Diagnostic Utility of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Small Solid Renal Tumors （≤4 cm） at 3.0T Magnetic Resonance Imaging

Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell carcinomas （RCCs） from small benign solid renal tumors （〈4 cm）. Methods： In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results： The tumors consisted of 33 cases of clear-cell RCCs （ccRCCs） and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors （[0.90 ±0.52] x 10 x mm2/s）, ccRCCs （[1.53 ± 0.31 ] x 10 ^3 mm2/s） and the normal renal parenchyma （[2.22 ± 0.12]x 10^-3 mmVs） （P 〈 0.001）. Moreover, there was statistically significant difference between high and low-grade ccRCCs （P = 0.004）. Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve （AUC）, sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor （inside the contour of the kidney） and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions： DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors （〈4 cm）, and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.

Renal granuloma misdiagnosed as renal papillary carcinoma: a case report

The imaging appearance of renal granuloma is very similar to that of a renal tumor.Granulomatous lesions usually do not require surgical treatment,while kidney tumors typically necessitate surgical removal.The diagnosis of renal granuloma typically relies on the history of bacillus Calmette-Guérin perfusion and the position of the renal pelvis in the image(malignant tumors usually destroy or compress the surrounding renal pelvis).However,in this case,the patient has no history of bacillus Calmette-Guérin perfusion,making the diagnosis more challenging.The ultrasound and enhanced CT findings were consistent with renal papillary carcinoma.Laparoscopic partial nephrectomy was performed,revealing degeneration and necrosis of the renal cortex and formation of granulomas.The imaging diagnosis of renal granuloma is difficult.Ultrasound-guided biopsy may be a preferable method to avoid unnecessary surgery.

Molecular genetics and immunohistochemistry characterization of uncommon and recently described renal cell carcinomas

Renal cell carcinoma （RCC） compromises multiple types and has been emerging dramatically over the recent several decades. Advances and consensus have been achieved targeting common RCCs, such as clear cell carcinoma, papillary RCC and chromophobe RCC. Nevertheless, little is known on the characteristics of several newly-identified RCCs, including clear cell （tubulo） papillary RCC, Xpl 1 translocation RCC, t（6;11） RCC, succinate dehydrogenase （SDH）-deficient RCC, acquired cystic disease- associated RCC, hereditary leiomyomatosis RCC syndrome-associated RCC, ALK translocation RCC, thyroid-like follicular RCC, tubulocystic RCC and hybrid oncocytic/chromophobe tumors （HOCT）. In current review, we will collect available literature of these newly-described RCCs, analyze their clinical pathologic characteristics, discuss their morphologic and immunohistologic features, and finally summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of RCCs, and eventually promote clinical management strategies.

“Zero ischemia”laparoscopic partial nephrectomy by high-power GreenLight laser enucleation for renal carcinoma:A single-center experience

BACKGROUND Laparoscopic partial nephrectomy has been widely used in renal cell carcinoma treatment.The efficacy of GreenLight laser on Laparoscopic partial nephrectomy is still unknown.AIM To present the first series of laparoscopic partial nephrectomy(LPN)by GreenLight laser enucleation without renal artery clamping.Due to the excellent coagulation and hemostatic properties of the laser,laser-assisted LPN(LLPN)makes it possible to perform a“zero ischemia”resection.METHODS Fifteen patients with T1a exogenous renal tumors who received high-power GreenLight laser non-ischemic LPN in our hospital were retrospectively analyzed.All clinical information,surgical and post-operative data,complications,pathological and functional outcomes were analyzed.RESULTS Surgery was successfully completed in all patients,and no open or radical nephrectomy was performed.The renal artery was not clamped,leading to no ischemic time.No blood transfusions were required,the average hemoglobin level ranged from 96.0 to 132.0 g/L and no postoperative complications occurred.The mean operation time was 104.3±8.2 min.The postoperative removal of negative pressure drainage time ranged from 5.0 to 7.0 d,and the mean postoperative hospital stay was 6.5±0.7 d.No serious complications occurred.Postoperative pathological results showed clear cell carcinoma in 12 patients,papillary renal cell carcinoma in 2 patients,and hamartoma in 1 patient.The mean creatinine level was 75.0±0.8μmol/L(range 61.0-90.4μmol/L)at 1 mo after surgery,and there were no statistically significant differences compared with pre-operation(P>0.05).The glomerular filtration rate ranged from 45.1 to 60.8 mL/min,with an average of 54.0±5.0 mL/min,and these levels were not significantly different from those before surgery(P>0.05).CONCLUSION GreenLight laser has extraordinary cutting and sealing advantages when used for small renal tumors(exogenous tumors of stage T1a)during LPN.However,use of this technique can lead to the generation of excessive smoke.

