post mastectomy or other post operative settings producing disruption of regional lymphatic channels and draining lymph nodes. Autologous healthy lymph nodes are transferred along with surrounding fat and vascular pedicle to the affected limb in a bid to promote lymphangiogenesis. Lymphoscintigraphy (LS) is a simple, noninvasive nuclear technique used in identifying upper or lower limb lymphatic dysfunction and obstruction with a high degree of sensitivity. Quantitative LS is extremely useful in follow-up assessment of lymphedema postmanual lymphatic drainage (MLD) or other forms of medical management. Aim: We hypothesize that LS can document perinodal lymphangiogenesis post VLNT. Material and Methods: Three cases of acquired lymphedema (suspected filariasis and postmastectomy conditions) who underwent VLNT in our institute were prospectively studied with LS. The imaging findings highlight the subtle lymphatic regeneration along with the vascularized graft in all three patients during the early postoperative period. Conclusion: This is the first (pilot) study documenting early spontaneous perinodal lymphangiogenesis after VLNT in human subjects.(99m)Tc Nanocolloid LS has been found to be incremental in demonstrating early lymphangiogenesis.

Lymphedema is characterized by progressive and chronic tissue swelling and inflammation from local accumulation of interstitial fluid due to lymphatic injury or dysfunction. It is a debilitating condition that significantly impacts a patient's quality of life, and has limited treatment options. With better understanding of the molecular mechanisms and pathophysiology of lymphedema and advances in tissue engineering technologies, lymphatic tissue bioengineering and regeneration have emerged as a potential therapeutic option for postsurgical lymphedema. Various strategies involving stem cells, lymphangiogenic factors, bioengineered matrices and mechanical stimuli allow more precisely controlled regeneration of lymphatic tissue at the site of lymphedema without subjecting patients to complications or iatrogenic injuries associated with surgeries. This review provides an overview of current innovative approaches of lymphatic tissue bioengineering that represent a promising treatment option for postsurgical lymphedema.

A comprehensive lymphatic system is indispensable for a well-functioning body; it is integral to the immune system and is also interrelated with the digestive system and fluid homeostasis. The main difficulty in examining the lymphatic system is its fine-meshed structure. This remains a challenge, leaving patients with uninterpreted symptoms and a dearth of potential therapies. We review the history of the lymphatic system up to the present with the aim of improving current knowledge. Several findings described throughout history have made fundamental contributions to elucidating the lymphatic system. The first contributions were made by the ancient Egyptians and the ancient Greeks. Vesalius obtained new insights by dissecting corpses. Thereafter, Ruysch (1638–1731) gained an understanding of lymphatic flow. In 1784, Mascagni published his illustration of the whole lymphatic network. The introduction of radiological lymphography revolutionized knowledge of the lymphatic system. Pedal lymphangiography was first described by Monteiro (1931) and Kinmonth (1952). Lymphoscintigraphy (nuclear medicine), magnetic resonance imaging, and near-infrared fluorescence lymphography further improved visualization of the lymphatic system. The innovative dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) transformed understanding of the central lymphatic system, enabling central lymphatic flow disorders in patients to be diagnosed and even allowing for therapeutic planning. From the perspective of the history of lymph visualization, DCMRL has ample potential for identifying specific causes of debilitating symptoms in patients with central lymphatic system abnormalities and even allows for therapeutic planning.

In the early days of the first global wave of the COVID-19 pandemic, the potential for a postviral syndrome to manifest following COVID-19 infection was first recognized. Here, we present an analysis of a case series of the first 20 patients' data collected in clinical practice to evaluate the potential of a possible alternative treatment for Long COVID. Methods: Face-to-face treatment sessions with Perrin technique practitioners occurred weekly involving effleurage/other manual articulatory techniques. The individuals being treated also undertook daily self-massage along with gentle mobility exercises. Patients recorded symptom severity using the self-report 54-item profile of fatigue-related states (PFRS) before and after treatment. Results: The mean age of male patients was 41.8 years (range, 29–53 years), and for female patients, 39.3 years (range, 28–50 years). None of the participants had a prior diagnosis of chronic fatigue syndrome, and all were new attendees to the clinics at the time of initial assessment. The average number of treatment sessions was 9.7 in men and 9.4 in women. The reduction in PFRS scores was 45% in men and 52% in women. The highest subscale scores on average were for fatigue, with the lowest for somatic symptoms. All subscale scores showed, on average, a similar reduction of approximately 50% postintervention, with the reduction in score relating to a decrease in the severity of symptoms. Conclusion: Our findings suggest that a specific manual lymphatic drainage intervention may help to reduce fatigue symptoms related to Long COVID. Perhaps preventing acute symptoms through early intervention.

