A rare case of coexistence of anca-associated vasculitis and malignancy

Abstract Background/Aims A 65-year-old man, with a background of COPD, peripheral vascular disease and a neurostimulator in situ for chronic back pain, presented with a range of symptoms initially treated as lower respiratory tract infection in the community. He complained of bitemporal headache, jaw-pain, transient visual loss and had raised inflammatory markers (CRP 157 and ESR 105). He was subsequently treated as giant cell arteritis with 60mg prednisolone daily despite equivocal temporal artery ultrasound. He continued to have drenching sweats, arthralgia, epistaxis, shortness of breath and haemoptysis although inflammatory markers had normalised. Immunology revealed a strongly positive anti-PR3 antibody at > 8 units suggestive of granulomatosis polyangiitis. There was no convincing end organ evidence of vasculitis. CT-chest identified nodules and non-specific inflammatory changes but no cavitation or pulmonary haemorrhage. He was intolerant of steroids with significant insomnia and mood changes therefore they were rapidly tapered to 20mg daily. Methods He was readmitted to hospital on 20mg prednisolone with acute abdominal pain. CT abdomen-pelvis showed a lesion at the hepatic flexure suspicious for colon cancer, and this was confirmed on colonoscopy and biopsy. PET-CT at this time showed no evidence for active large vessel vasculitis. His prednisolone was tapered further and omitted prior to right hemicolectomy. Histology revealed definitive adenocarcinoma along with a focus of necrotising vasculitis and granulomas in the subserosa close to the tumour, with a distant granulomatous lesion at the resected appendix. He developed post-operative ileus and desaturated leading to a CTPA which did not show PE but identified progressive enlargement of the pulmonary nodules reported as suspicious of metastases. Throughout this time PR3 remained elevated and repeat PET-CT off steroids showed increased uptake at the aorta and right common iliac artery suggestive of active vasculitis. The FDG uptake and rate of enlargement of the pulmonary nodules was felt to be out of keeping with metastases and an inflammatory cause was suspected. Results Episodic pyrexia continued with no identifiable infective source and so a decision to commence oral prednisolone 40 mg was made. Repeat PET-CT 4 weeks later showed complete resolution of the inflammation in the aorta and right common iliac and reduction in size of the lung nodules. Unfortunately, the patient developed acute pancreatitis on steroids, so the prednisolone was reduced to 20mg with a view to induction therapy with cyclophosphamide. Conclusion This case highlighted multiple diagnostic challenges with clinical features of large vessel involvement in a patient with a positive ANCA and concomitant occult malignancy. Co-existence of a vasculitis and a neoplastic disease is rare. ANCA positive vasculitis is most commonly reported with haematological malignancies but less so in solid tumours, presenting as a paraneoplastic phenomenon. This case also highlighted the challenges in management when both conditions co-exist. Disclosure S. Ahmed: None. E. Pathan: None. P. Brown: None. J. Heaney: None. A. Pratt: None.