The role of key biomarkers in lymphatic malformation: An updated review.

The lymphatic system, crucial for tissue fluid balance and immune surveillance, can be severely impacted by disorders that hinder its activities. Lymphatic malformations (LMs) are caused by fluid accumulation in tissues owing to defects in lymphatic channel formation, the obstruction of lymphatic vessels or injury to lymphatic tissues. Somatic mutations, varying in symptoms based on lesions' location and size, provide insights into their molecular pathogenesis by identifying LMs' genetic causes. In this review, we collected the most recent findings about the role of genetic and inflammatory biomarkers in LMs that control the formation of these malformations. A thorough evaluation of the literature from 2000 to the present was conducted using the PubMed and Google Scholar databases. Although it is obvious that the vascular endothelial growth factor receptor 3 mutation accounts for a significant proportion of LM patients, several mutations in other genes thought to be linked to LM have also been discovered. Also, inflammatory mediators like interleukin-6, interleukin-8, tumor necrosis factor-alpha and mammalian target of rapamycin are the most commonly associated biomarkers with LM. Understanding the mutations and genes expression responsible for the abnormalities in lymphatic endothelial cells could lead to novel therapeutic strategies based on molecular pathways.

[Lymphangioma of the scrotum].

INTRODUCTION: Lymphangioma (lymphatic malformation) is a congenital malformation of lymphatic vessels. According to the classification of the International Society for the Study of the Vascular Anomalies, there are macrocystic, microcystic and mixed types of lymphatic malformations. The typical location of the lymphangiomas is the area of large lymphatic collectors (head, neck, axillary areas), while the scrotum is not frequently affected. AIM: To present a rare clinical case of lymphatic malformation of the scrotum with successful minimally invasive treatment (sclerotherapy). MATERIALS AND METHODS: A clinical observation of a 12-year-old child with a diagnosis of "Lymphatic malformation of the scrotum" is presented. From the age of 4, there was a large lesion in the left half of the scrotum. In other clinic, a surgical removal with a diagnosis of "left-sided inguinal hernia", "spermatic cord hydrocele", "isolated left-sided hydrocele" was performed. However, there was a recurrence after the procedure. When contacting the Clinic of pediatrics and pediatric surgery, scrotal lymphangioma was suspected. The diagnosis was confirmed by magnetic resonance imaging. The patient underwent minimally invasive sclerotherapy using the drug "Haemoblock". After 6 months of follow-up, no relapse was seen. CONCLUSION: Lymphangioma (lymphatic malformation) of the scrotum is a rare urological pathology that requires specific diagnosis, in-depth differential diagnosis and treatment by a multidisciplinary team of doctors, including a specialist in the treatment of vascular pathology.

Cytological and Biochemical Analyses of Lymphatic Fluid from Patients with Lymphatic Malformations.

Background: Intracystic hemorrhage from lymphangiomas is a common phenomenon in lymphatic malformations (LMs); however, little is known about the associated compositional changes in the lymphatic fluid. Materials and Methods: We prospectively collected lymphatic fluid from children with LMs. Lymphatic fluid was divided depending on the bleeding status into the bleeding and nonbleeding groups. The fluid was subjected to cytological and biochemical analyses to determine protein and cytokine levels. The Mann-Whitney U test was used to compare the two groups. Results: There were significant differences in the levels of interleukin (IL)-6, IL-10, and glucose, and the percentage of white blood cells between the bleeding and nonbleeding groups. There was no significant difference in chlorine and protein content; white blood cell count; and IL-2, IL-4, tumor necrosis factor α, and interferon γ levels between the two groups. Conclusion: Lymphatic fluid is less stable in bleeding LMs than in non-bleeding LMs and is prone to inflammatory reactions. The inflammatory reaction in lymphatic fluid does not stimulate the cytokine storm in blood. The inflammatory reaction due to LMs does not affect the contents of protein and chlorine in lymphatic cyst fluid.

Endoscopic Resection for Vascular Anomalies in Children: A New Standard.

