Overview of primary adult retroperitoneal tumours

Open versus robot-assisted retroperitoneal tumors resection involving inferior vena cava, abdominal aorta, and renal hilum: a comparative study

INTRODUCTION

Surgery is currently the only effective treatment for retroperitoneal tumors that do not involve any specific organ. The use of robots for removing both benign and malignant retroperitoneal tumors is considered safe and feasible. However, there is insufficient evidence to determine whether robotic retroperitoneal tumor resection (RMBRs) is superior to open retroperitoneal malignant resection (OMBRs). This study compares the short-term outcomes of robotic excision of benign and malignant retroperitoneal tumors with open excision of the same-sized tumors.

METHODS

The study compared demographics and outcomes of patients who underwent robotic resection (n = 54) vs open resection (n = 54) of retroperitoneal tumors between March 2018 and December 2022. A 1:1 matching analysis was conducted to ensure a fair comparison.

RESULTS

The study found that RBMRs resulted in reduced operative time (OT), estimated blood loss (EBM), and postoperative hospital stay (PSH) when compared to OBMRs. Additionally, RBMRs reduced EBL, PHS, and OT for patients with malignant tumor involvement in major vessels. No significant differences were found in tumor size, blood transfusion rate, and morbidity rate between the RBMRs and OBMRs groups.

CONCLUSION

When comparing RMBRs to OMBRs, it was observed that RMBR was associated with lower (EBL), shorter postoperative hospital stays (PHS), and reduced operative time (OT) in a specific group of patients with both benign and malignant tumors.

Short- and long-term post-nephrectomy outcomes for retroperitoneal liposarcoma from a high-volume sarcoma center: a propensity score matching analysis

BACKGROUND

Multivisceral en bloc resection with the ipsilateral kidney is commonly performed in patients with retroperitoneal liposarcoma (RLPS). We evaluated the effect of nephrectomy on short- and long-term outcomes in patients with RLPS.

METHODS

Data from a prospectively maintained database of the Peking University Cancer Hospital Sarcoma Center between April 2011 and August 2022 were analyzed. We classified the RLPS patients who underwent surgery into nephrectomy group (NP) and non-nephrectomy group (non-NP). Patients were matched using a 1:1 propensity score to eliminate baseline differences between groups. Postoperative renal function outcomes, major morbidity, and mortality were analyzed to compare short-term outcomes after nephrectomy. Differences in local recurrence-free survival (LRFS) and overall survival (OS) were compared by Kaplan-Meier analysis with respect to oncological benefits.

RESULTS

In the matched cohort, patients in the NP group had significantly higher postoperative eGFR and CKD stages, but none required dialysis. Patients between NP and non-NP had a comparable major morbidity (p = 0.820) and 60-day mortality (p = 0.475). Patients in the NP group had a higher 5-year LRFS rates than those in the non-NP group (34.5 vs. 17.8%, p = 0.015), and similar 5-year OS rates (52.4 vs. 47.1%, p = 0.401). Nephrectomy was an independent risk factor for LRFS, but not for major morbidity or OS.

CONCLUSIONS

RLPS resection with nephrectomy is related to a mild progression of renal impairment; however, dialysis is rare. En bloc nephrectomy for complete resection of RLPS is safe and improves local control.

Deep learning radiomics-based prediction model of metachronous distant metastasis following curative resection for retroperitoneal leiomyosarcoma: a bicentric study

BACKGROUND

Combining conventional radiomics models with deep learning features can result in superior performance in predicting the prognosis of patients with tumors; however, this approach has never been evaluated for the prediction of metachronous distant metastasis (MDM) among patients with retroperitoneal leiomyosarcoma (RLS). Thus, the purpose of this study was to develop and validate a preoperative contrast-enhanced computed tomography (CECT)-based deep learning radiomics model for predicting the occurrence of MDM in patients with RLS undergoing complete surgical resection.

METHODS

A total of 179 patients who had undergone surgery for the treatment of histologically confirmed RLS were retrospectively recruited from two tertiary sarcoma centers. Semantic segmentation features derived from a convolutional neural network deep learning model as well as conventional hand-crafted radiomics features were extracted from preoperative three-phase CECT images to quantify the sarcoma phenotypes. A conventional radiomics signature (RS) and a deep learning radiomics signature (DLRS) that incorporated hand-crafted radiomics and deep learning features were developed to predict the risk of MDM. Additionally, a deep learning radiomics nomogram (DLRN) was established to evaluate the incremental prognostic significance of the DLRS in combination with clinico-radiological predictors.

RESULTS

The comparison of the area under the curve (AUC) values in the external validation set, as determined by the DeLong test, demonstrated that the integrated DLRN, DLRS, and RS models all exhibited superior predictive performance compared with that of the clinical model (AUC 0.786 [95% confidence interval 0.649-0.923] vs. 0.822 [0.692-0.952] vs. 0.733 [0.573-0.892] vs. 0.511 [0.359-0.662]; both P < 0.05). The decision curve analyses graphically indicated that utilizing the DLRN for risk stratification provided greater net benefits than those achieved using the DLRS, RS and clinical models. Good alignment with the calibration curve indicated that the DLRN also exhibited good performance.

