Comprehensive neurosurgical and visceral surgical therapy of retroperitoneal nerve tumors: a descriptive and retrospective analysis.

Nerve tumors in the retroperitoneal space are a rarity. Radical surgery according to soft tissue tumors can lead to persistent pain and neurological deficits. This study aims to evaluate clinical outcomes of patients treated by a visceral- / neurosurgical approach. 33 patients with a retroperitoneal nerve tumor underwent surgery between 01/2002 and 12/2022 at our department. A visceral surgeon provided access to the retroperitoneal space, followed by micro-neurosurgical tumor preparation under neuromonitoring. Clinical examination and MRI were performed 12 weeks after surgery and further 3 months (WHO grade > 1) or 12 months (WHO grade 1). Further examinations were based on MRI findings and residual symptoms with median follow-up time of 24 months. One patient was treated for two distinct masses resulting in a total of 34 histological findings. Schwannomas (n = 15; 44.1%) and neurofibromas (n = 10; 29.4%) were the most common tumors. Long-term improvements were noted in radicular pain (15/18 patients; 83.3%), motor deficits (7/16 patients; 43.8%), abdominal discomfort and pain (5/7 patients; 71.4%). Recurrences were observed in 3/33 (9,1%) patients. This study represents the largest series of retroperitoneal BPNSTs treated with microsurgical techniques. Prospective multicenter studies are warranted to establish standardized treatment guidelines.

Adrenal ganglioneuroma with retroperitoneal lymph node metastasis: A rare scenario.

ABSTRACT: Ganglioneuroma (GN) is the most differentiated and benign variant of neuroblastic tumors, most commonly located in the posterior mediastinum, followed by the retroperitoneum and adrenal gland. Children of <10 years of age are more commonly affected than adults. Though benign, GNs can very rarely metastasize to regional lymph nodes or distant sites like liver, bone, spleen, and soft tissues. Metastatic lesions are assumed to represent neuroblastomas in which the metastasis and the primary tumor, both have matured. This differentiation can occur spontaneously or after treatment. We present a primary ganglioneuroma of adrenal gland in a 4-year-old child with nodal metastasis, without any blastemal component at any site.

Retroperitoneal soft tissue sarcomas: Predictive factors for incomplete resection.

INTRODUCTION: Curative management of retroperitoneal sarcoma relies on surgery, and complete monoblock resection is one of the main prognostic factors. The goal of this study was to search predictive factors for incomplete resection. METHODS: All patients undergoing surgery for retroperitoneal sarcoma in two University hospitals between 2010 and 202 were included. The main endpoint was incomplete resection (R1 ad R2) after surgery. Secondary analysis was performed where marginal R0 resection was considered as complete. Univariate and multivariable analysis of demographics, radiological, surgical and pathologic criteria were performed. Overall survival, local and distant recurrence were evaluated. RESULTS: Fifty-eight patients were included in the study. Fifty patients had incomplete resection, of which seven had marginal R0 resection. In multivariable analysis, none of the factors analyzed were associated with incomplete resection. In secondary analysis, undifferentiated liposarcoma histology (OR 12.3, 95% CI [1.416-107.303], P=0.023) was statistically significantly associated with incomplete resection. Low grade (grade I) histology was predictive of complete resection (OR 0.24, 95% CI [0.060-0.959], P=0.043). Median follow-up duration was 27 months. Local and distant recurrence rates at three years were 37% and 22.4%, respectively. CONCLUSION: In this study, we highlighted several predictive factors for incomplete resection. These factors enable us to define target populations that could most benefit from complementary therapy along with surgery.

Efficacy of surgery in the management of multiple recurrences of retroperitoneal dedifferentiated liposarcoma.

BACKGROUND: Retroperitoneal dedifferentiated liposarcoma is associated with a high risk of recurrence; however, treatment strategies that are more effective than surgery remain to be established. This study aimed to determine the optimal number of surgeries that would be effective for patients with recurrent disease. Furthermore, the improvement in prognosis was evaluated according to the malignancy level. METHODS: The effect of each type of surgery on the prognosis of 118 patients with retroperitoneal dedifferentiated liposarcoma treated at the Osaka International Cancer Institute between 1997 and 2022 was investigated. Among the 118 patients, 103 underwent initial surgery, while 54 and 30 patients underwent second and third surgeries, respectively. The overall and disease-free survival rates of each group were compared using the Kaplan-Meier method, and the log-rank test was used to determine statistical significance in univariate analysis. 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) was used to assess malignancy. Maximum standardized uptake values (SUVmax) of ≥ 4 and < 4 were classified as high and low malignancy, respectively. RESULTS: The first and second surgeries resulted in a significant improvement in the overall survival rate, regardless of the malignancy level (p < 0.001); however, no significant improvement in prognosis was observed after the third surgery (p = 0.077). Low-grade malignancies are associated with a better postoperative prognosis, even in cases of recurrence. In contrast, high-grade malignancies exhibit a reduction in surgical efficacy. CONCLUSIONS: This study highlights the importance of considering the tumor malignancy level and the patient's overall condition when deciding whether to perform repeated surgical interventions. Surgical treatment can prolong overall survival, even in patients with recurrence; however, it is advisable to assess malignancy levels when determining the suitability of surgery beyond the second recurrence.

