Abstract Background/Aims Large vessel vasculitis refers to inflammation of the wall of the aorta or its main branches; it can be primary (giant cell and Takayasu arteritis) or secondary to infections or autoimmune diseases. We are reporting a rare case of aortitis co-existed with Jak2 positive myelofibrosis. Methods In June 2017, a 57-year-old man who was previously fit and well presented to haematology clinic with tiredness, weight loss, night sweat for the preceding 3 months. Investigations showed pancytopenia and bone marrow biopsy showed dysplasia and grade3 myelofibrosis. He was diagnosed with JAK2 positive myelofibrosis with myelodysplasia and was commenced on ruxolitinib. Three months later, he was admitted with fever and other constitutional symptoms but no evidence of active synovitis or vasculitic skin lesions or temporal arteritis. Investigations showed CRP of more than 200mg/l, HB: 41g/l, WBC: 38.4 x109/l, Neutrophil 18.2 x109/l, Blasts: 1.73 x109/l and Platelet: 68 x109/l; Total protein:creatinine ratio: 30.4 mg/mmol, whereas anti CCP, ANA, ANCA, T-spot test and Syphilis antibody were all negative. Blood cultures were negative. CT-chest abdomen and pelvis showed splenomegaly and subtle fat haziness in the mediastinum adjoining the distal aortic arch with new onset (compared to a previous CT scan) mild thickening of distal aortic arch and descending aorta. Cardiac MRI confirmed active aortitis and PET-CT scan showed focal increased uptake within the arch of the aorta. He was diagnosed with aortitis and cellulitis of the left arm and foot and commenced on antibiotics and prednisolone 40mg. After one month, the patient was doing well, with significant improvement of symptoms and inflammatory markers (CRP: 7mg/l). Prednisolone was tapered and stopped after one year, as there was no evidence of flare up of vasculitis. Results In the literature, there are only few reported cases linking haematological malignancies to different forms of vasculitis. In one case, aortitis was reported as a manifestation of myelodysplastic syndrome whereas the coexistence of aortitis with chronic myeloid leukemia and chronic myelomonocytic leukemia was reported in 2 separate cases raising the possibility of coincidental or paraneoplastic phenomenon. Vasculitic skin ulcers preceded the appearance of myelofibrosis in another case report. In the above case, aortitis can also be related to the chemotherapeutic agents; leukocytoclastic vasculitis was possibly induced by ruxolitinib in a case report. Moreover, bacterial Infection, as a common cause of aortitis can still be the cause here. Conclusion Early recognition of coexistent disorders in patients with haematological malignancies is crucial for successful management. However, it can prove a challenge as malignancy, vasculitis and infection share common clinical features and investigations. Vasculitis can be primary or secondary to a wide variety of disorders, and further research is required to confirm the relation between myelofibrosis and aortitis. Disclosure Z. Alkutobi: None. A. Ugwoke: None. A. Nandagudi: None.