Treatment of Gorham-Stout disease with zoledronic acid and interferon-α: a case report and literature review

Bisphosphonates Trigger Anti-Ageing Effects Across Multiple Cell Types and Protect Against Senescence

Bisphosphonates (BPs) have been the major class of medicines used to treat disorders of excessive bone loss for over five decades. Recently it has been recognized that BPs may also have additional significant beneficial extra-skeletal effects. These include a reduction of all-cause mortality and of conditions commonly linked to ageing, such as cancer and cardiovascular disease. Here we show that bisphosphonates co-localize with lysosomal and endosomal organelles in non-skeletal cells and stimulate cell growth at low doses. In vivo spatial transcriptomic analysis revealed differentially expressed senescence markers in multiple organs of aged BP-treated mice, and a shift in cellular composition toward those of young counterparts. Similarly, a 5000-plex plasma proteome analysis from osteopenic patients before and after BP-treatment showed significant alterations in ~400 proteins including GTPase regulators and markers of senescence, autophagy, apoptosis, and inflammatory responses. Furthermore, treatment with BPs protected against the onset of senescence in vitro. Proteome-wide target deconvolution using 2D thermal profiling revealed novel BP-binding targets (PHB2, ASAH1), and combined with RNA- and ATAC-seq of BP-treated cells and patient data, suggests downstream regulation of the MEF2A transcription factor within the heart. Collectively, these results indicate how BPs may beneficially modify the human plasma proteome, and directly impact multiple non-skeletal cell types through previously unidentified proteins, thereby influencing a range of pathways related to senescence and ageing.

Trametinib inhibits lymphatic vessel invasion of bone in a mouse model of Gorham-Stout disease

Objective

Gorham-Stout disease (GSD) is a rare lymphatic anomaly that can be caused by somatic activating mutations in KRAS. This discovery has led investigators to suggest that MEK inhibitors could be a novel treatment for GSD. However, the effect of MEK inhibitors on bone disease in animal models of GSD has not been investigated. We recently reported that Osx-tTA;TetO-Vegfc mice exhibit a phenotype that resembles GSD. Osx-tTA;TetO-Vegfc mice overexpress VEGF-C in bone, which stimulates the development of lymphatic vessels in bone and the gradual loss of cortical bone. The objective of this study was to characterize the effect of trametinib, an FDA-approved MEK1/2 inhibitor, on lymphangiogenesis and osteolysis in Osx-tTA;TetO-Vegfc mice.

Methods

Immunoblotting was performed to assess the effect of trametinib on VEGF-C-induced phosphorylation of ERK1/2, AKT, and S6 in primary human lymphatic endothelial cells (LECs). Prevention and intervention experiments were performed to determine the effect of trametinib on lymphangiogenesis and osteolysis in Osx-tTA;TetO-Vegfc mice.

Results

We found that trametinib blocked VEGF-C-induced phosphorylation of ERK1/2 in primary human LECs. We also found that trametinib prevented VEGF-C-induced lymphatic invasion of bone and cortical bone loss in Osx-tTA;TetO-Vegfc mice. Additionally, trametinib slowed the progression of disease in Osx-tTA;TetO-Vegfc mice with established disease. However, it did not reverse disease in Osx-tTA;TetO-Vegfc mice.

Conclusion

Our results show trametinib impacts bone disease in Osx-tTA;TetO-Vegfc mice. These findings further support the testing of MEK inhibitors in patients with GSD and other RAS pathway-driven complex lymphatic anomalies with bone involvement.