[The characteristics of pediatric primary retroperitoneal teratoma and the influencing factors of perioperative complications].

To explore the characteristics of pediatric primary retroperitoneal teratoma and the influencing factors of perioperative complications. The clinical data, imaging data, pathology results, perioperative complications, etc of patients with primary retroperitoneal teratoma admitted and treated at Shanxi Children's Hospital from March 2013 to September 2023 were retrospectively analyzed. The patients were divided into no complication group and complication group according to whether there were perioperative complications. The differences between the two groups were compared, and the influencing factors of complications were analyzed by multivariate logistic regression model. A total of 33 patients were included in this study, including 7 males and 26 females, with an age of [M (Q1, Q3), 9.0 (4.0, 24.0)] months. Nineteen cases had tumors located in the left upper abdomen and 14 cases in the right upper abdomen, among which 17 cases grew across the midline, with the maximum tumor diameter of (12.9±4.5) cm. All patients had anatomical displacement of retroperitoneal vessels and organs: the number of anatomical displaced arteries was 3 (3, 4), the number of anatomical displaced veins was 4 (3, 5), the number of anatomical displaced organs was 5 (4, 6). Pathologic examination revealed 28 mature teratomas (Grade 0 and Grade 1) and 5 immature teratomas (Grade 2 and Grade 3). There were 18 cases in no complication group and 15 cases in the complication group. The incidence of perioperative complications was 45.5% (15/33). The number of tumors crossing the midline (6/18 vs 11/15, P=0.037), the number of tumors adhering closely to the surrounding tissues (7/18 vs 12/15, P=0.033), the number of anatomical displaced veins [4 (3, 4) vs 5 (4, 5), P=0.001], and the number of anatomical displaced organs [4 (3, 5) vs 6 (5, 6), P=0.001] were significantly different between the two groups. Multivariate logistic regression model analysis showed that the number of anatomical displaced organs (OR=8.781, 95%CI: 2.155-35.784, P=0.002) was the influencing factor for perioperative complications of pediatric primary retroperitoneal teratoma.

A case report of retroperitoneal liposarcoma.

BACKGROUND: Retroperitoneal liposarcoma is a rare and complex tumor originating from the mesenchymal tissues, with no specific manifestations in the early stage, and a large tumor size in the late stage. Patients often consult a physician because of large abdominal mass, increased abdominal circumference, and abdominal pain, and rarely because of leukocytosis. PATIENT CONCERNS: A 54-year-old female presented to our hospital with complaints of "abdominal distension for over 3 months, left lumbar pain for over 2 months." Considering the comprehensive symptoms, examinations, computed tomography scans, and pathological results, the possibility of retroperitoneal liposarcoma is high. DIAGNOSES: Retroperitoneal liposarcoma with leukocytosis. INTERVENTIONS: Open retroperitoneal mass excision along with transcystoscopic left ureteral Double-J Ureterl Stent Insertion tube placement and left nephrectomy. OUTCOMES: The postoperative pathological findings of the abdominal mass, combined with morphological and immunohistochemical results, are consistent with retroperitoneal liposarcoma. The patient had no recurrence in 7 months of postoperative follow-up conducted on the telephone and is now in continued follow-up. CONCLUSION: Retroperitoneal liposarcoma is highly malignant and prone to recurrence. Radical surgery is currently the primary treatment modality for patients with this condition. Analogous to cancer patients, those with elevated white blood cell counts and retroperitoneal liposarcoma may have poor prognoses, with a high likelihood of local recurrence and distant metastasis. Close postoperative follow-up is necessary. Therefore, regular postoperative review of blood routine may be a relatively economical and convenient method for the early detection of recurrence and metastasis of retroperitoneal liposarcoma.

Complications following biopsy of an intraabdominal or retroperitoneal mass compared with a renal mass.

