Sirolimus as initial therapy for kaposiform hemangioendothelioma and tufted angioma

Consensus statement for the diagnosis, treatment, and prognosis of kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor that typically presents in infancy or early childhood. As awareness of KHE increases, it is imperative that the management of KHE be updated to reflect the latest evidence-based guidelines. The aim of this study was to integrate the literature and Chinese expert opinions to provide updated recommendations that will guide the diagnosis, treatment, and prognosis of patients with KHE. According to this consensus statement, 28 nationally peer-recognized experts in vascular anomalies and an expert in evidence-based medicine were assembled and formed three consensus subgroups. A series of key themes and questions were developed for each group, including recommendations for diagnosis, treatment, and prognosis. A systematic search was conducted for English-language articles published in PubMed and other relevant studies identified by the expert panel. A diagnosis of KHE necessitates the integration of clinical, imaging, and histologic features. The treatment of KHE should be tailored to the specific characteristics of each patient, including the size of the lesion, the presence of symptoms, the location, and the overall condition of the patient. In addition to focusing on the disease itself, it is also important to consider the complications of KHE and their impact on prognosis. The recommendations presented herein are intended to assist in the guidance of clinical practice and decision-making in patients with KHE, with the objective of improving patient outcomes.

Cost-utility of sirolimus in the treatment of vascular malformations

Sirolimus is being increasingly employed to manage specific vascular anomalies. We performed an exploratory cost-utility analysis to evaluate sirolimus as a treatment for vascular malformations from the Australian healthcare system perspective. Over a one-year time horizon, sirolimus treatment was associated with an increased expenditure of AU$2832.80 and a gain of 0.08 quality-adjusted life years (QALYs) when compared to supportive care, resulting in an incremental cost-effectiveness ratio of AU$35,410/QALY. By most metrics, sirolimus would be considered a cost-effective treatment for vascular malformations.

Sirolimus for vascular anomalies in the first year of life: a systematic review

Evidence on effectiveness and safety of sirolimus in congenital vascular anomalies in infancy is lacking. We aim to systematically review the efficacy and safety of sirolimus in treating congenital VA in infancy. We searched for and included all studies evaluating sirolimus for VA in the first year of life. The primary outcome was effectiveness. The secondary outcome was safety. We included 84 case series and reports (172 participants). Sirolimus decreased the size of the VA in >50% of participants, most of whom had minor transient side effects, and 27% had no adverse effects at all. When categorized by age (<1 month, 1-5 months and 6-12 months), the effectiveness was similar in all age groups. Available evidence suggests that sirolimus is effective and well tolerated. The effectiveness of sirolimus should be evaluated in a well-designed randomized controlled or observational studies.

Cost and effectiveness comparison of sirolimus versus standard treatment in Kasabach-Merritt phenomenon: a real-world evidence study in Thailand

The conventional treatment of Kasabach-Merritt Phenomenon (KMP) consists of corticosteroids with vincristine/vinblastine or others. The aim of the study is to compare the first-year direct costs and effectiveness between sirolimus and conventional treatment. A retrospective case-control study of KMP patients was conducted at a mean age of 9 months (1 day to 12 years) between 2000 and 2022 from four tertiary centers in Thailand. The direct costs, hematologic and clinical complete response (HCR, CCR), hospitalization, length of stay, and complications were compared. Of 29 patients, 13 underwent sirolimus (four upfront and nine were refractory to the conventional). The first-year total cost had no statistically significant difference between sirolimus VS conventional treatment (8,852.63 VS 9,083.56 USD: p value: 0.94). The therapeutics achievement was the same in both HCR (244.75 VS 168.94 days; p value: 0.60) and CCR (419.77 VS 399.87 days; p value: 0.90). The subgroup analysis of the first-line sirolimus (n = 4) compared with the conventional (n = 25) showed a more reduced total cost (4,907.84 VS 9,664.05 USD; p value: 0.26) rendered net total cost of -4,756.21 USD per patient (cost saving). A more significant contrast of therapeutic achievement by reduction of both HCR (11.67 VS 224.20 days; p value: 0.36) and CCR (38.50 VS 470.88 days; p value: 0.04) was shown. The sirolimus had no difference in hospitalization, length of stay, and complications. Even though, it was unable to identify significant differences in cost-effectiveness. Sirolimus is suitable for all patients who have diagnosis of KMP either for rescue therapy or first-line treatment.

