Positron emission tomography in a patient with renal malacoplakia.

Positron emission tomography is increasingly used for the diagnosis of occult infection or malignancy. The altered metabolic rate of cells in areas of malignancy or infection provides a sensitive method to identify pathology that is otherwise not identified by standard imaging methods. This case report describes a patient who presented with a pyrexia of unknown origin and renal impairment. She had a positron emission tomography scan that showed intense accumulation of fluoro-deoxy-glucose in both kidneys. Subsequent renal biopsy results showed a diagnosis of malacoplakia, the treatment of which resulted in a resolution of the fever and a stabilization of renal function. This is the first report of the positron emission tomographic appearance of renal malacoplakia.