PL 25. Invasive carcinoma of the renal pelvis is easy to be misdiagnosed (with 6 cases report)

To explore the clinical and imaging features of the invasive carcinoma of renal pelvis (ICRP). 6 Cases of ICRP were reviewed, five of them are man, median age 55(50-62) years. Case 1, 50 years old, right flank pain with continuous low heat (37-38 ℃) 3 months, CT scan shows the renal tumor is about 6-7 cm, on plain scan is 35 Hu, after administration of contrast media, the tumor was enhanced unequally and CT value is 86 Hu, accompanied by renal vein tumor emboli about 3 cm, the abdominal aorta and the inferior vena cava is bag around the multiple lymph node. Diagnosed of renal cell carcinoma (RCC) with retroperitoneal lymph node metastasis, CT and bone scaning confirmed the T12 vertebral bone metastases. Case 2, 60 years old, left flank pain with persistent fever a month (38- 39 ℃), without improvement after therapy of antibiotics, CT scan shows the tumor is about 6 cm, On plain scan is 8 Hu and enhancement have no obvious strengthening, diagnosis of renal cyst with infection. Case 3, 56 years old, low back pain and CT shows a tumor in the upper pole of the left kidney sites about 4 cm × 5 cm, on plain scan is 20 Hu, the tumor is enhanced unequally and CT value is 57 Hu, diagnosis of RCC. Case 4, 57 years old, waist pain and fever (37-38.5 ℃) continuous with the gross hematuria with clots for 2 months, CT shows the wedge line lesions about 2 cm × 3 m in the left kidney on upper pole of sites, on plain scan is 20 Hu, the tumor was enhanced unequally and CT value is 57 Hu, the ultrasound show the low echo with flow signals. As the disease progresses, the lesion increased rapidly to 8 cm × 9 cm after 1 month, diagnosis of renal parenchyma inflammation, give anti-inflammatory treatment but showed no improvement, after percutaneous puncture, the pathology of biopsy is RCC. Cases 5, 54 years old, waist pain with the gross hematuria 2 weeks, CT shows the lesions about 5 cm × 7 m in the right kidney on upper pole of sites, the tumor was enhanced unequally and CT value is 88 Hu, the ultrasound show the low echo with flow signals, diagnosis of RCC. Case 6, female, 36 years old, waist pain associated with intermittent fever (37-38 ℃) 2 weeks, CT shows inflammation, tuberculosis or tumor? On plain scan is 27- 40 Hu, the tumor is enhanced unequally and CT value is 30- 70 Hu, diagnosis of infection of renal parenchyma. 6 patients were accepted operation, and the pathologic returns were invasive papillary urothelial carcinoma of the renal pelvis (WHO II-III, III), 2 cases were followed up to 4 months and 6 months and still alive. One patient was dead 1 month after operation because the tumor transfer to liver and pericardial. 3 cases were followed up 4, 6 and 11 months and death for systemic failure. [Discussion] The clinical manifestations and imaging characteristics of the ICRP always not typical, is easy to be misdiagnosed. From our data, the ICRP always misdiagnosed as renal parenchyma inflammation, and followed by RCC. Through the cystoscopy, tumor can be found in bladder or not, be helpful to the formulation of operation program. At the same time, the ureteral retrograde intubation, can collect the urine of renal pelvis for cytology, improve the positive rate of cytology and provide reliable basis for diagnosis. When the tumor growth in the renal calices inside, the entire renal calices was occupied, and part of the tumor encroach on the renal pelvis, or tumor is in renal parenchymal central, it is very difficult to identify the tumor is RCC or urothelial carcinoma. The following is the main points to identify: (I) From CT scan to see, the ICRP can make renal appearance increase, but won't change a renal surface morphology. However, RCC always has more partial nature of growth, led to the change of renal shape. (II) Generally speaking, the CT value of carcinoma of the renal pelvis is often not even strengthened, and the enhanced CT value will not exceed 100 Hu, while the CT value of RCC always exceeds 100 Hu. (III) In the enhanced CT scan, renal pelvis carcinoma won't performance for "quick in quick out", but in RCC, the blood flow is rich, often present as a" quick in quick out. Considering the urothelial carcinoma is easy to be planted, percutaneous biopsy is not recommended.

Therefore, in order to make the misdiagnosis of the renal pelvis carcinoma fall to lowest, medical history and clinical manifestations must be in full understanding, and on the basis of comprehensive analysis of ultrasound, x-rays, CT scans, and other test results. Cytologic examination of urine and retrograde urography imaging or ureteroscopy in the diagnosis of urothelial carcinoma still has important significance. When ICRP cannot be excluded, nephroureterectomy with excision of bladder cuff is recommended. When the tumor was highly suspected of renal pelvis carcinoma, intraoperative frozen section examination is helpful for the choice of operation manner, also can directly choose the standard operation of the renal pelvis carcinoma, avoid the opportunity of implantation and the second surgery.