Multicompartment Dynamic Contrast Magnetic Resonance Lymphangiography in Diagnosis of Complicated Lymphatic Anomaly

Background: To describe the dynamic contrast magnetic resonance lymphangiography (DCMRL) findings of three patients with complicated lymphatic anomaly (CLA) and protein losing enteropathy. We further discuss the importance of a multicompartment (intrahepatic [IH], intramesenteric [IM], and intranodal [IN]) DCMRL in delineating central lymphatic flow pathologies. Methods and Results: This is a retrospective study of three patients-one adult and two children who individually underwent the three-compartment DCMRL, namely IN-DCMRL, IH-DCMRL, and IM-DCMCRL. Findings from the results of the DCMRL for these three patients were obtained from the medical records and compared. Using the multicompartment imaging modalities, chylous fluid leakage into the peritoneum was observed using IM-DCMRL and IH-DCMRL but not IN-DCMRL for one of the patients in the case series. In contrast, leakage of chyle into the mediastinum was noted using IN-DCMRL but not IH-DCMRL and IM-DCMRL on another patient in this case series. Conclusion: Owing to the variability in outlining lymphatic flow pathologies, multicompartment imaging gives a more global picture of individual conduction disorders, has the potential to improve clinical assessment, and in some cases leads to a diagnosis of the abnormality and thus provides a better understanding of lymphatic flow anomalies in patients with CLAs.

Gorham-Stout disease with life-threatening pleural effusion treated with a pleuro-peritoneal shunt: a case report

Summary

Gorham-Stout disease (GSD) is a rare bone disease characterized by massive osteolysis and lymphatic proliferation. The origin of the condition is unknown, and no established treatment protocol exists. Massive pleural effusion is a frequent complication of GSD in the thoracic region. We present the case of a 23-year-old male with thoracic GSD, subsequent paraparesis, and life-threatening pleural effusion. The patient was managed by a multidisciplinary team with a good recovery. The pleural effusion was successfully treated with a pleuro-peritoneal shunt. This is the first report of the use of this mini-invasive technique in the management of pleural effusion related to GSD. Further, we present the potential role of interleukin-6 and bone resorption markers in the measurement of the disease activity.

Learning points

Multidisciplinary approach is important in the management of rare and severe disorders such as Gorham-Stout disease. Pleuro-peritoneal shunting is a valuable option in the treatment of pleural effusion related to GSD. Interleukin-6 and bone resorption markers appear useful in measuring the disease activity of GSD.

[Unilateral subjective tinnitus «vanishing bone» disease (Goram-Stout syndrome).]

The article presents the case history of an 11-year-old girl with Goram-Stout disease, who debuted with unilateral subjective tinnitus. A review of the literature, cases with damage of the temporal bones and modern methods of treatment of this disease is made.

A Child with Early-Onset Gorham-Stout Disease Complicated by Chylothorax: Near-Complete Regression of Bone Lesions with Interferon and Bisphosphonate Treatment

We report a case of Gorham-Stout disease (GSD) complicated by chylothorax and treated with a combination therapy with interferon and bisphosphonates. This treatment may be helpful in improving the usually unfavorable prognosis of GSD beginning with a chylothorax before 1 year of age, and in reducing bone lesions. Moreover, the use of bisphosphonates appears to be useful in treating pain.

Gorham-Stout disease: good results of bisphosphonate treatment in 6 of 7 patients

Background and purpose - Gorham-Stout disease (GSD) is a rare mono- or polyostotic condition characterized by idiopathic intraosseous proliferation of angiomatous structures resulting in progressive destruction and resorption of bone. Little is known about the course of disease and no previous study has evaluated patients' quality of life (QoL).Patients and methods - This is a retrospective analysis of 7 consecutive patients (5 males) with a median age at diagnosis of 14 years and a median follow-up of 7 years who were diagnosed with GSD in our department between 1995 and 2018. Data regarding clinical, radiographic, and histopathological features, and treatment, as well as sequelae and their subsequent therapy, were obtained. QoL was assessed by Musculoskeletal Tumor Society Score (MSTS), Toronto Extremity Salvage Score (TESS), and Reintegration to Normal Living (RNL) Index.Results - 3 patients had a monoostotic and 4 patients a polyostotic disease. Besides a diagnostic biopsy, 4 of the 7 patients had to undergo 8 surgeries to treat evolving sequelae. Using an off-label therapy with bisphosphonates in 6 patients, a stable disease state was achieved in 5 patients after a median of 20 months. The median MSTS, TESS, and RNL Index at last follow-up was between 87% and 79%.Interpretation - Due to its rare occurrence, diagnosis and treatment of GSD remain challenging. Off-label treatment with bisphosphonates appears to lead to a stable disease state in the majority of patients. QoL varies depending on the individual manifestations but good to excellent results can be achieved even in complex polyostotic cases with a history of possibly life-threatening sequelae.