Construction and applications of the EOMA spheroid model of Kaposiform hemangioendothelioma

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a rare intermediate vascular tumor with unclear pathogenesis. Recently, three dimensional (3D) cell spheroids and organoids have played an indispensable role in the study of many diseases, such as infantile hemangioma and non-involuting congenital hemangiomas. However, few research on KHE are based on the 3D model. This study aims to evaluate the 3D superiority, the similarity with KHE and the ability of drug evaluation of EOMA spheroids as an in vitro 3D KHE model.

RESULTS

After two days, relatively uniform morphology and high viability of EOMA spheroids were generated by the rotating cell culture system (RCCS). Through transcriptome analysis, compared with 2D EOMA cells, focal adhesion-related genes such as Itgb4, Flt1, VEGFC, TNXB, LAMA3, VWF, and VEGFD were upregulated in EOMA spheroids. Meanwhile, the EOMA spheroids injected into the subcutaneous showed more obvious KMP than 2D EOMA cells. Furthermore, EOMA spheroids possessed the similar characteristics to the KHE tissues and subcutaneous tumors, such as diagnostic markers (CD31 and LYVE-1), cell proliferation (Ki67), hypoxia (HIF-1α) and cell adhesion (E-cadherin and N-cadherin). Based on the EOMA spheroid model, we discovered that sirolimus, the first-line drug for treating KHE, could inhibit EOMA cell proliferation and downregulate the VEGFC expression. Through the extra addition of VEGFC, the effect of sirolimus on EOMA spheroid could be weakened.

CONCLUSION

With a high degree of similarity of the KHE, 3D EOMA spheroids generated by the RCCS can be used as a in vitro model for basic researches of KHE, generating subcutaneous tumors and drug screening.

Case Report: Recurrent blepharal kaposiform hemangioendothelioma in an adult patient

Background

Kaposiform hemangioendothelioma (KHE) is a rare and invasive vascular tumor that mainly occurs in children and is rarely seen in adults. We report a case of KHE found on the eyelid of an adult patient.

Case report

We present an adult patient in whom KHE recurred 6 months after tumor resection. He underwent second surgical resection and intraoperative chemotherapy. There was no evidence of recurrence at the 3-year follow-up.

Conclusion

KHE in adults is easy to be misdiagnosed. KHE can be treated by surgical resection. Complete resection of the tumor and intraoperative chemotherapy may help prevent a recurrence.

Efficacy of transcatheter arterial chemoembolization combined with sirolimus for treating Kasabach-Merritt phenomenon in infants, a retrospective study

OBJECTIVE

This retrospective study aimed to observe the efficacy of transcatheter arterial chemoembolization (TACE) combined with sirolimus in the treatment of haemangioma combined with the Kasabach-Merritt phenomenon (KMP).

METHODS

A total of 11 infants with KMP who were treated at our hospital from January 2016 to September 2021 were selected and treated with arteriosclerosis embolotherapy using a microsphere emulsion formed by bleomycin + ultra-fluid lipiodol + dexamethasone + contrast agent or bleomycin mixed microspheres as the embolising agent. The patients were administered sirolimus orally after TACE. The clinical efficacy and examination indicators before and after treatment were observed and compared.

RESULTS

The 11 infants underwent TACE treatment by arteriosclerosis embolotherapy a total of 21 times; of these cases, 10 were cured, and 1 showed a moderate response. There were no cases of non-response or death. The platelet count rose from 10.0 (7.0, 18.0) x 10⁹/L before TACE to 236.0 (188.0, 275.0) x 10⁹/L six months after the first TACE, and the tumour size decreased from 49.0 (43.0, 111.7) cm³ before TACE to 7.0 (3.5, 17.0) cm³ six months after the first TACE. The differences were statistically significant (the Z values were -2.943 and -2.934, respectively, p < 0.05).

CONCLUSION

The combination of TACE and sirolimus has significant efficacy on critical children with KMP.

