56 year old woman with fever, chills and bilateral loin ache following a few days of dysuria. The urine was cloudy. Urinalysis showed leukocytes and casts.
The kidney is mildly enlarged due to oedema and hyperaemia, especially of the medullary pyramids. There are cream-coloured streaks corresponding to the alignment of collecting ducts with microabscesses. The latter are readily seen on the subcapsular renal cortex.
The pelvicalyceal system is not dilated. No calculus is seen.