A Machine Learning Model to Predict the Histology of Retroperitoneal Lymph Node Dissection Specimens.

BACKGROUND/AIM: While post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) benefits patients with teratoma or viable germ cell tumors (GCT), it becomes overtreatment if necrosis is detected in PC-RPLND specimens. Serum microRNA-371a-3p correctly predicts residual viable GCT with 100% sensitivity; however, prediction of residual teratoma in PC-RPLND specimens using current modalities remains difficult. Therefore, we developed a machine learning model using CT imaging and clinical variables to predict the presence of residual teratoma in PC-RPLND specimens. PATIENTS AND METHODS: This study included 58 patients who underwent PC-RPLND between 2005 and 2019 at the University of Tsukuba Hospital. On CT imaging, 155 lymph nodes were identified as regions of interest (ROIs). The ResNet50 algorithm and/or Support Vector Machine (SVM) classification were applied and a nested, 3-fold cross-validation protocol was used to determine classifier accuracy. RESULTS: PC-RPLND specimen analysis revealed 35 patients with necrosis and 23 patients with residual teratoma, while histology of 155 total ROIs showed necrosis in 84 ROIs and teratoma in 71 ROIs. The ResNet50 algorithm, using CT imaging, achieved a diagnostic accuracy of 80.0%, corresponding to a sensitivity of 67.3%, a specificity of 90.5%, and an AUC of 0.84, whereas SVM classification using clinical variables achieved a diagnostic accuracy of 74.8%, corresponding to a sensitivity of 59.0%, a specificity of 88.1%, and an AUC of 0.84. CONCLUSION: Our machine learning models reliably distinguish between necrosis and residual teratoma in clinical PC-RPLND specimens.

Lymph Node Dissection in Testicular Cancer: The State of the Art and Future Perspectives.

PURPOSE OF REVIEW: This narrative review provides a comprehensive overview of the evolving role of retroperitoneal lymph node dissection (RPLND) in the management of testicular cancer (TC). It explores the significance of RPLND as both a diagnostic and therapeutic tool, highlighting its contribution to accurate staging, its impact on oncological outcomes, and its influence on subsequent treatment decisions. RECENT FINDINGS: RPLND serves as an essential diagnostic procedure, aiding in the precise assessment of lymph node involvement and guiding personalized treatment strategies. It has demonstrated therapeutic value, particularly in patients with specific risk factors and disease stages, contributing to improved oncological outcomes and survival rates. Recent studies have emphasized the importance of meticulous patient selection and nerve-sparing techniques to mitigate complications while optimizing outcomes. Additionally, modern imaging and surgical approaches have expanded the potential applications of RPLND. In the context of TC management, RPLND remains a valuable and evolving tool. Its dual role in staging and therapy underscores its relevance in contemporary urological practice. This review highlights the critical role of RPLND in enhancing patient care and shaping treatment strategies, emphasizing the need for further research to refine patient selection and surgical techniques.

Modified versus three-level technique of retroperitoneal laparoscopic adrenalectomy for all patients with adrenal lesions ≤ 6cm: a retrospective, case-controlled study.

Objectives: The modified three-level technique for retroperitoneal laparoscopic adrenalectomy (RLA) has proven beneficial in the treatment of adrenal lesions in patients with BMI≥25 Kg/m2. This paper aims to summarize our institution's seven-year experience using this technique for all patients with Adrenal Lesions ≤ 6cm. Patients and methods: Between January 2016 and December 2022. The patients underwent laparoscopic adrenal surgery were categorized into Zhang's technique (ZT) (Three-level Technique) group and modified technique (MT) group. The fundamental characteristics and perioperative data were analyzed, with statistical significance set at p<0.05. Results: In total, 731 patients were stratified into two groups: ZT (n=448) and MT (n=283). Statistically significant distinctions were not detected between the two groups regarding sex, BMI, tumor location, tumor size, tumor type, or American Society of Anesthesiologists (ASA) score (p>0.05). The MT group demonstrated superior outcomes compared to the ZT group in terms of operative time, estimated blood loss, drainage volume, diet recovery time, complication rates, and postoperative hospitalization duration (p<0.05). 17 (4.34%) in the ZT group required unplanned adrenalectomy, while there was none in MT group (P<0.05). Conclusion: MT retroperitoneal laparoscopic adrenalectomy has demonstrated its benefits in the treatment of adrenal lesions across all patients with adrenal lesions ≤ 6cm, serving as a valuable point of reference for the surgical management of adrenal diseases. Patient summary: We have made modifications to the classic retroperitoneal laparoscopic adrenalectomy and achieved superior surgical outcomes, resulting in a procedure known as modified retroperitoneal laparoscopic adrenalectomy. This technique is suitable for both obese individuals and the general population with adrenal lesions ≤ 6cm.