Cerebral Tufted Angioma with Gradually Developing Peritumoral Edema: A Case Report

Tufted angioma is a benign vascular tumor in which immature endothelial and pericyte cells and lymphatic vascular endothelium grow. It manifests as a flat, painful erythema that gradually expands mainly on the trunk and extremities. Although tufted angiomas can also occur in other areas of the body and may be more locally invasive, they rarely occur intracranially. A 63-year-old man underwent magnetic resonance imaging (MRI) for a brain check-up 8 years before his visit to our institute, which detected a mass lesion with surrounding cerebral edema in the left frontal lobe. The patient was followed up with annual MRI analysis, which indicated slow tumor growth and gradual development of peritumoral edema. The tumor was treated by gross-total resection. Histological analysis showed a slightly dilated microvascular core surrounded by many capillary aggregates in the brain parenchyma. Immunohistochemical findings indicated that the vascular endothelial cells were positive for CD34 and Brahma-related gene-1 and were surrounded by smooth muscle actin-positive pericytes. These findings were consistent with tufted angioma. Intracranial tufted angioma is uncommon, but it should be considered in the differential diagnosis for intracranial tumorous lesions. Long-term follow-up is necessary to unravel the natural history of the disease.

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.

Cocktail therapy with prednisolone, vincristine and sirolimus for Kasabach‑Merritt phenomenon in 10 infants

Kasabach-Merritt phenomenon (KMP) is a life-threatening condition caused by rare vascular tumors. To reduce drug resistance observed in monotherapy of KMP with prednisone, vincristine (VCR) or sirolimus, the present study evaluated the efficacy and safety of triad therapy in the treatment of KMP. A total of 10 KMP infants managed with prednisolone, VCR and sirolimus in The Second Affiliated Hospital of Xi'an Jiaotong University (Xi'an, China) between April 2017 and August 2021 were retrospectively reviewed. The three female and seven male infants with KMP underwent cocktail therapy with prednisone, VCR and sirolimus. At diagnosis, the infants, aged 49.1±41.0 days, showed laboratory test results with platelet counts 22±15.4x10⁹/l, fibrinogen 81.7±26.9 mg/dl and D-dimer 38649±13443.6 ng/ml. The average maximal diameter of the tumors at diagnosis was 84.5±25.1 mm. KMP risk is increased by large tumors with deep lesions infiltrating the muscle. Platelet counts normalized after a median 10 days (range, 5-69 days) of treatment. With combination therapy maintained for 46.8±24.4 days, ultrasound showed that the thickness of the tumors decreased by 51% from 28.9±12.1 to 13.9±6.2 mm. Neutropenia and gastrointestinal disorders were the most common adverse effects. The present study found that the cocktail therapy with prednisolone, VCR and sirolimus has favorable tolerance and efficacy for life-threatening KMP. Once a stable condition has been achieved, cocktail therapy should be replaced by sirolimus monotherapy to reduce potential side effects.

Effective low-dose sirolimus regimen for kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon in young infants

AIMS

Management of kaposiform haemangioendotheliomas (KHE) with Kasabach-Merritt phenomenon is challenging in young infants who are subjected to developmental pharmacokinetic changes. Sirolimus, sometimes combined with corticosteroids, can be used as an effective treatment of KHE. Simultaneously, toxicities such as interstitial pneumonitis related to the use of sirolimus may be fatal. As infants have a very low CYP3-enzyme expression at birth, which rises during ageing, we hypothesize that a reduced metabolization of sirolimus might lead to high sirolimus serum levels and low dose may be sufficient without the side effects.

METHODS

A case series of 5 infants with kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon was analysed retrospectively. All infants were treated with sirolimus 0.2 mg/m2 every 24 or 48 hours according to their age. Prednisone was added to the therapy for additional effect in 4 patients.

RESULTS

In all patients, low dose of sirolimus led to therapeutic sirolimus levels (4-6 ng/mL). All infants (aged 4 days-7 months) had a complete haematological response, without serious adverse events. In all patients, the Kasabach-Merritt phenomenon resolved, the coagulation profile normalized and tumour size reduction was seen.

