Characterized by the association of a vascular tumor
with thrombocytopenia and coagulopathy. Histologically, it is either a
kaposiform hemangioendothelioma or a tuft angioma, not a hemangioma.
Approximately 300 cases have been reported in the
literature since 1940. Slightly more frequent in females. No racial
Unknown; seems to be more frequent in Asia.
Ecchymotic tumor develops on a vascular lesion; it
usually starts in the neonatal period and grows very quickly; tumoral growth
is accompanied by thrombocytopenia and hypofibrinogenemia. This disseminated
intravascular coagulation (DIC) picture is secondary to entrapment of
platelets within the vascular tumor.
The triad of thrombocytopenia, coagulopathy, and a
vascular tumor should be highly suggestive.
Enlarging hemangioma-like lesion, mainly
cutaneous (especially on the extremities) but also visceral. DIC (decreased
platelets and fibrinogen, presence of increased d-dimers). Often
inoperable. Treatment options: vincristine, interferon-α, steroids,
ticlopidine with aspirin, or radiotherapy. Untreated Kasabach-Merritt
syndrome has a 10 to 37% mortality rate.
Examine for airway involvement.
Check complete blood count (platelet count), coagulation profile, bleeding time, and
cross-match for blood even for minor surgical procedures.
Potential difficult airway if
oropharyngeal or neck involvement is present. Anticipate the need for blood
products to treat anemia and/or coagulopathy. Do not transfuse platelets because
they will immediately be trapped within the tumor with an ensuing increase in
size. Effect of chemotherapy on the cardiac and respiratory system must
No specific pharmacological
implications with this condition; however, patients treated with
chemotherapy and corticosteroids (perioperative stress dose) must be prepared for anesthesia
accordingly. Avoid nonsteroidal antiinflammatory drugs secondary to their effects on
Congenital Hemangiomas: Share many similarities with
Kasabach-Merritt syndrome, but without the coagulation disorders; they usually
regress between 5 and 9 years of age.
Klippel-Trenaunay Syndrome: Congenital arteriovenous malformation
usually located on a single extremity resulting in skeletal and soft tissue
David TJ: Hemangioma with thrombocytopenia (Kasabach-Merritt syndrome).
Arch Dis Child 58:1022, 1953.
Enjolras O, Wassef M, Mazoyer E, et al: Infants with Kasabach-Merritt
syndrome do not have “true” hemangiomas. J Pediatr
Maguiness S, Guenther L: Kasabach-Merritt syndrome. J Cutan Med Surg