Pulmonary lymphangiectasia revisited

Paediatric acute respiratory distress syndrome: consider the role of lymphatics

We present a case of a 7-day-old male infant with severe respiratory disease requiring venoarterial extracorporeal membrane oxygenation therapy with evidence of lymphangiectasia on lung biopsy. Differentiating primary versus secondary lymphangiectasis in this patient remains a riddle despite extensive investigations including an infective screen, lung biopsy and whole-genome sequencing. In addition to the standard therapies used in paediatric acute respiratory distress syndrome, such as lung-protective ventilation, permissive hypoxaemia and hypercarbia, nursing in the prone position, early use of muscle relaxants, rescue intravenous corticosteroids and broad-spectrum antibiotics, the patient was also given octreotide despite the absence of a chylothorax based on the theoretical benefit of altering the lymphatic flow. His case raises an interesting discussion around the role of lymphatics in the pathophysiology of paediatric and adult respiratory distress syndrome and prompts the exploration of novel agents which may affect lymphatic vessels used as an adjunctive therapy.

Non-immune hydrops fetalis secondary to congenital chylothorax with diffuse interstitial lung disease: a diagnostic conundrum

A Chinese male infant was born at 35 weeks weighing 2935 g to a mother with polyhydramnios and prenatal hydrops fetalis. He developed marked respiratory distress secondary to bilateral congenital chylothorax and required pleural drainage, high frequency oscillation and inhaled nitric oxide therapy. He was extubated to non-invasive ventilation by day 14. There was no bacterial or intrauterine infection, haematologic, chromosomal or cardiac disorder. He was exclusively fed medium-chain triglyceride formula. High-resolution CT showed diffuse interstitial lung disease. He received a dexamethasone course for chronic lung disease to facilitate supplemental oxygen weaning. A multidisciplinary team comprising neonatology, pulmonology, haematology, interventional radiology and thoracic surgery considered congenital pulmonary lymphangiectasia as the most likely diagnosis and advised open lung biopsy, lymphangiography or scintigraphy for diagnostic confirmation should symptoms of chylothorax recur. Fortunately, he was weaned off oxygen at 5 months of life, and tolerated human milk challenge at 6 months of life and grew well.

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.

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.

Congenital pulmonary lymphangiectasia

Congenital pulmonary lymphangiectasia (CPL) is a rare but fatal disease, usually having an onset from the first few hours to days after birth. Inconsistent nomenclatures were used for CPL in the past decades. Patients often present with intractable respiratory failure, hydrops fetalis and even sudden death. The etiologies of CPL remain unclear. Previous hypotheses suggested that CPL might be caused by conditions preventing normal regression of the lymphatics after the 18th-20th week of gestation. Up-to-date biological studies on lymphatic development, lymphatic valve formation and occurrence of hydrops fetalis revealed possible causative relations with mutations of genes of the vascular endothelial growth factor receptor (VEGFR), RAS/MAPK, PI3K/AKT and NF-κB signaling pathways. Lung biopsy with subsequent histological and immunohistochemical studies is a gold standard of CPL diagnosis. Apart from symptomatic and supportive treatments, novel regimens including sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, one of the inhibitors of the pertinent signaling pathways and ethiodized oil lymphatic embolization under ultrasound-guided intranodal lymphangiography have shown encouraging short-term therapeutic effects for lymphatic anomalies. Surgical operations (lobectomy or pneumonectomy) can be the treatment of choice for patients with CPL confined to one lobe or one lung. Patients with CPL usually have a poor prognosis and often die during the neonatal period. Their prognoses are expected to improve with the development of modern therapeutic agents.

Treatment of congenital pulmonary lymphangiectasia using ethiodized oil lymphangiography

Historically, congenital pulmonary lymphangiectasia (CPL) has had poor treatment outcomes despite aggressive therapy. There are recent reports of ethiodized oil (Lipiodol) lymphangiography successfully treating lymphatic leakage in adults. In this report, we describe two infants with CPL complicated by chylothoraces successfully treated by instillation of ethiodized oil into the lymphatic system. Congenital atresia of the thoracic duct was demonstrated on the lymphangiogram in both patients before treatment. Both patients have shown good short-term outcomes without supplemental oxygen or fat restricted diets at 9 months of age. Ethiodized oil lymphangiography represents a new treatment modality for some patients with CPL.