INTRODUCTION: This study aimed to assess the short-term complication rate after US-guided core needle biopsies with an 18-gauge needle of retroperitoneal or intraabdominal masses (non-kidney group) compared with complications after biopsy from a renal mass (kidney group). METHODS: This was a retrospective analysis of 330 consecutive patients in the non-kidney group and 330 control patients in the kidney group. We recorded baseline characteristics, diagnostic yield, complications graded as Clavien-Dindo (CD) and readmissions within one and seven days. RESULTS: In all, 245 patients in the non-kidney and 281 patients in the kidney group had a biopsy performed. A total of 54 (22%) patients in the non-kidney group had a complication registered. However, 47 were minor complications (minor bleeding or localised pain, CD 1). In the kidney group, 47 (17%) patients had a complication, with 44 being graded as CD 1. No major complications (CD 3 or higher) were associated with the biopsies. Only 0.8% of patients in the non-kidney group and 0.7% in the kidney group had a treatment-requiring CD 2 complication (i.e. blood transfusion) directly caused by the US-guided biopsy. These complications were recognised less than 30 minutes or more than four hours after the procedure. We found no significant difference in the complication rate, diagnostic yield or risk of re-admission between the two groups. CONCLUSION: The observation period for patients who undergo an uncomplicated US-guided biopsy from an intraabdominal or retroperitoneal mass can safely be reduced to 30 minutes. FUNDING: None TRIAL REGISTRATION. Not relevant.

Histology-Tailored Approach to Soft Tissue Sarcoma.

Soft tissue sarcomas are a diverse and heterogeneous group of cancers of mesenchymal origin. Each histological type of soft tissue sarcoma has unique clinical particularities, which makes them challenging to diagnose and treat. Multidisciplinary management of these rare diseases is thus key for improved survival. The role of surgery has been well established, and it represents the cornerstone curative treatment for soft tissue sarcomas. To date, local recurrence is the leading cause of death in low-grade sarcomas located at critical sites, and distant metastasis in high-grade sarcomas, regardless of the site of origin. Management must be tailored to each individual histologic type. We describe the most common types of extremity, trunk, abdominal, and retroperitoneal soft tissue sarcoma along with characteristics to consider for optimized management.

Learning curve in retroperitoneal sarcoma surgery.

INTRODUCTION: Retroperitoneal sarcoma (RPS) surgery poses unique challenges. This retrospective study aimed to analyze the learning curve (LC) in RPS surgery, assessing the relationship between surgical experience and outcomes. MATERIALS AND METHODS: Cumulative sum (CUSUM) analysis was used to analyze 62 RPS surgeries performed by a single surgeon between 2016 and 2022 at our center. RESULTS: The number of cases where the surgeon acted as first operator increased from 3 in 2016 to 13 in 2022. The surgeon operated with his mentor in 66.7 % of cases in 2016, whereas in 7.7 % of cases in 2022. LC consisted of 3 phases. Phase 1 (16 cases), with a negative slope, represented shorter operative time (OT) and fewer number of resected organs (RO). Phase 2 (30 cases) was the plateau phase. Phase 3 (16 cases), with a positive slope, indicated longer OT and more RO. Statistically significant differences were observed in terms of size (p = 0.003), presentation (p = 0.048), number of resected organs (p = 0.046), pattern of resection (p = 0.033), OT (p = 0.006), and length of stay (p = 0.026) between the three phases. CONCLUSION: This study focused on the critical role of LC in RPS surgery, emphasizing its influence on outcomes. We identified three phases, highlighting the surgeon's evolution. This offers a framework for educating sarcoma surgeons and ensuring exposure to increasing surgical complexity. In discussions on sarcoma referral centers and the correlation between case volume and outcomes, this study underlines the importance of evaluating LC to distinguish surgeons qualified to manage sarcoma cases within a referral center.

Giant retroperitoneal liposarcoma with multiple organ involvement: a case report and literature review.

BACKGROUND: Retroperitoneal liposarcoma (RPLPS) is a relatively rare disease. Liposarcomas vary in size, but sizeable RPLPS larger than 30 cm in diameter are very rare, and their diagnosis and treatment present significant challenges. CASE PRESENTATION: We report a 58-year-old male patient who was admitted to the hospital with an increased abdominal circumference and was later diagnosed with a giant RPLPS. The liposarcoma was found to adhere to the right kidney and the entire ureter, invading the ascending colon. The patient underwent complete combined surgical resection. The tumor was removed intact, measured 55.0 cm × 30.0 cm × 18.0 cm, and weighed 19.8 kg. Histopathologic analysis revealed well-differentiated liposarcoma (WDLPS). The patient was successfully discharged from the hospital and followed up for 6 months with no signs of recurrence. CONCLUSION: RPLPS is a rare tumor with atypical clinical presentation. Surgery remains the most effective method of treatment for retroperitoneal sarcomas, with complete removal if there is local invasion. Preoperative examination, including three-dimensional (3D) reconstruction, is essential for surgical success. The role of adjuvant radiotherapy or chemotherapy remains controversial. However, clinicians should not rule them out as viable options.

