Successful treatment of kaposiform hemangioendothelioma and tufted angioma with vincristine

The use of mTOR inhibitors for the treatment of kaposiform hemangioendothelioma. A systematic review

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a locally aggressive and potentially lethal vascular tumor of infancy. Current consensus recommendations include the use of vincristine and/or systemic steroids as first-line treatment. Mammalian target of rapamycin (mTOR) inhibitors represent a promising therapy for patients with KHE. The goal of our study is to critically assess the existing literature on outcomes of patients with KHE treated with mTOR inhibitors.

METHODS

We conducted a literature search from 1 January 2000, to 30 April 2022. Articles reporting outcomes of patients treated with mTOR inhibitors for KHE were included. Descriptive statistics were used to describe and summarize the outcomes of the treatment.

RESULTS

We included 327 patients with a mean age at diagnosis of 9.1 months (SD ± 9). Patients were treated with an mTOR inhibitor for a mean of 15.2 months (SD ± 4.1). A total of 315 (96.3%) patients had positive outcomes including improvement of the tumor size, symptoms and/or laboratory parameters in 227 (85%) and complete remission in 38 (12%). Seven (2%) patients did not respond to treatment and seven (2%) died of sepsis (4), Kasabach-Merritt phenomenon complications (1), cardiac and liver failure due to ductus arteriosus (1), or metastatic disease (1).

CONCLUSION

This systematic review supports the efficacy and safety of mTOR inhibitors for KHE. Their use resulted in positive outcomes in terms of decreased symptoms, reduction in tumor size and improvement in biochemical parameters with a mortality rate of 2%. According to these findings, we suggest revised consensus treatment guidelines for KHE with mTOR inhibitors potentially considered first-line therapy.

Multidisciplinary management of a neonate with kaposiform hemangioendothelioma with extensive cranial fossa destruction

Kaposiform hemangioendothelioma is a rare, benign, locally destructive vascular tumor. Kasabach-Merritt phenomenon, a consumptive coagulopathy, is a life-threatening complication associated with kaposiform hemangioendothelioma. We describe a case of kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon in a neonate born with a large facial mass with deep extension toward the cranium and airway. The mass was not identified prenatally. The patient was a 37-week gestation age female neonate born via spontaneous vaginal delivery and noted to have a large left-sided facial mass that was not noted on the most recent prenatal ultrasound at 22 weeks gestation age. At birth, the patient was in respiratory distress and required continuous positive airway pressure support. Imaging revealed a large highly vascularized soft tissue mass adjacent to the airway with intracranial extension and bony destruction. Fine needle aspiration confirmed kaposiform hemangioendothelioma. On day of life 6, the patient was noted to have thrombocytopenia, elevated d-dimer, anemia, and hypofibrinogenemia, consistent with Kasabach-Merritt phenomenon, which resolved at day of life 12. Given the location and extent of the mass, medical therapy with single agent oral sirolimus was chosen over surgery. At 13-month follow-up, the infant is well on sirolimus therapy, and the mass has decreased in size, both clinically and on imaging. This case highlights the importance of prompt diagnosis and management of kaposiform hemangioendothelioma with extensive craniofacial and bony involvement with Kasabach-Merritt phenomenon with single oral therapy of sirolimus. Fibrinogen concentrate may be considered in the Kasabach-Merritt phenomenon refractory to cryoprecipitate.

How we approach the diagnosis of a vascular anomaly

Vascular anomalies represent a diverse group of complex disorders that can cause significant complications, including coagulopathies, pain, and decreased function. The diagnosis of vascular anomalies is often challenging due to heterogeneity of presenting phenotypes and overlapping clinical features with other pediatric conditions. Pediatric hematologists/oncologists (PHO) are uniquely positioned for an essential role in diagnosing, managing, and coordinating the multidisciplinary care required to maximize the quality of life of these patients. Here, we review the diagnostic approach involved in patients with vascular anomalies and utilize cases to highlight the challenges involved, and how PHOs can play a vital part in the care of these patients.

Neonatal vascular anomalies manifesting as soft-tissue masses

The broad and heterogeneous spectrum of vascular anomalies ranges from an innocuous localized cutaneous discoloration to complex, extensive and life-threatening diagnoses. While many of these lesions are present at birth, smaller and deeper lesions might be clinically occult for months or years. Certain vascular anomalies commonly manifest in the prenatal or neonatal period and often have suggestive clinical and imaging features that can aid the radiologist in making a correct diagnosis. The characteristics of such lesions presenting very early in life, particularly those manifesting as soft-tissue masses, are the focus of this review.

Comparison of efficacy and safety of corticosteroid and vincristine in treating kaposiform hemangioendothelioma and tufted angioma: A multicenter prospective randomized controlled clinical trial

Kaposiform haemangioendothelioma (KHE) and tufted angioma (TA) are rare vascular tumors that can cause life-threatening Kasabach-Merritt phenomenon. No evidence-based treatment strategies have yet been established, and its management is still a challenge. The purpose of this multicenter prospective randomized controlled study was to evaluate and compare the efficacy of corticosteroid and vincristine (VCR) in the treatment of KHE and TA. All patients with KHE/TA who met the diagnostic criteria were consecutively recruited. The patients were randomized into a methylprednisolone (MP) group and a VCR group. The primary outcome was the single main parameter effective rate and overall effective rate of corticosteroid and VCR over 1 month after treatment. The single main parameters included platelets, fibrinogen, tumor size, texture, and appearance. From May 2016 to April 2018, a total of 59 patients completed the clinical trial, including 29 in the MP group and 30 in the VCR group. The results showed that VCR was superior to corticosteroid in the improvement of platelet (80.0% vs 44.0%, P = 0.019) and tumor texture (68.9% vs 30.8%, P = 0.007). Although the efficacy of VCR on fibrinogen (23.3% vs 20.7%, P = 1.000), tumor size (23.3% vs 13.8%, P = 0.273), and appearance (65.5% vs 46.2%, P = 0.120) was higher than that of corticosteroid, there was no significant difference (P > 0.05). Meanwhile, the overall effective rate of VCR was higher than that of corticosteroid (56.7% vs 31.0%), but the difference was also not statistically significant (P = 0.067). In conclusion, the therapeutic effect of VCR was significantly better than that of corticosteroid with regard to treating thrombocytopenia and tumor texture. We recommend that VCR could be an option for first-line treatment in KHE/TA patients.

