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.

A classification of abdominal lymphatic perfusion patterns after Fontan surgery.

OBJECTIVES: Complications after Fontan surgery have been associated with arise and classification of abnormal thoracic lymphatic perfusion pattern. This study compiles abnormal abdominal lymphatic perfusion patterns and investigates their impact on serum protein readings. METHODS: We performed a retrospective analysis of patients who underwent magnetic resonance imaging with T2-weighted lymphatic imaging and serum protein measurements 6 months after having Fontan surgery. The abdominal lymphatic images were classified according to the anatomical lymphatic drainage patterns into 2 categories: (1) para-aortic (types 1-4); (2) portal-venous (types 1-3). Thoracic lymphatic images were classified (types 1-4) as described earlier. RESULTS: A total of 71 patients were included in the study. Para-aortic lymphatic perfusion patterns were classified as type 1 in 4, type 2 in 13, type 3 in 37 and type 4 in16 out of 71 patients. Portal-venous lymphatic perfusion patterns were classified as type 1 in 20, type 2 in 10 and type 3 in 41 patients. Thoracic lymphatic perfusion patterns were classified as type 1 in 8, type 2 in 11, type 3 in 39 and type 4 in 13 patients. The serum protein level was 66 (interquartile range: 7.5) g/l (< standard value in 37%). Higher-grade para-aortic (p = 0.0062), portal-venous (p = 0.022) and thoracic (p = 0.011) lymphatic abnormalities were correlated with lower total serum protein levels. Higher ratings of para-aortic lymphatic abnormalities were significantly associated with higher ratings of portal-venous abnormalities (p < 0.0001). Ratings of para-aortic and portal-venous classifications were correlated with the thoracic classification (p < 0.001). CONCLUSIONS: Abnormal abdominal lymphatic perfusion patterns can be classified according to anatomical structures with increasing severity. Higher grade abdominal and thoracic lymphatic perfusion patterns are associated with lower serum protein values.

Pulmonary Manifestations of Congenital Heart Disease in Children.

This review addresses how anomalous cardiovascular anatomy imparts consequences to the airway, respiratory system mechanics, pulmonary vascular system, and lymphatic system. Abnormal formation or enlargement of great vessels can compress airways and cause large and small airway obstructions. Alterations in pulmonary blood flow associated with congenital heart disease (CHD) can cause abnormalities in pulmonary mechanics and limitation of exercise. CHD can lead to pulmonary arterial hypertension. Lymphatic abnormalities associated with CHD can cause pulmonary edema, chylothorax, or plastic bronchitis. Understanding how the cardiovascular system has an impact on pulmonary growth and function can help determine options and timing of intervention.

Magnetic resonance imaging and bioimpedance evaluation of lymphatic abnormalities in patients with breast cancer treatment-related lymphedema.

PURPOSE: Breast cancer treatment-related lymphedema (BCRL) evaluation is frequently performed using portable measures of limb volume and bioimpedance asymmetry. Here quantitative magnetic resonance imaging (MRI) is applied to evaluate deep and superficial tissue impairment, in both surgical and contralateral quadrants, to test the hypothesis that BCRL impairment is frequently bilateral and extends beyond regions commonly evaluated with portable external devices. METHODS: 3-T MRI was applied to investigate BCRL topographical impairment. Female BCRL (n = 33; age = 54.1 ± 11.2 years; stage = 1.5 ± 0.8) and healthy (n = 33; age = 49.4 ± 11.0 years) participants underwent quantitative upper limb MRI relaxometry (T2), bioimpedance asymmetry, arm volume asymmetry, and physical evaluation. Parametric tests were applied to evaluate study measurements (i) between BCRL and healthy participants, (ii) between surgical and contralateral limbs, and (iii) in relation to clinical indicators of disease severity. Two-sided p-value < 0.05 was required for significance. RESULTS: Bioimpedance asymmetry was significantly correlated with MRI-measured water relaxation (T2) in superficial tissue. Deep muscle (T2 = 37.6 ± 3.5 ms) and superficial tissue (T2 = 49.8 ± 13.2 ms) relaxation times were symmetric in healthy participants. In the surgical limbs of BCRL participants, deep muscle (T2 = 40.5 ± 4.9 ms) and superficial tissue (T2 = 56.0 ± 14.8 ms) relaxation times were elevated compared to healthy participants, consistent with an edematous micro-environment. This elevation was also observed in contralateral limbs of BCRL participants (deep muscle T2 = 40.3 ± 5.7 ms; superficial T2 = 56.6 ± 13.8 ms). CONCLUSIONS: Regional MRI measures substantiate a growing literature speculating that superficial and deep tissue, in surgical and contralateral quadrants, is affected in BCRL. The implications of these findings in the context of titrating treatment regimens and understanding malignancy recurrence are discussed.

A potential role of toll-like receptors, IFN-γ and the phosphatidylinositol 3-kinase pathway in the pathogenesis of acquired mediastinal lymphatic malformation.