Automated lattice radiation therapy treatment planning personalised to tumour size and shape.

PURPOSE: Lattice radiation therapy (LRT) alternates regions of high and low doses inside the tumour. Whilst this technique reported positive results in tumour size reduction, optimal lattice parameters are still unknown. We introduce an automated LRT planning method personalised to tumour shape and designed to allow investigation of lattice geometry. METHODS: Patients with retroperitoneal sarcoma were considered for inclusion. Automation was performed with the Eclipse Scripting Application Interface (v16, Varian Medical Systems, Palo Alto). By iterating over vertex size (V) and centre-to-centre distance (D), vertices were segmented within the gross tumour volume (GTV) in an alternating square pattern. Iterations stopped when the number of inserted vertices was contained between a prespecified lower and upper bound. Forty sets of lattices were considered, produced by varying V and D in five lower/upper bound pairs. Best-scoring sets were determined with a score favouring the maximization of GTV dose uniformity and heterogeneity whilst minimizing the maximum dose to organs at risk. RESULTS: Fifty patients with tumour volumes between 150 cm3 and 10,000 cm3 were included. Best-scoring sets were characterised by a low number of vertices (<15). Based on the best-scoring set, the predicted parameters to use for new patients were V = 0.19 (GTV volume)1/3 and D = 2V, in centimetres. The number of vertices (N) to insert in the GTV can be estimated with N ≤ (24 × 3% GTV volume)/(4πV3). CONCLUSIONS: The automated LRT treatment planning personalised to tumour size allows investigation of lattice geometry over a large range of GTV volumes.

Laparoscopic removal of retroperitoneal schwannoma in renal hilum: a case report.

BACKGROUND: Schwannomas in the renal hilum are rare among retroperitoneal tumors. However, the possibility of malignant findings cannot be ruled out, and surgery is often indicated. This case was expected to be difficult to remove laparoscopically because the tumor was sandwiched between the arteriovenous veins of the renal portal. Sometimes, the tumor should be resected with a conservative approach to the kidney to preserve the renal function. CASE PRESENTATION: Our patient was a 51-year-old Asian-Japanese man who was referred to our department for a retroperitoneal tumor in the renal hilum. Since malignancy could not be ruled out due to its size (45 × 48 × 55 mm) on imaging, the tumor was excised laparoscopically. Histopathology revealed schwannoma. CONCLUSIONS: We herein report a case in which a renal hilar tumor between renal arteriovenous vessels was successfully resected laparoscopically.

Primary retroperitoneal tumor: mucinous cystoadenocarcinoma.

Primary retroperitoneal mucinous cystadenocarcinomas (PRMCs) are extremely rare tumors with limited understanding of their pathogenesis and biological behavior. We describe a case of a 50-year-old female patient who underwent surgical treatment. The patient had a history of previous surgeries for mesenteric mucinous cystadenoma, without evidence of recurrence. During routine abdominal ultrasound a new tumor was found. An abdomen magnetic resonance imaging was done and confirmed the presence of a cystic lesion in the right iliac fossa. After discussion in multidisciplinary committee, surgical complete resection of the tumor, along with bilateral adnexectomy, was performed successfully. Histopathological examination revealed a mucinous adenocarcinoma adjacent to a mucinous cystadenoma. Immunohistochemical analysis supported the diagnosis of a primary retroperitoneal lesion. The patient had an uneventful recovery and has remained disease-free during the two-year postoperative follow-up. PRMCs are challenging to diagnose preoperatively due to nonspecific symptoms. Surgical excision is the mainstay of treatment. The long-term prognosis and optimal therapeutic strategies require further investigation.

