Bilateral loin pain and fever in a young woman: yet another pyelonephritis?

Excerpt

A 22-year-old woman from Bangladesh was admitted to our hospital in June 2022 for bilateral loin pain and fever. She had been living in Italy for 10 years and this was her first emergency room access. Her history was unremarkable for trauma, hematological abnormalities, liver disease or kidney disease with the exception of polycystic ovarian syndrome for which she was not taking any medication. She denied intake of medications, or toxic substances. She complained of bilateral flank pain arising a few days earlier, accompanied by fever. Dysuria or hematuria were not reported. At inspection, no signs of trauma were found, abdominal palpation revealed slight tenderness and bilateral costovertebral angle tenderness was observed. Her laboratory data showed hemoglobin 8.5 g/dl, high-sensitivity C reactive protein 180.9 mg/l and normal renal function. Urinalysis demonstrated no signs of infections or hematuria. (Online Resource 1). Sonography at admission (Online Resource 2) showed normal sized kidneys with an anechoic effusion under the renal capsula, with no signs of parenchymal compression, hydronephrosis or stones. Computed tomography urography (CTU) was performed immediately after sonography (Fig. 1) and revealed crescentic high density fluid collection surrounding the kidneys, with high density spots on the lower part of both kidneys. Magnetic Resonance Imaging (MRI) was performed after a few days (Online Resource 3). What is your interpretation of this clinical and radiological case?

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