CONCLUSION

Low-dose sirolimus treatment is safe for infants with kaposiform haemangioendothelioma and Kasabach-Merritt phenomenon. It is essential to realize that during the first months of life, metabolism is still developing and enzymes necessary to metabolise drugs like sirolimus still have to mature. To avoid toxic levels, the sirolimus dosage should be based on age and the associated pharmacological developments.

ISSVA Classification of Vascular Anomalies and Molecular Biology

Vascular anomalies include various diseases, which are classified into two types according to the International Society for the Study of Vascular Anomalies (ISSVA) classification: vascular tumors with proliferative changes of endothelial cells, and vascular malformations primarily consisting of structural vascular abnormalities. The most recent ISSVA classifications, published in 2018, detail the causative genes involved in many lesions. Here, we summarize the latest findings on genetic abnormalities, with the presentation of the molecular pathology of vascular anomalies.

Solid pancreatic masses in children: A review of current evidence and clinical challenges

Pancreatic tumors in children are infrequently encountered in clinical practice. Their non-specific clinical presentation and overlapping imaging characteristics often make an accurate preoperative diagnosis difficult. Tumors are categorized as epithelial or non-epithelial, with epithelial tumors further classified as tumors of the exocrine or endocrine pancreas. Although both are tumors of the exocrine pancreas, solid pseudopapillary neoplasm is the most prevalent solid pancreatic tumor in children, while pancreatoblastoma is the most common malignant tumor. Insulinoma is the most common pediatric pancreatic tumor of the endocrine pancreas. Malignant tumors require a complete, often radical, surgical resection. However, pancreatic parenchyma-sparing surgical procedures are utilized for benign tumors and low-grade malignancy to preserve gland function. This review will discuss the epidemiology, pathophysiology, clinical and diagnostic characteristics, and management options associated with both common and rare solid pancreatic masses in children. We will also discuss current challenges encountered in their evaluation and treatment.

Severe hypertriglyceridemia following sirolimus use in an infant

Inhibitors of mammalian target of rapamycin function to downregulate cell growth and proliferation and have off-label use in pediatrics for vascular malformations. Hypertriglyceridemia is a known side effect of mammalian target of rapamycin (mTOR) inhibitors. Further studies to better understand the incidence and treatment of hypertriglyceridemia in infants and neonates are warranted.

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.

Additive value of transarterial embolization to systemic sirolimus treatment in kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor in children, which can be accompanied by life-threatening thrombocytopenia, referred to as Kasabach-Merritt phenomenon (KMP). The mTOR inhibitor sirolimus is emerging as targeted therapy in KHE. As the sirolimus effect on KHE occurs only after several weeks, we aimed to evaluate whether additional transarterial embolization is of benefit for children with KHE and KMP. Seventeen patients with KHE and KMP acquired from 11 hospitals in Germany were retrospectively divided into two cohorts. Children being treated with adjunct transarterial embolization and systemic sirolimus, and those being treated with sirolimus without additional embolization. Bleeding grade as defined by WHO was determined for all patients. Response of the primary tumor at 6 and 12 months assessed by magnetic resonance imaging (MRI), time to response of KMP defined as thrombocyte increase >150 × 10³ /μL, as well as rebound rates of both after cessation of sirolimus were compared. N = 8 patients had undergone additive embolization to systemic sirolimus therapy, sirolimus in this group was started after a mean of 6.5 ± 3 days following embolization. N = 9 patients were identified who had received sirolimus without additional embolization. Adjunct embolization induced a more rapid resolution of KMP within a median of 7 days vs 3 months; however, tumor response as well as rebound rates were similar between both groups. Additive embolization may be of value for a more rapid rescue of consumptive coagulopathy in children with KHE and KMP compared to systemic sirolimus only.

Sirolimus for Kaposiform Hemangioendothelioma and Kasabach-Merritt Phenomenon in a Neonate

We present a case of a neonate born with kaposiform hemangioendothelioma (KHE), complicated by Kasabach-Merritt phenomenon (KMP) and other serious conditions, who was successfully treated with sirolimus. In addition to complications from thrombocytopenia and fluid overload, during the course of therapy, our patient experienced supratherapeutic drug levels at the commonly accepted starting dose of sirolimus. Patients with KHE and KMP should be closely monitored for potential complications of both the initial disease and unexpected side effects of treatments.

