An apparently standard investigation into a 63-year-old’s persistent left-sided lumbar pain has made radiologists think thrice.

The Moroccan patient had unremarkable results on physical examination, renal function tests and urinalysis, but ultrasonography revealed an “exceptional” congenital anomaly.

He had a midline horseshoe kidney plus two partly fused additional kidneys in the left renal fossa.

Contrast-enhanced CT urography confirmed three distinct kidneys, all of which had preserved parenchyma with no cortical thinning.