Renal pyelic fusion anomaly.

Renal pyelic fusion anomalies are rare and detected incidentally on imaging. Most cases of pyelic fusion anomalies reported are in patients with horseshoe kidney. We report a rare case of pyelic fusion anomaly in normally located kidneys, which has not been reported so far.

INTRODUCTION

Renal pyelic fusion anomalies are extremely rare in normally ascended kidneys. Most reported cases of pyelic fusion anomalies involve horseshoe kidneys. We present images of a previously unreported type of renal pyelic fusion anomaly.

CASE REPORT

A 24-year-old otherwise healthy patient reported with upper abdominal pain of 6 months duration. Ultrasonography showed a smaller right kidney and a normal left kidney. Computed tomography scan of the abdomen revealed the two kidneys in normal position. However, the right renal pelvis was found fused with the left lower moiety pelvis which crossed the vertebral column to form the right ureter. This ureter continued down as normal right ureter and the left upper moiety ureter continued down as left ureter to drain into the bladder normally [Figures 1-3]. The patient was managed symptomatically.

Figure 1

Volume rendered postcontrast image showing the left lower moiety pelvis crossing the mid-line and joining the right renal pelvis, anteroposterior view

Figure 3

Volume rendered postcontrast image showing the left lower moiety pelvis crossing the mid-line and joining the right renal pelvis and opening into the bladder normally, posterolateral view

Volume rendered postcontrast image showing the left lower moiety pelvis crossing the mid-line and joining the right renal pelvis, oblique view

DISCUSSION

There are only a few case reports of renal pyelic fusion and most are in horseshoe kidneys where the two fused pelves were drained by a single ureter.[1234] Most of these cases were associated with other congenital anomalies such as vertebral defects, vesico ureteric reflux, anorectal malformation, etc., Our patient did not have any other congenital anomaly. A previously reported case had pelvic fusion with the dilated left pelvicalyceal system draining into the common pelvis through an obstructed calyx in the isthmus of the horseshoe kidney.[5]