Apparent lost renal cortex due to focal pyelonephritis

Excerpt

A 52-year-old woman was referred to us with a temporary diagnosis of right atrophic kidney. Initial laboratory investigations revealed serum creatinine level of 0.79 mg/dl and blood urea nitrogen level of 10.2 mg/dl. Contrast-enhanced computed tomography of the abdomen during the cortical phase revealed focal cortical atrophy or defects in the right kidney with decreased cortical enhancement (Fig. 1a, b). After a detailed interview of her medical history, it was found that she had had multiple episodes—three times in approximately 2 years—of acute pyelonephritis approximately 40 years ago. To the best of our knowledge, there are no published reports on unilateral focal renal cortical defects as congenital anomalies of the kidney. We believe that the cortical lesion was the result of previous focal pyelonephritis. Renal cortical defects are considered a sequela of pyelonephritis; however, long-term changes in the kidneys due to acute focal pyelonephritis are quite rarely reported [1]. Acute focal pyelonephritis—also known as lobar nephronia—refers to an intermediate stage between acute pyelonephritis and renal abscess [2]. Apparent loss of the renal cortex on computed tomography suggests severe focal bacterial infections in the past.

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