==inizio objective==

Nephron Sparing surgery allows to eradicate renal cancer preserving renal function after surgery. The “Sutureless-Clampless” technique has the purpose to avoid residual renal parenchyma damages linked to renorrhaphy and prolonged ischemia time. However, the procedure is often characterized by postoperative bleeding. Aim of study is to analyse if preoperative HAS BLED score, normally applied to cardiac surgical patient, can predict acute bleeding in this urological procedure

==fine objective==

==inizio methodsresults==

After excluding patients undergone partial nephrectomy “clamp-suture”, we have retrospectively collected, from January 2015 to February 2022, 157 patients treated with nephron sparing surgery. We have subdivided these patients in two groups on basis of the preoperative HAS BLED score (Group 1: HAS BLED score ≤ 2 ; Group 2 HAS BLED score > 3). Student’s Test for unpaired samples was performed for intraoperative blood loss (cc) pre and postoperative Hb (g/dl), 1st day drainage count (cc),2nd day drainage count (cc) Logistic regression analysis was used to assess the association between the preoperative HAS BLED score and postoperative bleeding. We assumed p≤ 0.05 as level of statistical significance.

==fine methodsresults==

==inizio results==

Student’s T test for unpaired samples have shown the following results: we haven’t found a statistical difference for pre-operative Hb (13,36±1,82 vs 13,86±1,99, p=0.88). We have found a statistical difference in intraoperative blood loss (150,27±20,52 vs 211,05±50,74,p=0,042), postoperative Hb (11,74±1,58 vs 9,50±1,93, p=0.047) , 1st day drainage count (118,82±25,76 vs 156,00±27,95, p=0,032,and 2nd day drainage count (66,08±15,30 vs 101,80±25,63, p=0.038). Multivariate logistic regression analysis showed that a HAS BLED score > 3 is an independent risk factor for postoperative bleeding (OR: 2.84; p <0.05). ==fine results== ==inizio discussions== ==fine discussions== ==inizio conclusion== In our series we have found statistical different between the two examined groups in terms of bleeding risk. In Clampless Sutureless nephron sparing surgery is very important tailorized the patient before surgery in order to avoid massive postoperative bleeding. In our series the HAS BLED score has been shown to be useful in identifying patients at risk of mayor bleeding and used in the normal preoperative routine, although further multicentre prospective studies are needed. ==fine conclusion== ==inizio reference== ==fine reference==

==inizio objective==

Nephron Sparing surgery allows to eradicate renal cancer preserving renal function after surgery. The “Sutureless-Clampless” technique has the purpose to avoid residual renal parenchyma damages linked to renorrhaphy and prolonged ischemia time. However, accurate and safe haemostasis is required. Aim of our study is to evaluate the efficacy of haemostasis with human gelatine-thrombin matrix sealant vs sponge sealant matrix in “sutureless-clampless” partial nephrectomy.

==fine objective==

==inizio methodsresults==

After excluding patients undergone partial nephrectomy “clamp-suture”, we have retrospectively collected, from January 2015 to January 2020, 101 patients treated with nephron sparing surgery. We have subdivided these patients in two groups on basis of the hemostatic agent used (Group 1: human gelatine-thrombin matrix sealant; Group 2 sponge sealant matrix). Student’s Test for unpaired samples was performed for age (y), operative time (min), Dmax at preoperative CT scan (mm), intraoperative blood loss (cc) pre and postoperative Hb (g/dl), 1st day drainage count (cc),2nd day drainage count (cc). We assumed p≤ 0.05 as level of statistical significance.

==fine methodsresults==

==inizio results==

Student’s T test for unpaired samples have shown the following results: among pre and peri operative parameters evaluated ,we haven’t found a statistical difference for age (69,78±10,29 vs 68,10±12,p=0.09), operative time (84,16±26,09 vs 87,04±25,75 ,p=0,168) Dmax at preoperative CT scan (2,727±1,1841 vs 2,776±1,2839, p=0.84),pre-operative Hb (13,36±1,82 vs 13,86±1,99, p=0.88), and intraoperative blood loss (211,27±45,52 vs 211,05±50,74,p=0,81). Among postoperative parameters evaluated, postoperative Hb was similar between the two group (11,74±1,58 vs 12,50±1,93, p=0.057) as the 1st day drainage count (118,82±25,76 vs 117,00±27,95, p=0,32). However, we found statistically difference between the two groups in terms of 2nd day drainage count (66,08±15,30 vs 64,80±25,63, p<0.05). ==fine results== ==inizio discussions== ==fine discussions== ==inizio conclusion== Except for the 2nd postoperative day drainage count, in our series we have not found any statistical different between pre-, peri and postoperative parameters in the two groups examined. We can conclude that both human gelatine-thrombin matrix sealant and sponge sealant matrix in selected patients and in tailored procedures guarantee an accurate and safe haemostasis, although further multicentre prospective studies are needed ==fine conclusion== ==inizio reference== ==fine reference==

==inizio objective==

To compare the oncological and clinical outcomes for open (OPN) vs robotic (RAPN) partial nephrectomy performed in patients with totally endophytic renal tumours(TIT).

