Venous thromboembolism in patients with hairy cell leukemia.

Background: Hairy cell leukemia (HCL) is rare leukemia of mature B cells, accounting for 2% of all lymphoid neoplasms. Although the association of venous thromboembolism (VTE) with cancer is well established, there is no systematic study describing VTE in HCL.

Aim: To analyze prevalence and risk factors associated with VTE in HCL patients.

Methods: We retrospectively reviewed data from the medical records of 56 consecutive HCL patients evaluated in our Hematology/Oncology clinic between 1998 and 2023.

Results: The median age at diagnosis was 59 years (range, 37-94), and 49 patients (87%) were male. With a median follow-up of 122 months (1-291), we identified 11 episodes of VTE in 8 (14%) HCL patients: pulmonary embolism (PE) (5 cases) with or without concurrent deep venous thrombosis (DVT), and DVT alone (6 cases). All thrombotic episodes occurred after the diagnosis of HCL, or at the same time of it, as presenting clinical manifestation of the HCL. Risk factors for VTE other than cancer were identified in only 3 patients.

Conclusion: Our study found a high incidence of VTE in patients with HCL, mostly in the absence of other provoking factors, suggesting that this hematologic malignancy is associated with an underlying thrombophilic state.