Previous studies suggest that there may be an association between cancer and autoimmune diseases. We describe the case of a 59-year-old patient who did not have any significant diseases in the last year. She had new onset of fever of unknown aetiology, headache, fatigue and night sweats. We used laboratory methods to rule out infectious diseases. Significant laboratory findings reported increased signs of inflammation and anti-nuclear antibody (ANA) positivity. Positron emission tomography/computed tomography (PET/CT) imaging showed the origin of the patient's difficulties, arteritis, with increased metabolic activity in the aortic wall and other arteries. Doppler ultrasonography of the arteries did not show pathology in the temporal arteries but found accelerated blood flow in the superior mesenteric artery (AMS). Another finding from PET/CT was a tumour in the thyroid gland, later verified histologically as papillary thyroid carcinoma (PTC). We investigated the link between rheumatological disease and papillary carcinoma, applying similar therapy, corticosteroids and immunosuppressants.
Keywords: PET/CT; corticosteroids; fever; giant cell arteritis; papillary thyroid carcinoma; thyroid gland; vasculitis.