==fine objective==

==inizio methodsresults==

We retrospectively considered 35 consecutive patients who underwent PN in our department from January 2018 to September 2020. 19 patients underwent OPN (Group A) and 16 underwent RAPN (Group B) for TIT. TITs were defined as completely intraparenchymal masses, without any exophytic element. All OPNs were performed with a retroperitoneal approach, while all RAPNs were performed with a transperitoneal approach by a single surgical team. In the robotic approach an ultrasound probe (Robotic Drop-In Ultrasound Trasducer 8826-BK medical) and in two cases a 3D-modeling (Medics) were used. All data were collected in a prospectively maintained database and retrospectively analysed. The two groups were compared for preoperative data (age, gender, tumour dimensions and position), intraoperative variables, perioperative and postoperative outcomes. Post-operative complications were classified according to the Clavien-Dindo system.

==fine methodsresults==

==inizio results==

There was no difference between the two groups in terms of patients’ demographics as well as tumour characteristics in all variables. 23 tumours were clear cell carcinomas staged at pT1a, 6 were clear cell carcinomas staged at pT1b, 5 were renal oncocytoma staged at pT1a and 1 was a Type 1 Papillary Renal Cell Cancer staged at pT1b. Median tumour size was 34 mm for group A, and 29 mm for Group B (P=0.32). Group A was found to be similar to group B in terms of operation time (p=0.781), radical nephrectomy [RN] rate (p=0.504), positive surgical margins (p=0.338), estimated blood loss (p=0.205), intra-operative (p=0.104) and post-operative (p=0.304) transfusion rate, drains time (p=0.212), while post-operative pain (VAS scale) (<0.0001) and hospitalization time (<0.001) were significantly lower in Group B. Median follow-up was 35 and 31 months in Group A and Group B, respectively. Disease recurrence was recorded in two patients after OPN, and in one patient after RAPN, respectively (p=0.4). The decline of renal function at the last available follow-up (RAPN: 10.8%; OPN: 10.7%) was similar in both groups (p=0.801). ==fine results== ==inizio discussions== ==fine discussions== ==inizio conclusion== In experienced hands, RAPN for a TIT is technically feasible. Compared with OPN, it shows equivalent safety and efficacy for TIT with early functional advantages in terms of post-operative pain and slightly earlier discharge. ==fine conclusion== ==inizio reference== ==fine reference==

==inizio objective==

Inadvertent pleural injury may occur during open flank surgery for renal or adrenal disease. These injuries are usually suture repaired primarily with simultaneous evacuation of pleural air. Operative breach of the diaphragm is uncommon during laparoscopic renal and adrenal surgery [1–3]. However, with the widespread use of laparoscopy (for its clear advantages over open surgery) and the increasing surgical pathologies managed with this technique, there is a potential for an increased risk of carbon dioxide pneumothorax due to diaphragmatic injury. Capnothorax associated with laparoscopic surgery is different from air pneumothorax but, if such an injury is recognized intraoperatively, it should be repaired laparoscopically in a manner duplicating the principles of open surgery. We report the incidence and the laparoscopic repair for inadvertent diaphragm injury during upper abdominal urological laparoscopy.

==fine objective==

==inizio methodsresults==

The records of 384 laparoscopic kidney operations were reviewed. All procedures were performed by the same surgeon (R.S.) and included: 65 simple nephrectomies, 115 radical nephrectomies and 204 partial nephrectomies. A total of four cases (1.04%) of diaphragmatic injury were found. Mean patient age was 59.7 years (range from 18.5 to 85.3). Operative and clinical records were reviewed and patients’ outcomes were evaluated. Figure 1 shows the distribution of the patient’s age, BMI, time of surgery and blood loss, considering all kidney surgeries and each type of kidney surgery individually. For diaphragmatic repair, no additional trocars were needed. In all cases, usual working port configuration for nephrectomy, allowed intracorporeal suturing. However, if necessary, an additional 5 mm port was placed on left or right flank, respectively. In all cases of inadvertent injury, the pleural breach was identified intraoperatively (due to noticeable billowing of the diaphragm), followed by direct laparoscopic visualization of the injury. Laparoscopic suture repair of the diaphragm replicated the technique and repaired laparoscopically with interrupted 0-Vicryl sutures, whereas pneumoperitoneum was decreased in 12 mmHg and the anesthesiologist administered a large inspiratory breath. Criteria used for chest tube placement was pneumothorax greater than 20% of lung volume or associated with hemodynamic or ventilatory changes.

==fine methodsresults==

==inizio results==

A total of four cases (1.04%) of diaphragmatic injury were recorded during 384 laparoscopic nephrectomies. In all cases, the cause of pleural lesion was iatrogenic injury to the diaphragm. Two of these lesions occurred during partial nephrectomy, one during radical nephrectomy and another during simple nephrectomy. All four cases of diaphragmatic lesion occurred in the presence of a transperitoneal access and all in the course of left nephrectomy. As regards the pathology, in only one case the pathology was of a benign nature (being hydropyonephrosis). As regards the localization of the lesion, the distribution of the three malignant pathologies was as follows: one case with localization of the lower hemi-kidney and two cases with lesion of the upper pole of the kidney. Diaphragmatic repair was always carried out by intracorporeal suturing. All patients evolved uneventfully.