OBJECTIVE: To report an innovative endoscopic surgery for subcutaneous vascular malformations and intramuscular fibro-adipose vascular anomaly (FAVA) at our center. BACKGROUND: Historically, open surgical resection has been the treatment of choice. Recent advances in minimally invasive surgery have led to the successful application of endoscopic resection techniques for the surgical management of diseases of soft tissue. METHODS: Patients who underwent endoscopic resection of vascular anomalies were included in this retrospective review. Data were extracted from our Vascular Anomalies Center database between September 2019 and October 2022, including sex, age, symptoms, diagnosis, sites of surgery, previous treatment, surgery, and follow-up. RESULTS: There were 13 females and 15 males in the current study, with ages ranging from 1 to 17 years. The diagnoses included microcystic lymphatic malformation (LM) (n = 8), Klippel-Trénaunay syndrome (n = 7), venous malformation (n = 6), FAVA (n = 6), and mixed cystic LM (n = 1). Surgical sites included the lower extremity (n = 24), abdominal wall (n = 2), upper extremity (n = 1), and thoracic wall (n = 1). Five patients had an intramuscular lesion (FAVA). The endoscopic technique used 2 or 3 small ports in a gas inflation manner. Surgery included thrombectomy, radical resection, and debulking of vascular anomalies. Postoperative sclerotherapy with bleomycin was performed through a drainage tube in 6 patients with microcystic LM. Technical success was obtained in 27 patients. The conversion to open surgery was performed in one patient owing to the deep location of the lesion. No wound-related complication was observed. CONCLUSIONS: Endoscopic surgery is a minimally invasive, effective, and safe treatment for subcutaneous vascular malformations and intramuscular FAVA. This approach can set a new standard that minimizes wound complications and reduces recovery time in patients undergoing resection for benign soft-tissue lesions.

French national diagnosis and care protocol (PNDS, protocole national de diagnostic et de soins): cystic lymphatic malformations.

Cystic lymphatic malformations (LMs) are rare chronic conditions which management differs according to the type (macrocystic LMs, microcystic LMs or both). Studies are lacking due to rarity of the pathology. We aimed to establish a French National Diagnosis and Care Protocol (PNDS: Protocole National de Diagnostic et de Soins), to provide health professionals with free open access synthesis on optimal management and care of patients with LMs ( https://www.has-sante.fr/upload/docs/application/pdf/2021-03/malformations_lymphatiques_kystiques_-_pnds.pdf ). The process included a critical review of the literature and multidisciplinary expert consensus. LMs are congenital but are not always discovered at birth. Nearly 75% of them are located in the head and neck because of the highly dense lymphatic system in this region. Physical examination (showing painless masses with normal skin color and depressible consistency, or cutaneous/mucosal lymphangiectasia) and color Doppler ultrasonography, usually allow for diagnosis. MRI (involving T2 sequences with fat saturation in at least two spatial planes) is the tool of choice for evaluating anatomical extension, characterizing lesions (microcystic and macrocystic), and before considering therapeutic management. A biopsy, coupled to a blood sample, can also be used for molecular biology analyses, to search for activating mutations of the PIK3CA gene, particularly with LM integrating in a syndromic form (CLOVES or Klippel-Trenaunay syndrome) but also in certain isolated (or common) LMs. The spontaneous evolution of LMs, in particular microcystic forms, is often toward progressive aggravation, with an increase in the number of vesicles, thickening, increased oozing and bleeding, while pure macrocystic LMs may regress due to "natural sclerosis", i.e. fibrosis secondary to an inflammatory reorganization after common infantile infections. In case of voluminous LMs or syndromic forms, functional and psychological repercussions can be major, deteriorating the patient's quality of life. LMs must be treated by physicians integrated in multidisciplinary teams, and be personalized. Management is a life-long process that involves one or several of these therapies: conservative management, physical therapy (compression), sclerotherapy, surgery, drugs such as mTOR inhibitors (sirolimus), that has shown efficacy in decreasing the volume of LMs, and, more recently, PI3K-inhibitors in syndromic forms. Psychological and social support is necessary, taking into account the patient and his family.

Lymphatic malformations in children: retrospective review of surgical and interventional management.