CONCLUSIONS

The novel CECT-based DLRN developed in this study demonstrated promising performance in the preoperative prediction of the risk of MDM following curative resection in patients with RLS. The DLRN, which outperformed the other three models, could provide valuable information for predicting surgical efficacy and tailoring individualized treatment plans in this patient population.

TRIAL REGISTRATION

Not applicable.

Multi-omics joint analysis revealed the metabolic profile of retroperitoneal liposarcoma

Retroperitoneal liposarcoma (RLPS) is the main subtype of retroperitoneal soft sarcoma (RSTS) and has a poor prognosis and few treatment options, except for surgery. The proteomic and metabolic profiles of RLPS have remained unclear. The aim of our study was to reveal the metabolic profile of RLPS. Here, we performed proteomic analysis (n = 10), metabolomic analysis (n = 51), and lipidomic analysis (n = 50) of retroperitoneal dedifferentiated liposarcoma (RDDLPS) and retroperitoneal well-differentiated liposarcoma (RWDLPS) tissue and paired adjacent adipose tissue obtained during surgery. Data analysis mainly revealed that glycolysis, purine metabolism, pyrimidine metabolism and phospholipid formation were upregulated in both RDDLPS and RWDLPS tissue compared with the adjacent adipose tissue, whereas the tricarboxylic acid (TCA) cycle, lipid absorption and synthesis, fatty acid degradation and biosynthesis, as well as glycine, serine, and threonine metabolism were downregulated. Of particular importance, the glycolytic inhibitor 2-deoxy-D-glucose and pentose phosphate pathway (PPP) inhibitor RRX-001 significantly promoted the antitumor effects of the MDM2 inhibitor RG7112 and CDK4 inhibitor abemaciclib. Our study not only describes the metabolic profiles of RDDLPS and RWDLPS, but also offers potential therapeutic targets and strategies for RLPS.

Evaluation of AJCC staging system and proposal of a novel stage grouping system in retroperitoneal liposarcoma: the Fudan Zhongshan experience

Background

Overall survival (OS) varies significantly among individuals with heterogeneous retroperitoneal liposarcoma (RPLS), even among those with the same clinical stage. Improved staging of RPLS is a critical unmet need, given the disappointing results of external validations of the 8th American Joint Committee on Cancer (AJCC) TNM staging system.

Methods

The cohort study included 220 consecutive patients who underwent surgical resection for primary RPLS at the largest sarcoma centre of Fudan University in China from September 2009 to August 2021, combined with 277 adult patients with RPLS in the SEER database from 1975 to 2020. Data analysis was performed from December 2021 to December 2022. Patients were retrospectively restaged according to the 8th and 7th editions of the TNM staging system as well as the new TNM (nTNM) staging system. The primary endpoint was overall survival (OS). Comparative analysis of postoperative survival was performed using the Kaplan-Meier method, and differences between subgroups were tested using the log-rank test. The OS prediction nomogram was generated based on baseline variables and tumour characteristics. Harrell's consistency index (C-index), area under the curve (AUC) of receiver operating characteristic curves (ROC), and calibration curves were used to evaluate the performance of the nomogram.

Results

A total of 497 patients were enrolled in the study, including 282 (56.7%) male patients. The median follow-up was 51 months (interquartile range, IQR, 23-83), and the OS rates at 1, 3, and 5 years were 87.9%, 75.3%, and 64.9%, respectively. According to the staging distribution of the AJCC 7th edition, 6 patients were stage IA (1.2%), 189 patients were stage IB (38%), 12 patients were stage IIA (2.4%), 150 patients were stage IIB (30.1%), 131 patients were stage III (26.3%), and 9 patients were stage IV (1.8%). With the 8th edition staging, this distribution changed: 6 patients (1.2%) were stage IA, 189 patients (38%) were stage IB, 12 patients (2.4%) were stage II, 24 patients (4.8%) were stage IIIA, 257 patients (51.7%) were stage IIIB, and 9 patients (1.8%) were stage IV. 182 patients (36.6%) were reclassified according to the nTNM staging system with the new T stage classification. The C-index and log-rank score improved after implementation of nTNM implementation. The nTNM system was associated with improved identification of high-risk patients compared with the AJCC 7th and 8th TNM. The FNCLCC stage proved to be highly prognostic with significant intergroup differences in OS. The calibration curve shows a high degree of agreement between the actual OS rate and the nomogram estimated OS rate.

Conclusion

Compared with 8th AJCC TNM, 7th AJCC TNM staging system showed a more homogeneous staging distribution and a slight improvement in the prognostic accuracy of RPLS. The revised T-stage and nTNM systems showed better risk stratification performance. The FNCLCC stage was found to have high prognostic value, further emphasising histological grade is the least negligible prognostic factor in predicting patient survival. The constructed nomogram model enables individualized prognostic analysis and helps to develop risk-adapted therapy for RPLS patients.