Standards of care for Kasabach-Merritt phenomenon in China

Kasabach-Merritt phenomenon (KMP) is a rare disease that is characterized by severe thrombocytopenia and consumptive coagulation dysfunction caused by kaposiform hemangioendothelioma or tufted hemangioma. This condition primarily occurs in infants and young children, usually with acute onset and rapid progression. This review article introduced standardized recommendations for the pathogenesis, clinical manifestation, diagnostic methods and treatment process of KMP in China, which can be used as a reference for clinical practice.

Endothelial cell malignancies in infants, children and adolescents: Treatment results of three Cooperative Weichteilsarkom Studiengruppe (CWS) trials and one registry

BACKGROUND

Endothelial cell malignancies are extremely rare in childhood. New identification of genetic abnormalities (WWTR1:CAMTA1 translocation) helps to recognize potential therapeutic targets. Little is known about treatment and outcome of these patients.

METHODS

Clinical course, treatment, and outcome in patients with endothelial cell malignancies treated within the Cooperative Weichteilsarkom Studiengruppe (CWS) trials CWS-91, -96, -2002P, and the Soft-Tissue Sarcoma Registry (SoTiSaR) were analyzed (1991-2019).

RESULTS

Patients had angiosarcoma (AS) (n = 12), malignant epithelioid hemangioendothelioma (EHE) (n = 16), and kaposiform hemangioendothelioma (KHE) (n = 13). The median age was 5.39 years (range, 0.8-17.34); 33 patients had localized disease (LD), and 8 patients had metastatic disease. Therapy consisted of chemotherapy (CHT) (AS n = 8, EHE n = 9, KHE n = 5), interferon or new agent therapy (EHE n = 5, 2 KHE n = 2), microscopically or macroscopically complete resection (AS n = 3, EHE n = 6, KHE n = 3), and radiotherapy (AS n = 6, EHE n = 2, KHE n = 1). Two patients (KHE) had watch-and-wait strategy resulting in stable disease. Complete remission (CR) was achieved in AS (10/12; 83%), EHE (10/16; 63%), and KHE (5/13; 38%). The five-year EFS and OS for patients with AS was 64% (± 29 CI 95%) and 80% (± 25, CI 95%), with EHE 62% (± 24, CI 95%) and 78% (± 23, CI 95%), with KHE 33% (± 34, CI 95%) and 92% (± 15, CI 95%), respectively. Complete resection was a significant prognostic factor for AS, LD for EHE.

CONCLUSIONS

Endothelial cell malignancies in childhood have a fair outcome with multimodal treatment. New treatment options are needed for metastic disease.

Kaposiform hemangioendothelioma: current knowledge and future perspectives

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm with high morbidity and mortality. The initiating mechanism during the pathogenesis of KHE has yet to be discovered. The main pathological features of KHE are abnormal angiogenesis and lymphangiogenesis. KHEs are clinically heterogeneous and may develop into a life-threatening thrombocytopenia and consumptive coagulopathy, known as the Kasabach-Merritt phenomenon (KMP). The heterogeneity and the highly frequent occurrence of disease-related comorbidities make the management of KHE challenging. Currently, there are no medications approved by the FDA for the treatment of KHE. Multiple treatment regimens have been used with varying success, and new clinical trials are in progress. In severe patients, multiple agents with variable adjuvant therapies are given in sequence or in combination. Recent studies have demonstrated a satisfactory efficacy of sirolimus, an inhibitor of mammalian target of rapamycin, in the treatment of KHE. Novel targeted treatments based on a better understanding of the pathogenesis of KHE are needed to maximize patient outcomes and quality of life. This review summarizes the epidemiology, etiology, pathophysiology, clinical features, diagnosis and treatments of KHE. Recent new concepts and future perspectives for KHE will also be discussed.

Childhood Vascular Tumors

Vascular tumors in pediatric patients are an important entity for the clinician to recognize and correctly diagnose. They may present at birth or develop at any point during infancy, childhood, or adolescence. Most are benign, but even benign lesions may have significant morbidity without proper intervention. Malignant vascular tumors are also rarely seen in the pediatric population, and may be associated with various syndromes.

Vincristine and sirolimus in the treatment of kaposiform haemangioendothelioma

AIM

Kaposiform haemangioendothelioma (KHE) is a rare, potentially life-threatening vascular tumour that is often associated with thrombocytopenia and coagulopathy, known as the Kasabach-Merritt phenomenon (KMP). Because of the rarity and complexity of KHE, the optimal paradigm for treating KHE has yet to be elucidated. We aim to assess the efficacy and safety of vincristine and sirolimus for the treatment of KHE.

METHODS

A comprehensive review of the literature was conducted from January 1993 to June 2018. A total of 15 studies were selected for the meta-analysis. Five studies included 75 individuals and reported the response and side effects to vincristine in the treatment of KHE with or without KMP. A total of 10 studies that included 127 individuals reported the response and safety of sirolimus for treating KHE with or without KMP.

RESULTS

The pooled odds ratio (OR) for the effectiveness of vincristine was 0.72. The pooled OR for the effectiveness of sirolimus was 0.91. The side effects associated with vincristine during the treatment included neuropathy, abdominal pain, loss of appetite and mild elevations of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The side effects associated with sirolimus therapy included bronchitis; lymphopenia; elevated AST, ALT and platelets; hyperlipidaemia; opportunistic infection; mild reversible leukopenia; mucositis; fever; pain and skin rash/vomiting and diarrhoea.