Los cistoadenocarcinomas mucinosos primarios retroperitoneales (CMPR) son tumores extremadamente raros con una comprensión limitada de su patogénesis y comportamiento biológico. Describimos el caso de una mujer de 50 años sometida a tratamiento quirúrgico. La paciente tenía antecedentes de cirugías previas por cistodenoma mucinoso mesentérico, sin evidencia de recurrencia. Durante una ecografía abdominal de rutina se encontró un nuevo tumor. Se realizó una resonancia magnética abdomen que confirmó la presencia de una lesión quística en la fosa ilíaca derecha. Luego de discutir el caso en el comité multidisciplinario, se realizó con éxito la resección quirúrgica completa del tumor, junto con la anexectomía bilateral. El examen histopatológico reveló un adenocarcinoma mucinoso adyacente a un cistodenoma mucinoso. El análisis inmunohistoquímico apoyó el diagnóstico de lesión primaria retroperitoneal. La paciente tuvo una buena recuperación y permaneció libre de enfermedad durante dos años de seguimiento postoperatorio. Los CMPR son difíciles de diagnosticar debido a que presentan síntomas inespecíficos. La escisión quirúrgica es la base del tratamiento. El pronóstico a largo plazo y las estrategias terapéuticas óptimas requieren más investigación.

Clinical features and surgical strategy of retroperitoneal liposarcoma involving the kidney capsule: a retrospective comparative cohort study.

BACKGROUND: Valid and generalizable data on the clinical features and surgical strategies for retroperitoneal liposarcoma (LPS) involving the kidney capsule remain scarce. This study aimed to investigate the clinical characteristics, morbidity, mortality, and long-term survival of patients with retroperitoneal LPS involving the kidney capsule. METHODS: The authors analyzed a prospectively maintained database of patients who underwent surgical resection for retroperitoneal LPS between 2015 and 2020. The patients were categorized into kidney capsule or no kidney capsule groups based on the presence or absence of kidney capsule involvement. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule was developed. The primary outcome measure was overall survival (OS). The cumulative event probability curve was estimated using the Kaplan-Meier, and differences between groups using the Log-Rank. RESULTS: The study population consisted of 128 patients-54 with and 74 without kidney capsule involvement. Of these patients, 70 were female (54.7%) and 58 were male (45.3%), with a median age of 55. The median follow-up duration was 35 months. Postoperative morbidity, mortality, length of hospital stay, length of ICU stay, OS, and recurrence-free survival (RFS) did not differ significantly between the groups. Eleven patients developed postoperative acute kidney injury (AKI), and one patient required dialysis during the follow-up period. In multivariable logistic regression analysis, only nephrectomy was independently associated with postoperative AKI. Subgroup analysis of patients with kidney capsule involvement showed that nephrectomy did not improve OS or RFS but significantly decreased postoperative estimated glomerular filtration rate. CONCLUSION: Nephrectomy was associated with an increased risk of postoperative AKI after retroperitoneal LPS resection. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule achieved optimal clinical outcomes.

A Rare Case of a Gigantic Retroperitoneal Schwannoma.

Introduction: Schwannomas (Schs) are benign tumor masses that rarely occur intra-abdominally and rarely reach larger diameters. When present, they occur as rare solitary nerve sheath tumors of peri-neural Schwann cells. Schwannoma mostly affects the nerves of the extremities, trunk, or the head and neck region. They are more common in female patients, mostly among patients between the third and fifth decade. They occur spontaneously but could also be found in association with a group of genetic autosomal dominant disorders called type 2. When present intra-abdominally, schwannomas grow slowly without significant clinical signs and symptoms. Clinical importance is presented in cases of occupying intra-abdominal space and impingement of surrounding structures, which causes intermittent pain. Only 0.5-5% of all retroperitoneal tumors are schwannomas and their malignant transformation is very rare. Case report: The authors present a case of a large intra-abdominal schwannoma in a 70-year-old female patient. She underwent CT scanning due to refractory left-sided subcostal pain, which revealed a large tumor mass in the left-sided hemiabdomen. Preoperative cytologic biopsy confirmed Sch. The patient underwent an MRI scan upon admission to our department, which revealed the origin of the tumor at the left-sided L3 level and intra-abdominal tumor spreading with the largest diameter of 25 cm. The patient underwent multidisciplinary surgical excision, confirmed by MRI scan in a period of five months postoperatively. Conclusions: Its rare presentation leads to the necessity to adequately evaluate such patients, especially to avoid any hidden diagnosis which might lead to further complications. The goal of a multidisciplinary approach should be emphasized as maintaining a good postsurgical condition without neurological deficits.

Retroperitoneal Lymph Node Dissection in Patients with Stage II Seminomatous Germ Cell Tumour.

Treatment de-escalation strategies in patients with seminoma with retroperitoneal metastases are being investigated in ongoing clinical trials. Primary retroperitoneal lymph node dissection conducted by expert surgeons may avoid any cytotoxic treatment and related long-term side effects in ≥70% of patients with clinical stage IIA/B seminoma.