PURPOSE OF REVIEW: The recent (re)discovery of the meningeal lymphatic has brought a new player in brain neurophysiology. This review highlights the state of the current research on the meningeal lymphatic vasculature, from its specific physiology to its increasing implication in normal and pathological brain function. RECENT FINDINGS: Growing evidence are emerging about the uniqueness of the meningeal lymphatic vasculature and its implication in multiple neurological and neurotraumatic disorders. SUMMARY: These studies are highlighting a new and unexpected role for the lymphatic vasculature in brain function and a potential new therapeutic target for neurological disorders.

Alzheimer's disease (AD) is the most common cause of dementia worldwide. Pathological deposits of neurotoxic proteins within the brain, such as amyloid-ss and hyperphosphorylated tau tangles, are the prominent features in AD. According to recent studies, the newly discovered brain lymphatic system was demonstrated to be crucial in the clearance of metabolic macromolecules from the brain. Meningeal lymphatic vessels located in the dura mater, drain the fluid, macromolecules, and immune cells from cerebrospinal fluid (CSF) and transport them, as lymph, to the deep cervical lymph nodes. The glymphatic system provides the perivascular exchange of CSF with interstitial fluid (ISF) and ensures homeostasis of neuronal interstitial space. In this review, we aim to summarize recent findings of the role of the lymphatic system in AD pathophysiology and discuss possible therapeutic perspectives, targeting the lymphatic clearance mechanisms within the brain.

OBJECTIVE: To perform a preliminary usability evaluation of a novel, compact pneumatic compression device in patients with lymphoedema. METHODS: This open-label, single-arm trial had two phases: the first focused on the fitting of the pneumatic compression device (Aria Free(TM), Aria Health, San Diego CA, USA) and the second focused on evaluating the comfort of the entire system during a 45-min usage period. Both phases were conducted in a monitored clinical environment. Patients aged >/ = 18 years with a diagnosis of lower limb lymphoedema who had used a pneumatic compression device for >/ = 3 months were eligible. Patients rated subjective fit, comfort and usability on an 11-point Likert scale (where higher scores indicate better fit/comfort/usability). The truncated cone method was used to infer limb volume before and after therapy in phase 2. RESULTS: Twenty-four patients were screened, and 15 were enrolled (80% female; mean age 62 years); all completed both study phases. Patients rated the garment as easy to set up and fit (median score 6.5), and all reported that the therapy was comfortable (median score 10; p < 0.001 vs. reference score of 6). There was a 1.85% reduction in limb volume after device use for 45 min (p = 0.018 vs. before therapy). No safety issues were identified. CONCLUSIONS: The new pneumatic compression device fitted well, was easy to use and reduced leg oedema.

Background: Vascular endothelial growth factor (VEGF) C156S is an engineering variant of VEGF-C that has the potential to promote lymphangiogenesis, activating on VEGF receptor (VEGFR) 3, without promoting angiogenesis (i.e., not acting on VEGFR-2). We conducted a systematic review of publications assessing the use of this growth factor in lymphedema treatment. We hypothesized that VEGF-C156S specificity for VEGFR-3 was an important differential for the lymphangiogenesis promoted by it. Methods and Results: We conducted a comprehensive systematic review of the published literature on PubMed/Medline, Embase, and Cochrane Clinical Answers. Eligibility criteria included articles reporting data on the use of VEGF-C156S in lymphedema treatment. We excluded articles that investigated physiology action of VEGF-C156S and articles that focused on other therapies. From 304 potential articles found in the literature, four studies fulfilled the study eligibility criteria. To date, all studies about this growth factor have been experimental. The effect of VEGF-C156 on lymph node transfer was investigated in half of the experiments. Interestingly, delivery of VEGF-C156S was mostly performed through viral gene transfer, but injection (subcutaneously or intravenously) of it as a protein (liposomal or nonliposomal) was also investigated by one author to assess drug bioavailability. Conclusions: Although authors reported promotion of lymphangiogenesis, VEGF-C156S was correlated with lymphatic hyperplasia or nonstatistically significant lymphangiogenesis compared with controls. Scientific evidence about the use of VEGF-C156S in lymphedema treatment is still limited. However, authors have shown that its lymphangiogenic effect is inferior to VEGF-C.

