Clinical Features and Prognosis of Generalized Lymphatic Anomaly, Kaposiform Lymphangiomatosis, and Gorham-Stout Disease

A case report of Gorham-Stout disease diagnosed during the course of recurrent meningitis and cholesteatoma

Background

Gorham-Stout disease is a rare bone disorder. Here, we present a case of Gorham-Stout disease diagnosed during follow-up of a patient with cholesteatoma; the disease affected the temporal bone and other sites of the skull. To the best of our knowledge, this is the first report of Gorham-Stout disease diagnosed with recurrent cerebrospinal leakage after surgery to treat cholesteatoma.

Case presentation

A 25-year-old male patient re-presented to our department for the first time in 7 years with otorrhea in the right ear and recurrent meningitis. The patient had a history of multiple surgeries for cholesteatoma and suffered from recurrent cerebrospinal fluid leakage, which initially was thought to be caused by recurrence of cholesteatoma. Therefore, skull base reconstruction was planned. However, the underlying cause was identified eventually as defects in the temporal bone caused by massive osteolysis due to Gorham-Stout disease. Skull base reconstruction was abandoned because the osteolysis was considered to be progressive. Conservative treatment with infectious control was implemented as an alternative.

Conclusion

This case describes unusual temporal bone osteolysis after cholesteatoma surgery and the importance of considering the possibility of multiple concurrent diseases in such individuals. The distinguishing features of this case are the fact that the temporal bone had disappeared, and deconstruction was complicated by infection and inflammation caused by cholesteatoma, surgical invasion, and Gorham-Stout disease. Appropriate diagnosis saved the patient from ineffective multiple surgeries for cerebrospinal fluid leakage or cholesteatoma, and improved his quality of life.

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.

Thoracic duct-to-vein anastomosis for the management of thoracic duct outflow obstruction in newborns and infants: a CASE series

BACKGROUND

Thoracic duct (TD) outflow obstruction causes high morbidity and mortality in newborns. It can be congenital/idiopathic or acquired (secondary to central venous thrombosis or injury during cardiothoracic surgery). Re-routing the TD to the venous system by microsurgical techniques to restore lymphatic flow is a potential surgical solution. We present a series of newborns and infants who underwent thoracic duct-to-vein anastomosis (TDVA) to restore TD outflow.

MATERIALS AND METHODS

A retrospective review of all TDVA September 2015-March 2019 was performed. All patients underwent extensive pre-operative imaging evaluation by dynamic MRI and fluoroscopic lymphangiography. The TDVAs were done under high-power microscopy.

RESULTS

Eight patients underwent TDVA. Age at surgery was 1 to 9 months. Four patients had a history of cardiac surgery (one with complete thrombosis of the central venous system), one patient had a history of ECMO and thrombosis of the SVC, and three patients had a history of fetal hydrothorax and non-immune hydrops. Six patients had a successful TDVA with restoration of the lymphatic flow through the TD and clinical improvement. Two patients had a technically adequate TDVA but without improvement of the flow due to persistently high central venous pressure. Five patients remain alive, two patients died from complications of the lymphatic disorder, and one patient died from an unrelated cause.

CONCLUSIONS

Patients with congenital or acquired TD outlet obstruction for whom no improvement is achieved by non-surgical interventions may benefit from TDVA. A thorough understanding of the anatomy and physiology of each patient is critical for the success of the operation.

LEVEL OF EVIDENCE

Level IV.

Multidisciplinary guidelines for initial evaluation of complicated lymphatic anomalies-expert opinion consensus

OBJECTIVE

Complicated lymphatic anomalies (CLAs) are chronic, progressive, and debilitating conditions that share clinical features, yet key elements for optimal evaluation and management have not been established. We aimed to formulate expert opinion consensus-based guidelines for comprehensive evaluation of CLAs.

STUDY DESIGN

Patient support groups dedicated to CLAs organized an international conference for vascular anomaly experts from 16 specialties to address the objective. Participants received a set of questions before the meeting and reviewed the literature. Data extracted from international lymphatic anomaly registries were presented and the group separated for panel discussions during the conference. The recommendations achieving consensus within the panel were presented to the entire audience. Open debate occurred until majority approval was achieved.

