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.

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.

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.

Kaposiform haemangioendothelioma of the head and neck.

BACKGROUND: Kaposiform haemangioendothelioma (KHE) is a tumor of intermediate malignant potential derived from vascular endothelial cells. Due to rarity of head neck KHE (HN-KHE) this comprehensive review aims to compile, analyze and present details to develop a consensus and augment available literature on HN-KHE. MATERIALS AND METHODS: A comprehensive literature search was performed on PUBMED/MEDLINE, EMBASE, CINAHL and Science Citation Index for HN-KHE using MeSH words. Statistical analysis was performed using a variety of tests. RESULTS: Common sites of involvement were neck 41.5%, face and scalp 32.0% and tympanomastoid region in 13.2% patients. Kasabach-Merritt phenomenon was seen in 58.5% patients. Surgical excision was performed in 37.7% patients while 39.6% patients underwent medical management/chemotherapy (CT). Significantly better disease free survival (DFS) was seen in patients undergoing surgical excision vs. CT (p=0.001), without recurrence vs. with recurrence (p=0.001) and those presenting within 0-1year of life vs. 1-5 years (p=0.021). CONCLUSION: Recurrence and metastasis were seen in 35.8% and 20.0% patients respectively. Complete surgical excision with clear margins remains the treatment of choice.

Kaposiform hemangioendothelioma: atypical features and risks of Kasabach-Merritt phenomenon in 107 referrals.

OBJECTIVE: To examine the presentation characteristics of patients with Kaposiform hemangioendothelioma (KHE) to describe the spectrum of disease and risk factors for Kasabach-Merritt phenomenon (KMP). STUDY DESIGN: A retrospective review of 163 patients referred to the Vascular Anomalies Center at Children's Hospital Boston for KHE between 1991 and 2009 identified 107 patients with sufficient data for inclusion. RESULTS: The prevalence of KHE in Massachusetts is ∼0.91 case per 100000 children. KHE manifested in infancy in 93% of cases, with 60% as neonates. Common presenting features included enlarging cutaneous lesion (75%), thrombocytopenia (56%), and musculoskeletal pain or decreased function (23%). Cutaneous KHE favored the extremities, especially overlying joints. In our cohort, 71% developed KMP (11% after initial presentation), and 11% of patients lacked cutaneous findings. Retroperitoneal and intrathoracic lesions, though less common, were complicated by KMP in 85% and 100% of cases, respectively. Compared with superficial lesions, KHE infiltrating into muscle or deeper was 6.3-fold more likely to manifest KMP and 18-fold higher if retroperitoneal or intrathoracic. KHE limited to bone or presenting after infancy did not manifest KMP. CONCLUSION: An enlarging cutaneous lesion is the most common presenting feature of KHE in infancy. Older patients with KHE or those lacking cutaneous manifestations present with musculoskeletal complaints or atypical symptoms. The risk of KMP increases dramatically when tumor infiltrates muscle or when KHE arises in the retroperitoneum or mediastinum.

Microscopic Kaposiform hemangioendothelioma with extensive lymphangiomatosis: an extraordinary example of an unusual entity.

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.