CONCLUSIONS

This systematic review showed a high efficacy of vincristine and sirolimus in the treatment of KHE. Based on the available data in the literature, it appears that sirolimus is potentially an efficacious and safe treatment option for KHE. Further randomised, controlled trials are recommended.

Musculoskeletal complication in kaposiform hemangioendothelioma without Kasabach-Merritt phenomenon: clinical characteristics and management

PURPOSE

Musculoskeletal complications have been associated with kaposiform hemangioendothelioma (KHE) and can lead to disability and reduced quality of life. We aimed to determine the clinical characteristics of musculoskeletal complication in patients with KHE without Kasabach-Merritt phenomenon (KMP) in order to identify features that may aid clinicians in KHE treatment.

PATIENTS AND METHODS

We conducted a cohort study of KHE without KMP associated with musculoskeletal complication between January 2006 and February 2017 at three tertiary medical centers in China. The study included 29 nonthrombocytopenic patients with KHE and musculoskeletal complication.

RESULTS

The mean age at diagnosis of KHE was 4.5 years (range, 0.3-50.0 years). The mean follow-up was 4.1 years (range, 0.5-9.0 years). In most cases (72.4%), decreased range of motion (ROM) appeared within 2 years of KHE onset. Associated chronic pain was reported in 12 patients. Bone-joint changes were common in patients with decreased ROM (75.9%). All the patients received at least one medical therapy including corticosteroids, vincristine, propranolol, and sirolimus. Sirolimus demonstrated the highest efficacy rate, with 94.7% of patients showing improvements in ROM and chronic pain.

CONCLUSION

Musculoskeletal complication can occur early in the disease course of KHE without KMP. Although no uniformly effective treatment modality was found, sirolimus demonstrated the best response in patients with KHE with decreased ROM and chronic pain.

Kaposiform hemangioendothelioma in children: a benign vascular tumor with multiple treatment options

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor affecting infants and young children. Although benign, it can be associated with an aggressive locally growing tumor and/or a life-threatening Kasabach-Merritt phenomenon (KMP). To date, only reviews of limited cases have been performed. We, therefore, conducted a comprehensive literature search to collect relevant data and make recommendations for future treatment trials.

METHODS

Review of the available literature between 1993 and 2017 revealed a total of 105 publications involving 215 patients of less than 21 years of age. To this, we added 12 from our department and 4 from the Cooperative Weichteilsarkomstudie database.

RESULTS

We found that KMP was present in 79% of the infants, in 47% of the 1-5-year olds, in 43% of the 6-12-year olds, and in 10% of the 13-21-year-old patients. KMP was present in nearly all (94%) patients with retroperitoneal tumors and in all patients with extra-regional tumors. The median size of a KHE without KMP was 12 cm² as compared to 49 cm² when associated with a KMP. With complete (not further classifiable if R0 or R1) resection, all patients were cured. If inoperable, response regarding KMP/regression of tumor size was seen in 29/28% with steroid-, 47/39% with vincristine-, 44/43% with interferon alpha-, 65/61% with anti-platelet agents-, and in 97/100% with sirolimus-containing therapies.

CONCLUSIONS

Patients with progressive KHE should undergo resection whenever it is considered a safe option. If inoperable, sirolimus should be the first choice for treating KMP and reducing tumor size.

Classification and Pathology of Congenital and Perinatal Vascular Anomalies of the Head and Neck

Accurate histopathologic description in correlation with clinical and radiological evaluation is required for treatment of vascular anomalies, both neoplastic and malformative. It is important to examine current clinical, histologic, and immunophenotypical features that distinguish the major types of congenital and perinatal vascular anomalies affecting the head and neck. General discussions of pathogenesis and molecular diagnosis must also be taken into account. This article provides an overview of the features that distinguish the major types of congenital and perinatal vascular anomalies affecting the head and neck, and summarizes the diagnostic histopathologic criteria and nomenclature currently applied to these lesions.

Successful Management of Kaposiform Hemangioendothelioma with Long-Term Sirolimus Treatment: a Case Report and Review of the Literature

Background

Kaposiform Hemangioendothelioma (KHE) is a rare vascular tumour of the infancy and the first decade of life. It is locally aggressive and potentially life threatening when associated with consumptive coagulopathy, known as Kasabach-Merritt syndrome (KMS). No consensus or guideline for the therapy has been reached because of the lack of prospective trials, and the different standard care suggestions are based on retrospective case series.

Case report

We report the case of a 9-month-old male with KHE and KMS in which the initial response, obtained with prednisone and vincristine, was subsequently consolidated and strengthened by long-term treatment with sirolimus, a mTOR inhibitor. A summary of the published data is presented as well.

Conclusions

The inhibition of mTOR pathway represents the most important therapeutic innovation introduced in the last few years for KHE. Our case shows the effectiveness and good tolerance of long-term therapy with sirolimus.

A Case Report of 2 Sirolimus-Related Deaths Among Infants With Kaposiform Hemangioendotheliomas

Kaposiform hemangioendothelioma (KHE) is a rare infiltrative vascular tumor that is potentially life-threatening when presenting with Kasabach-Merritt phenomenon (KMP). KMP is clinically characterized as severe thrombocytopenia and hypofibrinogenemia and therefore is associated with a high mortality rate. There is no standard of cure for KHE currently. Potential medications, including corticosteroids, propranolol, and chemotherapy drugs such as sirolimus, are often used for alleviating KHE symptoms. Although some case reports of sirolimus treatment have shown promising results with recovered coagulant parameters, the off-target effects may cause severe problems. Here we describe 2 cases of infant patients with KHE and KMP who were scheduled to receive sirolimus on a long-term basis. However, both patients developed paroxysmal cough and tachypnea shortly after the onset of sirolimus treatment and succumbed to infection thereafter. This report reveals a potential risk of infection in sirolimus-treated infant patients. The fatal complication highlights the importance of antibiotic prophylaxis and serum sirolimus level monitoring to ensure the safe use of sirolimus in the treatment of infant patients with KHE.