Recurrence of locally invasive retroperitoneal dedifferentiated liposarcoma shortly after surgery: A case report and literature review.

RATIONALE: Retroperitoneal dedifferentiated liposarcoma (RPDDL) is an uncommon malignancy, which often remains undetected for many years due to having adequate space in the retroperitoneal cavity and lacking clinical manifestations in the early stage of the disease. Surgical procedure is usually used as the first choice for treatment. However, it is prone to local recurrence after the operation, resulting in an unfavorable prognosis. Our aim is to draw useful lessons from the new case and provide some experience for management of the disease. PATIENT CONCERNS: We describe a 55-year-old male patient who was admitted for a 3-week history of persistent dull ache of the left waist. A large mass of the left upper abdomen was palpated in physical examination. Moreover, the imaging examination revealed that the diameter of the mass was about 21 cm, and some adjacent vital organs were invaded, which brought great challenges to complete surgical resection. DIAGNOSIS: The postoperative pathological results confirmed that the mass was RPDDL with invasion of the surrounding vital structures including pancreas, spleen, left adrenal gland, left kidney, and vasculature with tumor emboli. INTERVENTIONS: Surgical resection of the mass was performed by our multidisciplinary team. The patient received chemotherapy 1 month after surgery. OUTCOMES: The effect of chemotherapy seemed to be unsatisfactory. Local multifocal recurrence of the tumor was considered about 2 months after surgery. Finally, he gave up any treatments and died of the disease. LESSONS: Regular physical examination and ultrasound screening may detect the disease as early as possible, especially for high-risk group aged 60 to 70, which should be popularized. Incomplete resection, vascular invasion, and interruption of postoperative treatment may lead to an unfavorable prognosis. Therefore, we think that patients with the disease may benefit from complete surgical resection and uninterrupted adjuvant therapy.

Anatomical Distribution of Sentinel Lymph Nodes Harvested by Retroperitoneal vNOTES in 34 Consecutive Patients With Early-Stage Endometrial Cancer: Analysis of 124 Lymph Nodes.

STUDY OBJECTIVE: To determine the anatomical distribution of sentinel lymph nodes (SLNs), the overall, unilateral, and bilateral detection rates, and the bilateral SLN concordance in patients with endometrial cancer (EC) mapped through a retroperitoneal transvaginal natural orifice transluminal endoscopic surgery (vNOTES) approach. DESIGN: Prospective single-center observational study. SETTING: Swiss teaching hospital. PATIENTS: Patients with EC or endometrial complex atypical hyperplasia who had undergone surgical staging with SLN mapping by a retroperitoneal vNOTES approach between October 2021 and November 2023. INTERVENTIONS: Patients were placed in a horizontal dorsal lithotomy position under general anesthesia, and indocyanine green (ICG) was injected into the cervix. Access to the retroperitoneal space was achieved through vaginal incisions. A 7 cm GelPoint V-Path Transvaginal Access Platform was used as a vNOTES port, and CO2 was insufflated to expand the retroperitoneal space. The pelvic retroperitoneal space was inspected for ICG uptake by lymph nodes. After identification, SLNs were removed and sent for definitive histological examination. MEASUREMENT AND MAIN RESULTS: A total of 34 patients were included in this study; 33 (97.1%) had a successful procedure (unilateral or bilateral mapping), and 1 (2.9%) had failed mapping. A total of 124 SLNs were identified and removed. SLNs were observed in the obturator region (81.5%), the external iliac region (10.5%), the internal iliac region (4.8%), and the common iliac region (3.2%). Similar proportions were observed on both pelvic sides. No SLNs were detected in other regions. The SLN locations were symmetrical in 22/31 (71.0%) patients. SLNs were negatives in 120 cases (96.8%), while 2 lymph nodes (1.6%) presented isolated tumor cells, and 2 others (1.6%) presented macrometastases. CONCLUSION: We report anatomical distributions and detection rates for SLNs mapped by retroperitoneal vNOTES. Our results suggest substantial differences in the localization of SLNs compared to those reported for laparoscopic mapping.