Background Lymphaticovenous anastomosis (LVA) surgery is an effective surgical treatment of secondary lymphedema in the extremities, but indocyanine green (ICG) fluorescent lymphography, the reference standard for imaging target lymphatic vessels, has several limitations. More effective methods are needed for preoperative planning. Purpose To evaluate whether contrast-enhanced US (CEUS) can be used to identify target lymphatic vessels for LVA surgery in patients with secondary upper extremity lymphedema and compare the results with those from ICG fluorescent lymphography. Materials and Methods In this single-center retrospective review, CEUS with intradermal injection of microbubbles was performed in patients before LVA surgery in the upper extremities between October 2019 and September 2021. All patients had secondary upper extremity lymphedema from breast cancer treatment. Technical success rate was defined as lymphatic vessels identified with use of CEUS that led to successful LVAs. Descriptive statistics were used. Results All 11 patients were women (mean age, 56 years +/- 8 [SD]). The median number of microbubble injection sites was 11 (range, 8–14). CEUS helped identify lymphatic vessels in all 11 women, including in six women in whom ICG fluorescent lymphography could not be performed or failed to help identify any targets. Thirty-five explorations (median, three per patient; range, two to four) were performed, and 24 LVAs (median, three per patient; range, zero to four) were created. Of the anastomoses, 33% (eight of 24) were mapped with use of both CEUS and ICG fluorescent lymphography, 58% (14 of 24) with CEUS only, and 8% (two of 24) with ICG fluorescent lymphography only. Among the 33 explorations on targets mapped with CEUS, an anastomosis could be made at 22 sites, for a technical success rate of 67%. Seven women had at least one additional LVA created from the use of CEUS. Conclusion Contrast-enhanced US is a promising tool for identifying lymphatic vessels in the upper extremities, especially when indocyanine green fluorescent lymphography fails to depict targets or cannot be used. Published under a CC BY 4.0 license.

Background: Skin infections are a recurring problem for people with lymphedema, and lymphedema has been proven to be the single most important risk factor for developing erysipelas in the leg. This study aimed to determine whether liposuction for late-stage lymphedema reduces the rate of erysipelas in lower extremity lymphedema. Methods: One-hundred twenty-four patients with a median age of 49 years who had liposuction and controlled compression therapy for lower extremity lymphedema were included. Excess volumes were calculated before and after surgery. Median preoperative and postoperative patient years at risk were 11 and 5 years, respectively. Results: With a total of 1680 preoperative person years at risk and 335 bouts of erysipelas experienced in 64 patients, the preoperative incidence rate was 0.20 bouts per person per year, and the period prevalence was 52%. Postoperatively, the patients were followed over a total of 763 person years at risk, and 28 patients experienced a total of 53 bouts of erysipelas, resulting in a postoperative incidence rate of 0.07 bouts per person per year, and a period prevalence of 23%. This represents a 65% decrease in the erysipelas incidence rate (P < 0.001). The preoperative median excess volume of 3158 ml was reduced with a median of 100% (P < 0.0001). Conclusions: Liposuction and controlled compression therapy significantly reduce the risk for erysipelas in lower extremity lymphedema and completely reduces the excess volume. This finding is similar to our previous research including patients with upper extremity lymphedema.

INTRODUCTION: Lymphovenous anastomoses (LVA) techniques for the treatment of lymphedema are well defined, and results restoring lymph function are reported in the literature. However, unsatisfactory results (poor-responders) are common, leading to persistent nonpitting edema. Blind liposuction eliminates fat and fibrous tissue but may result in inadvertent damage to the lymph vessel system. Indocyanine green imaging of the lymphatic system provides the potential preservation of functioning lymphatics while conducting liposuction to address the excess adipose and fibrous tissue in these patients. Our study reports the results of a prospectively conducted technique in patients with nonpitting edema after failing previous LVA. It consists of indocyanine green-guided liposuction. PATIENTS AND METHOD: Twenty poor-responders patients to LVA who presented with persistent nonpitting edema were operated with liposuction. Limb volume measurements, SPECT-CT/lymphoscintigraphy, and ICG lymphography were recorded and complemented with a satisfaction inquiry. RESULTS: The overall percentage of volume reduction was 46.2% after liposuction (p = 0.001). None of our patients reported any set back with respect to the improvements they had achieved after LVA nor new infections. Satisfaction showed a mean improvement of 5 points in a 20-point scale. SPECT-CT/lymphoscintigraphy showed further improvements in 17 cases after liposuction, such as dermal back-flow reduction, spots along the lymphatic system, or lymph nodes not described in preoperative reports, without showing significant differences when compared with overall volume reduction (p = 0.12). CONCLUSION: Controlled liposuction with ICG seems to be an effective technique for the reduction of residual non-pitting edema in poor responder patients after LVA. Overall, volume excess reduction after liposuction was 42.6%.