==fine results==

==inizio discussions==

In laparoscopic renal and adrenal surgery, iatrogenic injury of the diaphragm is an uncommon event; it does not exceed 0.6% in the largest series [2]. Soulie et al. reported 19 urological complications in 350 laparoscopic procedures (5.4%) [4] but none of these patients showed diaphragmatic injury, highlighting its rarity. The occasional occurrence of this complication is due to the clear separation between the kidneys and the diaphragm [5]. However, more surgeons have expanded the limits for laparoscopy by attempting very demanding procedures. This may sustain or even increase the incidence of iatrogenic diaphragmatic injuries. It is noteworthy that our series reflects the experience of a single surgeon that has surpassed the learning curve of standardized techniques (OAC). Obesity, large tumors, inflammatory intestinal pathologies, previous surgeries and chemotherapy can facilitate the occurrence of diaphragmatic lesions. However, adrenal surgery by itself has an inherent risk for diaphragmatic injury because the adrenal gland is juxtaposed against the diaphragm. Diaphragmatic injury can originate from improper trocar placement or direct contact with monopolar electrocautery or harmonic scalpel [2]. When the retroperitoneal approach is preferred for renal or adrenal surgery, improper trocar placement can easily lead to diaphragm injury [2]. The lesion can appear as an evident tear of the diaphragm or be invisible to the surgeon’s inspection and be alerted by changes in patient cardiopulmonary status [1]. In addition, an undetected injury may become evident by the floppy diaphragm sign, in which the diaphragm billows inferior with any degree of abdominal desufflation, reflecting the loss of negative pressure within the diaphragm [6]. All of our patients with inadvertent injury demonstrated undue billowing of the diaphragm, which prompted the rapid diagnosis of the diaphragmatic complication. So, this complication was recognized by the operating surgeon in all cases. None of our patients had hemodynamic instability as a result of the injury. Considering only single center experiences on this topic, our report is the second largest series after the work published by Castillo et al. [7]. Techniques of laparoscopic repair of the diaphragm have been described in the literature. In a multi-institutional review of 1765 patients, Del Pizzo et al. reported on eight patients who underwent laparoscopic repair of an iatrogenically injured diaphragm [2], using an EndoStitch device or freehand laparoscopic suturing with interrupted two-zero sutures. Before tying the last stitch, pleural gas was evacuated using a large inspiratory breath or a laparoscopic suction device. Upon the completion of repair, CO2 was aspirated from the pleural space using an intercostal 6 Fr catheter that was introduced by the Seldinger technique. In one patient (12%) a chest tube was necessary to evacuate residual pneumothorax. Fugita inserted a catheter into the diaphragmatic defect through the abdominal wall under laparoscopic vision [8]. No mention was made of whether the abdomen was desufflated before tying down the suture or whether the pleural space was evacuated under water seal. Similar to what was described by Del Pizzo [2] and by Castillo [7], we also chose interrupted sutures for the laparoscopic repair regardless of lesion size and location. Several reports confirm the feasibility of diaphragmatic repair by means of intracorporeal suturing [1, 9]. We believe that diaphragm suturing must always be attempted due to the simplicity and reliability of this technique. Although continuous suture tends to be faster, particularly for long defects and especially in laparoscopy, the risk of dehiscence is greater if the suture material breaks. For this reason, we prefer to perform an interrupted suture for its advantage of having a high tensile strength (although it takes a relatively long time to be placed). Nevertheless there has been one successful report of diaphragmatic injury repair without the use of stitches [10]. This was achieved by employing a matrix gel and a thrombin solution (Floseal) with interposition of the omentum over a 1 cm diaphragmatic lesion. The authors refer to their technique as a suitable option for small lesions. To reach an effective repair of the diaphragm, air must be evacuated before the stitches are secured by means of either a suction device or the administration of a long forced inspiratory breath. In addition, repair of diaphragmatic injury has to be timed according to patient parameters. When the patient is in stable condition surgery can continue and the injury may be addressed at the end of the procedure. In cases of large tumors that may obstruct the surgeon’s direct access to the lesion, surgical specimen should be removed first to ease repair. Nevertheless we think that if possible, the diaphragm injury should be repaired without delay. This was the case in all of our patients in which early recognition of diaphragmatic injury allowed for a prompt repair without the interference of the surgery. Pneumothorax greater than 20% of lung volume or associated with hemodynamic or ventilatory changes is managed with thoracostomy [9]. Pleural lesions produced by trocar placement or important residual capnothorax may also warrant thoracostomy. CO2 used for pneumoperitoneum is readily eliminated through the lungs and, compared with air, it has higher solubility and increased diffusion coefficient; this allows a greater amount of molecules to diffuse across a membrane in a given time. This explains why capnothorax usually resolves spontaneously and allows for expectant management in patients without hemodynamic instability [9]. Although the precise time frame for such resolution is not clear, Venkatesh et al. reported spontaneous resolution of a symptomatic pneumothorax within 3 h [9]. As such, whether to intervene depends on the individual clinical scenario and surgical judgment. Abreu et al. reported a higher incidence of gas collections associated with the retroperitoneal over the transperitoneal approach (6.6% vs. 0.7%) [3]. However, they concluded that asymptomatic, subclinical, spontaneously resolving gas collections in the chest are more common with retroperitoneoscopy but the incidence of symptomatic or serious thoracic complications is similar between transperitoneal and retroperitoneal laparoscopy [11]. We did not observe injuries from direct trocar entry in our series; this can be explained by the fact that we prefer the transperitoneal to the retroperitoneal approach for renal or adrenal surgery.