RESULTS

The expert group was composed of 52 physicians who defined the clinical elements required to evaluate and diagnose a CLA. The radiology panel established the preferred anatomical and functional imaging methods for diagnosis and the elements required to be described during interpretation. Two medical panels compiled the metabolic and hematologic tests at diagnosis and also recommended functional studies. The surgical group recommended precautions for biopsy and the pathology panel provided biopsy specimen processing guidelines.

CONCLUSIONS

Patients with CLAs require a comprehensive and targeted diagnostic plan for appropriate management, prevention of complications, and conservation of resources. As this population is managed by diverse medical and surgical specialties, we offer an expert multidisciplinary consensus-based opinion on the current literature and on data extracted from international lymphatic anomaly registries.

Detection of NRAS mutation in cell-free DNA biological fluids from patients with kaposiform lymphangiomatosis

Background

Kaposiform lymphangiomatosis (KLA) has recently been distinguished as a novel subtype of generalized lymphatic anomaly (GLA) with foci of spindle endothelial cells. All cases of KLA involve multiple organs and have an unfavorable prognosis. However, the molecular pathogenesis is unknown, and there are no useful biomarkers. In the present study, we performed genetic analysis to elucidate the cause of this disease and detect biomarkers for it.

Methods

We performed whole-exome sequencing of DNA samples from leukocytes and a biopsy specimen and analyzed cell-free DNA (cfDNA) from plasma and pleural effusion of patients to identify the NRAS c.182A > G (p.Q61R) mutation using the droplet digital polymerase chain reaction (ddPCR).

Results

All KLA patients (patients 1–5) had invasive and aggressive features (hemorrhagic pleural effusions, coagulation disorder, and thrombocytopenia) and characteristic findings of KLA in their pathological examinations. In whole exome sequencing for patient 1, c.182A > G missense variant (p.Q61R) in NRAS was identified in fresh frozen samples of a mass on the left chest wall at a frequency of 5% of total alleles but not in his blood leukocytes. Furthermore, the same mutation was detected in cfDNA isolated from plasma and pleural effusion by using ddPCR. ddPCR analysis of plasma/pleural effusion samples from an additional four KLA patients showed that the same mutation was detected in isolated cfDNA in three of the four, as well as in a tissue sample from one of the three plasma/effusion-positive patients that had been obtained to confirm the mutation.

Conclusion

These results provide the first evidence that NRAS oncogenic variant was identified in DNA samples from KLA patients from not only two affected lesions but also plasma and pleural effusion.

Abdominal lymphatic malformations

BACKGROUND

Abdominal lymphatic malformations (LM) are relatively rare findings in the differential diagnosis of focal abdominal lesions; however, they represent a challenge especially in younger patients. The aim of this review article is to provide up-to-date information about the different kinds of LM manifestations. In addition, related syndromes and typical imaging features to facilitate the diagnosis are discussed.

RESULTS

The clinical presentation of abdominal LM is unspecific, whereby most are asymptomatic and comprise incidental findings of thin-walled cystic masses anywhere in the abdomen. The fluid in the cystic masses may be proteinaceous, contain blood, or be infected. Radiological imaging features overlap with other cystic diseases; hallmark in LM is a lack of a solid component and exclusive enhancement of the walls and septa.

CONCLUSION

In cystic abdominal masses in early childhood or young adults, abdominal LM must be taken into account by the radiologist. Newly defined entities in this spectrum of diseases are central conducting lymphatic anomaly (CCLA) and generalized lymphatic anomaly (GLA).

Kaposiform lymphangiomatosis and kaposiform hemangioendothelioma: similarities and differences

BACKGROUND

Kaposiform lymphangiomatosis (KLA) and kaposiform hemangioendothelioma (KHE) are rare and aggressive vascular disorders. The aim of this study was to examine the clinical features and prognosis of KLA and KHE involving the thorax.

METHODS

The clinical features, imaging and pathological findings, treatments and outcome were retrospectively reviewed for 6 patients with KLA and 7 patients with KHE involving the thorax.

