Kaposiform hemangioendothelioma (KHE) is a rare and aggressive vascular tumor that occurs mainly in infants and children and was first described by Zukerberg et al. Kaposi-like hemangioendothelioma is not an infantile hemangioendothelioma in the traditional sense, but is primarily 2 vascular tumors distinct from infantile hemangioendothelioma.
The treatment of KME combined with Kasabach-Merritt phenomenon (KMP) is an extremely challenging challenge, and there is a lack of a single effective treatment, with a mortality rate of 20% to 50% without proper treatment.
In November 2011, a meeting of 28 experts from 23 institutions and 7 different specialties was held at the National Academy of Joint, Muscle and Skin Diseases. The experts attending the meeting had extensive clinical experience. Based on the available literature, a consensus was reached on issues related to KME with/without KMP, which is presented as follows.
1. Clinical manifestations
Clinically, KME can manifest as a combination of angiomatosis with thrombocytopenia and fibrinemia, which becomes the Kasabach-Merritt phenomenon (KMP), i.e., Kame syndrome. It was first described in 1940 and is characterized by rapidly enlarging hemangiomas combined with thrombocytopenia, hemolytic anemia, and acute or chronic diffuse intravascular coagulation. It occurs in about 1% of all hemangiomas, most commonly in newborns in the first few weeks of life, but can also occur in children or adults. This syndrome should be highly suspected when infants and children have dark purple hemangiomas with shiny surface skin, marked edema, increased tension, wood-like texture, cellulitis-like changes, especially when accompanied by pallor, spontaneous skin petechiae, ecchymosis, easy bruising, prolonged bleeding after puncture or abrasion, hematuria, blood in stool, and nosebleeds. Blood cell count, serum fibrinogen, fibrinolytic products, prothrombin time and partial thromboplastin time need to be checked immediately. In milder cases of KMP, only thrombocytopenia is observed, while in severe cases, depleting coagulopathy may occur, manifested by decreased serum fibrinogen and increased fibrinolytic products.
2.Diagnosis
KMP is not a hemangioma in the traditional sense of infantile hemangioma, but mainly two types of vascular tumors that are very different from infantile hemangioma. The diagnosis of KMP is consistent with a large vascular tumor with bleeding tendency, with imaging data such as ultrasound, CT, MRI, etc., and excluding other causes of thrombocytopenia. If necessary, biopsy of the lesion should be performed to confirm the diagnosis.
3.Treatment
KME combined with KMP
The principle of individualized treatment is adopted, and combined/single treatment is adopted according to the patient’s condition and tumor development.
The experts at the meeting agreed that pharmacological treatment should be preferred for this syndrome. 4 treatment options are as follows.
(1) The starting dose of prednisone (prednisone) should be 2mg/kg once in the morning, once/day. If it is ineffective, a high dose of prednisone (prednisone) should be given orally at 5mg/kg/dose in the morning, once/day. If the platelet count rises and the degree of edema decreases, the dose may be continued for at least 4 weeks and then slowly reduced to 5 mg/day for 2 months. If prednisone (prednisone) is ineffective or the effect is uncertain, the hormone dose can be increased to 10 mg/kg/dose.
(2) Vincristine (VCR) 0.05 mg/kg once a week by intravenous push for 4 times, changed to once a month for 6 times.
(3) Combination therapy of prednisone + VCR.
(4) If the above drugs are ineffective, sirolimus or everolimus may be used for treatment.
KME not combined with KMP
Participating experts believe that KME with mild symptoms and uncomplicated KMP can be treated with (1 of the following depending on the child’s condition).
(1) low dose (2 mg/kg/d) of prednisone orally.
(2) Propranolol (2mg/kg/d) orally.
(3) Vincristine (VCR) 0.05mg/kg once a week.
(4) Aspirin.