[Radiologic and gammagraphic findings in a case of pyonephrosis. Anatomopathologic correlation]

To describe a case of pyonephrosis in a child with special reference to the importance of scintigraphy in its evaluation.

We studied the correlation of the findings of conventional radiology (abdominal x-ray), ultrasound, abdominal CT, scintigraphy and anatomopathology (left kidney) in a 5-year-old boy with a history of renal lithiasis that was seen at our pediatric emergency services. The patient's clinical course and the scinscan findings using two tracers (Tc-99m DMSA, Ga-67 citrate) showed a severely compromised left renal function. The foregoing finding and the risk of major life-threatening complications prompted surgical treatment. Pathological analysis showed pyonephrosis of left kidney.

X-ray, ultrasound and abdominal CT showed left renal lithiasis, an enlarged left kidney, poor cortico-medullary differentiation and parenchymal destructuring with areas suggestive of cortical abscesses. A Ga-67 citrate scintiscan showed a notable intensity that completely affected the left renal parenchyma with no other changes. On the other hand, Tc-99m DMSA showed no uptake in the left kidney and normal uptake in the right kidney. A left nephrectomy was performed. Histological analysis demonstrated pyonephrosis of left kidney.

Tc-99m DMSA and Ga-67 citrate scintigraphy and the patient's poor clinical course showed the extent and severity of the underlying condition that was underestimated by the other imaging techniques.