Kaposiform hemangioendothelioma: a rare cause of spontaneous hemothorax in infancy. Review of the literature

Medical and interventional therapy of Kasabach-Merritt phenomenon associated with Kaposiform hemangioendothelioma: A case report

An infant with Kasabach-Merritt Phenomenon (KMP) presented with a giant subcutaneous mass in the right lower limb, severe hypofibrinogenemia, and thrombocytopenia. Glucocorticoids, along with supportive treatments including transfusion of blood products and clotting factors, were administered to reverse fatal disseminated intravascular coagulation and acute hemolysis. The glucocorticoid dose was tapered slowly, and sirolimus was added to treat the hemangiomas. The patient subsequently underwent interventional therapy. After 6 months of medical and interventional therapy, the patient was doing well with a normal platelet count, the tumor volume was markedly reduced, and the primary cutaneous lesion became pale pink. Currently, the patient remains on sirolimus, and no recurrence of thrombocytopenia or further growth of the mass was observed after six months of follow-up.

Impact of age and tumor size on the development of the Kasabach-Merritt phenomenon in patients with kaposiform hemangioendothelioma: a retrospective cohort study

Introduction

The Kasabach-Merritt phenomenon (KMP) is a severe complication of kaposiform hemangioendothelioma (KHE). The risk factors for KMP need further investigation.

Methods

The medical records of patients with KHE were reviewed. Univariate and multivariate logistic regression models were used for the risk factors for KMP, and the area under the receiver operator characteristic (ROC) curve was used to assess the predictive power of risk factors.

Results

A total of 338 patients with KHE were enrolled. The incidence of KMP was 45.9%. Age of onset (P < 0.001, odds ratio [OR] 0.939; 95% confidence interval [CI] 0.914-0.966), lesion size (P < 0.001, OR 1.944; 95% CI 1.646-2.296), mixed type (P = 0.030, OR 2.428; 95% CI 1.092-5.397), deep type (P = 0.010, OR 4.006; 95% CI 1.389-11.556), and mediastinal or retroperitoneal lesion location (P = 0.019, OR 11.864; 95% CI 1.497-94.003) were correlated with KMP occurrence through multivariate logistic regression. ROC curve analysis revealed that the optimal cutoffs were 4.75 months for the age of onset (P < 0.001, OR 7.206, 95% CI 4.073-12.749) and a lesion diameter of 5.35 cm (P < 0.001, OR 11.817, 95% CI 7.084-19.714). Bounded by a lesion size of 5.35 cm, we found significant differences in tumor morphology, age of onset, treatments, and hematological parameters. Using an onset age of 4.75 months as a cutoff, we found significant differences in tumor morphology, lesion size, hematological parameters, and prognosis.

Conclusion

For KHE patients with an onset age <4.75 months and/or lesion diameter >5.35 cm, clinicians should be wary of the occurrence of KMP. Active management is recommended to improve the prognosis.

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.

Kaposiform lymphangiomatosis and kaposiform hemangioendothelioma: similarities and differences

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Kaposiform hemangioendothelioma without cutaneous involvement

PURPOSE

We sought to characterize the clinical features and management of patients diagnosed as Kaposiform hemangioendothelioma (KHE) without cutaneous involvement.

METHODS

The electronic patient chats at six Triple A hospitals in China were searched to find all patient diagnoses with KHE without cutaneous involvement.

RESULTS

Of 30 patients (mean age at diagnosis, 55.6 months), 17 (56.7%) were male. Fourteen (46.7%) patients were associated with Kasabach-Merritt phenomenon (KMP). Patients with KMP were significantly more likely to have lesions involving truck compared to patients without KMP (odds ratio 10.000; 95% confidence interval 1.641-60.921; P = 0.011). Other common complication included severe anemia and decreased range of motion. In the majority of cases (93.3%), the lesions were highly infiltrative and locally invasive with ill-defined margins. Histological examination was required in all patients without KMP for precise diagnosis. In all, 16 (53.3%) patients received corticosteroid treatment, 19 (63.3%) received oral sirolimus treatment, 7 (23.3%) received intravenous vincristine, and 5 (16.7%) patients used propranolol. Patients had varied responses to conventional drugs, whereas all patients receiving sirolimus treatment had better response. In all, three patients (10%) died of disease, all presented with KMP. Feature of these recalcitrant cases (death) included young age, visceral location, extensive involvement, and lack of improvement with high-dose corticosteroids.

CONCLUSIONS

Our study clearly demonstrated that KHE without cutaneous involvement could be associated with important complication, which might result in death or severe morbidity. Increased awareness of KHE without cutaneous involvement is required for early diagnosis and aggressive therapy in an attempt to prevent complication.

Kaposiform haemangioendothelioma: clinical features, complications and risk factors for Kasabach-Merritt phenomenon

BACKGROUND

Few studies have reported the clinical features, complications and predictors of Kasabach-Merritt phenomenon (KMP) associated with Kaposiform haemangioendothelioma (KHE).