Sirolimus for the treatment of progressive kaposiform hemangioendothelioma: A multicenter retrospective study

Kaposiform hemangioendothelioma (KHE) is an aggressive disease with high morbidity and mortality. The aim of this study was to retrospectively evaluate the efficacy and safety of sirolimus for the treatment of progressive KHE. A multicenter, retrospective cohort study was conducted in patients with progressive KHE treated with sirolimus. A total of 52 patients were analyzed. Thirty-seven (71%) patients exhibited Kasabach-Merritt phenomenon (KMP) and were significantly younger than the patients without KMP [95% confidence interval (CI), 14.39-41.61; p < 0.001]. Patients without KMP were all treated with sirolimus alone, whereas 21 KMP patients with severe symptoms received short-term combination therapy with prednisolone. Overall, 96% and 98% of patients showed improved relief of notable symptoms and/or improved complications at 6 and 12 months after treatment, respectively. After sirolimus treatment, significant decreases in mean severity scores occurred at 6 months (95% CI, 2.23-2.54, p < 0.001) and 12 months (95% CI, 1.53-1.90, p < 0.001). Compared to KMP patients, patients without KMP showed a response that was similar to but less pronounced during the 12 months of treatment (95% CI, 40.87-53.80; p < 0.001). For subgroup analysis of KMP patients, there were no significant differences in tumor shrinkage between those treated with combination therapy and those receiving sirolimus alone (95% CI, 18.11-25.02; p > 0.05). No patients permanently discontinued treatment due to toxicity-related events, and no drug-related deaths occurred. Sirolimus was effective and safe for the treatment of progressive KHE. Sirolimus may be considered as a first-line therapy or as part of a multidisciplinary approach for the treatment of KHE.

Multimodal treatment of Kasabach-Merritt syndrome arising from tufted angioma: A case report

Kasabach-Merritt syndrome (KMS) is a rare type of vascular tumor associated with a severely decreased platelet count. No standard guidelines for the treatment of the disease have been established so far. In the present study, a 1-year-old pediatric patient with KMS arising from tufted angioma was successfully and variously treated with steroids, vincristine, surgery and propranolol for 18 months. Systemic steroids stabilized the platelet count stable, while vincristine reduced the size of the tumor. Due to unpredictable response, the patient was operated. Combination of vincristine and propranolol was introduced post-surgery to improve the severely low platelet count of the patient. Following multimodal therapy for 18 months, there has been no evidence of recurrence or metastasis during 2 years of follow-up. Currently, the patient is alive and well. The management of KMS presents a challenge, and well-designed studies are required to clearly determine the benefits and risks of multidisciplinary treatment.

Sirolimus for Vincristine-Resistant Kasabach-Merritt Phenomenon: Report of Eight Patients

BACKGROUND

The use of sirolimus for patients with multidrug-resistant Kasabach-Merritt phenomenon (KMP) has been reported in recent years. We present the experience of a single center in treating vincristine-resistant KMP using sirolimus alone.

METHODS

Children with vincristine-resistant KMP who were treated with oral sirolimus alone were eligible for inclusion in the study. We evaluated responses according to graded response criteria and acute toxicities according to the National Cancer Institute Common Toxicity Criteria.

RESULTS

Between March 2012 and October 2014, eight patients underwent sirolimus treatment. The response rate of hematologic parameters was 100% (8/8). Three tumors shrank enough to allow excision. The tumors were resected after hematologic parameters normalized. Of the five patients with unresectable vascular lesions, three had complete response, and two had partial response of their tumors at the completion of long-term (39.7 ± 24.4 wks) sirolimus treatment. Grade 3 or 4 adverse events were not documented during treatment or follow-up. No recurrence or progression of the disease was observed during follow-up.

CONCLUSION

In this small case series, we found sirolimus to be highly effective, with minimal side effects, for vincristine-resistant KMP. A larger study to compare sirolimus and vincristine for KMP is warranted.

Successful Treatment of a Complex Vascular Malformation With Sirolimus and Surgical Resection

Management of complex vascular malformation represents a challenge as it may include a wide variety of options such as embolization, laser therapy, sclerotherapy, and surgical resection but may lead to significant morbidity and is associated with high recurrence rates. In extreme and/or recurrent cases, successful use of sirolimus has been described. We report a case of large unresectable complex venous malformation treated with oral sirolimus for 24 months. Therapy was well tolerated. Patient had substantial improvement in symptoms and shrinkage of the lesion. The Medical Therapy made excision of the malformation possible and patient had a successful surgical procedure. This report provides further evidence that sirolimus should be considered as part of the armamentarium in the management of these rare conditions.

Excellent outcome of medical treatment for Kasabach-Merritt syndrome: a single-center experience

Background

Kasabach-Merritt syndrome (KMS) is a rare but life-threatening illness. The purpose of this study is to report our single-center experience with KMS.

Methods

We reviewed the medical records of 13 patients who were diagnosed with KMS between 1997 and 2012 at Samsung Medical Center. Treatment response was defined as follows: 1) hematologic complete response (HCR) – platelet count >130×10⁹/L without transfusion; 2) clinical complete response (CCR) – complete tumor disappearance or small residual vascular tumor displaying lack of proliferation for at least 6 months after treatment discontinuation.