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.

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.

Thoracic spine dislocation in Gorham-Stout Syndrome: Case report and literature review

Background

The Gorham-Stout syndrome (GSS), also known as phantom bone disease, is a rare bone condition of unknown etiology. Involvement of the spine is described in <50 cases in the literature. Here, we report a case of thoracic spine fracture dislocation in a young female who was known to have GSS.

Case Description

A 23-year-old female developed a left spontaneous hemothorax 10 years previously along with left ribs lytic lessions. Pleural and rib biopsies diagnosed angiomatosis and the clinical diagnosis of GSS was established. Following a minor trauma, she presented with a Frankel B deficit attributed to a T3-T4 fracture dislocation with severe spinal cord compression. The patient underwent halo traction with CT. Following reduction, decompression and C5 to T8 with instrumented fusion (posterior only), she neurologically improved to Frankel D, 2 years postoperatively.

Conclusion

Although GSS is a rare condition in the spine, it may lead to gross instability and catastrophic vertebral fracture/dislocation with paraparesis. Acute spinal cord decompression with stabilization may be warranted to achieve neurological improvement.

Chemical Pleurodesis Using Viscum album Extract in Gorham Disease Complicated with Chylothorax

Gorham disease, also known as massive osteolysis, is characterized by unregulated proliferation of lymphatic or vascular capillaries within bone, resulting in destruction and replacement with angiomatous tissue. This disease can lead to chylothorax that can be lethal. Viscum album extract from European mistletoe is a complementary anti-cancer drug which is commonly prescribed in many European countries and is considered as a new generation of chemical agent for pleurodesis. A 14-year-old girl presented with dyspnea and chest pain. She was diagnosed as Gorham disease who was definitively treated with V. album extract for chylothorax that was refractory to standard conservative management.

Left Functional Pneumonectomy Caused by a Very Rare Giant Intrathoracic Cystic Lesion in a Patient with Gorham-Stout Syndrome: Case Report and Review of the Literature

Gorham-Stout syndrome is an uncommon entity, with few cases reported in bibliography. It consists of osteolytic manifestations affecting various bones and replacing them with lymphangiomatous tissue. With pathophysiology unknown, Gorham-Stout disease affects also cardiorespiratory system usually causing lytic lesions to the bones of the thoracic cage or directly invading the thoracic duct. This is a case report of a unique respiratory manifestation of the disease and a review of its cardiorespiratory complications.

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.

Vascular anomaly cases for the pediatric hematologist oncologists-An interdisciplinary review

Vascular anomalies (VAs) are classified as tumors or malformations depending on their clinical characteristics, pathological diagnosis, and genomic information. Diagnosis can be challenging because of the heterogeneity of clinical presentation; thus, the best diagnosis and care are provided by an interdisciplinary team of specialists. Over the past 10 years, an increasing number of pediatric hematologist/oncologists are caring for patients with VAs secondary to new medical therapy options and clinical trials. This paper focuses on complicated VA issues often seen by the pediatric hematologist/oncologist. The paper reviews clinical pearls on diagnosis, histology, radiology, and treatment options.