Sarcoidosis is a multisystem disorder with non-caseating granulomas in various organs. The etiology of sarcoid granuloma formation is not clear and likely an antigen-induced process. We came across a previously treated sarcoidosis patient who presented with worsening dyspnea on exertion for several months and several days of difficulty swallowing. On Chest CT imaging, large posterior mediastinal mass was found that subsequently diagnosed as macrocystic lymphatic malformation after surgical resection. Pathophysiology of development of acquired lymphatic malformations in a sarcoidosis patient is currently not clear. We hypothesize there might be a complex interplay of Toll-like receptors, IFN-γ and the phosphatidylinositol 3-kinase pathway in the pathogenesis.

The mTOR Signal Pathway Is Overactivated in Human Lymphatic Malformations.

Background: Lymphatic malformations (LMs) are congenital low-flow vascular anomalies resulting from abnormal embryogenesis. Clinical researches have shown that rapamycin, a specific inhibitor of mTOR, is effective in treating LMs. It suggests the abnormality of mTOR signal pathway in LMs. Methods and Results: From January 2009 to December 2018, 10 patients who accepted the resection of LMs were enrolled into the study. Samples of each subtype of LMs (macrocystic, microcystic, and mixed subtypes) were further investigated. Expression of molecules in mTOR signal pathway-mTORC1, p70 S6, p-p70 S6, elF4EBP1, and p-elF4EBP1-in LMs were investigated by immunohistochemical staining. Location of mTORC1, p70 S6, and elF4EBP1 in LMs were shown by immunofluorescence co-staining. Phosphorylation level of mTOR signal pathway in LMs was examined by Western blotting. Immunohistochemical staining showed the expression of mTORC1, p70 S6, p-p70 S6, eIF4EBP1, and p-eIF4EBP1 in LMs. Immunofluorescence staining further verified the co-expression of mTORC1, p70 S6, and eIF4EBP1 in the lymphatic endothelium of LMs. Western blotting analysis revealed obviously higher phosphorylation level of mTOR signal pathway in LMs than that in normal skins (P < 0.05). Conclusions: The results showed that the mTOR signal pathway was overactivated in LMs. The study provides compelling evidence for treating LMs or syndromes with lymphatic anomalies by inhibiting mTOR signaling.

MRI Evaluation of Lymphatic Abnormalities in the Neck and Thorax after Fontan Surgery: Relationship with Outcome.

Background The Fontan operation is performed for surgical palliation of single ventricle physiology. This operation is usually preceded by a superior cavopulmonary connection (SCPC); lymphatic abnormalities after SCPC may be demonstrated at MRI and prior to the Fontan operation. Purpose To determine if the degree of neck and thoracic lymphatic abnormalities at T2-weighted MRI in patients after superior cavopulmonary connection (SCPC) correlated with surgical outcomes from the Fontan procedure. Materials and Methods Patients for whom SCPC was performed for palliation of single ventricle disease who underwent chest MRI between July 2012 and May 2015 at a single institution were retrospectively reviewed. T2-weighted images were scored as lymphatic type 1 (little or no T2 mediastinal and supraclavicular signal) to type 4 (T2 signal into both the mediastinum and the lung parenchyma). Fontan takedown, duration of post-Fontan hospitalization and pleural effusion, postoperative plastic bronchitis, need for transplant, and mortality were tabulated. The relationship between lymphatic type and clinical outcomes was evaluated by using analysis of variance (ANOVA), the Kruskal-Wallis H test, and the Fisher exact test. Results A total of 83 patients (mean age, 7.9 years ± 2.6) were evaluated. Among these 83 patients, 53 (64%) were classified with type 1 or 2 lymphatic abnormalities, 17 (20%) with type 3, and 12 (16%) with type 4. The rate of failure of Fontan completion was higher in patients with type 4 than in type 1 or 2 (54% vs 2%, respectively; P = .004). Need for cardiac transplant (one of 13 [8%]) and death (three of 13 [23%]) occurred only in type 4. Median postoperative length of stay was longer for patients with type 4 than for those with types 1 or 2 (29 days vs 9 days, respectively; P < .01). Conclusion Greater MRI-based severity of lymphatic abnormalities in patients prior to planned Fontan procedure was associated with failure of Fontan completion and longer postoperative stay. © RSNA, 2019 Online supplemental material is available for this article.

Oral Sirolimus: An Option in the Management of Neonates with Life-Threatening Upper Airway Lymphatic Malformations.

Background: Mechanistic target of rapamycin (mTOR) inhibitors are being used off-label showing promising results in patients with vascular anomalies. Children with lymphatic malformations (LMs) involving the airway benefit from sirolimus therapy soon after birth, reducing the need of tracheostomy. Available information about efficacy and side effects in neonates remains poor. We present seven newborns with severe head and neck LM showing response to sirolimus with no significant toxicity. Methods and Results: We performed a retrospective review of neonates with head and neck LM who received sirolimus between January 2014 and May 2018 with upper airway involvement needing ventilatory support. We analyzed type of LM, involved anatomical area, symptoms and response to sirolimus, including dosage, blood levels, response, side effects, and complications. Seven neonates received primary treatment with sirolimus in the context of cervical LM. Sirolimus was started at the recommended dose of 0.8 mg/m2/12 h and adjusted to maintain blood levels between 4 and 12 ng/mL. Median follow-up was 32 months (4-43) with a median treatment duration of 12 months (3-43). One patient had complete resolution of the malformation, one had complete resolution of symptoms, and five had partial resolution of the malformation with significant improvement in their respiratory conditions. Two patients required additional subtotal surgical resection and one tracheostomy. Four patients remain under treatment. Toxicity was not observed. Conclusions: Sirolimus is a safe drug in neonates and can be considered the first therapeutical option in newborns at high risk of respiratory failure before sclerosis or surgery. Close follow-up is mandatory to identify side effects at long-term use.

