Pathogenesis of vascular anomalies

Vascular anomalies are localized defects of vascular development. Most of them occur sporadically (ie, there is no familial history of lesions, yet in a few cases clear inheritance is observed). These inherited forms are often characterized by multifocal lesions that are mainly small in size and increase in number with patients' age. The authors review the known (genetic) causes of vascular anomalies and call attention to the concept of Knudson's double-hit mechanism to explain incomplete penetrance and large clinical variation in expressivity observed in inherited vascular anomalies. The authors also discuss the identified pathophysiological pathways involved in vascular anomalies and how it has opened the doors toward a more refined classification of vascular anomalies and the development of animal models that can be tested for specific molecular therapies.

Congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE) syndrome: CNS malformations and seizures may be a component of this disorder

A newborn girl was found to have a massive lymphatic truncal vascular malformation with overlying cutaneous venous anomaly associated with overgrown feet and splayed toes. These manifestations comprise the recently described CLOVE syndrome. She also had cranial asymmetry and developed generalized seizures, which were treated with anticonvulsants. Cranial CT showed encephalomalacia, widening of the ventricles and the sulci, hemimegalencephaly (predominantly white matter) and partial agenesis of corpus callosum. Review of the literature identified several other patients with CLOVE syndrome, some of whom were misdiagnosed as having Proteus syndrome, with strikingly similar manifestations. We conclude that CNS manifestations including hemimegalencephaly, dysgenesis of the corpus callosum, neuronal migration defects, and the consequent seizures, may be an rarely recognized manifestation of CLOVE syndrome.

Nonmalignant Adult Thoracic Lymphatic Disorders

The thoracic lymphatic disorders are a heterogeneous group of uncommon conditions that are associated with thoracic masses, interstitial pulmonary infiltrates, and chylous complications. Accurate diagnosis of the thoracic lymphatic disorders has important implications for the newest approaches to management, including embolization and treatment with antilymphangiogenic drugs. New imaging techniques to characterize lymphatic flow, such as dynamic contrast-enhanced magnetic resonance lymphangiogram, are redefining approaches to disease classification and therapy.

Treatment of severe Kaposiform lymphangiomatosis positive for NRAS mutation by MEK inhibition

BACKGROUND

Kaposiform lymphangiomatosis (KLA) is a complex lymphatic anomaly involving most commonly the mediastinum, lung, skin and bones with few effective treatments. In recent years, RAS-MAPK pathway mutations were shown to underlie the pathogenesis of several complex lymphatic anomalies. Specifically, an activating NRAS mutation (p.Q61R) was found in the majority of KLA patients. Recent reports demonstrated promising results of treatment with the MEK inhibitor, Trametinib, in patients with complex lymphatic anomalies harboring gain of function mutations in ARAF and SOS1, as well as loss of function mutation in the CBL gene, a negative regulator of the RAS-MAPK pathway. We present a 9-year-old child with a severe case of KLA harboring the typical NRAS (p.Q61R) mutation detected by plasma-derived cell free DNA, responsive to trametinib therapy.

METHODS

The NRAS somatic mutation was detected from plasma cfDNA using droplet digital PCR. Concurrent in-vitro studies of trametinib activity on mutant NRAS affected lymphatic endothelial cells were performed using a three-dimensional spheroid sprouting assay.

RESULTS

Trametinib treatment lead to resolution of lifelong thrombocytopenia, improvement of pulmonary function tests and wellbeing, as well as weaning from prolonged systemic steroid treatment. Concurrent studies of mutant NRAS-expressing cells showed enhanced lymphangiogenic capacity along with over activation of the RAS-MAPK and PI3K-AKT-mTOR pathways, both reversed by trametinib.

CONCLUSIONS

Trametinib treatment can substantially change the prognosis of patients with RAS pathway associated lymphatic anomalies.