RESULTS

The mean ages at the time of the presentation of signs/symptoms were 26.7 months and 4.1 months for KLA and KHE, respectively. Respiratory symptoms, pericardial and pleural effusion, thrombocytopenia and coagulopathy were common in both KLA and KHE. Diffuse lesions involving the lung and extrathoracic sites were observed in KLA but not in KHE. Histopathologically, all lesions had spindled tumor cells, which were immunoreactive for CD31 and D2-40. In KLA, the spindle cells were distributed in sparse and poorly marginated clusters, whereas the spindle cells formed more defined and confluent vascularized nodules in KHE. Unlike the refractory behavior of KLA, the majority of patients with KHE responded to medical treatments with regression of the lesion and normalization of the hematologic parameters.

CONCLUSIONS

The presenting and histological characteristics of KLA can overlap with those of KHE. The presence of diffuse vascular lesions in the mediastinum and lung with refractory thrombocytopenia and coagulopathy should suggest the diagnosis of KLA. Given the rarity and high morbidity and mortality of these disorders, the diagnostic process and therapeutic approach should include a multidisciplinary team review and consensus.

A report of two children with Gorham-Stout disease

BACKGROUND

Gorham-Stout disease is a rare condition characterized by unifocal and massive type IV osteolysis (variant of idiopathic nonhereditary osteolytic disease) with a slow progression, which is self-limiting for some years. It is characterized by recurrent vascular tumors with disruption of the anatomical architecture and intraosseous proliferation of vascular channels that leads to the destruction and resorption of the bone matrix. The aim of this study is to present the clinical features of this disease, as well as the importance of prompt diagnosis and treatment, with a review of the reported cases.

CASE REPORTS

We describe two cases of Gorham-Stout disease between 2013 and 2017 with surgical interventions, follow-up and results. Case one involves an 11-year-old male with involvement of the left iliac bone, with adequate evolution after a surgical procedure with a lyophilized cadaveric tricortical bone allograft. Case two involves a 6-year-old male with cervical spine C1-C3 repercussion; in the protocol for surgical treatment, he presented with signs of spinal cord compression and died.

CONCLUSION

Diagnosis of Gorham-Stout disease is made by exclusion, and its clinical presentation varies widely, from spontaneous remission to a fatal outcome.

The impact of sirolimus therapy on lesion size, clinical symptoms, and quality of life of patients with lymphatic anomalies

BACKGROUND

Lymphatic anomalies (LAs) include several disorders in which abnormal lymphatic tissue invades the neck, chest, and various organs. Progressive cases may result in lethal outcomes and have proven difficult to treat. Sirolimus is showing promising results in the management of vascular anomalies. We examined the efficacy and safety of sirolimus treatment in patients with progressive LAs.

METHODS

All patients with LAs treated with sirolimus from May 2015 to September 2018 were included. They received oral sirolimus once a day and the dose was adjusted so that the trough concentration remained within 5-15 ng/mL. We prospectively reviewed the response to drugs (the response rate of radiological volumetric change of the target lesion), severity scores, reported quality of life (QOL), and adverse effects at 6 months after administration.

RESULTS

Twenty patients (five with cystic lymphatic malformation (LM), three with kaposiform lymphangiomatosis, three with generalized lymphatic anomaly, six with Gorham-Stout disease, and three with central conducting lymphatic anomaly) were treated with sirolimus at our institution. Fifty percent of patients (10/20) demonstrated a partial response by a radiological examination and a significant improvement in disease severity and QOL scores (P = 0.0020 and P = 0.0117, respectively). Ten patients who had no reduction in lesion size (stable disease group) showed no significant improvement in disease severity and QOL scores. Eighty percent of patients (16/20) had side effects, such as stomatitis, infection, and hyperlipidemia.

CONCLUSIONS

Sirolimus impacts the reduction of the lymphatic tissue volume of LMs and could lead to improvement in clinical symptoms and QOL.

TRIAL REGISTRATION

UMIN Clinical Trials Registry, UMIN000016580 . Registered 19 February 2015.

