Lower Pelvicalyceal Transitional Cell Carcinoma of Right Kidney Mimicking a Peripelvic Cyst on Renal Ultrasound

Abstract

Transitional cell carcinoma of the kidney is an ominous condition, compared with benign renal cysts. The diagnosis is usually made by pathological examination of the specimen. The pelvicalyceal hypoechoic lesion on ultrasound combined with hematuria, flank pain and urine atypical transitional cells should raise the suspicion of possible malignancy. The differentiation between hemorrhagic or infected benign cysts and malignant hypoechoic lesions of the kidney on the renal ultrasound is a diagnostic challenge. We presented a male patient diagnosed with urine cytology, renal ultrasound, enhanced multidetector computerized tomography, ureterocystoscopic biopsy, and then surgical intervention. Case report and literature review. This 73-year-old gentleman presented to Taipei City Hospital, Zhongxiao Branch with right flank soreness and hematuria on August 12, 2016. Urine cytology revealed the presence of atypical transitional cells. The renal ultrasound revealed a hypoechoic lesion at B mode examination and hypovascular lesion at color Doppler examination (Fig 1a and Fig 1b). Enhanced multidetector computerized tomography showed bilateral renal cysts, chronic cystitis, enlargement of prostate gland and 2 filling defects in the lower pelvicalyceal areas (Fig 2a and 2b). The pathological findings of preoperative ureterocystoscopic biopsy showed low differentiated papillary transitional cell carcinoma of the lower pelvicalyceal system of right kidney (Fig 3), which arranged in papillary structure with mild to moderate nuclear atypia and showed no stromal invasion in this specimen. We highlighted that pelvicalyceal hypoechoic lesions combined with hematuria, flan pain and urine atypical transitional cells should be evaluated further for possible malignancy.