Kasabach-Merritt syndrome

Infobox_Disease
Name = PAGENAME

---

Caption =
DiseasesDB = 30701
ICD10 =
ICD9 = ICD9|287.39
ICDO =
OMIM = 141000
MedlinePlus =
eMedicineSubj = med
eMedicineTopic = 1221
eMedicine_mult = eMedicine2|ped|1234 | MeshID =

Kasabach-Merritt syndrome (KMS) is a rare disease, usually of infants, in which a vascular tumor leads to decreased platelet counts and sometimes other bleeding problems,cite journal
author=Hall G
title=Kasabach-Merritt syndrome: pathogenesis and management
journal=Br J Haematol
volume=112
issue=4
pages=851–62
year=2001
pmid=11298580
doi=10.1046/j.1365-2141.2001.02453.x] which can be life-threatening.cite journal
author=Shim W
title=Hemangiomas of infancy complicated by thrombocytopenia
journal=Am J Surg
volume=116
issue=6
pages=896–906
year=1968
pmid=4881491
doi=10.1016/0002-9610(68)90462-5] It is also known as hemangioma thrombocytopenia syndrome. It carries the names of Dr Haig Haigouni Kasabach and Dr Katharine Krom Merritt, the two pediatricians who first described the condition in 1940. [cite journal | author=Kasabach HH, Merritt KK | title=Capillary hemangioma with extensive purpura: report of a case | journal=Am J Dis Child | year=1940 | volume=59 | pages=1063] [WhoNamedIt|synd|3861|Kasabach-Merritt syndrome]

Pathophysiology

KMS is usually caused by a hemangioendothelioma or other vascular tumor, often present at birth.cite journal
author=Enjolras O, Wassef M, Mazoyer E, Frieden I, Rieu P, Drouet L, Taïeb A, Stalder J, Escande J
title=Infants with Kasabach-Merritt syndrome do not have "true" hemangiomas
journal=J Pediatr
volume=130
issue=4
pages=631–40
year=1997
pmid=9108863
doi=10.1016/S0022-3476(97)70249-X] cite journal
author=el-Dessouky M, Azmy A, Raine P, Young D
title=Kasabach-Merritt syndrome
journal=J Pediatr Surg
volume=23
issue=2
pages=109–11
year=1988
pmid=3278084
doi=10.1016/S0022-3468(88)80135-0] Although these tumors are relatively common, it is rare for them to cause KMS.

When these tumors are large or are growing rapidly, sometimes they can trap platelets, causing severe thrombocytopenia. The combination of vascular tumor and consumptive thrombocytopenia defines KMS. Tumors can be found in the trunk, upper and lower extremities, retroperioneum, and in the cervical and facial areas.

This consumptive coagulopathy also uses up clotting factors, such as fibrinogen which may worsen bleeding. The coagulopathy can progress to disseminated intravascular coagulation and even death.

Diagnostic workup

The diagnostic workupcite web
last =Krafchik
first =Bernice R
date = 2005-12-19
url =http://www.emedicine.com/MED/topic1221.htm
title =Kasabach-Merritt Syndrome
work =eMedicine - Hematology
publisher =WebMD
accessdate =2006-05-15] is directed by the presenting signs and symptoms, and can involve:
*blood counts, clotting studies, and other laboratory testing
*imaging tests (ultrasound, CT scan, MRI, sometimes angiography, and rarely nuclear medicine scans)
*biopsy of the tumor.

Patients uniformly show severe thrombocytopenia, low fibrinogen levels, high fibrin degradation products (due to fibrinolysis), and microangiopathic hemolysis.

Management

Management of KMS, particularly in severe cases, can be complex and require the joint effort of multiple subspecialists. This is a rare disease with no consensus treatment guidelines or large randomized controlled trials to guide therapy.

upportive care

Patients with KMS can be extremely ill and may need intensive care. They are at risk of bleeding complications including intracranial hemorrhage. The thrombocytopenia and coagulopathy are managed with platelet transfusions and fresh frozen plasma, although caution is needed due to the risk of fluid overload and heart failure from multiple transfusions. The possibility of disseminated intravascular coagulation, a dangerous and difficult-to-manage condition, is concerning. Anticoagulant and antiplatelet medications can be used after careful assessment of the risks and benefits.

Definitive treatment

Generally, treatment of the underlying vascular tumor results in resolution of KMS. If complete surgical resection is feasible, it provides a good opportunity for cure (although it can be dangerous to operate on a vascular tumor in a patient prone to bleeding, even with appropriate surgical subspecialists involved).

If surgery is not possible, various other techniques can be used to control the tumor::*embolization (by interventional radiology) can limit the tumor's blood supply:*external compression bandages can have similar effects:*certain medications, including::**corticosteroids:**alpha-interferon:**chemotherapy (e.g. vincristine):*radiation therapy has been used, often successfully, but now is avoided whenever possible due to the risk of long-term adverse effects (e.g. risk for future cancer).

Outcomes

KMS has a mortality rate of about 30%. For patients that survive the acute disease, supportive care may be required through a gradual recovery.

Furthermore, patients may need care from a dermatologist or plastic surgeon for residual cosmetic lesions. On long-term followup, most patients have skin discoloration and/or mild disfiguration from the dormant tumor.cite journal
author=Enjolras O, Mulliken J, Wassef M, Frieden I, Rieu P, Burrows P, Salhi A, Léauté-Labrèze C, Kozakewich H
title=Residual lesions after Kasabach-Merritt phenomenon in 41 patients
journal=J Am Acad Dermatol
volume=42
issue=2 Pt 1
pages=225–35
year=2000
pmid=10642677
doi=10.1016/S0190-9622(00)90130-0]

References