Systemic Cystic Angiomatosis Mimicking Metastatic Cancer: A Case Report and Review of the Literature

Systemic cystic angiomatosis is a rare benign disorder due to the maldeveloped vascular and lymphatic system with less than 50 cases reported in literature so far. We report here a case of systemic cystic angiomatosis (SCA) with multisystem involvement affecting the neck, thyroid, thoracic cavity, and skeletal system. The patient initially presented in her 4th decade of life with isolated lymphangioma in the neck requiring surgery. However, she experienced full-blown manifestations of SCA in her 6th decade which closely mimicked metastatic cancer. The diagnosis of SCA could only be established after multiple biopsies. The radiological and histological features of SCA with its course over 31 years in this patient have been described.

Identical Presentation of Scapular Osteolysis in Two Patients with Thoracic Kaposiform Hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor that does not metastasize. We report two unique cases of KHE involving the right hemithorax and the upper ipsilateral extremity. Kasabach-Merrit phenomenon and osteolytic lesions in the scapula were observed in both cases.

Cystic angiomatosis, a heterogeneous condition: Four new cases and a literature review

BACKGROUND

Cystic angiomatosis (CA) is a rare disorder causing bony cysts. It displays some similarity to Gorham-Stout disease (GSD), but has a much better local prognosis, despite the larger number of cysts. These 2 conditions also differ in terms of their location, visceral involvement, and response to treatment.

METHODS

We report 4 cases of CA, including 1 sclerosing form, which we compare with cases from a literature review performed with PRISMA methodology.

RESULTS

We reviewed 38 articles describing 44 other patients. Mean age at diagnosis for the 48 patients (our 4 patients + the 44 from the review) was 22.5 years, and 28 of the patients were men. The femur was involved in 81% (n = 39), the pelvis in 73% (n = 35), the humerus in 52% (n = 25), the skull in 48% (n = 23), and the vertebrae in 44% (n = 21). Visceral lymphangiomatosis (either clinical, or detected on autopsy) was also reported in 35% (n = 18) of the patients. The spleen was the most frequently involved organ (n = 12), followed by the lungs and pleura (n = 8). Liver cysts and/or chylothorax were rarely reported (5 cases), but were invariably fatal. Radiation therapy on bone or soft tissue masses was ineffective, as was interferon alpha, in the 2 patients in which this drug was tested. The efficacy of bisphosphonate was at best equivocal.

CONCLUSION

The progression of CA is unpredictable and treatments effective against GSD, such as bisphosphonates and radiotherapy, have proved ineffective for this condition. New treatments are thus urgently required.

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

BACKGROUND

Complex lymphatic anomalies are intractable lymphatic disorders, including generalized lymphatic anomaly (GLA), Gorham-Stout disease (GSD), and kaposiform lymphangiomatosis (KLA). The etiology of these diseases remains unknown and diagnosis is confused by their similar clinical findings. This study aimed to clarify the differences in clinical features and prognosis among GLA, KLA, and GSD, in Japanese patients.

PROCEDURE

Clinical features, radiological and pathological findings, treatment, and prognosis of patients were obtained from a questionnaire sent to 39 Japanese hospitals. We divided the patients into three groups according to radiological findings of bone lesions and pathology. Differences in clinical findings and prognosis were analyzed.

RESULTS

Eighty-five patients were registered: 35 GLA, 9 KLA, and 41 GSD. Disease onset was more common in the first two decades of life (69 cases). In GSD, osteolytic lesions were progressive and consecutive. In GLA and KLA, 18 patients had osteolytic lesions that were multifocal and nonprogressive osteolysis. Thoracic symptoms, splenic involvement, and ascites were more frequent in GLA and KLA than in GSD. Hemorrhagic pericardial and pleural effusions were more frequent in KLA than GLA. GSD had a significantly favorable outcome compared with combined GLA and KLA (P = 0.0005). KLA had a significantly poorer outcome than GLA (P = 0.0268).

