Vertebral artery thrombosis: a rare presentation of primary polycythaemia.

Primary polycythaemia, also known as polycythaemia vera (PV), is a myeloproliferative neoplasm (MPN) which is associated with arterial and venous thrombosis and which can contribute to significant morbidity and mortality if untreated. Arterial thrombosis accounts for a large proportion of PV-related thrombotic events which may manifest as stroke and myocardial infarction. There is an abundance of literature documenting thrombosis arising in the cerebral vasculature secondary to PV. However, vertebral artery thrombosis associated with PV has not been previously described. We present a case of vertebral artery thrombosis as the presenting manifestation of PV. This case demonstrates the importance of recognising MPNs as a cause of an unusual presentation of thrombosis. 2014 BMJ Publishing Group Ltd.