Imaging of central lymphatic abnormalities in Noonan syndrome.

BACKGROUND: Children with Noonan syndrome are known to have increased risk for lymphatic disorders, the extent and nature of which are poorly understood. OBJECTIVE: Our objective was to describe the imaging findings of the central lymphatic abnormalities in children with Noonan syndrome who underwent central lymphatic imaging. MATERIALS AND METHODS: We conducted a single-center retrospective review of all children with a confirmed history of Noonan syndrome who presented for lymphatic imaging over a 5-year period. Imaging evaluation was performed on unenhanced T2-weighted (T2-W) imaging, dynamic-contrast MR lymphangiography or conventional lymphangiography. Two readers evaluated the imaging in consensus for the distribution of fluid on T2-W imaging and for lymphatic flow of intranodal contrast agent and thoracic duct abnormalities on dynamic-contrast MR lymphangiography and conventional lymphangiography. We performed a chart review for clinical history and outcomes. RESULTS: We identified a total of 10 children, all but one of whom had congenital heart disease. Presenting symptoms included chylothorax (n=9) and ascites (n=1). Nine had T2-W imaging, seven had dynamic-contrast MR lymphangiography, and seven had conventional lymphangiography. All with T2-W imaging had pleural effusions. On both dynamic-contrast MR lymphangiography and conventional lymphangiography, perfusion to the lung was seen (n=6), with intercostal flow also seen on dynamic-contrast MR lymphangiography (n=6). The thoracic duct was not present in three children and the central thoracic duct was not present in three. A double thoracic duct was seen in two children. CONCLUSION: Children with Noonan syndrome and clinical evidence of lymphatic dysfunction have central lymphatic abnormalities characterized by retrograde intercostal flow, pulmonary lymphatic perfusion, and thoracic duct abnormalities.

DRESS syndrome with thrombotic microangiopathy revealing a Noonan syndrome: Case report.

RATIONALE: The life-threatening drug rash with eosinophilia and systemic symptoms (DRESS) syndrome occurs most commonly after exposure to drugs, clinical features mimic those found with other serious systemic disorders. It is rarely associated with thrombotic microangiopathy. PATIENT CONCERNS: We describe the unique case of a 44-year-old man who simultaneously experienced DRESS syndrome with thrombotic microangiopathy (TMA) after a 5 days treatment with fluindione. DIAGNOSES: Clinical evaluation leads to the discovery of an underlying lymphangiomatosis, due to a Noonan syndrome. INTERVETIONS: The anticoagulant was withdrawn, and corticosteroids (1 mg/kg/day) and acenocoumarol were started. OUTCOMES: Clinical improvement ensued. At follow-up the patient is well. LESSONS: The association of DRESS with TMA is a rare condition; we believe that the presence of the underlying Noonan syndrome could have been the trigger. Moreover, we speculate about the potential interrelations between these entities.

Lymphatic malformations.

PURPOSE OF REVIEW: To update current knowledge of basic science and clinical care of lymphatic malformations. RECENT FINDINGS: Advances in gene sequencing methods have allowed further elucidation of the genetic pathways involved in vascular development. New cell culture techniques are promising the development of practical models to test novel therapeutic interventions. Clinical treatment trends are continuing to shift more away from early surgery and toward sclerotherapy in appropriate cases. New emphasis has been placed upon quality of life analysis of treatment outcomes. SUMMARY: Basic science is increasing the understanding of vascular anomalies in general and may lead us soon toward more effective nonsurgical therapies. Focus on quality of life measures will help to elucidate the most effective therapeutic interventions.

Gorham's disease: an autopsy report.

We present the case report of a 35-year-old man with Gorham's disease (disappearing bone disease, massive osteolysis) with initial clinical findings of small bowel lymphangiomatosis and multicentric osteolysis. The patient, who otherwise was healthy, had a chylothorax develop and he died 9 months later of thoracic and pulmonary complications. An autopsy revealed absence of the proximal thoracic duct and significant lymphangiectatic abnormalities of the pleural, peritoneal, diaphragmatic, splenic, and small bowel tissue with lymphangiomatous masses in the thoracic and mediastinal regions. The findings suggest a subtype of Gorham's disease characterized by a dysplastic lymphatic system. Osteolysis was correlated anatomically with lymphangiectatic tissue, suggesting mediation of osteoclastic resorption via local lymphatic tissue factors.