IMPACT

This is the first description of successful trametinib treatment of a patient with KLA harboring the most characteristic NRAS p.Q61R mutation. Treatment can significantly change the prognosis of patients with RAS pathway-associated lymphatic anomalies. We devised an in vitro model of KLA enabling a reproducible method for the continued study of disease pathogenesis. Mutated NRAS p.Q61R cells demonstrated increased lymphangiogenic capacity.

Kaposiform lymphangiomatosis: Diagnosis, pathogenesis, and treatment

Kaposiform lymphangiomatosis (KLA) is a life-threatening rare disease that can cause substantial morbidity, mortality, and social burdens for patients and their families. Diagnosis often occurs long after initial symptoms, and there are few centers in the world with the expertise to diagnose and care for patients with the disease. KLA is a lymphatic anomaly and significant advancements have been made in understanding its pathogenesis and etiology since its first description in 2014. This review provides multidisciplinary, comprehensive, and state-of-the-art information on KLA patient presentation, diagnostic imaging, pathology, organ involvement, genetics, and pathogenesis. Finally, we describe current therapeutic approaches, important areas for research, and challenges faced by patients and their families. Further insights into the pathogenesis of KLA may advance our understanding of other vascular anomalies given that similar signaling pathways may be involved.

Sirolimus in the treatment of kaposiform lymphangiomatosis

BACKGROUND

Kaposiform lymphangiomatosis (KLA), which is a new subtype of generalized lymphatic anomaly, is a rare disease with a poor prognosis. Currently, there is no standard treatment due to the poor understanding of KLA. Sirolimus, which is an inhibitor of mammalian target of rapamycin, has been shown to have promising potential in the treatment of complicated vascular anomalies. The aim of this study was to introduce the use of sirolimus for the treatment of KLA and to highlight the challenges of managing this refractory disease.

RESULTS

We reported seven patients with KLA who received sirolimus therapy in our center. Combined with previously reported cases, 58.3% achieved a partial response, 25.0% had stable disease, and 16.7% experienced disease progression. No severe sirolimus-related adverse events occurred during treatment.

CONCLUSIONS

This study suggests that sirolimus is currently an option for the treatment of KLA, and it is hoped that more specific therapies will be developed in the future. Rapid advances in basic science and clinical practice may facilitate the development of important new treatments for KLA.

A single-center experience in the management of head and neck lymphangiomas

INTRODUCTION

Lymphangiomas are relatively uncommon head and neck region lymphatic malformations. Although surgery can be still considered the mainstay of treatment, sclerotherapy by OK-432 is becoming a widespread treatment option. The aim of this article is to present and discuss the management and outcomes of a series of cases of lymphangiomas.

METHODS

All patients with lymphangiomas who were treated from 2010 to 2018 were reviewed. The following data were recorded: age, gender, subtype, staging, type of treatment, outcome, and recurrence.

RESULTS

Fifteen patients (9 females, 6 males) were included with 2 microcystic and 13 macrocystic lymphangiomas. Six patients underwent surgery with excision (5 with a complete success, one with a fair success), whereas the remaining 9 subjects underwent sclerotherapy by OK-432 (6 with a complete success, 3 with a fair success). No postoperative complications were observed.

CONCLUSIONS

All modes of treatment are important in properly selected patients affected by lymphangiomas. OK-432 therapy is a safe and effective option in the treatment of head and neck lymphangiomas.

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.

Osteopathy in Complex Lymphatic Anomalies

Complex Lymphatic Anomalies (CLA) are lymphatic malformations with idiopathic bone and soft tissue involvement. The extent of the abnormal lymphatic presentation and boney invasion varies between subtypes of CLA. The etiology of these diseases has proven to be extremely elusive due to their rarity and irregular progression. In this review, we compiled literature on each of the four primary CLA subtypes and discuss their clinical presentation, lymphatic invasion, osseous profile, and regulatory pathways associated with abnormal bone loss caused by the lymphatic invasion. We highlight key proliferation and differentiation pathways shared between lymphatics and bone and how these systems may interact with each other to stimulate lymphangiogenesis and cause bone loss.