Full-term pregnancy with retroperitoneal giant mucinous cyst: A case report and literature review.

RATIONALE: Retroperitoneal benign cysts during pregnancy are extremely rare and often remain asymptomatic until they attain a very large size. Diagnosis typically relies on a pathological tissue biopsy. The decision to pursue 1-step or 2-step surgical treatment should be tailored to each individual case rather than generalized. PATIENT CONCERNS: This case report presents the unique scenario of a pregnant woman with a confirmed pregnancy complicated by a large retroperitoneal cyst. The patient had a retroperitoneal cyst during her initial pregnancy, which went undetected during the first cesarean section. However, it was identified during her second pregnancy by which time it had grown to 13.0 cm × 15.0 cm × 25.0 cm, and extended from the liver margin to right ovarian pelvic infundibulopelvic ligament. Consequently, it was removed smoothly during her second cesarean section. DIAGNOSES: Postoperative pathology results indicated a massive retroperitoneal mucinous cystadenoma. INTERVENTIONS: The giant retroperitoneal cyst was smoothly excised during the second cesarean delivery for 1-step surgical treatment. OUTCOMES: Under the combined spinal and epidural anesthesia, a live female infant was delivered at 38 3/7 gestational weeks and the neonatal weight was 3200g. Under general anesthesia with endotracheal intubation, the giant retroperitoneal cyst was excised smoothly without complications. LESSONS: The findings of this case report contribute to the understanding of the diagnostic modalities, surgical approaches and postoperative considerations of giant retroperitoneal cysts associated with pregnancy.

Hydrodissection During Computed Tomography-Guided Cryoablation for Renal Tumors: Where is the Effective Fluid Accumulation Space in the Retroperitoneum?

PURPOSE: This study was performed to investigate the effectiveness of hydrodissection during computed tomography-guided renal cryoablation by evaluation of the fluid distribution based on the retroperitoneal anatomy with the interfascial plane. MATERIALS AND METHODS: Between March 2014 and March 2021, 52 renal tumors were treated by cryoablation with hydrodissection (36 men; mean age 72.5 years). The hydrodissection needle was located in perirenal space. The spreading fluid space based on the retroperitoneal anatomy with the interfascial plane was retrospectively evaluated. The fluid space that most effectively separated the tumor from the adjacent organs was defined. The relationship of the needle tip position in the perirenal space (renal capsule or fascia side) and the most effective fluid space was also evaluated. RESULTS: Cryoablation was successfully completed in all cases with no major complications. Hydrodissection was effective in all cases. The distance between the tumors and the adjacent organs was significantly longer after hydrodissection (from 7.50 ± 7.43 to 22.6 ± 9.86 mm) (P < 0.0001). Although fluid spreading through multiple retroperitoneal spaces was frequently observed, the retromesenteric plane was observed more frequently as the most effective fluid space (67.3%) than the perirenal space (21.2%) (P < 0.0001). Regardless of the needle tip position, the most effective fluid space was also commonly the retromesenteric plane. CONCLUSIONS: The retromesenteric plane could be the most effective fluid space to separate the tumor from the adjacent organ, regardless of where the hydrodissection needle tip is positioned in the perirenal space. LEVEL OF EVIDENCE: 3b.

Intratumoral Heterogeneity, Chemoresistance and Lymph Node Landing Zone Prognosis in Testicular Tumors Based on Histopathological Characteristics.

