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In 2002 a 73-year-old woman (non-smoking, medical history of allergic rhinitis) was referred to a rheumatologist because of synovitis of the metacarpophalangeal and proximal interphalangeal joints of both hands which had slowly developed over 3 months. Late-onset rheumatoid arthritis was suspected. Morning stiffness, rheumatoid nodules, erosions of cartilage or bone, rheumatoid factor and antibodies to cyclic citrullinated peptides were absent. Prednisone (2.5–5 mg daily) and non-steroidal anti-inflammatory drugs were started.
In 2004 she was referred to a respiratory physician for analysis of a persistent dry cough and pleural effusion. CT scans of the lungs (six scans between 2004 and 2009, see representative scan in figure 1 revealed fleeting bilateral multifocal consolidations with ground-glass attenuation. Bronchoscopic examination was normal. The lavage fluid showed 39% macrophages, 58% lymphocytes and 2% neutrophils. Diffusing capacity (transfer factor) was low while spirometry was normal. These findings were interpreted as lung disease secondary to rheumatoid arthritis. Because polyarthritis had responded to low-dose glucocorticoid treatment and the pulmonary lesions appeared stable over time, this low-dose regimen was maintained over the years.
In 2005 diabetes mellitus type 2 was diagnosed which was treated with oral blood glucose lowering agents (metformin 500 mg twice daily) resulting in adequate control (glycosylated haemoglobin 7.1%). No diabetic retinopathy was present. In 2006 she developed painful polyneuropathy. The neurologist ascribed polyneuropathy to diabetes mellitus and started amitriptyline. No further tests were ordered.
In 2008 she developed persistent fevers, elevated inflammatory parameters (peak erythrocyte sedimentation rate 106 mm/h, C-reactive protein 135 mg/l) and normocytic anaemia (haemoglobin 8.7 g/dl (5.3 mmol/l)). Elaborate testing failed to provide new insights. These tests included serial blood cultures, tests for tuberculosis, syphilis, borrelia, hepatitis, HIV, bone marrow biopsy, CT scans of chest and abdomen, positron emission tomography, leucocyte scan, bronchoalveolar lavage and temporal artery biopsy.
A woman with presumed rheumatoid arthritis, associated lung disease, diabetes mellitus and polyneuropathy develops fevers of unknown origin. Which alternative diagnosis is possible based on the clinical information and the CT image (figure 1) and which tests would you order to confirm this?
See page 270 for answer
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