==fine discussions==

==inizio conclusion==

Primary laparoscopic repair/reconstruction of iatrogenic injury of the diaphragm should always be attempted with intracorporeal suture since this is a safe and effective technique. We believe that most laparoscopic surgeons with reasonable experience can reproduce this technique and iatrogenic injury to the diaphragm should not necessitate open conversion. Then, although when the retroperitoneal approach is preferred for renal or adrenal surgery, improper trocar placement can easily lead to diaphragm injury, and our experience has shown that transperitoneal access is not free from this complication.

==fine conclusion==

==inizio reference==

1. Potter SR, Kavoussi LR, Jackman SV. Management of diaphragmatic injury during laparoscopic nephrectomy. J Urol 2001;165:1203.
2. Del Pizzo JJ, Jacobs SC, Bishoff JT, Kavoussi LR, Jarrett TW. Pleural injury during laparoscopic renal surgery: early recognition and management. J Urol 2003;169:41.
3. Abreu SC, Sharp DS, Ramani AP, Steinberg AP, Ng CS, Desai MM, et al. Thoracic complications during urological laparoscopy. J Urol 2004;171:1451.
4. Soulie M, Seguin P, Richeux L, Mouly P, Vazzoler N, Pontonnier F, et al. Urological complications of laparoscopic surgery: expe- rience with 350 procedures at a single center. J Urol 2001;165: 1960.
5. Vallancien G, Cathelineau X, Baumert H, Doublet JD, Guillon- neau B. Complications of transperitoneal laparoscopic surgery in urology: review of 1,311 procedures at a single center. J Urol 2002;168:23–6.
6. Voyles CR, Madden B. The “f loppy diaphragm” sign with laparoscopic-associated pneumothorax. JSLS 1998;2:71–3.
7. Castillo OA, Vitagliano G, Moreno M, Diaz MA, Cortes O. Man- agement of diaphragmatic injury during transperitoneal laparo- scopic urological procedures. Int Braz J Urol 2007;33:323–8; dis- cussion 328–9.
8. Fugita O. Re: management of diaphragmatic injury during laparoscopic nephrectomy. J Urol 2001;166:1402.
9. Venkatesh R, Kibel AS, Lee D, Rehman J, Landman J. Rapid reso- lution of carbon dioxide pneumothorax (capno-thorax) resulting from diaphragmatic injury during laparoscopic nephrectomy. J Urol 2002;167:1387–8.
10. Bhayani SB, Grubb RL 3rd, Andriole GL. Use of gelatin matrix to rapidly repair diaphragmatic injury during laparoscopy. Urology 2002;60:514.
11. Shanberg AM, Zagnoev M, Clougherty TP. Tension pneumotho- rax caused by the argon beam coagulator during laparoscopic partial nephrectomy. J Urol 2002;168:2162.

==fine reference==

==inizio objective==

The use of common and non invasive imaging techniques [including the use of computed tomography (CT), ultrasonography and magnetic resonance imaging (MRI)], which has been increasing exponentially over the last few decades, has led to a similarly increased detection rate of small, localized, and often asymptomatic kidney tumors [1], involving a risk of cancer overdiagnosis [2]. Furthermore, a number of these tumors are shown to be benign following definitive pathological examination and, to date, there are no specific imaging findings that may be used to uniquely diagnose a tumor as malignant or benign [3,4]. According to Remzi et al [5], only 17% of renal masses are correctly classified as benign on performing preoperative CT. A total of 43% of these masses were subsequently overtreated with radical nephrectomy. Benign tumors are not uncommon, even in the case of renal masses with a diameter >4 cm and, if large, surgical treatment of these benign tumors is also associated with considerable morbidity [6]. This scenario has enabled a choice of partial nephrectomy (PN) to be made for the surgical treatment of these masses. As a result, starting from 2009, both American and European guidelines have recommended PN as the gold standard for patients with T1 masses that can be excised in a feasible manner [7]. In effect, compared with radical treatment, elective PN offers similar oncological outcomes, especially for those patients who are diagnosed with stage T1 renal cell carcinoma (RCC) [8 11]. Patard et al [11], in their study that included and assessed patients treated with PN (379) or radical nephrectomy (1,075) for T1N0M0 kidney tumors, demonstrated that no significant differences existed in the local or distant recurrence rates in halfway medical checks of >5 years. In their study, approx. 85% of the PNs were performed for renal masses ≥4 cm. According to several studies, 20-30% of small kidney tumors are benign at pathological examination after surgery, in spite of expert preoperative radiological estimations [9,10,12 15]. For this reason, considering the morbidity associated with nephron sparing techniques (regardless of whether they are open, laparoscopic or robot assisted), the appropriateness of this type of surgery for all masses suspected to be renal tumors must be challenged. In effect, according to the results of a review of nine studies which included >1,000 patients, performing PN led to low, but fundamentally operative morbidity and mortality rates [4]. Another study, assessing 180 patients who underwent PN [16] reported, following surgery, hemorrhage in 4 (2.2%) patients and urinary fistula in an additional 3 (1.7%) patients. Consequently, even though PN can be considered as a valid method for both diagnosis and treatment of small kidney lesions, its suitability for all suspicious masses remains questionable, and its widespread use has been debated, given the great impact of benign tumors and the morbidity rate that is associated with this surgical procedure. Therefore, given current guidelines that recommend treatment unless the patient is elderly or infirm, overtreatment of patients with benign renal tumors remains an inappropriate risk. For all the above reasons, the purpose of the present study was to investigate the incidence of benign tumors at the stage of receiving PN on preoperative imaging evaluations in a single center series of patients with a solitary renal lesion considered to be RCC.