BACKGROUND: Existing data on the histopathological correlation of testicular tumors with lymph node prognosis have been poorly explored. We aimed to investigate the relationship of the histopathological properties of testicular tumors with lymph nodes and their involvement with chemoresistance and heterogeneity of testicular tumors. METHODS: Patients with non-seminomatous germ cell tumor (NSGCT) were selected for histopathological correlation of testicular tumor with lymph nodes and its relationship with chemoresistance and heterogeneity. Histopathological and radiological parameters associated with the risk of chemoresistance and tumor progression were measured pre- and post-chemotherapy. Binomial logistic regression and Kaplan-Meier analysis were implemented to determine the predictors of progression and adverse overall patient survival. All categorical variables were analyzed using the Chi-square test, while Pearson's R coefficient determined the correlation. RESULTS: Male patients who were diagnosed with NSGCT from March 2017 to December 2018 at Guwahati Medical College, Guwahati, India, were included in this study. Lymph node groups were predominantly incriminated with the EYST or EYS groups and minimally linked with the pure E and YCS groups. Furthermore, the highest number of lymph node stations was associated with pre-chemotherapy. In salvage chemotherapy in the form of VIP, we found exciting outcomes, as approximately 41% of cases responded positively, especially in the EYS group. CONCLUSION: Our study classifies NSGCT according to the most favorable histopathological grouping and explores the tumoral response in different intrinsic and extrinsic variables. Our analysis can serve as a triumphant histopathological nomogram for a sublime management protocol to deal with the onerous histological pairing in NSGCT.

Primary retroperitoneal lymph node dissection for clinical stage II seminoma: A systematic review and meta-analysis of safety and oncological effectiveness.

To evaluate the oncological outcomes and safety of primary retroperitoneal lymph node dissection (RPLND) in patients with clinical stage (CS) II seminomatous testicular germ cell tumor (TGCT). A literature search using PubMed, Scopus, and Cochrane Library was conducted on July 2023 to identify relevant studies according to the Preferred Reporting Items for Systematic Review and Meta Analysis (PRISMA) guidelines. The pooled recurrence rate and treatment-related complications were calculated using a random effects model. Overall 8 studies published between 1997 and 2023 including a total of 355 patients were selected for systematic review and meta-analysis with the overall median follow-up of 38 months. The overall and infield recurrence rate were 0.14 (95% CI: 0.08-0.22) and 0.04 (95% CI: 0.00-0.11), respectively. The overall pooled rate of ≥ Clavien Dindo grade III complications was 0.04 (95% CI: 0.01-0.10); there was no significant heterogeneity (I^2 = 35.10%, P = 0.19). Antegrade ejaculation was preserved with the overall pooled rate of 0.98 (95% CI: 0.95-1.00); there was no significant heterogeneity on Chi-square and I2 tests (I^2 = 0.00%, P = 0.58). Primary RPLND is a safe and effective treatment option for patients with CS II seminomatous TGCT resulting highly promising cure rates combined with low treatment-associated adverse events, at medium-term follow-up. However, owing to the lack of comparative studies to the current standard of care and the limited follow-up, individual decision must be made with the informed patient in a shared decision process together with a multidisciplinary team.

Time to Flip the Approach: Retroperitoneoscopic Adrenalectomy.

INTRODUCTION: Retroperitoneoscopic adrenalectomy (RPA) has gained increasing popularity with its excellent perioperative outcomes and direct surgical access compared to other adrenalectomy approaches. We review perioperative outcomes of RPA by a specialized endocrine surgeon before and after expert intensive trainings (EITs), and to that of other laparoscopic adrenalectomy approaches at our center over a 9-year period, aiming to ascertain if RPA is worth the steep learning curve. MATERIAL AND METHODS: One hundred twenty one adrenalectomies were performed between January 2014 to June 2022. Patient demographic, tumor characteristics, and perioperative outcomes were retrospectively reviewed. The primary endpoints included procedure duration, complications, and length of stay. Part I of the study examined the effect of EITs on RPA's learning curve, and part II compared these outcomes with that of the alternative approach, transabdominal lateral adrenalectomy (TLA). RESULTS: Both procedure duration and days in hospital markedly decreased after the two EITs for RPA. RPA resulted in a shorter procedure duration and hospital stay compared to TLA, and had lesser and milder intraoperative and postoperative complications compared to TLA. CONCLUSIONS: RPA results in safe and excellent outcomes, and offers additional benefit of direct surgical access, feasibility in patients with previous abdominal surgery, high body mass index, and multiple comorbidities. The steep learning curve can be overcome and shortened by EITs, motivating centers with specialized endocrine surgery to integrate RPA training into its curriculum, given its foreseeable rewarding outcomes.