Results

Participants included 7 male and 6 female patients. The median initial hemoglobin levels and platelet counts were 9.7 g/dL (range, 6.6–11.6 g/dL) and 11×10⁹/L (range, 3–38×10⁹/L), respectively. Twelve patients received corticosteroid and interferon-alpha as initial treatment, and the remaining patient received propranolol instead of corticosteroid. Two patients with unsatisfactory response to the initial treatment received weekly vincristine. Successful discontinuation of medication was possible at a median of 301 days (range, 137–579) in all patients except one who was lost to follow-up. The median times to achieve HCR and CCR were 157 days and 332 days, respectively. The probabilities of achieving HCR and CCR were 77% and 54% at 1 year, and 88% and 86% at 2.5 years, respectively.

Conclusion

The prognosis of KMS in our cohort was excellent. Our data suggest that individualized treatment adaptation according to response may be very important for the successful treatment of patients with KMS.

Successful Propranolol Treatment of a Kaposiform Hemangioendothelioma Apparently Resistant to Propranolol

A newborn with unresectable kaposiform hemangioendothelioma associated with Kasabach Merritt phenomenon, unresponsive to vincristine and prednisone, received second-line treatment with propranolol at a dose of 2 mg/kg/day, starting at 2 months of life and continued for 13 months. There was only slight reduction in tumor mass, but measurement of propranolol levels showed extremely low plasma concentrations. The propranolol dose was progressively increased to 3.5 mg/kg/day, leading to a substantial increase in plasma levels associated with clinically relevant tumor reduction. This case highlights the importance of relating propranolol dose to its plasma concentration before considering the treatment ineffective for this vascular tumor.

Clinical Outcomes for Systemic Corticosteroids Versus Vincristine in Treating Kaposiform Hemangioendothelioma and Tufted Angioma

A meta-analysis was performed to evaluate the efficacy and safety of systemic corticosteroids versus those of vincristine in the treatment of kaposiform hemangioendothelioma (KHE) and tufted angioma (TA).A literature search of PubMed, Embase, and Web of Science was performed for clinical studies on systemic corticosteroid versus vincristine therapies in treating KHE/TA. Pooled relative risks (RRs) and response rate with 95% confidence intervals (CIs) were used to measure outcomes. Heterogeneity, subgroup analysis, sensitivity analysis, and publication bias analysis were performed for result evaluation.Thirteen studies, comprising 344 participants, were used in the analysis. Vincristine therapy was found to be relatively more effective than systemic corticosteroids (RRs = 0.45, 95%CI: 0.35-0.58). The result of pooled adverse reactions response rate for systemic corticosteroids was 0.31 (95%CI, 0.18-0.43), significantly higher than that for vincristine, which was 0.12 (95%CI, 0.06-0.19). In subgroup analyses, factors including mean age and race of patients, and period of follow-up were examined as possible sources of heterogeneity.This is the first meta-analysis estimating the clinical outcomes of systemic corticosteroids in comparison with those of vincristine in the treatment of KHE/TA. The results showed that vincristine was considerably more effective with lower complication rates than systemic corticosteroids; thus, vincristine could be suggested as the first-line therapy for KHE/TA.

Kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon in a neonate of life- and limb-threatening nature: A case report

Kaposiform hemangioendothelioma involving whole of a leg in a neonate with Kasabach-Merritt phenomenon causing limb and life-threatening situation has not been reported. One such case and its successful management is presented in this case report. Literature review is made.

Sirolimus for the treatment of children with various complicated vascular anomalies

Vascular anomalies include a heterogeneous group of disorders that are categorized as vascular tumors or vascular malformations. Treatment options include resection, embolization, laser therapy, and sclerotherapy or medical treatment such as propranolol, steroids, interferon, and cytostatic chemotherapy. Mammalian target of rapamycin seems to play a key role in the signal pathway of angiogenesis and subsequently in the development of vascular anomalies. Recently, the successful use of sirolimus has been reported in children with lymphatic malformations and kaposiform hemangioendotheliomas. We report on six patients with different vascular anomalies (kaposiform hemangioendothelioma n = 2, combined lymphatico-venous malformation n = 2, pulmonary lymphangiectasia n = 1, and orbital lymphatic malformation n = 1) who were treated with peroral sirolimus. Three of the children initially presented with a Kasabach-Merrit phenomenon. Median duration of treatment was 10 months; two children are still on treatment. Three children each achieved complete and partial remission. Kasabach-Merrit phenomenon resolved within 1 month in all patients. Treatment with sirolimus was tolerated well; only mild reversible leukopenia was observed.

CONCLUSION

Sirolimus proved to be effective in children with complicated lymphatic or lymphatico-venous malformations and kaposiform hemangioendotheliomas. Treatment was tolerated well with acceptable side effects. The optimum length of treatment and possible long-term side effects have to be evaluated.

WHAT IS KNOWN

• Vascular anomalies including vascular tumors and vascular malformations may lead to life-threatening conditions.• Some patients are refractory to established treatment and/or are not available for local invasive procedures.

WHAT IS NEW

• We reviewed the literature focusing treatment of vascular anomalies inc hildren and adolescents.• Our data support recent studies that sirolimus is an effective treatment option in patients with complicated vascular tumors andmalformations

Recent advances in the pathobiology and management of Kasabach-Merritt phenomenon

Kasabach-Merritt Phenomenon (KMP) refers to the clinical constellation of thrombocytopenia, consumptive coagulopathy and purpura associated with Kaposiform haemangioedothelioma or tufted angioma, but not the more common infantile haemangioma. It shows a variable and unpredictable response to traditional pharmacological agents, such as steroids, vincristine or interferon alpha 2a or 2b. More recently, the interaction between platelets and endothelial cells and the proangiogenic phenotype that results has been recognized to underly the pathogenesis of this disorder. Recent efforts have attempted to target the platelet by using antiplatelet agents and by the withholding of platelet transfusions even in those patients who have significant thrombocytopenia and laboratory evidence of coagulopathy. Excellent response rates and prompt results have been achieved by combining antiplatelet therapy with vincristine, without the need for steroid use. This synergistic approach moves away from the conventional wisdom of treating the underlying lesion to control the coagulopathy. Sirolimus, which is directed against the PI3/AKT/mTOR downstream signalling pathway involved in lymphangiogenesis, has also shown promising results, although further study is needed.

