Cancer-associated thrombosis presenting as multiple brain infarctions during complete remission of follicular lymphoma.

We report the case of a 76-year-old man with follicular lymphoma who developed cancer-associated thrombosis (CAT) presenting as multiple brain infarctions during complete remission (CR). After the fourth cycle of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) and pegfilgrastim, the patient presented with dysarthria and right upper-limb paresis. Brain magnetic resonance imaging demonstrated multiple brain infarctions with a positive three-territory sign, specific for cancer-associated brain infarctions. Laboratory tests revealed leukocytosis and thrombocytopenia. Whole-body computed tomography demonstrated CR without thrombosis. Anticoagulation with unfractionated heparin, followed by apixaban, resulted in neurological improvements. The patient was discharged without bleeding or any neurological sequelae. This case highlights that CAT can occur even in indolent lymphoma during CR and that anticoagulation is effective and safe despite the presence of thrombocytopenia.