Comprehensive treatment for primary right renal diffuse large B-cell lymphoma with a renal vein tumor thrombus:A case report

BACKGROUND Renal involvement in lymphoma is commonly associated with widespread nodal or extranodal lymphoma.Primary renal diffuse large B-cell lymphoma is an extremely rare extranodal lymphoma,accounting for fewer than 1%of all renal masses.Interestingly,the patient in this study had a renal vein tumor thrombus that was observed after laparoscopic radical nephrectomy.CASE SUMMARY We report the case of a 56-year-old female patient with primary renal lymphoma and a renal vein tumor thrombus whose first symptom was right pain in the back and gross hematuria.Histopathology revealed primary renal diffuse large B-cell lymphoma.The patient received 8 standard cycles of rituximab with cyclophosphamide,doxorubicin,vincristine,and prednisone chemotherapy after surgery,and no obvious signs of recurrence were observed during the one-year follow-up.CONCLUSION We evaluated comprehensive treatment of primary renal diffuse large B-cell lymphoma and multidisciplinary management of this malignancy.

Combined use of retroperitoneal laparoscopy and bladder resectoscope to treat renal and ureteral tumor occurring at the same side of transplanted kidney (report of 5 cases)

To evaluate the operative characteristics and efficacy of retroperitoneoscopic resection of renal,ureter and partial bladder for the treatment of native renal pelvic and ureteral transitional cell cancer occurring at the same side of transplanted kidney.Methods In 5 cases of renal transplantation,there were 2 cases of right native renal pelvic cancer,1 case of right native renal pelvic and ureter cancer and 2 cases of right ureter cancer respectively.The transplanted kidney was in the same iliac fossa side of the tumor.All 5 patients were subjected to nephroureterectomy and bladder cuff excision by retroperitoneoscopic technique.Results Five operations were completed successfully.The operative time was 180 to 280 min,and the blood loss was 50 to 200 ml.The recovery of intestinal function after operation was 12 to 36 h.The urine output was 1 500 to 4 000 per day.Postoperative serum creatinine was still normal.The mean hospital stay after operation was 4.5 days.Conclusion Retroperitoneal laparoscopic nephroureterectomy and bladder cuff excision is a good method to treat the native renal pelvic and ureteral transitional cell cancer occurring at the same side of transplanted kidney.The procedure is safe and less invasive,which provides a good protection of transplanted kidney.12 refs.

Unexplained Crying Episodes Reveling a Cystic Nephromas

Cystic nephromas (CNs) are uncommon, benign renal neoplasms reported in infants/young children of both genders and in adult females, concerning the pediatric population few studies have been conducted. The diagnosis of cystic nephroma is based on clinical signs, imaging tests, and anatomo-pathological study. In children, CNs can appear as a palpable abdominal mass in most of cases, hematuria or recurrent urinary infections. They are characterized by multycystic architecture and the exclusive presence of mature nephrogenic elements. Treatment is surgical with a very good prognosis in most of cases. We are going to report a case of a 13-month-old girl child diagnosed with Cystic nephromas who presented to pediatric emergency with unexplained crying episodes in order to increase clinicians awareness about this rare tumor.

Successful management of a mixed epithelial and stromal renal tumor masquerading as lower pole renal cyst:A laparoscopic deroofing approach

Background:Renal cysts are common in clinical practice,but some may harbor rare pathological entities such as mixed epithelial and stromal tumors(MEST).Imaging studies are crucial for accurate diagnosis.While laparoscopic deroofing is an established approach for symptomatic renal cysts,encountering MEST within a cyst is uncommon.Case Presentation:We present the case of a 37-year-old female who presented with persistent left flank pain.Imaging revealed a large renal cyst in the lower pole of the left kidney,classified as Bosniak 2.Despite analgesia,the patient's symptoms persisted,leading to a laparoscopic deroofing procedure.Histopathological examination postprocedure revealed a MEST.The patient reported complete resolution of symptoms at the 3-month follow-up.Conclusion:This unique case presents the successful identification and surgical management of a MEST masquerading as a lower pole renal cyst through laparoscopic deroofing.It also contributes to the existing literature by highlighting the importance of considering rare pathological entities in the evaluation of renal cysts and the value of laparoscopic techniques in their management.

Renal tumor in developing countries:142 cases from a single institution at Shanghai,China

Background:The clinical management of children with renal tumors including Wilms'tumor,clear cell sarcoma,rhabdoid tumor and other renal tumors in our center was designed according to the National Wilms'Tumor Study Group protocols.Methods:A total of 142 consecutive patients who had been diagnosed as having renal tumors at Shanghai Children's Medical Center were reviewed retrospectively in the period of December 1998 and September 2012.Diagnosis and treatment were decided by a multi-disciplinary team including oncologists,surgeons,pathologists and sub-specialized radiologists.Results:The median age of the patients at the time of diagnosis was 27 months.The tumor stages of the patients were as follows:stage I 24.6%,stage II 23.2%,stage III 32.3%,stage IV 14.1%,and stage V 5.6%.Favorable histology was diagnosed in 80.3%,anaplasia in 4.2%,clear cell sarcoma in 9.8%,rhabdoid tumor in 4.9%,and other renal tumors in 0.7%of the patients.The event-free and overall 5-year survival rates were 80%and 83%,respectively.Tumor relapse and progress was seen in 25 patients(17.6%).The median relapse time was 6 months(range:2-37 months).Seven relapsing patients were re-treated and four of them got second complete remission(three in stage II,one in stage I).Conclusion:A multi-disciplinary team work model is feasible in developing countries,and the renal tumors protocols basically from developed countries are safe in developing countries.