OBJECTIVES

To determine the clinical characteristics present at diagnosis and to identify features that may aid clinicians in managing KHE.

METHODS

We conducted a cohort study of 146 patients diagnosed with KHE.

RESULTS

KHE precursors or lesions were present at birth in 52·1% of patients. In 91·8% of patients, lesions developed within the first year of life. The median age at diagnosis of KHE was 2·3 months (interquartile range 1·0-6·0). The extremities were the dominant location, representing 50·7% of all KHEs. Among KHEs in the cohort, 63·0% were mixed lesions (cutaneous lesions with deep infiltration). Approximately 70% of patients showed KMP. A KHE diagnosis was delayed by ≥ 1 month in 65·7% of patients with KMP. Patients with KMP were more likely to have major complications than patients without KMP (P = 0·023). Young age (< 6 months), trunk location, large lesion size (> 5·0 cm) and mixed lesion type were associated with KMP in a univariate analysis. In the multivariate analysis, only age [odds ratio (OR) 11·9, 95% confidence interval (CI) 4·07-34·8; P < 0·001], large lesion size (OR 5·08, 95% CI 2·24-11·5; P < 0·001) and mixed lesion type (OR 2·96, 95% CI 1·23-7·13; P = 0·016) were associated with KMP.

CONCLUSIONS

Most KHEs appeared before 12 months of age. KHEs are associated with various major complications, which can occur in combination and develop early in the disease process. Young age, large lesion size and mixed lesion type are important predictors of KMP.

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.

Multifocal kaposiform hemangioendothelioma of soft tissue with bilateral pulmonary involvement in an adolescent

Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor of intermediate malignancy with resemblance to Kaposi sarcoma. It occurs predominantly in pediatric age groups as a cutaneous lesion with focal infiltration into the adjacent soft tissue and bone. Although visceral involvement is very uncommon, several cases with bone, retroperitoneal, or mediastinal involvement have been described. KHE has been reported to occasionally occur in unusual sites such as the thymus, tonsils, larynx, paranasal sinuses, deltoid muscle, spleen, uterine cervix, thoracic spine, and even the breast. Multifocal KHE is an extremely rare entity with few reports available in the literature, none of which describes pulmonary involvement. Herein, we report a unique case of multifocal KHE in a 13-year-old boy presenting with a huge soft tissue mass in the upper extremity complicated by bilateral pulmonary nodules that developed into large, necrotic tumor masses.

Non-traumatic and spontaneous hemothorax in the setting of forensic medical examination: a systematic literature survey

Spontaneous hemothorax is a well-known yet seldom-reported entity in forensic literature. While trauma-related hemothorax is frequently encountered in a medicolegal setting, non-traumatic and spontaneous hemothorax are relatively uncommon entities. The wide range of causes that can trigger fatal intrathoracic bleeding include thoracic aortic dissection, followed by vascular malformations, various oncological diseases, and connective tissue abnormalities. In rare instances, extramedullary hematopoiesis, ectopic pregnancy, congenital heart defects, amyloidosis, or parasitic diseases may constitute a source of bleeding. This etiological heterogeneity may, as a result, cause diagnostic difficulties during post-mortem elucidation of hemothorax. It should be borne in mind that hemothorax after low-energy trauma does not exclusively indicate traumatic hemorrhage, hence, the non-traumatic origin of bleeding must be taken into consideration. In this paper, we present a systematic review of the relevant literature enriched by the results of our observations to investigate the etiologies and recommendations for the post-mortem diagnosis of spontaneous hemothorax in an attempt to better delineate the possible medicolegal considerations. It is important that forensic pathologist as well as clinicians are aware of the diseases that could potentially give rise to fatal hemothorax.

Microscopic Kaposiform Hemangioendothelioma With Extensive Lymphangiomatosis

Kaposiform hemangioendothelioma (KHE) is presently classified as a vascular neoplasm of intermediate malignant potential. The clinical course of large, deep-seated tumors is frequently complicated by consumptive coagulopathy and life-threatening hemorrhage, while superficial tumors tend to behave in an indolent manner, with no known reports of distant metastasis. We describe an unusual example of KHE occurring as an incidental microscopic finding, within a background of extensive lymphangioma-like changes. The patient underwent 4 intralesional excisions over a period of 6 years, and the Kaposiform component accounts for less than 5% of the overall tissue excised. The patient remains clinically well with residual disease 5 years after conservative surgery, and there has been no evidence of regional or distant metastasis. Based on existing literature, it appears doubtful that KHE has any metastatic potential at all, which calls into question the appropriateness of its place in the spectrum of malignant vascular neoplasms.

Intra-abdominal Kaposiform hemangioendothelioma and the benefits of laparoscopic surveillance

We report a case of a neonate presenting with the rare vascular tumor, Kaposiform hemangioendothelioma. She had a lesion arising from the left ovary with multiple intraperitoneal metastases causing small bowel obstruction. We managed this case with primary surgical resection followed by laparoscopic surveillance of the peritoneal cavity and metastectomy. The child is fit and well and free of tumor after 32 months. Neither this presentation of this tumor nor this management approach has been previously described in the literature.

