Pediatric lymphangiectasia: an imaging spectrum

Clinical approach for pulmonary lymphatic disorders

In this editorial, we discuss the clinical implications of the article "Lymphatic plastic bronchitis and primary chylothorax: A study based on computed tomography lymphangiography" published by Li et al. Pulmonary lymphatic disorders involve abnormalities in the lymphatic tissues within the thoracic cavity. Specifically, pulmonary lymphatic perfusion syndrome describes a condition where the flow of lymphatic fluid in the lungs is redirected towards abnormally widened lymphatic vessels. Clinically, individuals with this syndrome may experience symptoms such as chyloptysis, plastic bronchitis (PB), chylothorax, chylopericardium, and interstitial lung disease. These disorders can be caused by various factors, including PB, chylothorax, and complex lymphatic malformations. Advancements in lymphatic imaging techniques, such as intranodal lymphangiography, computed tomography lymphangiography, and dynamic contrast-enhanced magnetic resonance lymphangiography, have enabled the detection of abnormal lymphatic flow. This has enhanced our understanding of the pathophysiology of these conditions. Additionally, innovative minimally invasive treatments, such as thoracic duct embolization, selective embolization of lymphatic channels, and surgical procedures aim to improve clinical condition of patients and address their dietary needs.

Computed tomography of the airways and lungs in congenital heart disease

The presence of airway and lung disease in children with congenital heart disease is commonly observed with both cardiac CT angiography and routine chest CT. In this review we discuss abnormalities encountered on CT imaging of the chest beyond the heart and central vasculature, focusing on the airways, lung parenchyma and peripheral vasculature. Preoperative and postoperative findings are reviewed as well.

State-of-the-art imaging for lymphatic evaluation in children

The lymphatic system has been poorly understood and its importance neglected for decades. Growing understanding of lymphatic flow pathophysiology through peripheral and central lymphatic flow imaging has improved diagnosis and treatment options in children with lymphatic diseases. Flow dynamics can now be visualized by different means including dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), the current standard technique to depict central lymphatics. Novel imaging modalities including intranodal, intrahepatic and intramesenteric DCMRL are quickly evolving and have shown important advances in the understanding and guidance of interventional procedures in children with intestinal lymphatic leaks. Lymphatic imaging is gaining importance in the radiologic and clinical fields and new techniques are emerging to overcome its limitations.

Imaging Findings of Thoracic Lymphatic Abnormalities

The lymphatic system plays an important role in balancing fluid compartments in the body. It is disrupted by various disease processes in the thorax, including injury to the thoracic lymphatic duct after surgery, as well as malignancy and heart failure. Because of the small size of lymphatic vessels, imaging of the lymphatics is relatively difficult, and effective imaging methods are still being optimized and developed. The standard of reference for lymphatic imaging has been conventional lymphangiography for several decades. Other modalities such as CT, noncontrast or contrast-enhanced MRI, and lymphoscintigraphy can also demonstrate lymphatic abnormalities and help in treatment planning. Imaging findings associated with lymphatic abnormalities can be seen in the pulmonary parenchyma, pleural space, and mediastinum. In the pulmonary parenchyma, common findings include interlobular septal thickening as well as reversal of lymphatic flow with intravasation of contrast material into pulmonary lymphatics. In the pleural space, findings include chylous pleural effusion and occasionally nonchylous pleural effusion. In the mediastinum, thoracic duct leak, plexiform thoracic duct, lymphatic malformations, and lymphangiectasis may occur. Management of chylothorax includes conservative or medical treatment, surgery, and interventional radiology procedures. The authors discuss thoracic lymphatic anatomy, imaging manifestations of lymphatic abnormalities in the various anatomic compartments, and interventional radiology treatment of chylothorax. Radiologists should be familiar with these imaging findings for diagnosis and to help guide appropriate management. ^©RSNA, 2022.

Spectrum of bowel wall thickening on ultrasound with pathological correlation in children

Applications for bowel US in children have been well described; however, less focus has been placed on patterns of bowel wall architectural change in specific disease states. This pictorial essay reviews normal bowel wall architecture and covers a variety of inflammatory, infectious, vascular and neoplastic disorders outside the neonatal period as seen on US, with illustrative pathological correlation. A thorough understanding of normal and abnormal bowel wall architecture can enrich sonographic interpretation and provide a valuable adjunct to appropriate clinical investigation.