Adjunctive Surgery Is Often Without Oncological Benefit at Time of Postchemotherapy Retroperitoneal Lymph Node Dissection.

PURPOSE: Postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) for advanced nonseminomatous germ cell tumors (GCTs) aims to resect all remaining metastatic tissue. Resection of adjacent visceral or vascular organs is commonly performed for complete resection. Resection of organs harboring only necrosis results in relevant overtreatment. The study aimed to describe the frequency of metastatic involvement of resected organs with teratoma or viable cancer and to analyze perioperative complications and relapse-free survival. MATERIALS AND METHODS: In a 2-center study, we reviewed a cohort of 1204 patients who underwent PC-RPLND between 2008 and 2021 and identified 242 (20%) cases of adjunctive surgery during PC-RPLND. We analyzed the removed adjacent structures and the pathohistological presence of GCT elements in the resected organs: viable GCT, teratoma, or necrosis/fibrosis. Surgery-associated complications were reported according to the Clavien-Dindo classification. RESULTS: Viable GCT, teratoma, and necrosis were present in 54 (22%), 94 (39%), and 94 (39%), respectively, of all patients with adjunctive resection of adjacent organs. Vascular resections or reconstructions (n = 112; viable: 23%, teratoma: 41%, necrosis: 36%) were performed most frequently, followed by nephrectomies (n = 77; viable: 29%, teratoma: 39%, necrosis: 33%). Perioperative complications of grade ≥ IIIa occurred in 6.6% of all patients, with no difference between the viable GCT and teratoma/necrosis groups (P = .1). A total of 76 patients have been followed without a relapse for at least 36 months. Median follow-up of the whole cohort was 22 months (quartile 7 and 48). Patients with viable GCT/teratoma in the resected specimens had a significantly increased risk of recurrence by 5 years compared to patients with only necrosis (19% vs 59% vs 81%, P < .001). CONCLUSIONS: This study shows that 33% to 40% of all resections of adjacent organs do not harbor teratoma or viable GCT. This highlights the need for better patient selection for these complex patients.

Primary Retroperitoneal Lymph Node Dissection for Seminoma Metastatic to the Retroperitoneum.

PURPOSE: Primary surgical treatment with retroperitoneal lymph node dissection aims to accurately stage and treat patients with node-positive pure seminoma while avoiding long-term risks of chemotherapy or radiation, traditional standard-of-care treatments. MATERIALS AND METHODS: We reported the pathologic and oncologic outcomes of patients with pure seminoma treated with primary retroperitoneal lymph node dissection in a retrospective, single-institution case series over 10 years. The primary outcome was 2-year recurrence-free survival stratified by adjuvant management strategy (surveillance vs adjuvant chemotherapy). RESULTS: Forty-five patients treated with primary retroperitoneal lymph node dissection for pure testicular seminoma metastatic to the retroperitoneum were identified. Median size of largest lymph node before surgery was 1.8 cm. Viable germ cell tumor, all of which was pure seminoma, was found in 96% (n=43) of patients. The median number of positive nodes and nodes removed was 2 and 54, respectively. Median positive pathologic node size was 2 cm (IQR 1.4-2.5 cm, range 0.1-5 cm). Four of 29 patients managed with postoperative surveillance experienced relapse; 2-year recurrence-free survival was 81%. Median follow-up for those managed with surveillance who did not relapse was 18.5 months. There were no relapses in the retroperitoneum, visceral recurrences, or deaths. Among the 16 patients who received adjuvant treatment, 1 patient experienced relapse in the pelvis at 19 months. CONCLUSIONS: Primary retroperitoneal lymph node dissection for pure seminoma with low-volume metastases to the retroperitoneum is safe and effective, allowing most patients to avoid long-term toxicities from chemotherapy or radiation.