Effective surgical treatment of life-threatening huge vascular anomalies associated with thrombocytopenia and coagulopathy in infants unresponsive to drug therapy

BACKGROUND

Systemic drug therapy is generally recommended for infant huge vascular anomalies associated with thrombocytopenia and coagulopathy, but some patients are not suitable due to drug unresponsiveness or life threatening conditions before the drug works, who will need to receive surgical treatment. This study retrospectively analyzed the clinical features, imaging features, and surgical outcomes of these patients.

METHODS

The clinical data of 4 infants with huge vascular anomalies (2 vein malformations (VMs) and 2 kaposiform hemangioendothelioma (KHE)) associated with thrombocytopenia and coagulopathy treated from June 2016 to December 2017 were retrospectively analyzed. All patients received glucocorticoids, propranolol, vincristine or sirolimus treatment before admission, but the treatment was ineffective. Skin petechia, thrombocytopenia and coagulopathy were present at the time of admission. CT scanning was performed before operation. The patient's general clinical data, hematological examination results, operation time, surgical bleeding volume, blood transfusion volume and surgical complications were collected for analysis. The patients were followed up for 10-26 months.

RESULTS

CT scanning results of 2 patients showed special CT features without detectable enhancement within the lesion after CT enhanced scanning and multiple phleboliths formation. Four patients underwent surgical treatment successfully. Two patients underwent complete resection of the lesion, and 2 underwent cytoreductive surgery. Preoperative clinical symptoms such as skin petechia, thrombocytopenia and coagulopathy were normal at 1 week after surgery. Postoperative pathological results showed 2 cases of KHE and 2 cases of VMs. All patients were discharged from hospital without physical dysfunction, recurrence, or death.

CONCLUSIONS

Timely and appropriate surgical intervention can achieve satisfactory results for infants with huge VMs and KHE who were unresponsive to drug therapy or suffering from life-threatening occasion before the drug become effective.

Sirolimus for Kaposiform Hemangioendothelioma With Kasabach-Merritt Phenomenon in Two Infants

Kaposiform hemangioendothelioma is an aggressive vascular tumor with infiltrative growth that commonly occurs in infancy and is associated with a life-threatening consumptive coagulopathy, as well as Kasabach-Merritt phenomenon. Recently, promising results have shown that sirolimus had been successfully used to treat Kasabach-Merritt phenomenon without significant toxicity. However, the situation the authors encountered in treating infants was not so satisfactory. Here, the authors present 2 patients younger than 3 months with refractory Kaposiform hemangioendothelioma treated with sirolimus and experienced severe pneumonia. The outcomes suggest that it is necessary to keep an eye on any symptoms indicate the infection of respiratory tract and use the antibiotics in time. The 2 cases also remind us of the potential sign that indicate the recurrence of KMP, which refers to firmer lesion with deepen color, especially when it comes with complications.

Treatment of superficial vascular anomalies with topical sirolimus: A multicenter case series

BACKGROUND

Systemic sirolimus (rapamycin) has recently been found effective in treating complex vascular anomalies by reducing the size and associated complications. Many vascular anomalies have a cutaneous component, and thus, we sought to determine whether topical administration of sirolimus may be an effective therapy, as data on the use of topical sirolimus are limited.

OBJECTIVE

We reviewed the efficacy and tolerability of topical formulations of sirolimus in the treatment of various simple and combined vascular malformations and tumors.

METHODS

Eighteen patients with any vascular anomaly treated exclusively with topical sirolimus were retrospectively reviewed.

RESULTS

Eleven patients had combined venous lymphatic malformations, three had tufted angiomas, two had a lymphatic malformation, one had a venous malformation, and one had a verrucous venous malformation. All (100%) patients reported some degree of improvement and 50% of patients reported marked improvement in one or more symptoms, most commonly blebs and lymphatic drainage, and bleeding.

LIMITATIONS

The retrospective nature, small number of patients, and differences in topical preparations limit the broad application of the results.

CONCLUSION

Topical sirolimus appears to be a safe and useful non-invasive therapy that is well-tolerated in the treatment of the cutaneous portion of a variety of vascular anomalies.

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.