Generalized Lymphatic Anomaly and Gorham-Stout Disease: Overview and Recent Insights

Significance: Generalized lymphatic anomaly and Gorham-Stout disease are extremely rare diseases with severe symptoms and poor prognosis. The etiology and clinical presentation of the patients remain poorly defined, but recent research has attempted to determine the pathogenesis of these diseases. Recent Advances: In recent years, the characteristics of complex lymphatic anomalies have been revealed. Kaposiform lymphangiomatosis is recognized as a new entity that has an aggressive course and poor prognosis. Genetic analysis revealed somatic mutations in genes associated with the phosphoinositide 3-kinase (PI3K) pathway in lymphatic malformation lesions. Somatic NRAS mutation in lymphatic endothelium from a generalized lymphatic anomaly patient was also detected as a potential cause of disease. Furthermore, studies demonstrated the efficacy of the mammalian target of rapamycin (mTOR) inhibitor sirolimus for these lymphatic diseases. Critical Issues: These diseases have overlapping symptoms, imaging features, and complications, leading to difficulty in their differential diagnosis. In addition, there are no standard therapies. Therefore, we need to determine the differences among these diseases to not only diagnose but also treat them appropriately. Future Directions: Further investigations should reveal differences in the clinical features and findings of radiological, pathological, and genetic examinations to manage each disease appropriately. Somatic mutation in genes encoding RAS/PI3K/mTOR signaling pathway components could be associated with the pathogenesis of these diseases and may be novel targets for drug therapies.

Efficacy of systemic sirolimus in the treatment of generalized lymphatic anomaly and Gorham-Stout disease

BACKGROUND

Generalized lymphatic anomaly (GLA) and Gorham-Stout disease (GSD) are rare complicated lymphatic malformations that occur in multiple body sites and are associated with significant morbidity and mortality. Treatment options have been limited, and conventional medical therapies have been generally ineffective. Emerging data suggest a role for sirolimus as a treatment option for complex lymphatic anomalies.

PROCEDURE

Disease response was evaluated by radiologic imaging, quality of life (QOL), and clinical status assessments in children and young adults with GLA and GSD from a multicenter systematic retrospective review of patients treated with oral sirolimus and the prospective phase 2 clinical trial assessing the efficacy and safety of sirolimus in complicated vascular anomalies (NCT00975819). Sirolimus dosing regimens and toxicities were also assessed.

RESULTS

Eighteen children and young adults with GLA (n = 13) or GSD (n = 5) received oral sirolimus. Fifteen patients (83%) had improvement in one or more aspects of their disease (QOL 78%, clinical status 72%, imaging 28%). No patients with bone involvement had progression of bone disease, and the majority had symptom or functional improvement on sirolimus. Improvement of pleural and pericardial effusion(s) occurred in 72% and 50% of affected patients; no effusions worsened on treatment.

CONCLUSIONS

Sirolimus appears effective at stabilizing or reducing signs/symptoms of disease in patients with GLA and GSD. Functional impairment and/or QOL improved in the majority of individuals with GLA and GSD with sirolimus treatment.

A Case of Suspected Adverse Reactions to Sirolimus in the Treatment of Generalized Lymphatic Anomaly

Generalized lymphatic anomaly (GLA) is characterized by diffuse or multicentric proliferation of dilated lymphatic vessels resembling common lymphatic malformation, and thoracic lesions can be related to a poor prognosis. Sirolimus, an inhibitor of the mammalian target of rapamycin, is effective against vascular anomalies with few severe adverse drug reactions. Here, we report the case of a patient with intractable hemothorax pleural effusion due to GLA who was treated with sirolimus and experienced disseminated intravascular coagulation. Although a standard treatment for GLA has not been established, pleural fluid might be reduced using the Kampo medicine Eppikajyutsuto.

Efficacy and safety of sirolimus treatment for intractable lymphatic anomalies: A study protocol for an open-label, single-arm, multicenter, prospective study (SILA)

Introduction

Lymphatic anomalies (LAs) refer to a group of diseases involving systemic dysplasia of lymphatic vessels. These lesions are classified as cystic lymphatic malformation (macrocystic, microcystic or mixed), generalized lymphatic anomaly, and Gorham–Stout disease. LAs occur mainly in childhood, and present with various symptoms including chronic airway problems, recurrent infection, and organ disorders. Individuals with LAs often experience progressively worsening symptoms with a deteriorating quality of life. Although limited treatment options are available, their efficacy has not been validated in prospective clinical trials, and are usually based on case reports. Thus, there are no validated standards of care for these patients because of the lack of prospective clinical trials.