Anticoagulation prophylaxis patterns following retroperitoneal lymph node dissection for testis cancer.

INTRODUCTION: Retroperitoneal lymph node dissection (RPLND) is the standard of care for testicular cancer in various disease settings. Deep vein thrombosis (DVT) complications have been reported to occur in <1% of primary RPLND cases and up to 3% of postchemotherapy (PC-RPLND) cases. While prophylactic anticoagulation (AC) has been well-documented to reduce DVT rates in patients undergoing surgery in general, the benefit of prophylactic AC in RPLND has not been assessed. In this retrospective cohort study, we seek to address this unmet need by evaluating the rates and associated risk factors of DVT and pulmonary embolism (PE) with a national and institutional database, assess the changing patterns in DVT prophylaxis with postoperative AC following RPLND, and quantify the potential benefit of prophylactic AC in patients who have undergone RPLND using a risk-stratified approach. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for patients who underwent RPLND during the 10-year period from 2011 to 2021. An institutional database was queried for all patients undergoing RPLND from 2013 to 2022. Patient characteristics and operative outcomes were compared between the NSQIP and the institutional database. The institutional database was stratified by prior oncologic treatment (i.e., primary RPLND vs. PC-RPLND) and outcomes were compared. Postoperative AC rate was determined and trended by year. The use of postoperative AC and PE events were stratified by clinical stage. The absolute risk reduction (ARR) of AC prophylaxis on PE events and the number needed to treat (NNT) with AC prophylaxis to prevent a single PE event was determined. RESULTS: In total, the NSQIP database query resulted in 779 patients and our institutional database query resulted in 188 patients. The rate of DVT and PE was 1.2% and 0.5% vs. 2.1% and 1.6% in the NSQIP and institutional cohort, respectively. The rate of postoperative AC following RPLND in patients from the institutional database increased from 5% in 2013 to 43% in 2022 (P = 0.01). There were no statistically significant differences in complication rates, including bleeding events, chyle leaks, or hospital readmissions amongst patients who were prescribed AC at discharge and those who were not. No stage I patients developed PEs and no stage I patients were prescribed AC. The ARR for AC prophylaxis for development of PE was found to be 0.023 for the clinical stage II and stage III cohorts. The NNT to prevent a single PE with AC was 44 and 43 for the stage II and stage III cohorts, respectively. CONCLUSIONS: AC appears beneficial with minimal risk of harm after RPLND, especially in patients with higher risk of developing DVT/PE, highlighting the safety and efficacy of this regimen. There was a significant increase in the rate of AC prophylaxis at discharge amongst patients undergoing RPLND in the institutional database from 2013 to 2022. A risk-stratified protocol of postoperative AC following RPLND appears reasonable, and further prospective trials are warranted to formally confirm this recommendation.

Predictors and outcomes of recurrent retroperitoneal liposarcoma: new insights into its recurrence patterns.

BACKGROUND: The clinical profiles of recurrent retroperitoneal liposarcoma (RLS) need to be explored. The recurrence patterns of RLS are controversial and ambiguous. METHODS: A total of 138 patients with recurrent RLS were finally recruited in the study. The analysis of overall survival (OS) and recurrence-free survival (RFS) was performed by Kaplan‒Meier analysis. To identify independent prognostic factors, all significant variables on univariate Cox regression analysis (P ≤ 0.05) were subjected to multivariate Cox regression analysis. The corresponding nomogram model was further built to predict the survival status of patients. RESULTS: Among patients, the 1-, 3-, and 5-year OS rates were 70.7%, 35.9% and 30.9%, respectively. The 1-, 3- and 5-year RFS rates of the 55 patients who underwent R0 resection were 76.1%, 50.8% and 34.4%, respectively. The multivariate analysis revealed that resection method, tumor size, status of pathological differentiation, pathological subtypes and recurrence pattern were independent risk factors for OS or RFS. Patients with distant recurrence (DR) pattern usually had multifocal tumors (90.5% vs. 74.7%, P < 0.05); they were prone to experience changes of pathological differentiation (69.9% vs. 33.3%, P < 0.05) and had a better prognosis than those with local recurrence (LR) pattern. R0 resection and combined organ resection favored the survival of patients with DR pattern in some cases. CONCLUSIONS: Patients with DR pattern had better prognosis, and they may benefit more from aggressive combined resection than those with LR pattern. Classifying the recurrence patterns of RLS provides guidance for individualized clinical management of recurrent RLS.