Mutations that activate growth factor signaling often drive cancer growth. Many also arise in isolation, causing developmental growth disorders. PIK3CA, that encodes a catalytic subunit of phosphatidylinositol 3-kinase (PI3K), is a cardinal example of this paradigm. Recent exciting progress towards the key goal of cancer drug repurposing for PIK3CA-driven overgrowth is discussed.

Glymph is a fluid that circulates in the brain interstitium and, under pathological conditions, unusually accumulates and enhances the buildup of other noxious molecules. The study of this process of circulation, accumulation, and clearance is called glymphatics. We review the physiology of glymphatics and then dive into recent innovative research surrounding this neurological field of study and how it has applied to mainstream pathological processes, including Alzheimer's disease and spectrums of traumatic brain injury that range from a concussion to chronic traumatic encephalopathy (CTE). Furthermore, we explore the implications of glymphatics and a new and developing frontier of healthcare in space travel; with the advent of a Space Force and the introduction of space travel to consumer markets, this is an exciting time to develop novel techniques in enhancing its safety and optimizing human physiology for best outcomes. Therefore, we also propose that osteopathic manipulative treatment (OMT) plays an intuitive role in the treatment of abnormal glymphatics, as adjunctive therapy in Alzheimer's and CTE, and as a future staple before, during, and after space travel for the benefit of both enhancing healthcare in chronic conditions and advancing the capabilities of the human race in its shining new endeavor.

Background: A standardized lymphedema grading system is a prerequisite for accurately and objectively evaluating its severity, both preoperatively and postoperatively. The purpose of this study was to establish a clinically feasible noncontrast magnetic resonance lymphangiography (NMRL) protocol and a standardized scoring system for the evaluation of lymphedema. Methods and Results: From January 2020 to February 2021, 39 patients who had been clinically diagnosed with lymphedema and had undergone NMRL were included. The severity and circumferential extent of lymphedema were assessed using magnetic resonance imaging, and a combined index was devised as the sum of the product of the severity and extent scores determined at four different levels. A magnetic resonance imaging (MRI) stage was allocated based on the combined index score, its correlation with clinical indices was analyzed. The MR and clinical staging showed a percentage agreement of 85.9% and a kappa coefficient of 0.641, indicating moderate agreement (p < 0.001). Both the interlimb volume and interlimb impedance ratios differed significantly between groups (p < 0.001 for both). The correlation analysis revealed a significant correlation between the combined index score and the inter-limb volume ratio (r = 0.70, p < 0.001) and inter-limb impedance ratio at both 1 kHz (r = 0.71, p < 0.001) and 5 kHz (r = 0.71, p < 0.001). The interobserver agreement was moderate for the severity score, extent score, and combined score. Conclusion: The proposed standardized scoring system for evaluating lymphedema based on NMRL can reproducibly determine the severity and extent of lymphedema in both the upper and lower extremities, and correlates strongly with established clinical measures.

Hypertension (HTN) is associated with gonadal dysfunction and impaired reproductive health in both men and women. An imbalance in the systemic and renal pro-inflammatory (M1)/anti-inflammatory (M2) macrophage ratio, increased inflammation, and inflammation-associated lymphangiogenesis have been observed in animals with HTN. However, the impact of HTN on gonadal macrophages, inflammation, and lymphatics remains obscure. We hypothesized that salt-sensitive HTN (SSHTN) and HTN alters gonadal macrophage polarization, which is associated with inflammation, inflammation-associated lymphangiogenesis and reproductive dysfunction. Flow cytometry analyses revealed a significant increase in M1 macrophages in the testes of SSHTN and nitric oxide synthase inhibition-induced HTN (LHTN) mice, with a concurrent decrease in M2 macrophages in SSHTN mice yet an increase in M2 macrophages in LHTN mice. Ovaries from SSHTN mice exhibited increase in M1 and a decrease in M2 macrophages, while ovaries from LHTN mice had a significant increase in M2 and a decrease in M1 macrophages. Gene expression patterns of pro-inflammatory cytokines revealed gonadal inflammation in all hypertensive mice. Increased lymphatic vessel density in the gonads of both male and female hypertensive mice was confirmed by immunofluorescence staining for LYVE-1. HTN adversely affected the expression pattern of steroidogenic enzymes, hormone receptors, and secretory proteins in both the testes and ovaries. In line with these results, male hypertensive mice also presented with decreased sperm concentration, and increased percentage of sperm with abnormal morphology, damaged acrosome, and non-functional mitochondrial activity. These data demonstrate that HTN alters gonadal macrophage polarization, which is associated with gonadal inflammation, inflammation-associated lymphangiogenesis, and dysfunction.