PURPOSE: Lymphatic malformations (LMs) are classified as macrocystic, microcystic or mixed. Treatment depends on their characteristics: surgery, sclerotherapy, both combined, systemic treatment or observation. This study aims to analyze the surgical and interventional management of LMs in children over the last two decades in our university hospital. METHODS: Management of children born with LMs between 2000 and 2019 was reviewed. Parameters collected were: malformation characteristics, type of treatment, symptoms, imaging, timing of diagnosis and first treatment, number of interventions, recovery rate, complications and length of stay. RESULTS: Files of 48 children were reviewed: 27 with macrocystic and 21 with microcystic LMs. There was no statistically significant difference in type of treatment except for combined treatment, more performed in microcystic LMs (p = 0.04). Symptoms, imaging, timing of diagnosis and first treatment, number of interventions and complications were not statistically significant. Overall, the number of surgeries was lower than sclerotherapies (p = 0.04). Recovery rate after surgery was higher in macrocystic LMs (p = 0.01). Complications and length of stay were not statistically significant. CONCLUSION: A good rate of recovery was observed when surgery was performed, with no significant increase in complications and length of stay. A prospective study will be determinant to create a decisional algorithm for children with LMs.

The VASCERN-VASCA working group diagnostic and management pathways for lymphatic malformations.

Lymphatic malformations (LMs) are developmental defects of lymphatic vessels. LMs are histologically benign lesions, however, due to localization, size, and unexpected swelling, they may cause serious complications that threaten vital functions such as compression of the airways. A large swelling of the face or neck may also be disfiguring and thus constitute a psychological strain for patients and their families. LMs are also highly immunologically reactive, and are prone to recurrent infections and inflammation causing pain as well as chronic oozing wounds. The European Reference Network on Rare Multisystemic Vascular Diseases (VASCERN) is dedicated to gathering the best expertise in Europe. There are only few available guidelines on management and follow up of LMs, which commonly focus on very specific situations, such as head and neck LM (Zhou et al., 2011). It is still unclear, what constitutes an indication for treatment of LMs and how to follow up the patients. The Vascular Anomalies Working Group (VASCA-WG) of VASCERN decided to develop a diagnostic and management pathway for the management of LMs with a Nominal Group Technique (NGT), a well-established, structured, multistep, facilitated group meeting technique used to generate consensus statements. The pathway was drawn following 2 face-to-face meetings and multiple web meetings to facilitate discussion, and by mail to avoid the influence of most authoritative members. The VASCA-WG has produced this opinion statement reflecting strategies developed by experts and patient representatives on how to approach patients with lymphatic malformations in a practical manner; we present an algorithmic view of the results of our work.

Topical sirolimus solution for lingual microcystic lymphatic malformations in children and adults (TOPGUN): study protocol for a multicenter, randomized, assessor-blinded, controlled, stepped-wedge clinical trial.

BACKGROUND: Lingual microcystic lymphatic malformations (LMLMs) are rare congenital vascular malformations presenting as clusters of cysts filled with lymph fluid or blood. Even small well-limited lesions can be responsible for a heavy burden, inducing pain, aesthetic prejudice, or oozing, bleeding, infections. The natural history of LMLMs is progressive worsening punctuated by acute flares. Therapeutic options include surgery, laser excision, and radiofrequency ablation but all are potentially detrimental and expose to local relapse. Therefore, the management frequently relies on a "watchful waiting" approach. In complicated LMLMs, treatment with oral sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, is often used. Topical applications of sirolimus on the buccal mucosae have been reported in other oral diseases with good tolerance and none to slight detectable blood sirolimus concentrations. We aim to evaluate the efficacy and safety of a 1 mg/mL sirolimus solution applied once daily on LMLM of any stage in children and adults after 4, 8, 12, 16, 20, and 24 weeks of treatment compared to usual care (no treatment). METHODS: This is a randomized, multicentric study using an individually randomized stepped-wedge design over 24 weeks to evaluate topical application of a 1 mg/mL sirolimus solution once daily, on LMLM, versus usual care (no treatment), the control condition. Participants begin with an observational period and later switch to the intervention at a randomized time (week 0, 4, 8, or 12). Visits occur every 4 weeks, either in the study center or by teleconsulting. The primary outcome will be the evaluation of global severity of the LMLM on monthly standardized photographs by 3 independent blinded experts using the physical global assessment (PGA) 0 to 5 scale. Secondary outcomes will include lesion size measurement and quality of life assessment, investigator, and patient-assessed global disease and specific symptoms (oozing, bleeding, sialorrhea, eating impairment, taste modification, aesthetic impairment, pain, and global discomfort) assessment. A biological monitoring will be performed including residual blood sirolimus concentration and usual laboratory parameters. DISCUSSION: Given the disappointing state of current treatment options in LMLMs, topical sirolimus could become firstline therapy in treating LMLMs if its efficacy and safety were to be demonstrated. TRIAL REGISTRATION: ClinicalTrials.gov NCT04128722 . Registered on 24 September 2019. EudraCT: EUCTR2019-001530-33-FR Sponsor (University Hospital Center of Tours - CHRU Tours): DR190041-TOPGUN French regulatory authorities: ID RCB: 2019-001530-33.

