A 62-year-old man presented with a 3-year history of recurrent episodes of high fever up to 40 C accompanied by rigors, sweating, flu-like sensation, and malaise. These episodes occurred roughly 3-4 times a year and would last between 2 to 3 days. A markedly elevated C-reactive protein of up to 64 mg/L but without a leucocytosis or elevation of the ESR was evident with the most closely monitored of the episodes. Risk factors for brucellosis, endocarditis, tuberculosis, travel to tropical countries, and retrovirus infection were negative. The patient denied anorexia and weight loss, and there was no family history of fevers, lymphoproliferative disease, or cancer. A complete physical examination was normal and without lymphadenopathy, heart murmurs, clubbing of the nails, skin rashes, joint effusions, and synovitis. 
A CT scan of the chest and abdomen was completely normal as was a barium enema performed 2 years earlier. Urine cultures were negative for growth. Numerous blood tests were returned as normal or negative. These included full blood count and blood film analysis, several blood cultures, creatine kinase, and lymphocyte subset analysis, as well as tests of organ-specific autoimmunity on a liver, kidney, stomach tissue block. There was also no evidence of antinuclear antibodies, rheumatoid factor, and antineutrophil cytoplasmic antibodies. Serum immunoglobulins were normal, and there was no abnormality on serum immunoelectrophoresis. The kappa and lambda free light chain estimation by Freelite (Binding Site, UK), serum-angiotensin-converting enzyme, quantiFERON for mycobacterial infection and tests of liver and renal function as well as lactate dehydrogenase were also either normal or negative. 
Following a routine positive faecal occult blood analysis, the patient underwent colonoscopy and an adenocarcinoma of the sigmoid colon was discovered. This was recorded as a stage 1 sigmoid adenocarcinoma without lymph node involvement and without abscess formation or necrosis (T1N0M0, Dukes A). The patient made an uneventful recovery and has remained free of further bouts of fever for the previous 2 years.