==fine objective==

==inizio methodsresults==

The medical records of patients receiving PN at our center (Department of Urology, Umberto I Hospital) over the course of the last 10 years were retrospectively reviewed. Elective PN was offered to patients whose renal tumors were either solitary, solid masses or complicated renal cysts preoperatively classified as Bosniak type III or IV cysts, which were not located in the renal hilum or were with central sinus invasion if patients had a normal contralateral kidney. After the operation, the pathological features were reviewed by an experienced pathologist according to the World Health Organization classification system. Angiomyolipomas (AMLs), oncocytomas, benign cystic nephromas, adenomas, hydatid cysts and various other non malignant lesions were classified as benign, whereas malignant lesions comprised clear cell, chromophobe, papillary, collecting duct, sarcomatoid variant and multilocular cystic RCC. A total of 195 patients were identified who had undergone elective PN for a solitary renal mass with the intention of curing presumed RCC, and these patients were included in this retrospective study. During the study period, no patients had undergone surgery with the preoperative diagnosis of a benign lesion or urothelial carcinoma. No patients with a renal mass and no metastases underwent biopsy or in vivo ablation. Consequently, we have not recommended active surveillance for small renal tumors presumed to be RCC. Furthermore, no patients had a known genetic predisposition to RCC or AMLs (such as von Hippel Lindau disease, Birt Hogg Dube syndrome or tuberous sclerosis). All operations were performed using the laparoscopic surgical technique with a transperitoneal or retroperitoneal approach based on the patient’s history of abdominal surgery, the patient’s habitus, tumor location and surgeon preference. Furthermore, for better preservation of the renal function, the off clamp technique was chosen in all cases. Signed informed consent was obtained from all the patients for publication of this study and for processing their medical data.

==fine methodsresults==

==inizio results==

Among the 195 kidney lesions removed, 30 (15.4%) of them were classified as benign by the pathologist. Considering the 30 patients with a benign renal mass, in one case conversion to open surgery was required owing to uncontrollable bleeding. In two other cases, it was necessary to place a double J pyeloureteral stent for the urinary fistula during the post operative period. Consequently, the complication rate was 10% (3/30 cases) among patients diagnosed with a benign renal mass. The blood loss ranged from 150 1,800 ml (mean: 523 ml), whereas the operation time ranged from 75 330 min (mean: 186 min). The pathological results (in order of decreasing incidence) were: 1) oncocytoma (n=26 cases; 86.8%); and =2) angiomyolipoma (n=2 cases; 6.6%) and renal cysts (n=2 cases; 6.6%).

==fine results==

==inizio discussions==

Previously, urologists used to claim that >90% of solid kidney lesions were RCC at surgery. However, according to daily results, after surgical treatment up to 27% of suspected kidney lesions are identified as benign tumors on final histological examination, and this incidence rate increases discernibly as the tumor size decreases [17-20]. The likelihood of the tumor being benign was found to be greater when the kidney mass was small and solitary; therefore, in the present study, we have retrospectively reviewed all PNs for a solitary renal mass performed at our department. Our analysis revealed that 15.4% of the PNs performed for a suspected solitary RCC revealed the presence of a benign tumor (30/195 patients). In this scenario, we have to consider two important aspects. First is the fact that the clinical manifestations of these incidental masses were either absent or non specific. Secondly, and more important than the first aspect, is the role of renal biopsy. Patel et al [21] reported that core biopsies were highly sensitive and specific when a diagnostic result was obtained. However, approx. 80% of patients did not undergo surgery following the benign biopsy result. After PN, 36.7% of patients with a negative biopsy result showed malignant disease on surgical specimens. For these reasons, imaging studies fulfill a fundamental role in evaluating small renal masses (SRMs). A CT scan is currently the most commonly used imaging technique for initial diagnosis and staging of suspected kidney lesions [22]. In adults, both malignant (such as RCC) and benign (such as AML and oncocytoma) kidney tumors may present as a solid mass. On performing a CT, a renal mass is generally considered to be non enhancing if the change in attenuation is ≤10 Hounsfield units (HU) or enhancing if the change is >20 HU. However, a renal mass with a borderline enhancement (with a change of 10-20 HU), is suspected to be RCC [23,24]. In addition, some small RCCs, in particular papillary RCCs, show a low level enhancement and, for this reason, these masses could be misidentified as hyperdense cysts [25]. On performing CT, macroscopic fat has an attenuation of <10 HU [26,27], and its presence is specific for a diagnosis of AML. In the majority of cases, this benign mass does not need to be treated, except when the volume is high (usually >4 cm, due to the increased risk of bleeding) or the patient complains of symptoms. Almost always on CT scans, the fat of AMLs is readily discernible but, if present in only small amounts, this may be obscured on a contrast enhanced scan. Therefore, in these cases, performing an unenhanced scan with thin slice sections is useful [27]. AMLs without macroscopic or visible fat on imaging (“lipid poor AMLs”) mimic RCCs; in addition, in very rare cases, macroscopic fat can be present in RCCs for: engulfment of adjacent fat; osseous metaplasia [28]; or cholesterol necrosis [29]. In our series, two AMLs were surgically removed from the patients (6.6%). On CT, in approximately one third of cases, oncocytomas manifest themselves as well capsulated solid lesions with a central scar; however, this feature is also observed in RCCs [22]. According to several studies, oncocytomas reveal a “segmental enhancement inversion” pattern during the corticomedullary and early excretory phases [30,31]. However, the same also applies for RCCs [32-34]. In the present study, 26 oncocytomas were resected. With common imaging techniques, the kidney masses that are most commonly identified are simple cysts that do not require any kind of treatment. According to the data in the previously published literature, at PN the impact of complex renal cysts varies from 2 to 14% [35]. In the current study, two renal masses (6.6%) were identified as benign cysts at surgery. The relatively high occurrence of non malign tumors after radical treatment indicates that proceeding directly to surgery should be avoided whenever possible, including the use of mildly intrusive methods, such as laparoscopic nephron sparing surgery. Renal lesions, if small, usually increase and evolve tardily, especially over a short time period. Therefore, active surveillance has been chosen for patients who are at greater risk, and for whom it would be better to avoid surgery. Especially for renal masses with a diameter of 2 cm or less, due to the higher incidence of benign pathology, active surveillance may obviate the need for more unnecessary surgical treatments, with its consequent morbidity Patients who choose active surveillance must be informed of low but non negligible risk of progression. Percutaneous surgeries, including cryoablation and radiofrequency ablation, are also used as an alternative option to PN. Even though metastasis and not noticing RCC have occurred in a relatively small number of subjects going through cryoablation and radiofrequency ablation, the occurrence of regional relapse following cancer ablation has been shown to be higher compared with that following nephrectomy (both PN and radical nephrectomy), highlighting the relevance of careful employment of these latest methods. Consequently, PN remains a fundamental surgical method in the treatment of small renal cancer. In our series, 6.6% of benign renal tumors were AML, 86.6% were oncocytoma and 6.6% were cystic masses. The exact proportion of histological types varies between several studies. Clearly, selection bias has an impact on the proportion of histological types. It should be noted that the present study had a number of limitations. First, sorting misconceptions may have existed since the study was a retrospective one, and secondly, the patients included were all subjects of a single center. In spite of this, the procedures for elective PN at our department were the same as those of other centers.

