Discharging loin sinus: Unusual manifestation of ruptured horseshoe kidney.

We present a 20-year-old man with a chronic discharging sinus in the left loin arising from a horseshoe kidney with a large pelvicalyceal calculus on its left side. The left moiety was non-functional, so a left hemi-nephrectomy, together with excision of the whole fistula tract, was carried out. Histopathology was suggestive of chronic interstitial nephritis.