Methods

This open-label, single-arm, multicenter, prospective study will assess the efficacy and safety of a mammalian target of the rapamycin inhibitor sirolimus in the treatment of intractable LAs. Participants will receive oral sirolimus once a day for 52 weeks. The dose is adjusted so that the nadir concentration remains within 5–15 ng/ml. The primary endpoint is the response rate of radiological volumetric change of the target lesion confirmed by central review at 52 weeks after treatment. The secondary endpoints are the response rates at 12 and 24 weeks, respiratory function, pleural effusion, ascites, blood coagulation parameters, bleeding, pain, quality of life, activities of daily living, adverse events, side effects, laboratory examinations, vital signs, and pharmacokinetic data.

Results

This is among the first multicenter studies to evaluate sirolimus treatment for intractable LAs, and few studies to date have focused on the standard assessment of the efficacy for LAs treatment. Our protocol uses novel, uncomplicated methods for radiological assessment, with reference to the results of our previous retrospective survey and historical control data from the literature.

Conclusions

We propose a multicenter study to investigate the efficacy and safety of sirolimus for intractable LAs (SILA study; trial registration UMIN000028905). Our results will provide pivotal data to support the approval of sirolimus for the treatment of intractable LAs.

•

This is among the first multicenter studies to evaluate sirolimus for intractable LAs.

•

The study design is useful for evaluating sirolimus treatment in LAs.

•

Our study protocol uses novel, uncomplicated methods of radiological assessment.

Somatic activating mutations in PIK3CA cause generalized lymphatic anomaly

Generalized lymphatic anomaly (GLA) is a vascular disorder characterized by diffuse or multifocal lymphatic malformations (LMs). Here, Rodriguez-Laguna et al. report that somatic activating PIK3CA mutations can cause GLA, and we provide preclinical and clinical evidence to support the use of rapamycin for the treatment of GLA.

Generalized lymphatic anomaly (GLA) is a vascular disorder characterized by diffuse or multifocal lymphatic malformations (LMs). The etiology of GLA is poorly understood. We identified four distinct somatic PIK3CA variants (Glu542Lys, Gln546Lys, His1047Arg, and His1047Leu) in tissue samples from five out of nine patients with GLA. These same PIK3CA variants occur in PIK3CA-related overgrowth spectrum and cause hyperactivation of the PI3K–AKT–mTOR pathway. We found that the mTOR inhibitor, rapamycin, prevented lymphatic hyperplasia and dysfunction in mice that expressed an active form of PIK3CA (His1047Arg) in their lymphatics. We also found that rapamycin reduced pain in patients with GLA. In conclusion, we report that somatic activating PIK3CA mutations can cause GLA, and we provide preclinical and clinical evidence to support the use of rapamycin for the treatment of this disabling and deadly disease.

Proliferative Cells From Kaposiform Lymphangiomatosis Lesions Resemble Mesenchyme Stem Cell-like Pericytes Defective in Vessel Formation

Kaposiform lymphangiomatosis (KLA) is a vascular anomaly featuring lymphatic expansion. It has no known cause, no effective treatment, and is associated with high morbidity. Proliferative cells from 3 KLA patient lesions were characterized relative to adiopose-derived mesenchyme stem cells (ADSCs) and cells derived from a patient with the related disease kaposiform hemangioendothelioma (KHE). KLA cells variably expressed markers of mesenchyme stem cells (CD73, CD90, CD105, CD146) and lacked endothelial cell markers (CD31, CD34) as determined by flow cytometry. They expressed markers of vascular pericytes (neural/glial antigen 2, alpha-smooth muscle actin, platelet-derived growth factor-beta receptor, and CXCL12) as determined by quantitative reverse transcription polymerase chain reaction. Lesion cells transcribed vascular markers VEGFC and VEGFD, as well as VCAM-1, the latter of which was confirmed by flow cytometry, consistent with angiogenic MSC-like pericytes. Furthermore, conditioned medium from each was shown to promote the proliferation of growth factor-starved lymphatic endothelial cells. Unlike kaposiform hemangioendothelioma-derived MSC-like pericytes and ADSCs, KLA isolates were defective in support of vascular network formation in co-cultures with either vascular or lymphatic endothelial cells. Genetic analysis by whole exome sequencing revealed novel variant alleles in 2 populations of KLA cells (BAD, TSC1) that may bear on aberrant pericyte growth and function.