Vincristine for successful treatment of steroid-dependent infantile hemangiomas

Infantile hemangiomas (IHs) are common, although systemic therapy has been generally limited to circumstances of potential compromise of vital functions (airway, vision, feeding, or cardiac), risk of disfigurement, or bleeding. IHs have previously been shown to express high levels of type III deiodinase, which catabolizes active thyroid hormone, resulting in a state of severe hypothyroidism, termed "consumptive hypothyroidism." We describe an infant with diffuse hepatic hemangiomas who developed consumptive hypothyroidism who was initially treated successfully with systemic glucocorticoids and β-blockers. Several efforts to wean her medications were unsuccessful. She subsequently developed severe growth restriction and treatment alternatives were sought. Although previously limited to treatment of life-threatening hemangiomas, a trial of vincristine was initiated. She was ultimately weaned from all systemic therapies, with recovery of a normal growth trajectory. This case highlights broader indications for vincristine as a safe and effective systemic therapy for treatment of IHs. It also stresses the importance of close anthropometric monitoring of infants and toddlers receiving glucocorticoid therapy and intervention when growth compromise becomes evident.

Clinical observations in mesh suture treatment for infants of Kasabach-Merritt phenomenon

AIM

This study aims to evaluate the efficacy and adverse effects of the mesh suture treatment for infants of Kasabach-Merritt phenomenon and to report our treatment experience.

METHODS

Of the three patients, two of the cases occurred in the scalp and one occurred in the back of the chest, with platelet counts < 40 × 10⁹ /L before the treatment, reduced fibrinogen levels and increased D-dimer levels. All the three patients underwent the mesh suture treatment of the tumour area. Post-treatment observations were made regarding the surface colour and texture of the tumours, periodic routine blood examination results, fibrinogen and D-dimer levels.

RESULTS

After treatment, the degree of swelling on the tumour surface was reduced, surface tension was decreased, the tumour colour turned pale red from dark red and the skin gradually returned to normal. Two days after treatment, the platelet counts increased to 70 × 10⁹ /L or higher; the platelet count reached a normal level after 1 week in two cases. The fibrinogen level increased in varying degrees after treatment, whereas the D-dimer level was reduced. One case showed a small amount of exudate at the suture area, 1 month after the treatment; improvements were observed 3 days after changing the local dressing. All the patients were followed up for 6 months to 1 year, during which the patients showed complete regression of the lesion and relapse, normal platelet counts and normal fibrinogen and D-dimer levels.

CONCLUSIONS

We recommend the mesh suture treatment as the first treatment of choice for paediatric Kasabach-Merritt phenomenon.

The importance of early diagnosis and treatment of kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon

Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular tumor that may be complicated by Kasabach-Merritt phenomenon (KMP), a profound thrombocytopenia resulting from platelet trapping within a vascular tumor, either KHE or tufted angioma (TA). Typical features also include low fibrinogen and elevated D-dimers. It is well known that KMP is not caused by infantile hemangiomas. Management of vascular tumors complicated by KMP is challenging, and it is common for referral centers to receive patients in critical medical condition after multimodality treatment failure of vascular anomalies. Our aim is to communicate the importance of early diagnosis and treatment of KHE associated with KMP. A full-term male newborn with KHE complicated by KMP is reported. Treatment with vincristine, aspirin and ticlopidine normalized the coagulation parameters within one week, requiring a total of six doses of vincristine, seven months of ticlopidine and 17 months of aspirin. Early diagnosis and treatment of KHE complicated by KMP may allow the administration of fewer doses of vincristine and avoid the use of corticosteroids.

Mediastinal kaposiform hemangioendothelioma and Kasabach-Merritt phenomenon in a patient with no skin changes and a normal chest CT

A 16-month-old previously healthy boy was admitted to the hospital with respiratory distress and thrombocytopenia. Initial workup demonstrated large pleural and pericardial effusions. The patient had no cutaneous abnormality on physical examination, and his initial chest CT (computed tomography) was nondiagnostic. He required multiple platelet transfusions, chest tube placement, and pericardiocentesis. Sixteen days after admission, a chest MRI (magnetic resonance imaging) revealed a large infiltrative mass of the superior mediastinum, consistent with kaposiform hemangioendothelioma (KHE). The patient's thrombocytopenia was due to associated Kasabach-Merritt phenomenon (KMP). The patient now has complete resolution of KMP after medical treatment with prednisolone, aminocaproic acid, vincristine, and aspirin.

Successful treatment of mild pediatric kasabach-merritt phenomenon with propranolol monotherapy

Kasabach-Merritt phenomenon (KMP) is relatively rare in childhood and adolescents with high mortality rate because of its hemorrhagic complications and unresponsiveness to treatments such as corticosteroids, vincristine, intravascular embolization, and/or surgery. Propranolol, a β -adrenergic receptor blocker, has a promising efficacy against vascular tumors such as infantile hemangiomas. But limited and variable data has been reported regarding the role of propranolol in treatment of KMP. We herein reported the successful treatment of mild pediatric KMP with propranolol monotherapy in a case of a five-week-old child with kaposiform hemangioendothelioma with successful treatment of both clinical and hematologic responses. After eight months of follow-up, patient still had stable cutaneous lesion while receiving propranolol monotherapy. Regular hematologic monitoring was done in order to detect any late relapse of the disease. Six months after discontinuation of propranolol, patient has still remained free of hematologic relapse, and primary cutaneous lesion has become a pale pink, 1 cm sized skin lesion.