Comprehensive treatment of massive macroglossia due to venous and lymphatic malformations

This study evaluated the outcomes of comprehensive treatment for massive macroglossia. Eleven patients with massive macroglossia due to venous malformations (VMs) and lymphatic malformations (LMs) underwent incision excision of two-thirds of the central wedge of the tongue; two of these patients underwent resection of lesions in the lower lip or floor of the mouth during initial treatment. In subsequent treatment, three patients underwent orthognathic surgery or resection of lesions in the lower lip and submental region, and four patients underwent one or two sclerotherapies. No patient had complications resulting from anaesthesia or surgery. Patients were followed up at 6 months postoperative, and all signs associated with the lesions had disappeared. The mean follow-up duration was 30.8 months. The aesthetic outcome was excellent for nine patients and satisfactory for two. Nine patients could take a soft diet and two a solid diet. Eight patients presented normal speech and three presented intelligible speech. Comprehensive treatment including incision excision of two-thirds of the central wedge of the tongue, as well as orthognathic surgery, the resection of lesions in the oral and maxillofacial region, and sclerotherapy, is effective for patients with massive macroglossia due to VMs and LMs.

Different lymphscintigraphic patterns in patients with lymphedema distichiasis

Mutation of the transcription factor FOXC2 gene has been identified as the cause of lymphedema-distichiasis syndrome (LD). Subjects with LD usually present with lower extremity lymphedema and distichiasis--an additional row of eyelashes. Typically, lymphscintigrams of patients with LD show good transport of the radiotracer from the feet to the inguinal lymph nodes accompanied by reflux of tracer to the skin of the lower extremities ("dermal backflow"). We have examined two patients with LD syndrome and were able to demonstrate two different distinct lymphscintigraphic patterns: lymphatic hyperplasia with reflux and obstructive.

[Sclerosis of lymfangiomas in the head and neck area: evaluation with the use of stereophotogrammetry]

Lymangiomas are congenital malformations of the lymphatic system. They can appear at any age and in any part of the body. In the head and neck area lymangiomas can give rise to functional as well as esthetic problems. Therapy consist of sclerosis, possibly followed by surgical excision. Stereophotogrammetry is a relatively new technique which, by means of superimposition of pre- and postoperative images, provides the possibility to quantify treatment results. In this paper 3 patients who underwent treatment of a lymphatic malformation and in whom treatment results were measured with stereophotogrammetry are discussed. The conclusion can be drawn that stereophotogrammetry is a promising technique for evaluation of treatment results of superficially localised lymphatic malformations that displace the skin in the head and neck area.

[Application of surgery combined with bleomycin irrigation for complex cervical-facial lymphatic malformations in children]

Objective:To present experience and evaluate the safety and efficacy of surgery combined with bleomycin irrigation for the management of head and neck lymphatic malformations in children. Methods:The medical records of all patients with cervical-facial lymphatic malformations who presented to Shanghai Children's Hospital from August 2014 to December 2020 were reviewed. 97 children were divided into surgery group（81 cases） and sclerotherapy group（16 cases）. Conventional contrast-enhanced magnetic resonance imaging（MRI） and B-ultrasound examinations were performed both preoperatively and postoperatively. The surgical group received lymphangioma resection combined with bleomycin irrigation. The sclerotherapy group was treated with B-ultrasound-guided percutaneous lymphangioma aspiration and bleomycin sclerotherapy. SPSS 21.0 software was used to evaluate the clinical cure rate and postoperative complications of lesions in both groups by chi-square test. Kaplan-Meier method was used to calculate the disease-free survival rate and draw survival curve. Results:In the surgery group of 81 children, 64 cases were cured and 17 cases were effective while in the sclerosis group, 8 cases were cured and 8 cases were effective. Cox proportional risk model found that children in the surgery group had a higher cure rate and a lower risk of 5-year recurrence than those in the sclerotherapy group, with statistically significant differences（χ²=5.814, P<0.05）. The risk of recurrence in the surgery group was 35.4% of that in the sclerotherapy group（HR=0.354, P<0.05）. In regards to postoperative complications, the surgical group had no higher rate of temporal facial paralysis and other nerve injuries compared to the sclerotherapy group（χ²=1.041, P=0.308）. Conclusion:Surgery combined with bleomycin irrigation in the complex cervical-facial lymphatic malformations was confirmed to be effectively and safely. The principle of the surgery was to protect the structure and function of normal tissue while excising the lesions as much as possible. When the lesions involved the posterior two-thirds of the tongue, the floor of the mouth, parapharynx, retropharynx, or hypopharynx spaces. Radiofrequency ablation was used in the surgical excision, which made the surgery more minimally invasive, accurate and personalized.

