Primary renal sinus tumor: Three case reports with a review of the literature.

The aim of the present study was to investigate the clinical characteristics and management of primary renal sinus tumors. We retrospectively analyzed three cases of primary renal sinus tumors. The first patient was a 33-year-old man who presented with right flank pain for 6 months. Based on the imaging results, the patient was diagnosed with renal sinus tumor. The second case was a 34-year-old woman who presented with sudden lumbago in the right flank for 3 days. The imaging results confirmed the diagnosis of right renal angiomyolipoma. The third case was a 55-year-old woman with flank pain, which had persisted for 1 year. The imaging tests revealed lipoma of the left renal sinus. All three cases underwent surgical procedures. The first case was diagnosed with benign angioleiomyoma following pathological analysis. During surgery, the tumor was ablated and the kidney was spared. The second case was scheduled for tumor enucleating, but a nephrectomy was performed due to serious hemorrhaging and a damaged renal pelvis. Pathological analysis identified angiomyolipoma. The third case was scheduled for lipoma enucleating; however, nephrectomy was performed as the tumor encapsulated the renal vascular pedicle. Pathological analysis revealed lipoma. In the three cases, no relapse over 3 years, 10 months and 4 years of follow-up, respectively, was observed. In addition, this review examined previous literature and concluded that the occurrence of tumors in the renal sinus is rare and the majority of such tumors are benign. Furthermore, cases are easily misdiagnosed as renal pelvic tumors. Computed tomography, magnetic resonance imaging and intravenous urography are the best imaging examination methods for differential diagnosis. In conclusion, surgery is the usual approach for the treatment of renal sinus tumors and radical nephrectomy should be performed for malignant tumors.