Utilizing lymphatic cell markers to visualize human lymphatic abnormalities

In vivo visualization of the human lymphatic system is limited by the mode of delivery of tracing agents, depth of field and size of the area examined, and specificity of the cell markers used to distinguish lymphatic endothelium from the blood vessels and the surrounding tissues. These limitations are particularly problematic when imaging human lymphatic abnormalities. First, limited understanding of the lymphatic disease aetiology exists with respect to genetic causes and phenotypic presentations. Second, the ability of a tracer to reach the entire lymphatic network within the diseased tissue is suboptimal. Third, what is known about the expression of lymphatic endothelial cell (LEC) markers, such as podoplanin, lymphatic vessel endothelial hyaluronan receptor, Drosophila melanogaster homeobox gene prospero-1 and vascular endothelial growth factor receptor-3 in rodent lymphatic vessels and healthy human LECs may not necessarily apply in human lymphatic disease settings. The aim of this review is to highlight challenges in visualizing lymphatic vessels in human lymphatic abnormalities with respect to distribution patterns of the cellular markers currently employed to visualize abnormal human lymphatic vessels in experimental settings. Allowing for these limitations within new diagnostic visualization technologies is likely to improve our ability to image human lymphatic diseases.

Pseudotumor cerebri in kaposiform lymphangiomatosis: a case report and pathogenetic hypothesis

CASE REPORT

A 4-year-old boy with kaposiform lymphangiomatosis (KLA) developed progressive headaches and papilloedema and was diagnosed with pseudotumor cerebri initially treated with acetazolamide. Clinical deterioration prompted placement of a ventriculoperitoneal shunt. After the surgery, the child's condition has markedly improved.

DISCUSSION AND CONCLUSIONS

A network of intracranial lymphatics is presently being investigated. Neuroimaging excluded KLA infiltration of the skull and/or meninges, leaving as the most plausible explanation for the child's pseudotumor cerebri the existence of an increase in intracranial venous pressure by venous compression at the thorax. To our knowledge, our case constitutes the first report of pseudotumor cerebri occurring in the context of KLA.

Multifocal osteolysis with chylous polyserositis and intrathoracic vein thrombosis: a diagnostic challenge for rheumatologists

Vanishing bone disease with multisystemic involvement may mimic systemic autoimmune or autoinflammatory diseases. We present a 19-year-old man who was hospitalized due to chest pain following a progressive osteolysis of the bony thorax. The disease later expanded into the pleura, peritoneum and pericardium in a form of massive chylous polyserositis. The patient also developed thrombosis of multiple central veins, which in turn worsened the chylothorax by increasing the pressure in the thoracic duct. This is the first case of vanishing bone disease complicated by triple chylous effusions and central vein thrombosis.

Chylothorax and constrictive pericarditis in a woman due to generalized lymphatic anomaly: a case report

Background

Generalized lymphatic anomaly (GLA) is characterized by diffuse or multicentric proliferation of dilated lymphatic vessels resembling common lymphatic malformations. Compared with soft tissue or bone involvement, thoracic involvement may be associated with a worse prognosis.

Case presentation

We reported a case of GLA with chylothorax and constrictive pericarditis in a 29-year-old woman. This patient exhibited remarkable features, including a continuously hemorrhagic chylothorax, constrictive pericarditis, and involvement of bone and neck lymph nodes. After attempting to manage her condition with conservative treatment, the patient underwent pericardial stripping surgery. Exploration revealed abundant hyperplasia of tubular tissue in the aortopulmonary window in both pleural cavities.