CONCLUSIONS

This survey revealed the clinical features and prognosis of patients with GLA, KLA, and GSD. Early diagnosis and treatment of KLA are crucial because KLA has high mortality. Further prospective studies to risk-stratify complex lymphatic anomalies and optimize management for KLA are urgently needed.

Gorham-Stout Disease Successfully Treated With Sirolimus and Zoledronic Acid Therapy

Gorham-Stout disease is a life-threatening disorder often manifested by lymphatic malformation and osteolysis. Unfortunately, available therapies are not uniformly effective and often carry substantial morbidity. We report an 18-year-old male with Gorham-Stout disease manifested by lytic rib lesions and an intractable pleural effusion that responded dramatically to the combination of the mammalian target of rapamycin (mTOR) inhibitor sirolimus and the aminobisphosphonate zoledronic acid after failing interferon therapy. This tolerable therapeutic combination has demonstrated synergism in preclinical cancer models and merits further study in vascular anomalies.

Disappearing bone disease of the humerus and the cervico-thoracic spine: a case report with 42-year follow-up

BACKGROUND CONTEXT

Disappearing bone disease (DBD) is a rare idiopathic musculoskeletal disorder that is distinguished by bone resorption without bone formation, vascular or lymphatic vessel proliferation, and soft-tissue swelling. Long-term follow-up of a patient with DBD has rarely been reported in the literature.

PURPOSE

The following is a case report of a female patient with DBD of the humerus and the spine who was followed for 42 years, documenting the progression of the disease and outcomes.

STUDY DESIGN

Case report.

METHODS

A review of the medical records since the time of initial hospital admission throughout follow-up was performed.

RESULTS

A female patient was first seen at our institution at the age of 14. She later developed DBD of the humerus and the spine. The initial difficulty encountered was reaching the diagnosis, and later on with management of the patient as the disease progressed. The case was complicated by syrinx and arachnoid cyst formation, which caused neurologic changes leading to tetraplegia and shunt infection. The patient's inability to form a solid fusion mass led to repeated implant loosening and progressive deformity despite efforts made to stabilize both the humerus and the spine. The treatment modalities used were oral bisphosphonates, rhBMP, repeated surgeries, and instrumentation with adjunct bone graft and substitutes. At the age of 56 years, the patient died because of septicemia secondary to urinary tract infection from tetraplegia.

CONCLUSIONS

To our knowledge, this is the first report documenting a 42-year follow-up of a patient with DBD of the humerus and the spine. Our report showed that DBD greatly affects the quality of life of the patient. Close follow-up, a multidisciplinary approach, and supportive care are stressed when managing patients with DBD.

Thoracic osteotomy for Gorham-Stout disease of the spine: a case report and literature review

INTRODUCTION

Gorham-Stout syndrome is an aggressive, non-heritable skeletal disease characterized by osteolysis following minor trauma. The primary involvement of the spine is less common (10 %) and has been described in only about 20 cases; there is no consensus about the best way to treat this condition.

PURPOSE OF THE STUDY

To report a case of Gorham-Stout syndrome involving the thoracic spine and to review the literature to suggest a post-operative treatment to prevent osteolysis.

CASE REPORT

A thirty-year-old female patient was admitted to the unit in March 2013 for a pathologic T4 fracture. X-rays and CT scan revealed the onset of T4 osteolysis and an increase in thoracic kyphosis (the local kyphosis was up to 100°). We performed surgery by posterior approach, combining posterior fixation with screws and rods from T3 to T9, decompression and vertebral osteotomy of 65°. The immediate outcome of surgery was good and the patient returned home after 24 days. At 6 and 12 months of follow-up, the patient was walking normally with no neurological sequelae.

CONCLUSION

We report a case of Gorham-Stout syndrome involving the thoracic spine that was successfully treated by interpedicular osteotomy associated with a 6 month follow-up. We suggest that this strategy can provide good results, because after fusion, the disease process remains stable. Because of the lack of cases reported, surgeons must be careful when using multiple treatments, because these treatments have many side effects.