Recurrent haemoptysis: a rare diagnosis of kaposiform lymphangiomatosis and review of literature

Kaposiform lymphangiomatosis (KLA) is a rare clinicopathological entity among lymphatic anomalies. The main involved sites are the mediastinum and the lungs but the disease can also affect multiple extrathoracic organs. Little is known about the pathophysiology, the natural history, the treatment response and the long-term outcome of this disorder. KLA is typically diagnosed in childhood. We present here the case of an adult man with 13 years recurrent episodes of haemoptysis who was finally found to suffer from KLA. Following this, we present a comprehensive review of the literature.

Lymphoscintigraphy Findings are Associated with Outcome in Children with Chylothorax After Cardiac Surgery

Postoperative chylothorax in patients with congenital heart diseases (CHD) results in poor outcomes if anatomical and functional abnormalities of the lymphatic system are present. While these abnormalities are typically diagnosed by intranodal lymphangiography and dynamic contrast magnetic resonance lymphangiography, the usefulness of lymphoscintigraphy in these patients has not been evaluated. Between January 2019 and December 2021, 28 lymphoscintigraphies were performed in our institution for investigating prolonged pleural effusion after cardiac surgery. The images were assessed by three board-certified pediatric cardiologists retrospectively to determine the likelihood of a central lymphatic flow disorder. The likelihood was scored (range 1-3) based on structural abnormalities and congestive flow in the lymphatic system. Those scores were summed and the likelihood was categorized as low to intermediate (< 8 points) or high (8 or 9 points). Median age at lymphoscintigraphy was 129 days (IQR, 41-412 days), it was performed at a median of 22 days (IQR, 17-43) after surgery, and median score was 6 points (IQR, 4-7.5). Kendall's coefficient of concordance (0.867; p < 0.05) indicated high inter-rater reliability. Overall survival at 6 months after surgery was 92.5% in the low-to-intermediate group but 68.6% in the high group (p < 0.05), and duration of postoperative thoracic drainage was 27 and 58 days, respectively (p < 0.05). Lymphatic abnormalities detected by lymphoscintigraphy were associated with poorer outcomes. Lymphoscintigraphy was thought to be useful in assessing anatomic and functional lymphatic abnormalities, despite its minimal invasiveness.

[Intralesional pingyangmycin injection in the management of macrocystic lymphatic malformations in cervical region]

PURPOSE

To investigate the therapeutic effects of pingyangmycin injection as a primary therapy of macrocystic lymphatic malformations in cervical region.

METHODS

Thirty-six patients with macrocystic lymphatic malformations in cervical region underwent the therapy of pingyangmycin injection between 2009 and 2012 at School of Stomatology, China Medical University. Among them, 16 patients had unilateral submandibular lesions, 20 patients had lesions in anterior cervical regions. The age of patients was from 6 months to 25 years old. The concentration of the drug was 1.6 mg /mL with an addition of lidocaine. The dose and cycle of treatment were dependent on the lesions' size and patients' age. The follow-up period was 12 months to 2 years after the last treatment.

