Kaposiform Haemangioendothelioma-spectrum Lesions with Kasabach-Merritt Phenomenon: Retrospective Analysis and Long-term Outcome

Abstract

Kasabach-Merritt phenomenon (KMP) is a rare life-threatening vascular condition of infancy. Prognosis factors and long-term follow-up data are lacking. We retrospectively analysed the records of 24 infants (10 females, 14 males) treated for KMP in the Department of Dermatology of Necker-Enfants Malades Hospital, Paris, France, from 1984 to 2012. Mean duration of thrombocytopaenia (2,000-38,000 platelets/mm3, mean 10,500/µl) was 8.8 months (range 3 days-84 months), which correlated with tumour infiltration depth on imaging. D-dimer levels were always elevated, even before KMP onset. Each patient received a mean of 4.8 different treatments (range 1-10). Median follow-up was 6.5 years (range 2 months-22 years). All infants had residual cutaneous lesions, along with inflammatory manifestations (n = 9), elevated D-dimer (n = 5) and orthopaedic sequelae (n = 5). The permanent coagulopathy (elevated D-dimer) even after resolution of KMP suggests the presence of chronic low-grade platelet trapping, with possible sudden worsening, and raises the possibility of prophylactic anti-platelet therapy.

The effects of sirolimus on Kasabach-Merritt phenomenon coagulopathy

“…Dear Editor , Kasabach–Merritt phenomenon (KMP) is a very rare life‐threatening condition that combines a vascular tumour belonging to the kaposiform haemangioendothelioma (KHE) spectrum, lesions and thrombocytopenia . Thrombocytopenia results from platelet trapping within the tumour.…”

“…This coagulopathy is frequently protracted after thrombocytopenia resolution. Several treatments have been proposed with variable efficiency . Sirolimus is a mammalian target of rapamycin inhibitor.…”

“…We hypothesized that the ongoing low‐grade coagulopathy was due to long‐lasting low‐grade platelet trapping in the remaining vascular lesion following thrombocytopenia resolution. Complete healing is associated with definitive D‐dimer level normalization, which typically occurs several years after the onset of KMP . Sirolimus dramatically reduced the duration of this long‐lasting chronic condition.…”

Sirolimus for treatment of Kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon: a retrospective cohort study

“…Dear Editor , Kaposiform haemangioendothelioma (KHE) is a locally aggressive vascular tumour that occurs mainly during childhood and invades adjacent tissue and organs . It is commonly complicated by Kasabach–Merritt phenomenon (KMP), in about 50–70% of cases .…”

“…Sirolimus is an inhibitor of mammalian target of rapamycin that has recently been prescribed off‐label for KHE. Several studies have demonstrated a beneficial effect of sirolimus for KHE, but the numbers of patients were small and the treatment and follow‐up periods were short. Here we retrospectively analysed a cohort of 22 patients with KHE with KMP who were treated with sirolimus for compassionate use.…”