Four patients with secondary lower limb lymphedema developed cellulitis at their lymphedema lesion following COVID-19 mRNA vaccinations. They did not develop adverse effects at their vaccination site. All the patients were Japanese females aged &lt;60 years. Three patients developed cellulitis following the first vaccination. The date of onset of cellulitis following the first vaccination varied from 0 to 21 days. Two received BNT162b2 mRNA vaccines and the others received mRNA-1273 vaccines. All the patients were treated with oral antibiotics and recovered. Two patients had repeated cellulitis. The patients with the repeated development of cellulitis could not perform good skincare. One patient had joint contractures in their lower limbs and could not reach her lymphedema lesions, and the other patient could not master the skincare. According to previous studies, the development of cellulitis following vaccination was rare. In this study, four patients aged &lt;60 years developed cellulitis among the eight patients that regularly visited our hospital for rehabilitation for their lower limb lymphedema. In patients with lymphedema, prolonged inflammation may impair lymphatic functions and worsen edema. Therefore, at the time of vaccination, we should keep in mind the prevention and immediate management of cellulitis using intensive skincare and antibiotic treatment.

Lymphedema in children is rare; however, it is usually a progressive and chronic condition. Accurate diagnosis of lymphedema in the pediatric population often takes several months and sometimes is delayed for years. Lymphedema can be isolated or associated with genetic syndromes, thus it is very important to identify the correct diagnosis, to select carefully which patients to refer for genetic testing, and to initiate appropriate treatment in a timely fashion. In this article, we review key information about diagnosis of lymphedema, associated conditions and syndromes, and current treatment modalities.

Milroy disease is a form of congenital primary lymphedema that usually affects the lower limbs. Predominant genital lymphedema in Milroy disease is uncommon and disabling. When conservative management is ineffective, surgical treatment becomes necessary. Here, we present a rare case of congenital primary penile lymphedema in a 4-year-old child.

BACKGROUND: Despite the new lymphatic imaging methods, there is still a need for a straightforward method of detecting lymphatic abnormalities. Our goal was to investigate the feasibility of applying a contrast enhanced ultrasound (CEUS) procedure as a new approach for visualising the superficial lymphatic vessels of the upper limb. METHODS: Thirty healthy volunteers were examined with CEUS after bilateral intradermal injection of Sonazoid(R) contrast agent in distal antebrachium. We registered factors affecting intradermal injections, imaging of the superficial lymphatic vessels and the enhancement time of contrast agent reaching the levels of elbow and axilla. RESULTS: CEUS imaging of superficial lymphatic vessels was successful in 59 of 60 upper limbs (98.3%). Median [interquartile ranges] enhancement times of contrast agent to reach the elbow (right 18 s [11–25], left 15 s [12–25]) and axilla (right 77 s [33–118], left 66 s [42–115]) were equally fast. Successful intradermal injections were found to result in two types of contrast enhancement (strong or moderate), while the enhancement time depended on the type of the successful injection. No major differences in enhancement times were observed related to sex, body mass index, age, or side of the arm. CONCLUSIONS: The superficial lymphatic pathways of the upper limb can be visualised with CEUS imaging. Since enhancement time is dependent on the success of intradermal injections, one must pay attention to the injection technique. Further studies are needed to evaluate the method in patients with lymphatic function disorders such as breast cancer therapy related lymphoedema.

