Spontaneous large renal pelvis hematoma in ureteropelvic junction obstruction presenting as an acute abdomen: Rare case report

Patients with ureteropelvic junction (UPJ) obstruction can present with flank pain or hematuria. We present 20-year-old male presenting with acute pain in lumbar and right fossa with tenderness and guarding, this case was clinically mimicking general surgical emergency. On computed tomography with urography and angiography, there was 15 cm x 11 cm x 10 cm size non-enhancing hyperdense lesion (average Hounsfield units - +64) in right renal pelvis suggestive of hematoma. Patient's diethylenetriaminepentaacetic acid diuretic renography was suggestive of right kidney glomerular function rate of 48.4 ml/min with the relative function of 43%, Peak to half peak was not achieved. The patient was managed by retrograde ureteropyelography and double J stenting. After 1 month, clot size decreased to 4 cm x 3 cm x 2 cm. The patient had undergone open reduction Anderson hynes dismembered pyeloplasty with the removal of pelvis clot after 6 weeks. We report the first case of UPJ obstruction presenting as an acute abdomen and spontaneous hematuria with large pelvis clot without rupture of the renal pelvis.