==fine discussions==

==inizio conclusion==

In conclusion, the present study has shown the incidence rate of benign tumors in patients who have been subjected to laparoscopic partial nephrectomy due to a suspected solitary renal mass. Based on these results, the patient should be counseled not only about the intra- and post-operative risks of nephron sparing surgery, but also about its dual therapeutic and diagnostic role. Therefore, patients ought to be informed about the considerably high probability of a benign histological result. Furthermore, considering the crucial problem of the socioeconomic burden of PN and its associated complications in patients with benign kidney tumors (where a complication rate of 10% was noted in our study among patients diagnosed with benign renal mass), it is clear that urologists need to focus on trying to reduce non malignant final pathological diagnoses.

==fine conclusion==

==inizio reference==

1) Hollingsworth JM et al. Rising incidence of small renal masses: a need to reassess treatment effect. J Natl Cancer Inst. 2006;98:1331 1334.
2) Welch HG, Black WC. Overdiagnosis in cancer. J Natl Cancer Inst. 2010;102:605 613.
3) Marszalek M et al. Elective open nephron sparing surgery for renal masses: Single center experience with 129 consecutive patients. Urology. 2004;64:38 42.
4) Uzzo RG, Novick AC. Nephron sparing surgery for renal tumors: Indications, techniques and outcomes. J Urol. 2001;166:6 18.
5) Remzi M et al (2007). Renal tumour size measured radiologically before surgery is an unreliable variable for predicting histopathological features: benign tumours are not necessarily small. BJU Int 99:1002–1006.
6) Romis L et al (2004). Frequency, clinical presentation and evolution of renal oncocytomas: multi centric experience from a European database. Eur Urol 45:53–57 (discussion 57).
7) Campbell SC, Novick AC, Belldegrun A, et al. Guideline for management of the clinical T1 renal mass. J. Urol. Oct 2009;182(4):1271 1279.
8) Hafez KS, Fergany AF, Novick AC. Nephron sparing surgery for localized renal cell carcinoma: Impact of tumor size on patient survival, tumor recurrence and TNM staging. J Urol. 1999;162: 1930 1933.
9) McKiernan J, Yossepowitch O, Kattan MW, et al. Partial nephrectomy for renal cortical tumors: Pathologic findings and impact on outcome. Urology. 2002;60:1003 1009.
10) Pahernik S, Roos F, Hampel C, et al. Nephron sparing surgery for renal cell carcinoma with normal contralateral kidney: 25 years of experience. J Urol. 2006;175:2027 2031.
11) Patard JJ, Shvarts O, Lam JS, et al. Safety and efficacy of partial nephrectomy for all T1 tumors based on an international multi center experience. J Urol. 2004;171:2181 2185.
12) Gill IS, Matin SF, Desai MM, et al. Comparative analysis of laparoscopic versus open partial nephrectomy for renal tumors in 200 patients. J Urol. 2003;170:64 68.
13) Kural AR, Demirkesen O, Onal B, et al. Outcome of nephron sparing surgery: elective versus imperative indications. Urol Int. 2003;71:190 196.
14) Kutikor A, Fossett LK, Ramchandani P, et al. Incidence of benign pathologic findings at partial nephrectomy for solitary renal mass presumed to be renal cell carcinoma on preoperative imaging. Urology. 2006;68:737 740.
15) Marszalek M, Ponholzer A, Brossner C, et al. Elective open nephron sparing surgery for renal masses: Single center experience with 129 consecutive patients. Urology. 2004;64:38 42.
16) FilipasD,FichtnerJ,SpixC,etal.Nephron sparingsurgeryofrenal cell carcinoma with a normal opposite kidney: Long term outcome in 180 patients. Urology. 2000;56:387 392.
17) Frank I, Blute ML, Cheville JC, et al. Solid renal tumors: an analysis of pathological features related to tumor size. J Urol 2003; 170:2217 20.
18) Lane BR, Babineau D, Kattan MW, et al. A preoperative prognostic nomogram for solid enhancing renal tumors 7 cm or less amenable to partial nephrectomy. J Urol 2007; 178:429 34.
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==inizio objective==