A systematic review of pN0 testicular seminoma: a new clinical entity and future directions.

Retroperitoneal lymph node dissection (RPLND) for testicular seminoma with enlarged retroperitoneal lymph nodes has received increased consideration and exposed a new clinical entity: pN0 disease. Enlarged, nonmetastatic retroperitoneal lymph nodes provide insight into the natural history of seminoma while offering a benchmark for improving the accuracy of staging. The purpose of this systematic review was to report the pN0 rates, describe risk factors associated with it, and discuss emerging research that may reduce its incidence. We performed a systemic review of published literature on PubMed, Embase, Web of Science, as well as oncology meeting abstracts evaluating histology of lymph nodes in patients with testicular seminoma treated primarily with retroperitoneal lymph node dissection. Studies were excluded if histology was not reported. A total of 15 publications and abstracts were included. Although study designs were heterogeneous, there was a minimal risk of bias. Overall, the reported pN0 rates were 0% to 22%. In prospective clinical trials it was 9% to 16%. The presence of pN0 was associated with preoperative smaller lymph nodes, a solitary enlarged lymph node, or negative serum miRNA-371. The incidence of pN0 seminoma is concerning as it points to a potential historical overtreatment; however, it also represents an important inflection for testicular cancer research as quantifiable improvements in clinical staging will translate to clear benefits to patients.

Solitary Fibrous Tumor in the Retroperitoneal Space Arising from the Diaphragm.

BACKGROUND/AIM: We present a case of solitary fibrous tumor, arising from the diaphragm in the retroperitoneal space, that was resected with robotic assistance. CASE REPORT: An 85-year-old female patient was referred to our hospital for evaluation of a suspected right renal tumor. Abdominal contrast-enhanced computed tomography revealed a tumor (maximum diameter, 36 mm) protruding from the superior pole of the right kidney. The patient was scheduled for robot-assisted, retroperitoneoscopic, partial nephrectomy based on a preoperative diagnosis of renal cell carcinoma. Intraoperative findings revealed that the tumor originated from the diaphragm and had no continuity with the renal parenchyma. Pathological examination revealed a solitary fibrous tumor. CONCLUSION: Solitary fibrous tumors are rare soft-tissue neoplasms with a distinct molecular feature of the fusion of nerve growth factor-inducible A gene-binding protein 2 with signal transducer and activator of transcription 6 gene (NAB2::STAT6). We believe that this is the first reported case of a solitary fibrous tumor arising from the diaphragm in the retroperitoneal space.

Intraoperative motive for incomplete resection in primary retroperitoneal sarcoma.

INTRODUCTION: Surgical resection is the current standard of care for retroperitoneal sarcoma (RPS). Recent data suggests that up to 5% of patient have incomplete (R2) resection. The exact reason why patients scheduled for surgery with a curative intent to treat ended up with an R2 resection is largely unknown. AIM OF THE STUDY: To identify intraoperative findings responsible for incomplete (R2) resection in primary RPS. METHODS: All records of consecutive patients scheduled for a non-metastatic primary RPS surgery between 1995 and 2020 in a tertiary care sarcoma centre were retrospective analyzed. RESULTS: Among the 347 patients scheduled for surgery, 13 (3.7%) had an incomplete (R2) resection. The reasons for incomplete surgery were intraoperative finding of vascular involvement of great vessels in 5 patients, previously undetected peritoneal metastases in 5 patients, invasion of contralateral kidney/ureter in 2 patients and the need to preserve both kidneys in 1 patient because of his past medical history. Among these patients, 3 had a laparotomy without resection and 10 had a partial resection (i.e. debulking surgery). Severe postoperative complications occurred in 5 patients. The median length of stay in hospital was 19days. After a median follow-up of 12months, the median survival of patients after incomplete resection was 18months. The 1-y, 5-y and 8-y overall survival (OS) for these patients were 46%, 14%, and 7%, respectively. CONCLUSION: Incomplete (R2) resection for a primary RPS surgery is rare in specialized sarcoma center. The next steps should be to identify the preoperative criteria that lead to this accurate selection and to define the best practice in front of a peroperative discovery of an unresectable RPS. LEVEL OF EVIDENCE: III.

