Cerebral Thrombosis As an Initial Presentation of Pediatric Acute Promyelocytic Leukemia

Disseminated intravascular coagulopathy and bleeding are common manifestations of acute promyelocytic leukemia(APL) which are both associated with significant mortality and morbidity. However APL related thrombosis is very rare and majority of the reported cases are adults in the literature. In the past 14 years, 14 cases with APL were found in our hospital database.There were 6 female and 8 male children with a mean age of 10.7±4.6 years (2-17y). Here, we report two pediatric APL case who presented with cerebral thrombosis at the initial presentation. 8/14(57%) had disseminated intravascular coagulation at the initial presentation and one patient had intracardiac and cerebral sinovenous thrombosis during the induction period.

Case 1:A 13-year-old boy was admitted to our hospital with a complaint of headache for two days. His physical examination revealed a papilledema and cranial MRI did show sinovenous thrombosis. At the time of the evaluation his WBC count was found to be low and there were myeloid blasts on his peripheral smear,bone marrow aspiration was done and diagnosed as translocation t(15;17)positive APL. He remain in remission more than 4 years without any event however deceased after relapse.

Case 2: A 8-year-old boy was admitted to our hospital with a complaint of right hemiparesis, there was a thrombotic occlusion of the left middle cerebral artery associated cerebral infarct on his MRI.His WBC was 5.9x109/l with 76% blasts and bone marrow aspiration and flow-cytometry were both compatible with APL. Patient died after 2 weeks of admission because of thrombosis and bleeding.

The incidence of APL related thrombosis was 4.5 and 5.6% in two large adult cohorts. Both arterial and venous thrombosis may ocur in patients with APL. To the best of our knowledge there were limited number of pediatric APL case reports in the literature who presented with thrombosis. In our small group of pediatric APL patients 14% presented with thrombosis and the total number of thrombotic events were found to be 28% during the follow up.