Update on pediatric extracranial vascular anomalies of the head and neck

PURPOSE

Vascular anomalies most frequently present at birth or in early childhood, and the craniofacial region is the most common site of involvement. A long history of misleading nomenclature born of confusion about the presentation and natural history of various vascular anomalies has made appropriate diagnosis difficult. The present article emphasizes the importance of clarity of nomenclature for proper diagnosis, both clinically and radiographically, to guide appropriate therapy. In addition, updates on clinical concepts, imaging, and treatment strategies will be discussed. Pediatric vascular anomalies can be divided into two broad categories: vascular tumors and vascular malformations. This biologic classification is based on differences in natural history, cellular turnover, and histology. An updated classification was introduced in 1996 by the International Society for the Study of Vascular Anomalies (ISSVA) to include infantile hemangioma variants, other benign vascular tumors, and combined lesions. Widespread confusion propagated throughout the literature and in clinical practice stems from the continued improper use of many of the terms used to describe vascular tumors and malformations ignoring their pathophysiology. This leads to errors in diagnosis and the dissemination of misinformation to patients and clinicians. Certain terms should be abandoned for more appropriate terms. The clinical presentation usually identifies what general type of vascular anomaly is present, either vascular tumor or vascular malformation. Imaging provides crucial information about the initial diagnosis and aids in follow-up.

CONCLUSIONS

Adoption and use of uniform nomenclature in the ISSVA classification system is the first vital step in correct diagnosis and treatment of often complicated vascular tumors and vascular malformations. A multidisciplinary team approach is necessary to provide optimal care for patients, and the necessity for specialists in all areas to communicate using standardized terminology cannot be overemphasized.

Kaposiform hemangioendothelioma arising in the deltoid muscle without the Kasabach-Merritt phenomenon

Kaposiform hemangioendothelioma (KHE) is a rare tumor that occurs nearly exclusively during infancy and childhood. It has features common to both capillary hemangioma and Kaposi sarcoma and for that reason many terms have been used for these tumors including "Kaposi-like infantile hemangioendothelioma" and "hemangioma with Kaposi sarcoma-like features." KHE typically presents as an ill-defined, red to purple, indurated plaque and is often complicated by the Kasabach-Merritt phenomenon (KMP), a condition of severe thrombocytopenia and consumptive coagulopathy. Knowledge of the radiological findings of this uncommon tumor might be helpful for diagnosis. We present the MRI features of a case of KHE with neither typical skin lesions nor the Kasabach-Merritt phenomenon.

Update on vascular tumors of infancy

PURPOSE OF REVIEW

Advances have been made in the pathogenesis, diagnosis and management of vascular tumors of infancy in the past year. Propranolol therapy for infantile hemangiomas (IH) is now being used widely, and case reports, series, and adverse effects are reviewed. Kaposiform hemangioendothelioma and tufted angioma are less common than IH but more often associated with coagulopathy (Kasabach-Merritt phenomenon).

RECENT FINDINGS

Recent work suggests that stem cells, mediated by the Notch signaling pathway, may become proliferating endothelial cells that comprise IH. Large, segmental IH are more likely to develop complications that can include life-threatening bleeds; however, solitary large IH do not appear to increase the risk of hepatic IH. Segmental IH may herald underlying structural anomalies of the brain, cerebral, and cardiac vessels (PHACE syndrome--Posterior fossa defects, Hemangiomas, Arterial anomalies, Cardiac defects and Coarctation of the aorta, Eye anomalies), and new criteria aid in diagnosis. Propranolol therapy is effective in life-threatening IH and appears to stop growth and hasten involution in proliferative and plateau phase IH. Adverse effects include bradycardia, hypotension, hypoglycemia, and bronchospasm. A recent review of kaposiform hemangioendothelioma finds that an associated coagulopathy (Kasabach-Merritt phenomenon) occurs in 72%.

SUMMARY

Propranolol appears to be tremendously efficacious with fewer side effects than systemic corticosteroids, but its proper place in the therapeutic algorithm for IH and other vascular tumors awaits controlled study.

Kaposiform hemangioendothelioma in multiple spinal levels without skin changes

Kaposiform hemangioendothelioma is a rare vascular tumor of childhood that is locally aggressive but has little metastatic potential and by itself is not known to be lethal. It most commonly presents as a superficial or deep soft tissue mass with associated cutaneous lesions. Kasabach-Merritt phenomenon, a condition characterized by profound thrombocytopenia and life-threatening hemorrhage, often is associated with kaposiform hemangioendothelioma. Six cases of kaposiform hemangioendothelioma have been reported in bone, two of which were located in extracraniofacial bones. We report a diagnostically challenging case of a 6-year-old girl with kaposiform hemangioendothelioma of the thoracolumbar spine without Kasabach-Merritt phenomenon or cutaneous lesions.