LEVEL OF EVIDENCE

Level IV case report.

Cerebrospinal fluid leakage in Gorham-Stout disease due to dura mater involvement after progression of an osteolytic lesion in the thoracic spine

Patients with Gorham-Stout disease (GSD), a rare disease of poorly understood etiopathophysiology, suffer from progressive osteolysis. Destruction of bone matrix is caused by lymphatic vessels, which can lead to CSF leakage if parts of bony structures adjacent to CSF spaces are involved. So far, fewer than 200 patients have been reported in the literature; only 4 of these patients presented with CSF leakage. The authors report the case of a 30-year-old man with GSD and CSF leakage due to dura mater involvement after progression of an osteolytic lesion in the thoracic spine. Neurosurgical intervention, including dura repair, was needed. Experimental medical therapy with rapamycin was started, leading to disease control for more than 12 months. Progression of GSD can lead to destruction of the meninges, causing CSF leakage. The authors review 4 other cases reported in the literature and discuss therapeutic options.

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.

Viewpoints on vessels and vanishing bones in Gorham-Stout disease

Gorham-Stout disease (GSD) is a rare disorder characterized by the proliferation of endothelial-lined vessels in bone and the progressive destruction of bone. Although Jackson described the first case of GSD in 1838, the clinical and histological features of GSD were not defined until Gorham and Stout published their report on massive osteolysis in 1955. In the years since Gorham and Stout's groundbreaking publication, more than 300 cases of GSD have been described in the literature. These reports have revealed that the progressive resorption of bone in GSD causes severe physical deformities, disabilities, and life-threatening complications. Unfortunately, the underlying cause of GSD remains unknown and, as a result, the therapeutic options for individuals with GSD are limited. Here we review the latest advances in GSD research and present strategies to address basic and clinical research questions related to GSD.

Rare bone diseases and their dental, oral, and craniofacial manifestations

Hereditary diseases affecting the skeleton are heterogeneous in etiology and severity. Though many of these conditions are individually rare, the total number of people affected is great. These disorders often include dental-oral-craniofacial (DOC) manifestations, but the combination of the rarity and lack of in-depth reporting often limit our understanding and ability to diagnose and treat affected individuals. In this review, we focus on dental, oral, and craniofacial manifestations of rare bone diseases. Discussed are defects in 4 key physiologic processes in bone/tooth formation that serve as models for the understanding of other diseases in the skeleton and DOC complex: progenitor cell differentiation (fibrous dysplasia), extracellular matrix production (osteogenesis imperfecta), mineralization (familial tumoral calcinosis/hyperostosis hyperphosphatemia syndrome, hypophosphatemic rickets, and hypophosphatasia), and bone resorption (Gorham-Stout disease). For each condition, we highlight causative mutations (when known), etiopathology in the skeleton and DOC complex, and treatments. By understanding how these 4 foci are subverted to cause disease, we aim to improve the identification of genetic, molecular, and/or biologic causes, diagnoses, and treatment of these and other rare bone conditions that may share underlying mechanisms of disease.

Novel molecular pathways in Gorham disease: implications for treatment

Rapid advances in evidence-based treatment schedules are a hallmark of modern oncology. In rare neoplastic diseases, however, clinical expertise is hard to build and evidence based on randomized trials almost impossible to collect. Gorham disease is a rare form of lymphatic proliferation accompanied by osteolysis, which usually occurs in young adults. Despite the fact that the clinical course of Gorham disease is often devastating and occasionally fatal, insights into its biological background are sparse and standardized treatment unavailable. Interestingly, recent knowledge on the mechanisms of lymphangiogenesis may help elucidate the pathophysiology of Gorham disease and lead to novel treatment targets. Here, we discuss our current understanding of Gorham disease, discuss established and emerging therapeutic strategies, and attempt to frame a treatment rationale.

