Vincristine can induce regression of vascular malformation in long standing refractory Kasabach Merritt phenomenon

Abstract

Vascular lesion with consumptive anaemia and thrombocytopenia (Kasabach Merritt phenomenon, KMphenomenon) is considered to be related to congenital vascular malformation rather than genuine haemangioma. Unlike the classical strawberry haemangioma, patients with KM phenomenon are often resistant to both steroid and interferon treatment, and the vascular malformation does not regress spontaneously. In the past 2 decades, various forms of treatment have been advocated but few with consistent effect. Recently vincristine, a commonly used chemotherapeutic agent with an anti-angiogenesis action, has demonstrated encouraging clinical effect in infants and young children with KM phenomenon with tolerable side effects. Recent data suggested that vincristine could control the vascular malformation in KM phenomenon if used early. However, its efficacy on patients with long-standing, refractory KM phenomenon remains unknown. We reported here a young adolescent girl with long and refractory KM syndrome who responded to weekly vincristine treatment. The thrombocytopenia resolved completely within 12 weeks of treatment and the size of the vascular malformation continued to shrink over a span of 1.5 years. Future study targeted at this group of patients will help to verify its efficacy in this clinical setting.