Excellent outcome of medical treatment for Kasabach-Merritt syndrome: a single-center experience

BACKGROUND: Kasabach-Merritt syndrome (KMS) is a rare but life-threatening illness. The purpose of this study is to report our single-center experience with KMS. METHODS: We reviewed the medical records of 13 patients who were diagnosed with KMS between 1997 and 2012 at Samsung Medical Center. Treatment response was defined as follows: 1) hematologic complete response (HCR) – platelet count >130×10(9)/L without transfusion; 2) clinical complete response (CCR) – complete tumor disappearance or small residual vascular tumor displaying lack of proliferation for at least 6 months after treatment discontinuation. RESULTS: Participants included 7 male and 6 female patients. The median initial hemoglobin levels and platelet counts were 9.7 g/dL (range, 6.6–11.6 g/dL) and 11×10(9)/L (range, 3–38×10(9)/L), respectively. Twelve patients received corticosteroid and interferon-alpha as initial treatment, and the remaining patient received propranolol instead of corticosteroid. Two patients with unsatisfactory response to the initial treatment received weekly vincristine. Successful discontinuation of medication was possible at a median of 301 days (range, 137–579) in all patients except one who was lost to follow-up. The median times to achieve HCR and CCR were 157 days and 332 days, respectively. The probabilities of achieving HCR and CCR were 77% and 54% at 1 year, and 88% and 86% at 2.5 years, respectively. CONCLUSION: The prognosis of KMS in our cohort was excellent. Our data suggest that individualized treatment adaptation according to response may be very important for the successful treatment of patients with KMS.