Congenital pulmonary lymphangiectasis

Congenital pulmonary lymphangiectasis (CPL) is a rare vascular malformation causing dilated lymph vessels and disturbed drainage of lymph fluid. Based on the pathogenesis and clinical phenotype it can be classified as primary or secondary CPL. Associated genetic syndromes with or without lymphedema, familial occurrence and gene mutations have been described. In utero, it may present as non-immune hydrops with pleural effusions. At birth neonates may have respiratory failure due to chylothorax and pulmonary hypoplasia, causing very high short term mortality rates. Other cases may become symptomatic any time later in childhood or even during adult life. CPL is usually diagnosed based on the combination of clinical signs, imaging and histological findings. Open-lung biopsy is considered the gold standard for the diagnosis of CPL. Treatment is primarily supportive featuring aggressive mechanical ventilation and the management of problems associated with congenital chylothorax including chest-drainage, medium-chain triglycerides (MCT) diet, and octreotide.

Management of visceral vascular anomalies

Vascular malformations affect the viscera less commonly than the head and neck, extremities, and extra-cavitary soft tissues. They present with a wide spectrum of symptoms and findings including pain, respiratory compromise, hemoptysis, chylothorax, ascites, gastrointestinal bleeding, and obstruction. Management options depend upon the subtype of malformation and anatomic extent and may include sclerotherapy, embolization, surgical extirpation, coloanal pull-through, and occasionally more innovative individualized surgical approaches.

Pneumonectomy case in a newborn with congenital pulmonary lymphangiectasia

Congenital pulmonary lymphangiectasia (CPL) is a rare lymphatic pulmonary abnormality. CPL with respiratory distress has a poor prognosis, and is frequently fatal in neonates. We report a case of pneumonectomy for CPL in a newborn. An infant girl, born at 39 weeks' after an uncomplicated pregnancy, exhibited respiratory distress 1 hr after birth, which necessitated intubation and aggressive ventilator care. Right pneumonectomy was performed after her symptoms worsened. Histologic examination indicated CPL. She is currently 12 months old and developing normally. Pneumonectomy can be considered for treating respiratory symptoms for improving chances of survival in cases with unilateral CPL.

Pulmonary lymphangiectasia resulting from vascular endothelial growth factor-C overexpression during a critical period

RATIONALE

Lymphatic vessels in the respiratory tract normally mature into a functional network during the neonatal period, but under some pathological conditions they can grow as enlarged, dilated sacs that result in the potentially lethal condition of pulmonary lymphangiectasia.

OBJECTIVE

We sought to determine whether overexpression of the lymphangiogenic growth factor (vascular endothelial growth factor-C [VEGF-C]) can promote lymphatic growth and maturation in the respiratory tract. Unexpectedly, perinatal overexpression of VEGF-C in the respiratory epithelium led to a condition resembling human pulmonary lymphangiectasia, a life-threatening disorder of the newborn characterized by respiratory distress and the presence of widely dilated lymphatics.

METHODS AND RESULTS

Administration of doxycycline to Clara cell secretory protein-reverse tetracycline-controlled transactivator/tetracycline operator-VEGF-C double-transgenic mice during a critical period from embryonic day 15.5 to postnatal day 14 was accompanied by respiratory distress, chylothorax, pulmonary lymphangiectasia, and high mortality. Enlarged sac-like lymphatics were abundant near major airways, pulmonary vessels, and visceral pleura. Side-by-side comparison revealed morphological features similar to pulmonary lymphangiectasia in humans. The condition was milder in mice given doxycycline after age postnatal day 14 and did not develop after postnatal day 35. Mechanistic studies revealed that VEGF recptor (VEGFR)-3 alone drove lymphatic growth in adult mice, but both VEGFR-2 and VEGFR-3 were required for the development of lymphangiectasia in neonates. VEGFR-2/VEGFR-3 heterodimers were more abundant in the dilated lymphatics, consistent with the involvement of both receptors. Despite the dependence of lymphangiectasia on VEGFR-2 and VEGFR-3, the condition was not reversed by blocking both receptors together or by withdrawing VEGF-C.