Conclusions

This case highlights the importance of maintaining the clinical suspicion of GLA during the follow-up of chylothorax patients. Aggressive pericardial surgery, which is important for both diagnosis and treatment, should be performed in patients with GLA with constrictive pericarditis.

VEGF-C promotes the development of lymphatics in bone and bone loss

Patients with Gorham-Stout disease (GSD) have lymphatic vessels in their bones and their bones gradually disappear. Here, we report that mice that overexpress VEGF-C in bone exhibit a phenotype that resembles GSD. To drive VEGF-C expression in bone, we generated Osx-tTA;TetO-Vegfc double-transgenic mice. In contrast to Osx-tTA mice, Osx-tTA;TetO-Vegfc mice developed lymphatics in their bones. We found that inhibition of VEGFR3, but not VEGFR2, prevented the formation of bone lymphatics in Osx-tTA;TetO-Vegfc mice. Radiological and histological analysis revealed that bones from Osx-tTA;TetO-Vegfc mice were more porous and had more osteoclasts than bones from Osx-tTA mice. Importantly, we found that bone loss in Osx-tTA;TetO-Vegfc mice could be attenuated by an osteoclast inhibitor. We also discovered that the mutant phenotype of Osx-tTA;TetO-Vegfc mice could be reversed by inhibiting the expression of VEGF-C. Taken together, our results indicate that expression of VEGF-C in bone is sufficient to induce the pathologic hallmarks of GSD in mice.

Malignancy-Induced Hypercalcemia-Diagnostic Challenges

Hypercalcemia in children is a rare metabolic finding. The clinical picture is usually non-specific, and the etiology includes several entities (metabolic, nutritional, drug-induced, inflammatory, cancer-associated, or genetic) depending on the age at presentation, but severe hypercalcemia is associated mainly with malignancy in childhood and sepsis in neonates. Severe parathyroid hormone (PTH)-suppressed hypercalcemia is challenging and requires multidisciplinary diagnostic and therapeutic approaches to (i) confirm or rule out a malignant cause, (ii) treat it and its potentially dangerous complications. We report a case of severe and complicated PTH-independent hypercalcemia in a symptomatic 3-year-old boy. His age, severity of hypercalcemia and its complicated course, and the first imaging reports were suggestive of malignancy. The first bone and kidney biopsies and bone marrow aspiration were normal. The definitive diagnosis was a malignant-induced hypercalcemia, and we needed 4 weeks to assess other differential diagnoses and to confirm, on histopathological and immunochemical base, the malignant origin of hypercalcemia. Using this case as an illustrative example, we suggest a diagnostic approach that underlines the importance of repeated histology if the clinical suspicion is malignancy-induced hypercalcemia. Effective treatment is required acutely to restore calcium levels and to avoid complications.

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.

Pulmonary and pleural lymphatic endothelial cells from pediatric, but not adult, patients with Gorham-Stout disease and generalized lymphatic anomaly, show a high proliferation rate

Background

Gorham-Stout disease (OMIM 123880) and generalized lymphatic anomaly are two rare disorders of lymphendothelial growth in which thoracic involvement with chylothorax is a feared complication. Currently it is believed that both disorders are prenatal malformations that progress slowly after birth. Several pharmaceuticals with antiproliferative properties, including interferon-α-2b, rapamycin and propranolol, have however been shown to affect the disease course in some patients. Deeper knowledge of the growth characteristics of these malformations are therefore needed to guide the clinical approach.

Methods

Lymphatic vessels in lung and pleural tissue from both children and adult patients with generalized lymphatic anomaly or Gorham-Stout disease were studied using an immunohistochemical approach, targeting lymphendothelial markers (D2-40/Prox-1) and a proliferation marker (Ki-67).

Results

We found significant proliferation and growth in these lesions in pediatric patients but not in adults. Furthermore, the data may suggest that the disease process is at least partly reversible.

Conclusions

These malformations of the lymphatic system proliferate at a significant rate long after birth, which could suggest that the clinical approach for children should be different from adults.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-016-0449-4) contains supplementary material, which is available to authorized users.