RESULTS

The total effective rate was 100%, and the curative rate was 94.4%. No serious complications were encountered.

CONCLUSIONS

Intralesional Injection of pingyangmycin provides a safe and effective treatment for macrocystic lymphatic malformations in cervical region as a primary treatment.

The various meanings and imperfections of words

In this reply to a letter, the Authors discuss the raised points regarding the nomenclature and management of Lymphatic Malformations / Lymphangiomas.

Interventional treatment of refractory non-traumatic chylous effusions in patients with lymphoproliferative disorders

To report results of interventional treatment of refractory non-traumatic abdomino-thoracic chylous effusions in patients with lymphoproliferative disorders. 17 patients (10 male; mean age 66.7 years) with lymphoproliferative disorders suffered from non-traumatic chylous effusions (chylothorax n = 11, chylous ascites n = 3, combined abdomino-thoracic effusion n = 3) refractory to chemotherapy and conservative therapy. All underwent x-ray lymphangiography with iodized-oil to evaluate for and at the same time treat lymphatic abnormalities (leakage, chylo-lymphatic reflux with/without obstruction of central drainage). In patients with identifiable active leakage additional lymph-vessel embolization was performed. Resolution of effusions was deemed as clinical success. Lymphangiography showed reflux in 8/17 (47%), leakage in 2/17 (11.8%), combined leakage and reflux in 3/17 (17.6%), lymphatic obstruction in 2/17 (11.8%) and normal findings in 2/17 cases (11.8%). 12/17 patients (70.6%) were treated by lymphangiography alone; 5/17 (29.4%) with leakage received additional embolization (all technically successful). Effusions resolved in 15/17 cases (88.2%); 10/12 (83.3%) resolved after lymphangiography alone and in 5/5 patients (100%) after embolization. Time-to-resolution of leakage was significantly shorter after embolization (within one day in all cases) than lymphangiography (median 9 [range 4-30] days; p = 0.001). There was no recurrence of symptoms or post-interventional complications during follow-up (median 445 [40-1555] days). Interventional-radiological treatment of refractory, non-traumatic lymphoma-induced chylous effusions is safe and effective. Lymphangiography identifies lymphatic abnormalities in the majority of patients and leads to resolution of effusions in > 80% of cases. Active leakage is found in only a third of patients and can be managed by additional embolization.

Prenatal Diagnosis of Fetal Lymphangioma: A Case Series

Fetal lymphangioma is an uncommon congenital malformation that is mainly comprised of the subcutaneous tissue of the neck. This malformation can develop in other areas like the thoracic and axillary regions, though rarely. We report 6 consecutive cases of lymphatic malformation in a fetal center in Dominican Republic. In our case series fetal chest lymphangiomas were present in 2 fetuses. In addition, 2 cases of axillary lymphangiomas also involved the thoracic region. Adequate management by a multidiciplinary team is necessary to provide a better approach to delivery.

Acquired cryptorchidism: an unexpected consequence of inguinoscrotal lymphatic malformation treated with Eppikajutsuto

Lymphatic malformation (LM) that causes inguinoscrotal swelling is extremely rare. Surgery, sclerotherapy and pharmacotherapy have been reported as possible treatment options for LM. Recently, Eppikajutsuto (TJ-28), a traditional Japanese herbal medicine has emerged as therapeutic option for LM. We report the case of a 2-year-old boy who presented with a left inguinoscrotal swelling, which was diagnosed as retroperitoneal LM extending into the left scrotum. The surgical approach was less favourable, given the risk of damaging the testicular vasculature or the spermatic cord. Therefore, the patient received medical treatment with TJ-28. As a result, a volume reduction of 83% was obtained, as well as the unexpected consequence of the left testicle retracting into the inguinal area. Laparoscopic exploration was performed and a small bulge on the internal inguinal ring was detected. The patient's acquired cryptorchidism was subsequently treated by orchidopexy.