CONCLUSIONS

The findings indicate that VEGF-C overexpression can induce pulmonary lymphangiectasia during a critical period in perinatal development.

[Congenital pulmonary lymphangiectasis: an unusual cause of respiratory distress in neonates]

Congenital pulmonary lymphangiectasis (CPL) is a rare condition in neonates characterized by abnormal dilatation of the lymphatics draining the interstitial and subpleural spaces of the lungs. Diagnosis is difficult in the neonatal period because respiratory features and radiological findings are not specific of the disease. Definitive diagnosis of CPL can be made only by pathologic examinations. We report a case of a male near-term neonate presenting with severe respiratory distress at birth. The initial chest X-ray showed frosted glass-like infiltrates with air bronchogram suggesting a maternofetal infection or respiratory distress syndrome. The infant required mechanical ventilation and chest tube insertion for right then bilateral pneumothorax. The child died 15 days later in spite of optimal high-frequency ventilation, bilateral pneumothorax drainage, and hemodynamic support. Autopsy revealed features consistent with the diagnosis of CPL. Although CPL is very rare, we should be aware that it is a possible cause of severe unexplained respiratory distress in neonates.

Outcome of children with pulmonary lymphangiectasis

Pulmonary lymphangiectasis (PL) is a very rare developmental defect of the lungs, which has previously been reported to have a very poor prognosis. However, recent reports have suggested improved outcomes, possibly as a result of advances in neonatal and pediatric intensive care medicine. We performed a retrospective study on the outcome of children with PL between 1990 and 2008 referred to our tertiary center. Seven patients with histologically proven PL were identified over the 18-year period. Six patients presented in the neonatal period and one patient at 7 months of age, all of them requiring intensive care treatment. Three neonatal patients required extracorporeal membrane oxygenation (ECMO). Six of the seven patients did not survive including all those who received ECMO. Two of the six non-survivors died of other causes than their underlying disease. The only survivor had an antenatal diagnosis of hydrops and required in utero chest drain insertion. Postnatally he was managed with maximal medical treatment for bilateral pleural effusions and persistent pulmonary hypertension. A 7-month follow-up showed this infant to be doing well. In conclusion overall the prognosis of congenital PL remains poor. The one survivor demonstrates that this condition is survivable with aggressive intervention and as current evidence suggests gradual improvement of symptoms may occur over time, and that maximal medical treatment remains warranted.

Clinico-pathological characteristics of congenital pulmonary lymphangiectasis: report of two cases

Congenital pulmonary lymphangiectasis (CPL) is a rare, poorly documented disease, characterized by abnormal dilatation of pulmonary lymphatics without lymphatic proliferation. This disease is seen almost exclusively in infancy and early childhood. It can usually be divided into primary (congenital) and secondary forms. The primary form presents in neonates, and the patients mostly die due to the respiratory distress, shortly after birth. The authors experienced two cases of primary CPL in a 13-day-old male neonate and a one-day-old male neonate, showing prominent lymphatic dilatation in the septal, subpleural, and peri-bronchial tissue throughout both lungs. The latter case was associated with congenital cardiac anomaly including single ventricle. These are unique cases of CPL in Korea of which the diagnosis was established through post-mortem examination. Therefore, the authors report these two cases with primary CPL with a review of the literature.

Congenital pulmonary lymphangiectasia

Congenital pulmonary lymphangiectasia (PL) is a rare developmental disorder involving the lung, and characterized by pulmonary subpleural, interlobar, perivascular and peribronchial lymphatic dilatation. The prevalence is unknown. PL presents at birth with severe respiratory distress, tachypnea and cyanosis, with a very high mortality rate at or within a few hours of birth. Most reported cases are sporadic and the etiology is not completely understood. It has been suggested that PL lymphatic channels of the fetal lung do not undergo the normal regression process at 20 weeks of gestation. Secondary PL may be caused by a cardiac lesion. The diagnostic approach includes complete family and obstetric history, conventional radiologic studies, ultrasound and magnetic resonance studies, lymphoscintigraphy, lung functionality tests, lung biopsy, bronchoscopy, and pleural effusion examination. During the prenatal period, all causes leading to hydrops fetalis should be considered in the diagnosis of PL. Fetal ultrasound evaluation plays a key role in the antenatal diagnosis of PL. At birth, mechanical ventilation and pleural drainage are nearly always necessary to obtain a favorable outcome of respiratory distress. Home supplemental oxygen therapy and symptomatic treatment of recurrent cough and wheeze are often necessary during childhood, sometimes associated with prolonged pleural drainage. Recent advances in intensive neonatal care have changed the previously nearly fatal outcome of PL at birth. Patients affected by PL who survive infancy, present medical problems which are characteristic of chronic lung disease.

