Kasabach Merritt syndrome is a rare disease consisting of a vascular tumor (kaposiform hemangioendothelioma, tufted or congenital angioma), thrombocytopenia and consumptive coagulopathy (hypofibrinogenemia). When microangiopathic hemolytic anemia is also present, the condition is called Kasabach Merritt phenomenon. This pathology has a lethal potential, due to its natural evolution to disseminated intravascular coagulopathy.
Patients with Kasabach Merritt syndrome may present for the evaluation of cutaneous lesions , for symptoms caused by visceral vascular tumors or for milder dermal manifestations of the disease , like petechiae, bruising  or bleeding. With hepatic angiomas, patients can have hepatomegaly and jaundice. If the vascular tumor is large, a great amount of blood circulates within it, causing symptomatic high output heart failure . Large lesions may also cause compression of the neighboring structures, with various signs, depending on their location. Death can be due to cerebral bleeding from an intracranial pathology , or secondary to disseminated intravascular coagulation, multiorgan failure, shock, and sepsis. Hemangiomas may be located anywhere: the skin, retroperitoneal organs, mediastinum, pelvis, neck, limbs, musculoskeletal, visceral organs. Symptoms may become worse as the child grows older and subsequently, the vascular tumor grows larger. However, patients may remain asymptomatic until they become adults or may present during the first weeks of life.
When no cutaneous lesions are present, the diagnosis is easily missed unless a thorough examination that suggests liver or spleen enlargement, for instance, is performed . Still, clinical examination may be uninformative in some patients, like those with intraosseous disease  , therefore the diagnosis relies on a high level of suspicion, laboratory and imaging data.
Entire Body System
The medicolegal examination concluded that the appearance of the lesion was only mildly suggestive of an ecchymosis. A second, temporally remote examination confirmed this doubt. [ncbi.nlm.nih.gov]
[Medline]. de la Hunt MN. Kasabach-Merritt syndrome: dangers of interferon and successful treatment with pentoxifylline. J Pediatr Surg. 2006 Jan. 41(1):e29-31. [Medline]. Haisley-Royster C, Enjolras O, Frieden IJ, et al. [emedicine.medscape.com]
A number of events such as sclerotherapy, surgery, bone fracture, prolonged immobilization and pregnancy or menstruation triggered conversion of the LIC to disseminated intravascular coagulation (DIC), with bleeding related to factor consumption and multiorgan [ncbi.nlm.nih.gov]
In such patients, operative management of long bone hemangiomatous lesions, including percutaneous needle aspirations, may be contraindicated, and nonoperative management may be preferable. [ncbi.nlm.nih.gov]
Biopsy of the scalp lesion was deemed too risky and fine needle aspiration of the liver was nondiagnostic. [pagepress.org]
Thus, it is possible that KHE and tufted angiomas are the part of the same neoplastic spectrum and histologic continuum. ,  The trigger factors for the development of KMS include surgical intervention, pregnancy, angiography, and needle aspiration [jcnonweb.com]
However, the mass continued to grow, resulting in inspiratory stridor. Magnetic resonance imaging revealed encroachment into the thecal sac and compression of the spinal cord. The lesion was embolized, and vincristine therapy was commenced. [ncbi.nlm.nih.gov]
Kasabach-Merritt syndrome (KMS) consists of large and rapidly growing vascular tumors associated with thrombocytopenia, generalized petechiae, and bleeding. [ncbi.nlm.nih.gov]
O/e: Visible cutaneous giant hemangioma or multiple smaller hemangiomas, usually on the extremities, Petechiae, bruising, and frank bleeding, Hepatomegaly, enlarged abdomen is seen. [dailyrounds.org]
Patients with Kasabach Merritt syndrome may present for the evaluation of cutaneous lesions, for symptoms caused by visceral vascular tumors or for milder dermal manifestations of the disease, like petechiae, bruising or bleeding. [symptoma.com]
If the baby’s blood platelet count is low, we may see multiple tiny red spots on the skin (petechiae). At Mount Sinai, we can usually diagnose KHE visually and with bloodwork. [mountsinai.org]
However, the platelet count remained low and the skin lesion enlarged gradually. Trans-feeding-arterial embolotherapy with a 5 ml pure ethanol (1 ml/kg) injection was performed at four months of age. [ncbi.nlm.nih.gov]
CASE REPORT A 2-month-old male infant presented with a skin lesion on his left pubis 2 weeks after birth. He had no complications during birth. [synapse.koreamed.org]
Acute enlargement of the hemangiomas and the appearance of new retroperitoneal hemangiomas were detected at 27 weeks, along with skin edema and cardiomegaly. [ncbi.nlm.nih.gov]
Spastic diplegia and other motor disturbances in infants receiving interferon-alpha. Laryngoscope. 2004 Jul. 114(7):1231-6. [Medline]. de la Hunt MN. Kasabach-Merritt syndrome: dangers of interferon and successful treatment with pentoxifylline. [emedicine.medscape.com]
Michaud AP, Bauman NM, Burke DK, Manaligod JM, Smith RJ: Spastic diplegia and other motor disturbances in Infants receiving interferon-alpha. Laryngoscope. 2004, 114: 1231-1236. 10.1097/00005537-200407000-00017. 9. [bmcpediatr.biomedcentral.com]
Clinical examination may reveal pallor, reddish-brown, indurated lesions , classical capillary hemangiomas or tufted angiomas. Patients may be tachycardic due to the anemia, heart failure or shock. Lesion ulceration and infection are rarely seen.
In Kasabach Merritt syndrome, blood workup should include complete blood count, peripheral smear, fibrinogen, fibrin degradation products, D-dimers, prothrombin time and activated partial thromboplastin time. The laboratory personnel should look for Burr cells and schistocytes. Disseminated intravascular coagulation is accompanied by prolonged prothrombin time and activated partial thromboplastin time, low fibrinogen level, elevated fibrin degradation product and D-dimer levels. Intravascular coagulation may also have a chronic, low-grade character.
It is important to determine the extent of cutaneous lesions and the existence of other involved sites, therefore radiography, ultrasonography- especially Doppler flow, computed tomography, Indium or Chromium radionuclide scintigraphy  magnetic resonance imaging scans and angiographic scans should be performed. Angiography can be followed by embolization. When the nature of the tumor is uncertain, histologic findings are important to evaluate its nature , but biopsies are usually not performed due to the critical state of the patient unless surgical procedures are performed with curative intent. Most frequently, kaposiform haemangioendothelioma and tufted angiomas are found . Both contain dilated capillary vessels with endothelial lesions, microthrombi, lymphlike vessels and hemosiderin deposits, and both may be found in the same patient.
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