Successful management of a small infant with Kasabach-Merritt phenomenon using vincristine: a case report

Kasabach-Merritt Phenomenon (KMP) is characterized by profound thrombocytopenia, microangiopathic haemolytic anaemia and consumptive coagulopathy in the presence of an enlarging vascular lesion. The syndrome usually develops in infancy and is associated with a high morbidity and mortality rate. We report a case of successful management of refractory KMP in a very small infant with the use of vincristine. A female neonate was born with a giant haemangioma on the right thigh and soon presented with coagulopathy and severe thrombocytopenia due to rapid enlargement of the lesion. The condition proved refractory to steroids and propranolol, and the baby was on supportive therapy with daily administration of red blood cells, platelets and cryoprecipitate. Treatment failure and the risk of serious bleeding led to the decision of starting vincristine on the 45th day of life. During the first week of therapy, haematological parameters improved rapidly, and on the second week, the infant had no need for blood products. By the third week of treatment, platelet count and fibrinogen levels had normalized, and the tumour size was dramatically reduced. The infant completed therapy without experiencing any side-effects and had no relapse during the two years that followed. Vincristine proved to be safe, effective and well tolerated in the treatment of this young baby with severe form of KMP. The report, also, highlights the need for considering vincristine early in the management of KMP, especially in cases of rapidly expanding haemangiomas that raise the suspicion of possible malignant lesions (kaposiform haemangioendothelioma/tufted angiomas).

Sirolimus, a promising treatment for refractory Kaposiform hemangioendothelioma

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular tumor that usually occurs in infants. It is commonly associated with Kasabach-Merritt phenomenon which is directly responsible for the significant morbidity and mortality, including hemodynamic instability, local invasion, and compression of vital structures. Treatment is particularly difficult for those who had no response to conventional therapies. This paper wants to share experience of mTOR inhibitors sirolimus in the treatment of refractory KHE.

MATERIALS AND METHODS

Six cases of refractory KHE were diagnosed and treated in Children's Hospital of Fudan University from Jan 2010-June 2013; all of them were treated with sirolimus in June 2012 after failing multiple other therapies.

RESULTS

In six patients, gender was equally distributed between male and female patients. The mean age at the time of initial diagnosed as KHE was 3.1 ± 1.8 months. All of them had been pretreated with at least 2 medical therapies. All of them showed significant improvement in clinical status with tolerable side effects. The average time to response was 5.3 ± 1.0 days; the average stabilization time of platelet was 15.1 ± 8.0 days; and the average time for sirolimus treated as single agent was 1.7 ± 0.4 months. No recurrence of their symptoms happened.

CONCLUSIONS

Sirolimus appears to be effective and safe in patients with life-threatening KHE and represents a promising tool in treating refractory KHE.

Congenital and infantile skin lesions affecting the hand and upper extremity, part 1: vascular neoplasms and malformations

Many dermatologic conditions may be present on a newborn infant's upper extremity that can evoke concern for parents and/or primary caregivers. Although the pediatrician typically remains the first care provider, often these children are referred to specialists to diagnose and treat these lesions. Hand surgeons should be familiar with different infantile skin lesions on an upper extremity. Some lesions are best observed, whereas others require treatment with nonoperative measures, lasers, or surgical interventions. A 2-part series is presented to aid the hand surgeon in becoming familiar with these lesions. This part 1 article focuses on vascular neoplasms and malformations. Particular attention is paid to the multiple types of hemangiomas and hemangioendotheliomas, telangiectasias, angiokeratomas, as well as capillary, venous, and lymphatic malformations. Diagnostic tips and clinical photographs are provided to help differentiate among these lesions. In addition, the recommended treatment for each is discussed.

Long-term outcome of vincristine-aspirin-ticlopidine (VAT) therapy for vascular tumors associated with Kasabach-Merritt phenomenon

BACKGROUND

. This study aimed to clarify the combinatorial treatment effect of agents as aspirin and ticlopidine associated with vincristine in the management of Kasabach-Merritt phenomenon (KMP), a severe thrombocytopenic coagulopathy that occurs in the presence of an enlarging vascular tumor such as kaposiform hemangioendothelioma (KHE) and tufted angioma (TA).

PROCEDURE

. A retrospective review was conducted of medical records of all children with diagnosis of KHE or TA associated with KMP treated with vincristine-aspirin-ticlopidine (VAT) therapy at two different institutions in the same country from 1994 to 2011. Clinical features, response to VAT therapy and outcomes were recorded.

RESULTS

. Eleven patients (mean age 11 months, range 0-36), including seven females (64%) and four males (36%), were identified. Seven patients underwent incisional biopsy and two different histologies were found, KHE in four patients and TA in three patients. Tumors were located in the head and neck (n = 5), chest wall (n = 2), arm (n = 2) and retroperitoneum (n = 2). Mean platelet level was 10,200/mm(3) (range 4,000-21,000). A plaque-like lesion with ecchymosis was the most common cutaneous manifestation (63%). All patients underwent VAT therapy. Mean duration of treatment was 3.9 months for vincristine, 13.9 months for aspirin, and 13.4 months for ticlopidine. All patients are alive with a mean follow-up of 4.5 years (range, 2-17).

CONCLUSIONS

. Antiaggregant therapy is helpful in combination with vincristine in the treatment of KMP associated with KHE and TA. Prognosis is excellent if severe thrombocytopenia is controlled despite failure in reduction of tumor size.

Intratesticular kaposiform haemangioendothelioma in adults: a report of two cases

Kaposiform haemangioendothelioma is a very rare vascular tumour of intermediate (borderline) malignancy, typically occurring in the skin and soft tissues of the extremities in infants and children. We report two morphologically and immunophenotypically classical cases occurring in the testicular parenchyma of old adults, review the literature on vascular tumours of the testis and discuss the differential diagnosis of these unusual cases.