Lymphoedema is a chronic debilitating condition characterised by diffuse swelling caused by lymphatic obstruction. The secondary form of lymphoedema is more common than the primary form. Untreated filariasis remains an important cause of lymphoedema in developing countries. The most common complication of chronic lymphoedema is cellulitis. It is also a risk factor for the development of neoplasms such as lymphangiosarcoma, squamous cell carcinoma, melanoma, lymphoma and malignant fibrous histiocytoma. We report a case of a woman in her 60s who developed squamous cell carcinoma in the background of chronic lymphoedema.

Angiosarcomas are uncommon malignant mesenchymal neoplasms of endothelial origin. They may be primary or secondary to radiation exposure, chronic lymphedema or to other associated risk factors. They can occur anywhere in the body, with the most common location being the skin of the head and neck. Radiation-induced angiosarcomas of the gynecologic tract are very rare with only few cases reported in the literature. We report a case of a 54-year-old lady who developed angiosarcoma of the vagina and vulva 9 years following radiotherapy for cervical cancer. She was treated with chemoradiotherapy and died nine months following the diagnosis of angiosarcoma. We also performed a literature review of the radiation-induced angiosarcomas arising in the vagina and vulva. Angiosarcomas should always be considered in the differential diagnosis when dealing with a tumor located in a previously irradiated area, as they may clinically mimic recurrence of the original tumor the patient had.

BACKGROUND: Indocyanine green (ICG) lymphography is a newer technique for diagnosing lymphedema. Our study aimed to find whether the abnormality of ICG lymphography can predict the occurrence of early lymphedema and then select candidates at high risk of developing lymphedema. METHODS: Postoperative breast cancer patients who visited the lymphedema clinic of Peking University People's Hospital from December 2016 to September 2019 were consecutively enrolled and received ICG lymphography and circumference measurement. Data were collected on the patients' characteristics and correlation between ICG lymphography and the occurrence of lymphedema. RESULTS: The analysis included 179 patients. There were 91 patients in the lymphedema group and 88 patients in the non-lymphedema group. By multivariate analysis, age, axillary surgery, radiotherapy, and time since breast cancer surgery were regarded as risk factors for lymphedema (p &lt; 0.05). According to the results of ICG lymphography, patients in the non-lymphedema group (n = 88) were divided into ICG-positive (n = 47) and ICG-negative (n = 41) groups. The incidence of lymphedema in the ICG-positive group was significantly higher than that in the ICG-negative group (19.1% vs. 2.4%, p = 0.027). CONCLUSION: Lymphatic disorder can be detected before circumference change using ICG lymphography. Abnormal ICG lymphography is an independent risk factor for lymphedema. Patients with abnormal dermal backflow patterns are considered to be a high-risk group for lymphedema and should undergo early interventions to prevent lymphedema.

Lymph node (LN) metastasis is associated with unfavorable prognosis of bladder cancer (BCa). Although lymphangiogenesis is functionally important in LN metastasis of tumors, the potential mechanism in BCa remains unclear. Here, we clarified a regulatory mechanism of circRNA-mediated lymphangiogenesis and LN metastasis in BCa based on next-generation sequencing data. We revealed that circDHTKD1 was positively associated with LN metastasis and significantly upregulated in BCa. By analyzing the co-expression patterns of circDHTKD1 and differentially expressed mRNAs, we identified that circDHTKD1 facilitated lymphangiogenesis by upregulating CXCL5. Mechanistically, circDHTKD1 directly interacted with miR-149-5p, and antagonized the repression of miR-149-5p on CXCL5. Furthermore, circDHTKD1-induced CXCL5 expression recruited and activated neutrophils, which participated in lymphangiogenesis by secreting VEGF-C. Our study supports circDHTKD1 as a promising diagnostic and therapeutic target for LN metastasis in BCa.

BACKGROUND: Lymphedema is a serious complication of axillary lymph node dissection (ALND) with an incidence rate of 20%. Simplified Lymphatic Microsurgical Preventing Healing Approach (SLYMPHA) is a safe and relatively simple method, which decreases incidence of lymphedema dramatically. Our initial study showed an 88% decrease in clinical lymphedema rate. In the initial study, we used arm circumference measurement for the diagnosis of lymphedema and median follow up was 15 months. The aim of this study was to confirm these results after a long-term follow up period and by using bioimpedance spectroscopy (L-Dex) technology in detecting lymphedema. STUDY DESIGN: All patients, undergoing ALND with or without SLYMPHA between January 2014 and November 2020 were included in the study. Patients with no postoperative L-Dex measurements were excluded. A L-Dex score outside the normal range (+/-10 L-Dex unit) or >/ = 10 L-Dex unit increase above patient's baseline was considered as lymphedema. The incidence of lymphedema was compared between patients with and without SLYMPHA. RESULTS: 194 patients were included in the study. 57% of cohort underwent SLYMPHA. Mean follow-up time was 47 +/- 37 months. Patients, who underwent SLYMPHA, had a significantly lower rate of lymphedema (16% vs 32%; p = 0.01; OR 0.4 [0.2–0.8]). CONCLUSION: SLYMPHA is a safe and relatively simple method, which continued its efficacy after a long-term follow up period. It should be considered as an adjunct procedure to ALND for all patients during initial surgery.