The exponential increase in the use of noninvasive abdominal imaging techniques has led to an increase in the number of small, often asymptomatic, kidney tumors incidentally detected that generally migrate to lower clinical stage [1, 2]. In addition, according to studies from Western countries, 15–20% of small kidney tumors are benign [3-5]. Furthermore, frequently, small renal masses (SRMs) have an indolent course [6]. Commonly, Computed Tomography (CT) is needed in the evaluation of kidney masses [7, 8]; at this radiological examination, contrast-enhancing renal nodules are classified as malignant and, in most cases, are surgically excised without previous biopsy. Traditionally, renal biopsy is performed only in the case of suspected lymphoma, abscess or metastatic disease. Although most masses are Renal Cell Carcinoma (RCC) after surgical treatment, a non-negligible number of these masses may be benign on final pathology; as a result, some patients undergo unnecessary surgery with an associated significant morbidity. This has an important impact on health policy [9]. In effect, for these patients, the treatment planning is uncertain due to the failure of current imaging techniques and renal biopsy to accurately distinguish RCC from benign tumors before surgery [1, 10]. Surveillance might be an appropriate alternative to immediate surgery for patients with indolent tumors, considering the low risk of progression if the treatment is delayed [6]. In effect, patients under surveillance rarely progress to metastatic disease [11]. However, choosing which patients are suitable for surveillance can be difficult because the distinction between benign masses or indolent malignant tumors and aggressive cancer may not be possible without complete surgical removal. For evaluating the potential aggressiveness of small renal masses, several tools have been used to facilitate the choice between surveillance and immediate surgery. The current retrospective report describes the incidence and predictive factors of benign renal masses by surgery. Understanding this analysis allows us to identify which patients are more likely to have benign tumors, and who would therefore benefit from additional diagnostic testing (such as renal biopsy) or active surveillance.

==fine objective==

==inizio methodsresults==

This retrospective study was conducted at an independent institution; written informed consent was obtained from each patient. The study sample was composed of patients who underwent surgery for solid renal masses that were suspected RCCs. Overall, 307 patients at our Department of Urology met the inclusion criteria for enrollment in the study. The patients underwent radical or partial nephrectomy (either laparoscopic or open) due to the preoperative suspicion of RCC, according to the radiographic aspect of the renal mass by ultrasonography and CT scan. If a preoperative diagnosis could not be made with the above imaging techniques, magnetic resonance (MR) was performed to provide further detail. Three criteria were used to raise suspicion of renal cell carcinoma for surgical treatment: 1) Solid enhanced nodules (showing an increase of 10 Hounsfield units at CT scan); 2) Absence of intra-tumor fat in the kidney lesions in order to exclude angiomyolipomas; and 3) Complicated renal cysts of type III or IV (Bosniak classification [12]). Exclusion criteria were genetic predisposition for von Hippel-Lindau disease or Birt–Hogg–Dube syndrome, tumor biopsy, primary urothelial cell carcinoma, metastatic tumors, tuberous sclerosis, or patients with multiple masses, bilateral masses, cystic masses, or if the solid renal mass was classified as angiomyolipoma due to the presence of fat on the preoperative CT. For the analysis, we assessed demographic data for each patient (such as age and gender) and the following tumor features: size of mass (widest diameter), body site affected (right or left kidney), histology and year of surgery.

==fine methodsresults==

==inizio results==

Males represented the majority of patients at 60.6%. The overall mean age (SD) was 60 (13) years. The number of malignant cases was 212, which represented 69% of the cases overall. The majority of malign cases were attributed to RCC at 72.6%, with papillary tumors at 12.3%, chromophobe tumors at 7.5% and other types at 7.5%. For the benign conditions, 35.8% were oncocytomas, 22.1% pyelonephritis, 11.6% angiomyolipomas, 10.5% hydronephrosis and 20% were other types of benign conditions. Univariate logistic regression showed that increasing tumor size, male sex and increasing age were all positively associated with an increase in malignancy risk. In particular, when categorized, lesions > 5 cm were the only category with a statistically significant coefficient difference when compared to the reference group of ≤ 3 cm, while age < 50 years was the only age category with a statistically significant coefficient difference when compared to the reference group of ≥ 70 years. In univariate analysis, the year of intervention was also positively associated with an increase in malignancy risk. The results are reported uncorrected for multiple testing. Correlation analysis showed that year of analysis was positively correlated with patient age, tumor dimension and male sex, all of which inferred an increased malignancy risk. The univariate result for year of intervention may thus be explained in terms of the demographic changes occurring in the sample over time. In multivariate analysis, both patient age and tumor dimension were positively associated with increased malignancy risk when treated as continuous variables, while only tumor size >5 cm remained statistically significant when the variables were categorized.