Case Report: A Relatively Mild Presentation of Unilateral Congenital Pulmonary Lymphangiectasia

Pulmonary lymphangiectasia (PL) is a rare congenital disorder of pulmonary lymphatic development. Although it was traditionally a fatal disorder of infancy, some cases in later childhood have been reported, suggesting a spectrum of severity. We present an unusual case of unilateral, congenital pulmonary lymphangiectasia. Our patient presented with neonatal respiratory distress, a chronic wet cough and recurrent episodes of bronchitis. Chest CT revealed thickening of the interlobular septae of the right lung. A lung biopsy confirmed the diagnosis of lymphangiectasia. His clinical course is characterized by chronic coughing and recurrent bronchitis but normal growth and development. This case illustrates a relatively mild presentation of unilateral PL, which, along with other reports, suggests variability in the presentation and severity of this disorder. In the absence of imaging and histological examination, mild presentations may go undiagnosed.

Imaging of fetal lymphangiectasias: prenatal and postnatal imaging findings

Lymphangiectasias are lymphatic malformations characterized by the abnormal dilation and morphology of the lymphatic channels. The classification and treatment of these disorders can be challenging given the limited amount of literature available in children. Various imaging modalities are used to confirm suspected diagnosis, plan the most appropriate treatment, and estimate a prognosis. Prenatal evaluation is performed using both prenatal US imaging and fetal MRI. These modalities are paramount for appropriate parental counseling and planning of perinatal care. During the neonatal period, chest US imaging is a useful modality to evaluate pulmonary lymphangiectasia because other modalities such as conventional radiography and CT display nonspecific findings. Finally, the recent breakthroughs in lymphatic imaging with MRI have allowed us to better classify lymphatic disorders. Dynamic contrast-enhanced lymphangiography, conventional lymphangiography and percutaneous lymphatic procedures offer static and dynamic evaluation of the central conducting lymphatics in children, with excellent spatial resolution and the possibility to provide treatment. The purpose of this review is to discuss the normal and abnormal development of the fetal lymphatic system and how to best depict it by imaging during the prenatal and postnatal life.

Abnormal pulmonary lymphatic flow in patients with paediatric pulmonary lymphatic disorders: Diagnosis and treatment

Pulmonary lymphatic disorders are characterized by the presence of the abnormal lymphatic tissues in the thoracic cavity, presenting clinically as chylothorax, chylopericardium, chyloptysis, interstitial lung disease and plastic bronchitis. These conditions include: neonatal chylothorax, cardiac and non-cardiac plastic bronchitis, non-traumatic chylothorax, post congenital cardiac surgery chylothorax and complex lymphatic malformations. Recently developed lymphatic imaging techniques, such as intranodal lymphangiography and dynamic contrast enhanced magnetic resonance lymphangiography demonstrated abnormal pulmonary lymphatic flow from thoracic duct into pulmonary parenchyma as a pathophysiological mechanism of these diseases. Novel minimally invasive lymphatic interventions, such as thoracic duct embolization, interstitial lymphatic embolization and surgical lympho-venous anastomosis, provide an effective treatment of these conditions.

Nodal and Pedal MR Lymphangiography of the Central Lymphatic System: Techniques and Applications

Novel lymphatic imaging and interventional techniques are increasingly used in the diagnostic workup and treatment of pathologies of the central lymphatic system and have opened a new field of interventional radiology. The mainstay of lymphatic imaging today is magnetic resonance lymphangiography (MRL). It provides information on the anatomy of the central lymphatic system, lymphatic flow, as well as lymphatic pathologies and therefore is a valuable tool for treatment planning. There are two techniques to perform contrast-enhanced MRL: nodal dynamic contrast-enhanced MRL (nodal DCE-MRL) and interstitial transpedal MRL (tMRL). Nodal DCE-MRL yields superior information on lymphatic flow dynamics and is therefore best suited for suspected lymphatic flow pathologies and lymphatic malformations. tMRL is a technically simpler alternative for central lymphatic visualization without the need for sonographically guided lymph node cannulation. This review article describes current MRL techniques with a focus on contrast-enhanced MRL, their specific advantages, and possible clinical applications in patients suffering from pathologies of the central lymphatic system.