BACKGROUND: There has been a delay in the detection and treatment of lymphedema in breast cancer patients during the lockdown owing to quarantine and limited social activity. Moreover, this scenario has caused psychosocial issues in these patients. Given that there is scarce information on the prevalence and influence of lymphedema during the coronavirus disease (COVID-19) pandemic, we aimed to estimate the prevalence of lymphedema recurrence and its influencing factors among discharged breast cancer patients during the COVID-19 pandemic. METHODS: This was a multicenter, cross-sectional, hospital-based survey of discharged breast cancer patients was conducted during the COVID-19 pandemic in eight first-class hospitals in Wuhan, China. The Norman Questionnaire was used to assess lymphedema. Univariable and multivariable binary logistic regression analyses were performed to identify factors influencing moderate or severe lymphedema. Differences in living characteristics, anxiety, and depression were compared between the no/mild lymphedema group and the moderate/severe lymphedema groups. Preferences for lymphedema management during the pandemic were determined. RESULTS: Overall, 202 patients were included in this study, and 191 of them reported recurrent lymphedema (prevalence: 94.6%, 95% confidence interval [CI] 90.5% to 97.3%). Among them, 134 and 57 had mild and moderate/severe lymphedema, respectively. In 191 patients, the main symptoms were swelling (140; 69.3%) and pain (56, 27.7%). Multivariable regression showed that older age (odds ratio [OR], 1.06; 95% CI: 1.02–1.10), radical surgery (OR = 4.35, 95% CI: 1.54–12.50), and fully complete radiotherapy (OR = 2.62, 95% CI: 1.17–5.87, p = 0.019) were associated with an elevated risk of moderate/severe lymphedema. The moderate/severe lymphedema group experienced a higher rate of anxiety and depression than the no/mild lymphedema group did. Patients equally preferred treatment in the hospital and self-care at home. CONCLUSION: During the COVID-19 pandemic, high prevalence of lymphedema was observed in patients Age, radical surgery and fully completed radiotherapy were associated with increased risk of severer lymphedema. Meanwhile, the patients with severe lymphedema experienced psychological distress. While the Covid-19 pandemic was still raging, continuous efforts should be made to identify patient at risk of lymphedema and distribute feasible guidance and education for self-management in lymphedema.

OBJECTIVES: To describe clinical and molecular findings in a French multicenter cohort of fetuses with prenatal diagnosis of congenital abnormality and suspicion of a localized overgrowth disorder (LOD) suggestive of genetic variants in the PI3K-AKT-mTOR signaling pathway. METHODS: We analyzed retrospectively data obtained between 1 January 2013 and 1 May 2020 from fetuses with brain and/or limb overgrowth referred for molecular diagnosis of PI3K-AKT-mTOR pathway genes by next-generation sequencing (NGS) using pathological tissue obtained by fetal autopsy. We also assessed the diagnostic yield of amniotic fluid. RESULTS: During the study period, 21 subjects with LOD suspected of being secondary to a genetic variant of the PI3K-AKT-mTOR pathway were referred for analysis. Of these, 17 fetuses had brain overgrowth, including six with isolated megalencephaly (MEG) and 11 with hemimegalencephaly (HMEG). Of the six with MEG, germline variants were identified in four cases, in either PIK3R2, AKT3 or MTOR, and a postzygotic PIK3R2 variant was found in the other two cases. Of the 11 with HMEG, a postzygotic PIK3CA variant was found in three fetuses with extracerebral features of PIK3CA-related overgrowth spectrum, and in seven fetuses with isolated HMEG. No pathogenic variant was identified in the 11(th) case with HMEG. Four fetuses with limb overgrowth also had one or more lymphatic malformations (LM) and harbored a postzygotic PIK3CA variant. NGS on cultured amniocytes performed in 10 cases, of which nine had been found positive on analysis of pathological fetal tissue, showed variants in four, in either PIK3CA, PIK3R2 or AKT3. CONCLUSIONS: Isolated MEG or HMEG may lead to identification of genetic variants in the PI3K-AKT-mTOR signaling pathway. Cases of limb overgrowth and LM or isolated HMEG are likely associated with PIK3CA variants. (c) 2021 International Society of Ultrasound in Obstetrics and Gynecology.