Hemangioendothelioma

Hemangioendothelioma is the term used to name those vascular neoplasms that show a borderline biological behavior, intermediate between entirely benign hemangiomas and highly malignant angiosarcomas. Although originally spindle cell hemangioendothelioma was proposed as a specific clinicopathologic variant of hemangioendothelioma, currently, it is considered as an entirely benign lesion, and thus, the name spindle cell hemangioma seems to be the most accurate for this lesion. Authentic hemangioendotheliomas involving the skin and soft tissues include papillary intralymphatic angioendothelioma (also known as Dabska tumor), retiform hemangioendothelioma, kaposiform hemangioendothelioma, epithelioid hemangioendothelioma, pseudomyogenic hemangioendothelioma (also known as epithelioid sarcoma-like hemangioendothelioma), and composite hemangioendothelioma. Each of these neoplasms exhibit characteristic histopathologic features. The most characteristic finding of papillary intralymphatic hemangioendothelioma consists of papillary tufts, with a central hyaline core lined by hobnail-like endothelial cells protruding into the lumina. Retiform hemangioendothelioma is an infiltrative neoplasm composed of elongated arborizing vessels, arranged in an anastomosing pattern that resembles that of the rete testis, and lined by a single layer of hobnail-like endothelial cells that protrude within the narrow lumina. Kaposiform hemangioendothelioma is composed of several solid poorly circumscribed nodules, and each nodule is composed of a mixture of small capillaries and solid lobules of endothelial cells arranged in a glomeruloid pattern. A frequent finding consists of the presence of areas of lymphangiomatosis adjacent to the solid nodules. Epithelioid hemangioendothelioma is composed of cords, strands, and solid aggregates of round, oval, and polygonal cells, with abundant pale eosinophilic cytoplasm, vesicular nuclei, and inconspicuous nucleoli, embedded in a fibromyxoid or sclerotic stroma. Many neoplastic cells exhibit prominent cytoplasmic vacuolization as an expression of primitive vascular differentiation. Pseudomyogenic hemangioendothelioma is a poorly circumscribed, fascicular lesion with infiltrative borders composed of round or oval neoplastic cells, with vesicular nuclei and inconspicuous nucleoli, and ample homogeneous eosinophilic cytoplasm, giving them a rhabdomyoblastic appearance. Finally, composite hemangioendothelioma is the term used to name locally aggressive vascular neoplasms of low-grade malignancy showing varying combinations of benign, low-grade malignant, and high-grade malignant vascular components. From the immunohistochemical point of view, proliferating cells of all hemangioendotheliomas express a lymphatic endothelial cell immunophenotype. Most hemangioendotheliomas are low-grade vascular neoplasms, with a tendency to recur locally and a low metastatic potential, mostly to regional lymph nodes. Epithelioid hemangioendothelioma, especially large lesions and those located in deep soft tissues, seems to have a more aggressive biological behavior.

Variable response to propranolol treatment of kaposiform hemangioendothelioma, tufted angioma, and Kasabach-Merritt phenomenon

Propranolol is a non-selective beta-adrenergic antagonist successfully used in a case of kaposiform hemangioendothelioma (KHE) associated with Kasabach-Merritt phenomenon (KMP). We report 11 patients treated with propranolol for KHE and the related variant tufted angioma (TA), six of whom also had KMP. The varied responses to treatment, with only 36% responding in our series, demonstrate the need for further study of this medication before routine use for these indications.

Kasabach-Merritt syndrome with large cutaneous vascular tumors

A case series of four patients who presented with large surface vascular tumors and low platelet count and their management is reported. Medical management was done with steroids, propranolol and vincristine in different combinations. The final response was excellent without surgery.

Paclitaxel-based chemotherapy for aggressive kaposiform hemangioendothelioma of the temporomastoid region: Case report and review of the literature

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of infancy and childhood. This tumor results in poor prognosis, and therefore, development of a more effective treatment is needed.

METHODS AND RESULTS

We describe an 11-year-old boy presenting with left facial palsy caused by aggressive KHE of the left temporomastoid region. He was treated with paclitaxel-based chemotherapy, because of the difficulty with complete surgical resection for anatomic factor, multiple lung metastases on diagnosis, and no response to conventional treatments. This treatment reduced the volume of primary tumor and lung metastatic lesions, but the efficacy was transitory.

CONCLUSIONS

Paclitaxel-based chemotherapy for aggressive KHE may be effective, therefore the multimodality therapy including paclitaxel of aggressive KHE, particularly in the head and neck, needs to be investigated in further studies.

Neonatal soft tissue sarcomas

Soft tissue tumors in very young children pose diagnostic and therapeutic challenges. Vascular tumors are the most prevalent soft tissue neoplasms in the neonatal period. They are generally benign tumors, but may exhibit aggressive behaviour and cause life-threatening complications. Fibroblastic tumors of intermediate prognosis, more prevalent in very young children (especially infantile fibrosarcoma), are locally aggressive. Since metastases are unusual in this group of tumors, complete surgical resection is generally curative. However, these tumors often present a therapeutic challenge because of the location which makes complete surgical resection difficult. Among the malignant soft tissue tumors, rhabdomyosarcoma is most frequent. It is an aggressive high-grade tumor, with local invasiveness and a propensity to metastasize. These tumors respond to chemotherapy and radiotherapy. Neonates with rhabdomyosarcoma seem to have a worse prognosis than in older age groups. This may be a result of inappropriate dosing of chemotherapeutic agents and decreased use of radiation therapy among other factors.

Thrombotic microangiopathies

Thrombotic microangiopathy results from thrombotic occlusion of the microvasculature leading to fragmentation of red blood cells, profound thrombocytopenia, and a microangiopathic hemolytic anemia with elevation of lactate dehydrogenase and negative direct Coomb's test. This constellation of clinical and laboratory findings is not due to one disease entity; rather, it represents a variety of underlying diagnoses. Among the major disease entities are TTP/HUS, which can be congenital or acquired, bacterial infections, medications, vascular or endothelial pathology like Kasabach-Merritt phenomenon, and stem cell transplantation. In this paper, we offer a review of some of the major causes of thrombotic microangiopathy.