Thrombocytopenia due to Kasabach-Merritt Syndrome

Authors: A. Kumar, M.D., V. Dimov, M.D., The Cleveland Clinic

An one-year old boy presented to the hospital with right upper arm swelling since birth (click to enlarge the picture) and a low platelet count done by the primary care physician. No other skin lesions were found. CT of the chest and abdomen were negative.

The child has had a normal development.

Steroids were started for suspected immune thrombocytopenia (ITP) but despite a 10-day course the platelet count went down to 1,500.

PMH:
RUE hemangioma

Medications:
None


Fig. 1: Hemangioma of right upper arm

What do you think is going on?
The boy has a hemangioma and thrombocytopenia. Kasabach-Merritt syndrome presents with this combination of symptoms.

What would you do?
Confirm platelet count.
Consult pediatric hematology and vascular surgery.

What happened?
The pediatric hematologist recommended a trial of Vincristine to shrink the hemangioma. The vascular surgeon recommended embolization of the hemangioma if there is no effect from Vincristin therapy.

Final Diagnosis:
Kasabach-Merritt syndrome

What did we learn from this case?
Suspect Kasabach-Merritt syndrome in patients with hemangioma and thrombocytopenia. Thrombocytopenia is caused by sequestration and destruction of platelets in a large cavernous hemangioma. The syndrome is usually seen in infants but can also be rarely observed in adults.

No single treatment approach is consistently effective.

References:
Kasabach-Merritt Syndrome. eMedicine, topic 1234.
Kasabach-Merritt Syndrome. eMedicine, topic 1221.

Related:
Propranolol for Severe Hemangiomas of Infancy. NEJM, 06/2008.

Published: 03/09/2006
Updated: 06/14/2008