A 23-day-old boy with prenatal diagnosis of basilar artery aneurysm presented with multiple congenital red patches consistent with capillary malformations. Genetic testing confirmed the presence of a heterozygous pathogenic variant of the RASA1 gene, confirming the diagnosis of capillary malformation-arteriovenous malformation (CM-AVM) syndrome. This case illustrates an atypical presentation of the RASA1 associated CM-AVM syndrome, with the intracranial vascular malformation diagnosis preceding the identification of the skin lesions. Arterial aneurysms have been associated with CM-AVM syndrome in rare instances but to our knowledge this is the first reported case of an aneurysm of the basilar artery.

Infantile hemangioma (IH) is the most common infantile tumor, affecting 5–10% of newborns. Propranolol, a nonselective beta-adrenergic receptor (ADRB) antagonist, is currently the first-line treatment for severe IH; however, both its mechanism of action and its main cellular target remain poorly understood. Since betablockers can antagonize the effect of natural ADRB agonists, we postulated that the catecholamine produced in situ in IH may have a role in the propranolol response. By quantifying catecholamines in the IH tissues, we found a higher amount of noradrenaline (NA) in untreated proliferative IHs than in involuted IHs or propranolol-treated IHs. We further found that the first three enzymes of the catecholamine biosynthesis pathway are expressed by IH cells and that their levels are reduced in propranolol-treated tumors. To study the role of NA in the pathophysiology of IH and its response to propranolol, we performed an in vitro angiogenesis assay in which IH-derived endothelial cells, pericytes and/or telocytes were incorporated. The results showed that the total tube formation is sensitive to propranolol only when exogenous NA is added in the three-cell model. We conclude that the IH's sensitivity to propranolol depends on crosstalk between the endothelial cells, pericytes and telocytes in the context of a high local amount of local NA.

Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children's Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesionalNRASvariant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

BACKGROUND: PROS disorders are driven by somatic, gain-of-function mutations in PIK3CA that result in hyperactivation of the phosphatidylinositol-3-kinase (PI3K) signaling pathway. PROS encompasses a broad spectrum of overlapping phenotypes (including overgrowth and vascular malformations) that vary significantly in their severity; every case is unique, leading to different, complex experiences. Here, we aim to describe the PROS experience from the patients' and caregivers' points of view, from onset to diagnosis to treatment and support. RESULTS: The PROS patient journey was developed using a literature review, an ethnography study, health care professional (HCP) research, and social listening. It was then validated with patients, caregivers, and patient advocates. Physician research included 94 PROS centers and other vascular anomaly centers throughout the United States and Europe. Ethnographic research included 24 patients, caregivers, and/or advocates; selected data from 223 patients were reviewed. Key priority areas of need were identified, along with barriers to and potential enablers of quality care. Visual mapping of the PROS patient and family journey was developed to identify key personal health and system issues, and opportunities for improvements throughout patients' lifespans. Maps were also developed for 3 specific conditions: Klippel-Trenaunay syndrome (K-T); congenital lipomatous overgrowth, vascular malformations, epidermal nevi, scoliosis/skeletal and spinal anomalies (CLOVES) syndrome; and megalencephaly-capillary malformation syndrome (M-CM). Overall, most patients with PROS conditions and their families struggle with a long path to diagnosis, access to genetic testing, and finding qualified specialists. Following diagnosis, patients and families are frequently challenged with major medical events, comorbidities, unpredictability, frequent hospitalization, impact on school and work, the need for multidisciplinary care, unwanted attention, adverse impact on mental and emotional health, and financial pressures. Lack of effective pain management emerged as a substantial issue. Challenges and barriers to quality care shift throughout patients' lifespans; transition from pediatric to adult care can be especially difficult. CONCLUSIONS: This patient journey in PROS was created in collaboration with patients, caregivers, and advocates as key partners. This novel methodology, which could be applied elsewhere, can more accurately identify areas of unmet need, barriers to care, education topics, and assist HCPs to understand the patient and family perspective.