Microcystic lymphatic malformation presenting as firm, skin-colored papules of the lips.

Microcystic lymphatic malformation (MiLM), also known as lymphangioma circumscriptum, is a superficial collection of lymphatic vessels measuring <1 cm in the largest diameter, often with a more extensive deeper malformation. It commonly presents as discrete or grouped plaques of clear or hemorrhagic vesicles classically described as "frogspawn"; however, here we describe a case of its unique presentation as firm papules on the lips of a healthy six-year-old child. These skin-colored papules in the absence of vesicles with lymphatic and/or hemorrhagic fluid may not be clinically indicative of MiLM. This case represents a diagnostic challenge due to the unique morphology of pink, fleshy papules as opposed to the clear or hemorrhagic vesicles typically observed in MiLM.

Respiratory Failure in Noonan Syndrome Treated by Microsurgical Thoracic Duct-Venous Anastomosis.

Noonan syndrome is a disorder characterized by central and peripheral lymphatic conducting anomalies, leading to chylothorax, chylous ascites, and metabolic derangement. Novel imaging methods, including dynamic contrast magnetic resonance lymphangiography and intranodal lymphangiography, have allowed for increased visualization of lymphatic pathology. Severe pulmonary insufficiency and chylothoraces developed in a 61-year-old man with Noonan syndrome. Dynamic contrast magnetic resonance lymphangiography and intranodal lymphangiography demonstrated central thoracic duct (TD) occlusion. The patient's condition significantly improved after a microsurgical TD-venous anastomosis assisted by TD catheterization for imaging guidance, resulting in decompression of the lymphatic system and resolution of the pulmonary symptoms.

Malformação venolinfática em borda lateral de língua: relato de caso / Venolymphatic malformation in lateral edge of the tongue: case report

Resumo As malformações vasculares são anomalias que podem acometer veias, vasos linfáticos e artérias de forma isolada ou mista. Quando se apresentam de forma mista, com componentes venosos e linfáticos, são denominadas malformação venolinfática ou linfático-venosa, de acordo com sua constituição predominante. Embora seja um distúrbio benigno de bom prognóstico, é localmente invasivo, podendo levar a deformidade e havendo, ainda, a propensão de recorrência local. O presente artigo traz um caso de malformação venolinfática com localização incomum em borda lateral de língua, abordando-se a conduta clínica e o referencial teórico vigente.

Abstract Vascular malformations are vascular anomalies that can affect veins, lymphatic vessels, and/or arteries in isolated or mixed form. When they present in the mixed form with venous and lymphatic involvement, they are called venolymphatic or lymphatic-venous malformations, depending on their predominant component. Although these are benign disorders with good prognosis, they are locally invasive and may lead to deformity, while there is also a propensity for local recurrence. This article presents a case of venolymphatic malformation with unusual localization on the lateral border of the tongue, addressing the clinical conduct and the current theoretical framework.

Topical Tacrolimus 0.1% for treatment of cutaneous microcystic lymphatic malformations.