Abnormal Pulmonary Lymphatic Flow in Patients With Lymphatic Anomalies and Respiratory Compromise

BACKGROUND

Pulmonary involvement in lymphatic anomalies (LA) is associated with significant morbidity and mortality. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) is capable of imaging the lymphatic system in a variety of pulmonary lymphatic disorders.

RESEARCH QUESTION

The objective of this study is to describe the central lymphatic anatomy in patients with LA and pulmonary involvement on DCMRL.

STUDY DESIGN AND METHODS

This prospective observational study enrolled 16 patients with LA (mean age, 17 years; range, 6-63 years; ratio of female to male patients, 9:7) with pulmonary involvement. All patients underwent DCMRL. The lymphatic system was assessed for the presence of mediastinal masses, interstitial lung disease, size and tortuosity of the thoracic duct (TD), and presence of abnormal pulmonary lymphatic flow.

RESULTS

T2-weighted imaging showed the following: mediastinal soft tissue masses in 10 patients, diffuse pulmonary interstitial thickening in 13 patients, and bone involvement in 15 patients. DCMRL revealed abnormal pulmonary lymphatic flow in 14 of 16 patients. Abnormal pulmonary lymphatic flow originated from the TD in three of 14 patients, the retroperitoneum in six of 14 patients, and both the TD and retroperitoneum in four of 14 patients. In nine of 16 patients, the TD was dilated and tortuous. In two patients the TD was not identified, and in five patients it was normal.

INTERPRETATION

Abnormal pulmonary lymphatic flow/perfusion from the TD or retroperitoneum into the lung parenchyma occurred in the majority of patients in this study. These findings can explain the interstitial lung disease and chylothorax resulting in deterioration of respiratory function in these patients. Future studies will determine whether mechanical cessation of this abnormal flow can improve pulmonary function and prolong survival in patients with LA.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov; No.: NCT02744027; URL: www.clinicaltrials.gov.

Pediatric localized intestinal lymphangiectasia treated with resection

Introduction

Primary intestinal lymphangiectasia (PIL) is a very rare disorder usually diagnosed before the third year of life or later in adulthood, presenting with pitting edema, hypoproteinemia and low immunoglobulin levels. The location and the extent of the affected bowel greatly influence the clinical manifestation. The localized or segmental form of PIL is extremely rare with only five pediatric cases reported worldwide.

Case presentation

A 10 year-old Caucasian boy presented with 3 months history of recurrent abdominal pain and a 1 month history of diarrhea. An ultrasound scan was performed on two separate occasions 10 days apart, revealing a growing cystic mass on the right side of the abdomen, in front of the psoas muscle. Subsequently an MRI scan confirmed that the mass originated from the mesenteries and infiltrates a short segment of the small bowel. Surgical resection of the affected segment was performed. Histopathological examination of the removed segment of ileum was consistent with intestinal lymphangiectasia. We could not identify any associated genetic syndromes or any other conditions that could have caused secondary intestinal lymphangiectasia. The patient’s recovery from surgery was uneventful and no recurrence was observed in the following 4 years.

Conclusion

Despite being a benign condition, mortality of PIL can be as high as 13% due to the difficulties associated with the management of the disease. PIL should be considered as a rare but potential cause for an abdominal mass, even in the older child, when cystic mesenterial involvement might be seen on ultrasound or MRI. In selected cases of PIL affecting only a short segment of the bowel or following unsuccessful conservative treatment, surgical resection of the affected bowel segment can be curative.

Neonatal Lung Disorders: Pattern Recognition Approach to Diagnosis

OBJECTIVE

Lung disease is a common indication for neonates to require medical attention, and neonatal chest radiographs are among the most common studies interpreted by pediatric radiologists. Radiographic features of many neonatal lung disorders overlap, and it may be difficult to differentiate among conditions.

CONCLUSION

This review presents an up-to-date practical approach to the radiologic diagnosis of neonatal lung disorders, with a focus on pattern recognition and consideration of clinical history, patient age, and symptoms.