Pulmonary Lymphangiectasis in an Asymptomatic Adult

Pulmonary lymphangiectasis is a rare anomaly in infancy that is characterized by dilatation of pulmonary lymphatic vessels resulting in fetal respiratory distress. Pulmonary lymphangiectasis is considered to occur exclusively in young children and neonates, and very few survive beyond an early age. We herein present an asymptomatic adult case of localized pulmonary lymphangiectasis with multiple nodules. A 27-year-old asymptomatic female presented with multiple nodules on chest computed tomogram images. An exploratory video-assisted thoracoscopy revealed multiple yellowish cysts on the visceral pleura, which were histologically diagnosed as lymphangiectasis. In the present study, the pathogenesis and clinical characteristics are discussed.

Congenital pulmonary lymphangiectasia presenting as nonimmune fetal hydrops and severe respiratory distress at birth: not uniformly fatal

Pulmonary lymphangiectasia is a rare cause of respiratory distress in the newborn associated with a very poor outcome. We describe three premature newborns presenting at birth with nonimmune hydrops, bilateral chylothorax, and severe respiratory distress in the immediate newborn period secondary to pulmonary lymphangiectasia. We review the similarities of these cases and discuss their antenatal and neonatal course. One patient survived and is thriving at 9 months of age. With continuing advances in antenatal and neonatal care, an improved outcome may be possible in what was previously described as a uniformly fatal condition.

Hidden pathologies associated with (and concealed by) early gestational isolated fetal hydrothorax

Isolated fetal hydrothorax is an uncommon finding on routine prenatal ultrasound and is associated with a variable prognosis. We believe this is the first report of a patient whose antenatal hydrothorax was associated with both congenital diaphragmatic hernia and congenital pulmonary lymphangiectasia. This rare combination caused significant problems in diagnosis and subsequent treatment.

Pulmonary lymphangiectasia: diagnosis and clinical course

Pulmonary lymphangiectasia (PL) is a rare disease characterized by dilation of the normal lung lymphatics. The disease was previously associated with a poor prognosis. However, several recent case reports and case studies indicate that survival is possible in the severe neonatal form of PL, and the prognosis is good for infants who present after the neonatal period. In this report, we describe the etiology, clinical presentation, diagnosis, management, and outcome of PL. A revised classification of PL is proposed, based on the current state of knowledge of its etiology and presentation.

Unilobar congenital pulmonary lymphangiectasis mimicking congenital lobar emphysema: an underestimated presentation?

BACKGROUND

Congenital lobar emphysema (CLE) is characterized by unilobar alveolar distension secondary to bronchomalacia or absent cartilage. In contrast, congenital pulmonary lymphangiectasis (CPL) is defined as distended lymphatics in the bronchovascular bundle, in the interlobular septa, and in the subpleural space. Little information is available regarding the radiologic presentation of CLE as it correlates with histological diagnosis.

METHODS

In a retrospective chart review from 1995 to 2002, 8 patients (5 boys and 3 girls) with clinical and radiologic diagnosis of CLE were reviewed.

RESULTS

The mean age at diagnosis was 26 months (range, 11 days to 10 years). All but one had classic respiratory symptoms of CLE. Six of 7 chest computed tomography (CT), scans were suggestive of CLE. Of 8 patients, 3 were treated without pulmonary resection with resolution of symptoms. Five patients underwent lobectomies, and histology results showed CPL in 3. CT failed to identify CPL in all cases.

CONCLUSIONS

Diagnosis of CLE is not as straightforward as the literature suggests. Even retrospectively, radiologic distinction between CLE and CPL could not be achieved by an experienced pediatric radiologist. CPL, thus, mimics CLE clinically and radiologically and, therefore, should be considered in the differential radiologic diagnosis of CLE.