Development of Takayasu arteritis during deep molecular response of chronic myeloid leukaemia: a case report and literature review.

The coexistence of Takayasu arteritis (TA) and chronic myeloid leukaemia (CML) is extremely rare, with most reported cases occurring either concurrently or during active disease. We report a unique case of TA developing during a deep molecular response (MR) of CML. A 28-year-old female was diagnosed with CML in December 2020 and achieved a deep MR with bosutinib treatment. After 3.5 years of successful CML treatment, she developed symptoms including fatigue, low-grade fever, and chest pain. Imaging revealed wall thickening of multiple large vessels characteristic of TA. The patient responded well to prednisolone therapy while maintaining the MR of CML. A review of published cases identified eight previous reports of TA associated with myeloid disorders. Our case is distinctive for the development of TA during sustained deep MR of CML, contrasting with previous reports where vasculitis typically occurred during active disease or at initial presentation. This case highlights the importance of monitoring for vasculitic complications in CML patients, even during MR. The temporal relationship between these conditions suggests that inflammatory mechanisms leading to vasculitis might persist or develop independently of CML disease activity, challenging the conventional understanding of their association as a purely paraneoplastic phenomenon.