Sirolimus as initial therapy for kaposiform hemangioendothelioma and tufted angioma.

Background: Sirolimus has been used to manage various complex vascular anomalies. Kaposiform hemangioendothelioma and tufted angioma may develop Kasabach-Merritt phenomenon in infancy.

Methods: We retrospectively reviewed the clinical and laboratory data of eight patients with kaposiform hemangioendothelioma and tufted angioma who were initially treated using oral sirolimus in our center, including six with Kasabach-Merritt phenomenon.

Results: Five girls and three boys seen between September 2012 and March 2015 were included. Age at initiation of sirolimus ranged from 30 days to 14 weeks (mean±SD 8.6 ± 3.5 weeks). Six of these eight patients had kaposiform hemangioendothelioma, and two had a tufted angioma. Platelet count before start of oral sirolimus ranged from 5 × 10 /L to 189 × 10 /L ((78.8 ± 65.2)×10 /L) and fibrinogen level from 68 to 215 mg/dL (123.1 ± 50.5 mg/dL). All patients received standard doses of sirolimus (0.05 mg/kg orally, twice daily) as initial therapy. All patients with thrombocytopenia or hypofibrinogenemia reached a normal platelet count and a normal fibrinogen level within 3 to 4 weeks after sirolimus treatment. Length of treatment ranged from 12 to 79 weeks (39.9 ± 15.3 weeks). Two patients developed grade 2 oral mucositis during treatment.

Conclusion: Sirolimus as first-line therapy shows great promise in the treatment of kaposiform hemangioendothelioma and tufted angioma.