Renal Tumor Biopsy Technique

Objective： To review hot issues and future direction of renal tumor biopsy （RTB） technique. Data Sources： The literature concerning or including RTB technique in English was collected from PubMed published from 1990 to 2015. Study Selection： We included all the relevant articles on RTB technique in English, with no limitation of study design. Results： Computed tomography and ultrasound were usually used for guiding RTB with respective advantages. Core biopsy is more preferred over fine needle aspiration because of superior accuracy. A minimum of two good-quality cores for a single renal tumor is generally accepted. The use of coaxial guide is recommended. For biopsy location, sampling different regions including central and peripheral biopsies are recommended. Conclusion： In spite of some limitations, RTB technique is relatively mature to help optimize the treatment of renal tumors.

Retrospective study of the efficacy and complication of thoracoabdominal incision for nephrectomy: a comparison with flank approach

This retrospective study was performed to compare the outcome of thoracoabdominal incision versusflank incision for radical nephrectomy in the patients with large renal tumors.A questionnaire assessing postopera-tive pain,administration of pain medications and the return to activities and work was sent to the patients who underwent radical nephrectomy through the 11th rib(group 1:undergoingflank incision,including 96 patients)or the 9th to 10th rib(group 2:undergoing thoracoabdom-inal incision,including 98 patients)from 2003 to 2007 in our hospital.A case retrospective analysis assessing operation time,perioperative hemorrhage volume,size of tumor,success in the treatment of tumor thrombus in renal vein or vena cava,time length of presence of drainage tube,postoperative analgesia usage and length of stay was conducted in patients whose questionnaires were returned.A total of 56 patients(58%)in group 1 and 60(61%)in group 2 responded to the questionnaire.Time lengths of operation and presence of abdominal drainage tube were shorter in group 2 than those in group 1.Perioperative hemorrhage volume in group 2 was obviously less than that in group 1.The mean size of tumors in group 1 was significantly smaller than that in group 2(P<0.0005).The success rate of treating thrombus in renal vein or vena cava in group 2 was significantly higher than that in group 1(P<0.05).Lengths of off-bed time and stay were the same in both groups.There were no differences between groups in terms of pain severity on postoperative day 1,on day of discharge and 1 month postoperatively(P>0.05).There were no significant differences between groups in the time following surgery when pain completely disappeared,when pain medications were discontinued,and when the patient returned to daily activities and work(P>0.05).The thoracoabdominal incision provides excellent exposure and allows for early vascular control.Efficacy and complication was comparable for thoracoabdominal andflank incisions in terms of incisional pain,analgesic requirements after discharge and return to normal activities.

Long-term oncologic outcomes of laparoscopic versus open partial nephrectomy

Background Most of the literatures on laparoscopic partial nephrectomy （LPN） versus open partial nephrectomy （OPN） focus on technical details and early or mid-term oncologic outcomes, reflecting that the approach is safe and provides mid- term benefits compared with traditional open surgery. However, the difference of long-term oncologic outcome between LPN and OPN remains unclear. The aim of this meta-analysis was to evaluate the long-term oncologic outcome of LPN in the treatment of localized renal tumors compared with that of OPN. Methods A systematic search of electronic databases including Medline, Embase, and Cochrane library was conducted. Comparative studies reporting on long-term oncologic outcome of LPN versus OPN were regarded eligible. The odds ratio （OR） and its corresponding 95% confidence intervals （CO were calculated for the oncologic outcomes. The methodologic quality of the included studies was evaluated using the strict criteria of the Newcastle-Ottawa scale. Results Six comparative studies （1495 participants including 555 LPN and 940 OPN） were included in the present study. There was no significant difference between LPN and OPN in 5-year overall survival （OS） rates （OR=1.83, 95% Cl （0.80, 4.19））, 5-year cancer specific survival （CSS） rates （OR=1.09, 95% CI （0.62, 1.92））, and 5-year recurrence free survival （RFS） rates （OR=0.68, 95% CI （0.37, 1.26））. Conclusion The results of this meta-analysis revealed that there was no significant difference in long-term oncologic outcome between LPN and OPN for treatment of localized renal tumors.

Expanding the horizons of endoscopic ultrasound:diagnosis of non-digestive pathologies

Endoscopic ultrasound(EUS)is mainly used for the evaluation and sampling of mediastinal and abdominal lymph nodes,luminal and submucosal lesions of the upper and lower gastrointestinal tract,as well as in the diagnostic approach for pancreatic,biliary and liver disease.However,several non-digestive pathologies may be encountered as well,expanding the diagnostic potential of EUS.In this article,we present nine examples of extra-digestive abnormalities detected by means of EUS,including pathologies of the thyroid gland,mediastinal and abdominal vessels,lungs,kidney and the urinary bladder.The purpose of this article is to review the capabilities of EUS beyond routine evaluation of gastrointestinal organs.