Endocarditis, pyrexia of unknown origin and occult abdominal malignancy

Two patients who presented with pyrexia of unknown origin were found to have carcinoma of the caecum without gastrointestinal symptoms. Blood cultures were positive for Escherichia coli, and in one patient the diagnosis of endocarditis was confirmed by echocardiography. This rare association may be fortuitous, but a common pathogenetic basis cannot be excluded.