Mixed Renal Cell Carcinoma With Metastasis To The Ipsilateral Ureter, A Case Report

摘要

We describe a patient who presented on two separate occasions with post-traumatic hematuria in which mixed renal cell carcinoma of the kidney and ureter were found. Diagnostic studies were conducted and a surgical nephrectomy as well as a ureterectomy were performed with histological reports confirming mixed renal cell carcinoma (RCC). There are no reports in the literature describing metastasis of RCC to an ipsilateral ureter. We describe such a case with a focus on RCC metastasis. Introduction Clear cell renal cell carcinoma (CRCC) comprises a majority of all renal tumors with 70 percent of renal masses being diagnosed histologically as CRCC1. Clear cell RCC arise from the proximal tubule and macroscopically can appear either solid or cystic2. Meanwhile, papillary renal cell carcinoma (RCC) only accounts for 10 to 15 percent of patients with RCC3, 4, 5, 6. Papillary RCC also arises from the proximal tubule but presents frequently as small, multifocal tumors in the early stage7. Mixed renal carcinomas consisting of both clear cell and papillary RCC are very rare, but have gained increasing acknowledgment through the use of cytokeratin 7 staining, CD 10, and FISH8. In cases of localized disease, radical nephrectomy has been the most popular surgical approach for management. Patients who present with metastatic renal cell carcinoma disease typically have involvement of the perinephric fat, ipsilateral adrenal gland, neighboring lymph nodes, the lungs, liver, bones, or the brain. Our case is unique in that there are no prior reports of RCC metastasizing singularly to the ipsilateral ureter without any local or distant sites of metastases. We report a case of mixed RCC metastasizing to the ipsilateral ureter. Case report A 36-year-old African American male presented to the ER with gross hematuria secondary to blunt trauma of the left flank region. The patient’s past medical history was significant for hypertension. He was referred to urology and a computed tomography scan with contrast displayed a left lower pole homogenous renal mass. The mass was 11.9 x 9.1 x 7.9 cm and had minimal peripheral enhancement. A left nephrectomy was then performed. A unifocal renal tumor was noted upon gross examination. The mass was a well circumscribed, yellow/red/tan appearing tumor with areas of friable and necrotic tissue located at the lower pole and measured 12 x 9.8 x 8.5 cm. The tumor did not grossly involve the renal pelvis. Renal tumor tissues obtained from the operation were fixed in formalin and embedded in paraffin. The specimens were serially sectioned using three-micrometer thick cuts. Microhistologic investigation revealed tumor extension into perinephric tissues, but not into the ipsilateral adrenal gland nor beyond Gerota’s fascia. The histology grade of the mixed RCC containing papillary and clear cell renal cell carcinoma was a Fuhrman Grade 3. The patient’s clinical course was uneventful 4 months postoperatively until he presented with a four-day history of gross hematuria after blunt trauma that involved his left flank hitting a fence. At that time the patient reported left flank pain and hematuria. A diagnostic cystoscopy and left ureterogram were performed in which bleeding from the left ureteral orifice was visualized. Ureteral washings as well as bladder washings were sent for cytology. Cytology reported the presence of malignant cells consistent with residual renal cell carcinoma embedded within a blood clot measuring 0.8 x 0.6 x 0.2 cm. Subsequently the patient underwent a complete ureterectomy. The left ureter specimen measured 5 cm in length with a diameter ranging from 0.4 cm-0.7cm at either end. Examination of the tissue revealed a focal, microscopic cluster of malignant cell consistent with renal cell carcinoma. Immunostaining with CD 10 confirmed malignant RCC. A left pelvic lymph node was sampled and found to be negative for malignancy. The pathology results provide evidence that mixed RCC can arise within a singl