Microcystic lymphatic malformations as described in the international literature form a subgroup of low-flow congenital vascular malformations (VM) resulting from irregular embryological development. Microcystic lesions normally manifest as an accumulation of lymph- and blood-filled vesicles that, when externalized, cause skin maceration with consequent pain and potential infection resulting in the impairment of the patient's quality of life. There is no consensus on a standardized algorithm nor clear guidelines for successful treatment of this type of lymphatic malformation, and treatment options employed often result in ambivalent and transient outcomes with a high rate of recurrence. The topical formulation of tacrolimus is a well-known FDAapproved anti-T cell agent that was recently identified as a potent activator of ALK1, which is involved in several processes and functions including angiogenesis. We investigated if topical administration of tacrolimus may be an effective therapy for directly targeting cutaneous microcystic lymphatic malformations as a complement to systemic treatment. The study enrolled four patients with cutaneous microcystic lymphatic malformations: three male (ages: 13,15,18) and one female (age: 30). Two of the patients presented lesions on their backs, one patient on the left hand and one on the left lower limb. All four patients received treatment with topical tacrolimus 0.1% twice a day for 10 weeks on a previously selected area for application. Weekly clinical follow-ups were conducted along with close physician-patient contact. All patients displayed a satisfactory response after treatment. Lymphorrhea and bleeding were stopped in all cases and the esthetic aspect of lesions improved in two patients. To date, all patients presented no clinically significant changes to the size or extension of the lesion. Topical tacrolimus treatment is a promising and reasonable option for microcystic lymphatic malformations. Our results encourage further exploration in larger populations with the consideration that it is a safe and effective alternative or complementary therapy to systemic treatment.

Effect of long-term phosphodiesterase-5 inhibitor use on refractory lymphatic malformations in adult and teen patients.

Lymphatic malformations (LMs) are rare congenital anomalies. LMs are often refractory to standard treatments, including surgical resection, debulking, and sclerotherapy. Use of sildenafil, a phosphodiesterase-5 inhibitor, for treatment of pediatric LMs has been reported with demonstrated benefit to some patients. This case series reports treatment of three patients (aged 14-37 years) suffering from complicated or refractory LMs with a low-dose oral phosphodiesterase-5 inhibitor, resulting in significant clinical improvement.

Intralesional Bleomycin for Orbital Lymphatic Malformations: Comparison of Clinical Versus Radiologic Regression by Volumetric Analysis.

PURPOSE: The aim of the study was to investigate the clinical resolution versus radiologic regression of orbital lymphatic malformations (LMs) following treatment with intralesional bleomycin sulfate sclerotherapy. METHODS: A retrospective interventional study of 24 eyes with orbital LMs treated with nonimage-guided bleomycin sclerotherapy. The clinical and radiologic outcomes were classified as excellent, good, fair, and poor. Regression was assessed clinically and by radiologic volumetrics. RESULTS: Mean age at presentation was 17 ± 18 years (median 11, range 5 months to 70 years). Lesion morphology was microcystic in 11 (46%), macrocystic in 8 (34%), and mixed in 5 (21%) eyes. Mean units of bleomycin injected per session were 4 ± 2 IU (median 5 IU, range 1-6 IU). Mean number of treatment sessions required was 2 ± 1 (median 2, range 1-6). Cumulative units of bleomycin injected were 11 ± 9 (median 9, range 1-38 IU). The clinical response was excellent in 19 (79%), good in 4 (17%), and fair in 1 (4%). The mean preoperative and postoperative lesion volumes were 7 ± 4 cm3 and 0.8 ± 1.2 cm3, respectively (p < 0.0001, 95% CI, -7.89 to -4.51). Radiologic resolution of LM was excellent in 6 (25%), good in 8 (33%), fair in 7 (29%), and poor in 3 (13%) eyes. Spearman's rank correlation coefficient for correlation between clinical and radiologic grading was 0.51 (p = 0.01, 95% CI, 0.13-0.75%). There was a sustained tumor resolution without recurrence over a mean follow-up duration was 2 years (median 18 months; range 12-60 months). CONCLUSIONS: Bleomycin sclerotherapy for orbital LMs gives an excellent to good clinical response in 93%. However, a parallel radiologic regression is seen only in 58%. The endpoint to assess response should be clinical. Treatment till complete radiologic resolution may not be necessary.