Diagnosis of secondary pulmonary lymphangiectasia in congenital heart disease: a novel role for chest ultrasound and prognostic implications

BACKGROUND

Secondary pulmonary lymphangiectasia is a complication of congenital heart disease that results from chronic pulmonary venous obstruction.

OBJECTIVES

We aimed to evaluate the performance of chest ultrasound (US) in diagnosing secondary pulmonary lymphangiectasia and to review the clinical course of children with secondary pulmonary lymphangiectasia.

MATERIALS AND METHODS

Chest US was performed on 26 children with hypoplastic left heart syndrome, total anomalous pulmonary venous connection or cor triatriatum in a prospective observational study. Thirteen children had pulmonary venous obstruction (62% male; median age: 17 days old, range: 1-430 days old) and 13 children did not have obstruction (62% male; median age: 72 days old, range: 4-333 days old). US features of secondary pulmonary lymphangiectasia were documented and diagnostic performance was determined. Clinical course of patients with secondary pulmonary lymphangiectasia was reviewed.

RESULTS

Eleven of 13 (84.6%) patients in the obstructed group had a clinical and/or biopsy diagnosis of secondary pulmonary lymphangiectasia. Statistically significant chest US criteria for diagnosis were presence of irregular lung surface (likelihood ratio [LR] 6.8, 95% confidence interval [CI] 1.9-25.1), subpleural cystic appearing structures (LR 3.6, 95% CI 1.2-10.7), and combination of subpleural cystic appearing structures and surface irregularity together (LR 10.9, 95% CI 1.6-75.0). Seven of 11 (63.6%) patients with secondary pulmonary lymphangiectasia died during follow-up, the majority due to cardiopulmonary failure or complications.

CONCLUSION

Chest US is an accurate and reproducible bedside method for diagnosing secondary pulmonary lymphangiectasia in patients with pulmonary venous obstruction. These patients may have worse prognoses.

Magnetic Resonance Lymphangiography and Lymphatic Embolization in the Treatment of Pulmonary Complication of Lymphatic Malformation

Lymphatic malformations (LMs; especially those involving the central conducting lymphatic channels) are characterized by dysplastic and incompetent lymphatic channels in multiple tissues and organs. The major cause of mortality and morbidity in patients with thoracic LM is deterioration of pulmonary function due to chronic chylous effusions and progressive interstitial lung disease. The etiology of these pulmonary processes is unknown, although lymphatic involvement is certain. Understanding of the changes in the lymphatic anatomy in patients with LM has been hindered by difficulty of imaging of the lymphatic system. Recently developed dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) allows dynamic MR imaging of the lymphatic system by injecting gadolinium contrast agent in the groin lymph nodes. Using this technique, pathological lymphatic flow from the central lymphatic system and/or retroperitoneal and mediastinal masses into lung parenchyma ("pulmonary lymphatic perfusion syndrome") has been demonstrated in patients with LM. This abnormal lymphatic perfusion overflows pulmonary parenchyma and results in deterioration of pulmonary function due to interstitial process and/or compression effect of chylous effusions. Percutaneous thoracic duct embolization or lymphatic interstitial embolization of the lymphatic masses results in cessation of the pulmonary lymphatic overflow and significant improvement in pulmonary symptoms in these patients.

Everolimus for Primary Intestinal Lymphangiectasia With Protein-Losing Enteropathy

Primary intestinal lymphangiectasia (PIL), also known as Waldmann's disease, is an exudative enteropathy resulting from morphologic abnormalities in the intestinal lymphatics. In this article, we describe a 12-year-old boy with PIL that led to protein-losing enteropathy characterized by diarrhea, hypoalbuminemia associated with edema (serum albumin level: 1.0 g/dL), and hypogammaglobulinemia (serum IgG level: 144 mg/dL). Severe hypoalbuminemia, electrolyte abnormalities, and tetany persisted despite a low-fat diet and propranolol. Everolimus (1.6 mg/m(2)/day) was added to his treatment as an antiangiogenic agent. With everolimus treatment, the patient's diarrhea resolved and replacement therapy for hypoproteinemia was less frequent. Hematologic and scintigraphy findings also improved (serum albumin level: 2.5 g/dL). There were no adverse reactions during the 12-month follow-up. To the best of our knowledge, this is the first report of everolimus use in a patient with PIL.