Cystic bone angiomatosis: a case report treated with aminobisphosphonates and review of the literature

Cystic angiomatosis (CA) is a rare disease characterized by multifocal hemangiomatous and/or lymphangiomatous lesions of the skeleton with possible visceral organ involvement. The exact pathogenetic mechanism of the disease is still unknown. We describe a patient affected by CA of bone treated with surgical procedures and subsequently with intravenous aminobisphosphonates for 7 years. During the follow-up progression of lesions, the painful symptoms, markers of bone turnover, computed tomographic examination, and bone mineral density were evaluated. Aminobisphosphonate therapy showed an immediate effectiveness in reducing bone pain, with a significant decrease in circulating bone alkaline phosphatase and stable radiological findings during clinical follow-up. In addition, at baseline, high levels of bone biomarkers and cytokines (osteoprotegerin, osteopontin, and interleukin-6) capable of controlling bone metabolism and angiomatosis were identified. Aminobisphosphonate treatment produced a decrease of all these increased markers. Local cell therapy with bone marrow osteoblast precursors did not produce any measurable clinical improvement. Aminobisphosphonate therapy represents an elective treatment for bone angiomatosis syndromes, but further studies are necessary to understand the molecular basis of these disorders and of their pharmacological treatment.

Gorham's Disease complicated with bilateral chylothorax and successfully treated with Interferon-alpha-2a

Gorham's disease (GD) is rare and characterized by non-neoplastic lymphovascular proliferation and massive osteolysis. Its clinical course is usually protracted, but sometimes life threatening when vital structures are involved or when complicated with chylothorax. There is no optimal treatment guideline for GD complicated with chylothorax. Surgical ligation of thoracic duct, pleurectomy, pleurodesis, interferon-alpha-2b, and radiotherapy, are reported to manage chylothorax. We present the case of a 32-year-old man with Gorham's disease complicated by bilateral chylothorax, which was refractory to radiotherapy but remitted dramatically two weeks after interferon-alpha-2a therapy. The patient was free of relapse four months after discontinuing four-month interferon therapy. To date, only 11 cases (including ours) of GD with chylothorax have received interferon as single or salvage therapy, and 10 of them survived. Early intervention with interferon therapy can be considered as an effective treatment for GD complicated with bilateral chylothorax.

An aggressive lymphatic malformation (Gorham's disease) leading to death of a child

Here in, we present a case of aggressive Gorham's disease in a 10 year old boy. We document its evolution from a seemingly benign buttock mass to a widely invasive disease that was ultimately fatal. We highlight the challenges in the management of such an aggressive, yet benign process and review the available literature on the subject.

Bisphosphonates use in children

Bisphosphonates are synthetic analogues of pyrophosphate that inhibit bone resorption by their action on osteoclasts. In recent years, bisphosphonates have been used in children for treatment of a growing number of disorders associated primarily with generalized or localized osteoporosis, genetic and acquired metabolic bone diseases, heterotopic calcifications in soft tissues, and for hypercalcemia. In this review, the authors address the role of and experience with bisphosphonate therapy in disorders of childhood.

[Chylothorax as a complication of coronary artery bypass grafting operation]

The authors present the case of a 72-year-old woman who underwent coronary bypass grafting. Left sided chylothorax due to accidental dissection of a thoracic duct branch developed 2 months after sternotomy. As conservative therapy has failed, surgical pleurodesis was performed successfully. Chylothorax is a rare and underestimated complication of coronary bypass grafting. The worldwide increasing number of coronary artery bypass grafting surgeries makes it important to pay attention to this condition. Thus diagnosis of the chyle is relatively easy by its high chylomicron and triglyceride content, but identification of the etiology and its treatment is sometimes challenging for the physician. The treatment of chylothorax is usually conservative. The main goal is to keep the volume of the chyle under control. The number of surgical interventions because of chylothorax is increasing due to an increase of iatrogenic etiology.