Deep Cerebral Vein Thrombosis Triggered by Contraceptive Use in a Woman with Non-Overt Essential Thrombocythemia.

Cerebral venous thrombosis is common in individuals using contraceptives. However, the potential existence of an underlying occult prothrombotic condition is frequently overlooked. We report a case of a 46-year-old woman who experienced acute cerebral venous thrombosis, primarily affecting the deep cerebral veins, after a month of contraceptive use. The distinctive "unicorn" pattern observed in the attenuated vein signs on the sagittal plane of non-contrast brain computed tomography served as crucial indicators for diagnosing deep cerebral vein thrombosis. The patient's platelet counts slightly increased during initial admission. However, a gradual increase in the platelet count coupled with the presence of the JAK2 V617F mutation over the subsequent 2 years led to the diagnosis of essential thrombocythemia. After the initiation of cytoreductive treatment, the platelet counts rapidly decreased to the normal range. Myeloproliferative neoplasms (MPNs) should be considered in individuals with cerebral venous thrombosis. The JAK2 V617F mutation is a valuable target for MPNs screening. Clinicians can choose a more appropriate course of treatment and lower the risk of recurrent thrombosis if they promptly detect other prothrombotic states in the patient.