Risk Factors for Relapse in Nonseminomatous Testicular Cancer After Postchemotherapy Retroperitoneal Lymph Node Dissection With Viable Residual Cancer.

PURPOSE: No consensus exists on the management of men with nonseminoma and viable nonteratomatous germ cell tumor in the postchemotherapy retroperitoneal lymph node dissection (pcRPLND) specimen after first-line chemotherapy. We analyzed surveillance versus different adjuvant chemotherapy regimens and the influence of time to pcRPLND on oncologic outcomes. METHODS: Data on 117 men treated with cisplatin-based first-line chemotherapy between 1990 and 2018 were collected from 13 institutions. All patients had viable nonteratomatous germ cell tumor in the pcRPLND specimen. Surgery was performed after a median of 57 days, followed by either surveillance (n = 64) or adjuvant chemotherapy (n = 53). Primary end points were progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). RESULTS: After controlling for International Germ Cell Cancer Cooperative Group risk group and percent of viable malignant cells found at RPLND, no difference was observed between men managed with surveillance or adjuvant chemotherapy regarding PFS (hazard ratio [HR], 0.72 [95% CI, 0.32 to 1.6]; P = .4), CSS (HR, 0.69; 95% CI, 0.20 to 2.39; P = .6), and OS (HR, 0.78 [95% CI, 0.25 to 2.44]; P = .7). No statistically significant differences for PFS, CSS, or OS were observed on the basis of chemotherapy regimen or in men treated with pcRPLND ≤57 versus >57 days after first-line chemotherapy. Residual disease with <10% versus ≥10% viable cancer cells were associated with a longer PFS (HR, 3.22 [95% CI, 1.29 to 8]; P = .012). Relapse in the retroperitoneum was observed in 34 (29%) men. CONCLUSION: Men with a complete resection at pcRPLND and <10% viable cells have favorable outcomes without further treatment. Complete retroperitoneal resection seems more important than early pcRPLND.

Postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) for seminoma: Limitations of surgical intervention after first-line chemotherapy.

PURPOSE: Patients with relapsed seminoma after first-line chemotherapy can be treated with salvage chemotherapy or postchemotherapy retroperitoneal lymph node dissection (PC-RPLND). Based on prior experience, surgical management can have worse efficacy and increased morbidity compared to nonseminomatous germ cell tumor. Our aim was to characterize the surgical efficacy and difficulty in highly selected patients with residual disease after first-line chemotherapy. MATERIALS AND METHODS: The Indiana University testis cancer database was queried to identify men who underwent PC-RPLND for seminoma between January 2011 and December 2021. Included patients underwent first-line chemotherapy and had evidence of retroperitoneal disease progression. RESULTS: We identified 889 patients that underwent PC-RPLND, of which only 14 patients were operated on for seminoma. One patient was excluded for lack of follow-up. Out of 13 patients, only 3 patients were disease free with surgery only. Median follow up time was 29.9 months (interquartile ranges : 22.6-53.7). Two patients died of disease. The remaining 8 patients were treated successfully with salvage chemotherapy. During PC-RPLND, 4 patients required nephrectomy, 1 patient required an aortic graft, 2 patients required a partial ureterectomy, and 3 patients required partial or complete caval resection. CONCLUSION: The decision between salvage chemotherapy and PC-RPLND as second-line therapy can be challenging. Salvage chemotherapy is effective but is associated with short and long-term morbidity. Surgical efficacy in this setting seems to be limited, but careful selection of patients may lead to surgical success without affecting the ability to receive any systemic salvage therapies if necessary or causing life-threating morbidity.