Rare PECAM1 variants in three families with lymphedema.

PECAM1 is a member of the immunoglobulin superfamily and is expressed in monocytes, neutrophils, macrophages and other types of immune cells as well as in endothelial cells. PECAM1 function is crucial for the development and maturation of B lymphocytes. The aim of this study was to link rare PECAM1 variants found in lymphedema patients with the development of lymphatic system malformations. Using NGS, we previously tested 246 Italian lymphedema patients for variants in 29 lymphedema-associated genes and obtained 235 negative results. We then tested these patients for variants in the PECAM1 gene. We found three probands with rare variants in PECAM1. All variants were heterozygous missense variants. In Family 1, the unaffected mother and brother of the proband were found to carry the same variant as the proband. Lymphoscintigraphy was performed to determine possible lymphatic malformations and showed that in both cases a bilateral slight reduction in the speed and lymphatic clearance of the lower limbs. PECAM1 function is important for lymphatic vasculature formation. We found variants in PECAM1 that may be associated with susceptibility to lymphedema.

Lymphatic system malformations in Noonan syndrome: Two case reports and imaging analysis.

L ymphedema is a well-known complication of Noonan syndrome (NS) but the lymphatic malformations in NS are poorly understood. We report clinical, genetic, and imaging information about a boy and girl with NS and late-onset lower extremity lymphedema. A de novo missense mutation of RIT1 (NM_006912.5) c.246T>A, p.Phe82Leu was identified in the girl, who also showed systemic lymphatic hyperplasia and dysfunction. Magnetic resonance lymphangiography (MRL) of the boy clearly demonstrated segmental dilated and hyperplastic lymphatics with impaired transport function in an affected limb and pelvic region. Indocyanine green lymphography (ICGL) showed delayed and partial enhancement of the lymph vessels in the affected limb but no lymph reflux was detected. No causative mutation was identified in the second case. Lymphoscintigraphy (LSG) failed to show lymph vessels in either of the children. Our study showed that MRL is a reliable and accurate test that can be used to demonstrate morpho-logical and functional defects of the lymphatic system. Moreover, ICGL is sufficiently sensitive to determine the functional condition of peripheral lymph vessels. The combined use of imaging modalities can give an accurate diagnosis of complex lymphatic system anomalies in NS and other syndromic diseases.

Management of visceral vascular anomalies.

Visceral vascular anomalies are common in patients with vascular malformations in other parts of the body and can include lymphatic, venous, and arteriovenous malformations. Depending on the organ or organs involved they may present differently and pose different treatment challenges. Defining the malformation and understanding its extent is paramount in devising management regimens. Medical, interventional, and surgical therapies are often required in combination to treat these complex lesions. There are new and promising advances in the development of therapeutic agents targeting the PI3K/AKT/mTOR pathway. Due to the complex nature of these lesions a coordinated, multi-disciplinary approach is necessary to manage and mitigate symptoms and complications of this diverse group of vascular malformations.

Vascular anomalies of the head and neck.

The head and neck are the most common site of involvement for vascular tumors and malformations, with more than half of all vascular anomalies seen in this region. Lesions in this location can cause significant disfigurement and can be associated with airway obstruction, impairment in vision or hearing, swallowing disorders and hemorrhage. Accurate diagnosis is critical in determining treatment, and interdisciplinary care is essential for optimal management. We review clinical and imaging features that are key to establishing the correct diagnosis, and review treatment modalities, with emphasis on interventional and surgical procedures.

Lymphatic malformations.

Lymphatic malformations are low-flow vascular malformations that arise due to errors in vascular development. Lymphatic malformations are benign and usually noted at birth or in the first few years of life. Lymphatic mass lesions are composed of varying size of cysts; this article focuses on discussion of cystic lymphatic malformations. Lymphatic malformations can occur throughout the body especially in lymphatic rich areas such as the cervical and axillary locations as well as the groin, trunk, retroperitoneum, extremities, abdominal or thoracic cavities. Treatment options vary based upon size of cysts and location. A multimodal and interdisciplinary approach is essential to care for patients with lymphatic malformations. Management options include observation, pharmacotherapy, sclerotherapy, and surgical procedures.