==fine results==

==inizio discussions==

Due to the widespread use of common and non-invasive imaging techniques, the incidental diagnosis of kidney mass has become increasingly common. Considering that a non-negligible share of these masses are found to be non-malignant after surgery at pathological examination, it is crucial to identify features that can correctly diagnose a mass as benign or not. According to the results of our report, female gender and tumor size < 3 cm are independent predictors of benign nature. Contrary to that demonstrated by P. Violette et al. [13], increasing patients age was also positively associated with a greater risk of malign pathology. Overall, our results were in agreement with previous series. In effect, Zisman et al. [14] found that female gender was associated with an increased probability of benign tumors, as in another study in which women had a 27.3% probability of being affected by a benign tumor, while in men the probability was 14.5% [15]. A Japanese study evaluated patients who undergone partial nephrectomy for small renal masses: unlike 5.4% of men, 26.1% of women were affected by benign tumors [16]. According to the literature, female gender is considered uniformly protective against renal malignant tumors; however, the impact of mass size on the probability of malignant nature is less codified. In our study, tumor size < 3 cm was linked to a decreased risk of malignant nature, with smaller kidney masses being more likely to be benign. This result was in agreement with other series [17, 18]. In another study, a significant correlation between benign pathology and tumor size was reported [17]. Furthermore, according to another study, for every 1 cm increase in tumor diameter, the probability of RCC as opposed to a benign tumor increased by 17% [18]. However, other series have failed to demonstrate this correlation [14, 15, 19, 20]. According to the findings of our report, women with renal masses ≤ 3 cm will likely have a benign tumor on pathological examination. Consequently, the risk of such women being exposed to surgery and its potential morbidity unnecessarily is significant. In order to avoid this risk, these patients may benefit from further investigation, such as a core needle biopsy, considering its improved accuracy and safety and low false-negative rates [21, 22]. However, although the performance of renal biopsy to predict RCC subtypes is excellent, with a success rate of 90% in some studies [23], the same results have not been obtained for tumor grade evaluation and, therefore, biological risk [24-28]. Indeed, unfortunately, the diagnosis of low-grade malignant tumors on renal biopsy does not yet exclude high-grade lesions [23]. An alternative approach to upfront surgery is active surveillance of small tumors; indeed, according to some authors, selected patients with small renal masses can be safely followed [29-30], as also demonstrated by Chawla et al. [11], who evaluated the outcome of 234 observed small renal masses, from which there were only three documented reports of metastases. In addition, in a prospective study, Jewett et al. [31], using biopsies and serial imaging examinations, evaluated the rate of progression and metastases in patients with small renal masses (≤ 4 cm maximum diameter) in an overall study sample of 127 patients. The results showed that only 25 patients progressed locally and two developed metastases. The above studies further support the hypothesis that small renal masses grow slowly, with rare metastases. Consequently, adding the results of the present study to data from the existing literature, active surveillance may be even more highly recommended for older women with small renal masses (especially those ≤ 3 cm) due to their high probability of harboring benign or clinically indolent tumors. Lastly, like other authors, we found a correlation between young age and incidence of benign or less aggressive tumors. All of these findings indicate that these patients should be considered suitable candidates for a preoperative biopsy of the renal mass or active surveillance. This medical strategy would also help in making decisions about future treatment options [32-34]. Future prospective studies should therefore evaluate whether a preoperative renal biopsy or active surveillance in cases at high risk of benign pathological findings reduces the incidence of indications for surgery. The strengths of the present study include its large sample size and the analysis of clinically relevant, readily available baseline patient and tumor characteristics. The present study was limited by its retrospective nature, with intrinsic associated biases. However, we used radiological specimen dimensions (at TC scan) to quantify tumor size. This probably allowed us not to underestimate the effective size of the masses in vivo, because formalin fixation causes tumors to shrink. This is noteworthy because, in previous studies examining non-small cell lung cancer, formalin was shown to cause sufficient shrinkage such that there was stage migration in a minority of tumors [35]. ==fine discussions== ==inizio conclusion== In conclusion, the incidental diagnosis of small renal tumors represents a challenge to urologists due to the likelihood that many of these tumors are benign or show less aggressive biology. We identified a subgroup of patients, namely young women with tumors < 3 cm, who have significantly reduced odds of harboring malignant tumors. Thus, according to our findings, significant predictive factors for benign renal pathology include younger age (<50 years), female gender and small tumor size (< 3 cm), and the choice of renal biopsy and active surveillance may therefore be more strongly recommended for the patient population with these characteristics. ==fine conclusion== ==inizio reference== 1. Hollingsworth JM et al: Rising incidence of small renal masses: a need to reassess treatment effect. J Natl Cancer Inst 2006; 98: 1331. 2. Cooperberg MR et al: Decreasing size at diagnosis of stage 1 renal cell carcinoma: analysis from the National Cancer Data Base, 1993 to 2004. J Urol 2008; 179: 2131. 3. Snyder ME et al: Incidence of benign lesions for clinically localized renal masses smaller than 7 cm in radiological diameter: influence of sex. J Urol 2006;176:2391–2395. 4. 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