Advancements in Diagnosis and Multimodal Treatment Strategies for Retroperitoneal Tumors: A Comprehensive Review

Retroperitoneal tumors (RPTs) encompass both benign and malignant entities, constituting ~0.1% to 0.2% of all malignant tumors, of which 70% to 80% manifest malignancy. Predominantly, retroperitoneal sarcomas (RPS) represent the most prevalent subtype among RPT. With over 70 histologic forms identified, liposarcomas and leiomyosarcomas emerge as the primary constituents of RPS. Accurate diagnosis of RPTs necessitates preoperative core-needle biopsy and comprehensive imaging assessment. The current staging protocol for RPS relies on the eighth edition of the American Joint Committee on Cancer/TNM classification. Surgical excision remains the established gold standard for treating RPS. Therapeutic approaches vary according to the underlying pathophysiology. Although chemotherapy and radiotherapy exhibit efficacy in managing metastatic and recurrent unresectable RPS, their role in primary RPS remains unresolved, necessitating further clinical trials for validation. Concurrently, ongoing research explores the potential of targeted therapies and immunotherapy. This literature review aims to provide a comprehensive overview of existing research, delineating diagnostic pathways and optimal therapeutic strategies for RPT.

Case Report: Successful R0 resection in locally advanced retroperitoneal sarcomas

We present a case series of three successfully resected tumors in our center at Al-Makassed Hospital in Jerusalem, Palestine, all of which primarily involved or invaded adjacent structures and needed a multidisciplinary approach to achieve R0 resection. Our first patient is a 42-year-old previously healthy female with intermittent attacks of dull aching abdominal pain. Her tumor was a leiomyosarcoma that involved major vessels and other adjacent vital structures. Ultimately, she needed major highly advanced surgery necessitating the need for vascular reconstruction of the IVC, as well as R0 resection. The surgery was performed by a multidisciplinary team of highly specialized surgeons in related fields. Our second case is a 75-year-old female patient with a well-differentiated liposarcoma invading the upper pole of the right kidney, necessitating a nephrectomy. Consequently, this case demanded the interdisciplinary involvement of nephrology. Our third patient is a 59-year-old male with dedifferentiated liposarcoma that involved the spleen, pancreas, and splenic flexure while engulfing the left kidney and ureter. Beyond the removal of the tumor, multiorgan resection was imperative to achieve microscopic margin-free resection. This extensive local spread needed broad collaboration from the medical team and other surgical subspecialties. All surgeries went well, and their outcomes were promising. All patients had an uneventful follow-up and, to date, no recurrence. Invasive retroperitoneal sarcomas of different histological types and clinical stages represent a technical challenge. Careful preoperative investigation and an experienced, dedicated multidisciplinary team of surgeons and non-surgeons from related fields, including vascular, urologic, and hepatobiliary surgeons, are usually needed for a safe and successful R0 resection despite extensive tumor involvement in light of difficulty achieving early diagnosis.

Diagnostic accuracy and safety of percutaneous core needle biopsy of retroperitoneal tumours

BACKGROUND

Histologic subtype of cancer guides treatment sequencing and the extent of surgery for retroperitoneal tumours (RPTs) but concerns persist regarding percutaneous core needle biopsy (CNB).

OBJECTIVE

Endpoints were the incidence of early complications, needle tract seeding (NTS) after CNB, diagnostic accuracy.

METHODS

Between 2015 and 2022, data from patients with RPT who underwent a CNB and who operated on at Institut Curie were collected. We retrospectively reviewed the medical records and microscopic analysis of both CNB and surgical specimens to evaluate the diagnostic accuracy of CNB (quantified using positive and negative predictive values, PPV/NPV).

RESULTS

313 patients underwent CNB. In 10/326 (3 %) procedures, minor complications were observed. One of 212 (0.47 %) resected RPSs exhibited a local recurrence compatible with NTS. Microscopic analysis of CNB specimens allowed the classification of tumours between groups of cancers and benign/intermediate mesenchymal tumours in 307/313 (98 %) patients. Among the 204 patients with retroperitoneal sarcoma, the overall concordance between CNB and final pathology following resection was 178/204 (87.2 %). The respective PPVs of solitary fibrous tumour, dedifferentiated liposarcoma, leiomyosarcoma and well-differentiated liposarcoma were 100 %, 98 %, 97 % and 68 %, respectively. The diagnosis of a high-grade (G 2-3) sarcoma resulted in a high specificity (97 %) and PPV (98 %) but low sensitivity (76 %).

CONCLUSIONS

CNB allowed the classification of RPT in the vast majority of patients with a low morbidity rate. Concordance with final diagnosis was high for sarcomas with the exception of well-differentiated liposarcoma. As a result, CNB results should be integrated with imaging/radiomics by multidisciplinary tumour boards.

Retroperitoneal liposarcoma: unveiling diagnostic delays and multimodal treatment dilemmas

Liposarcomas are a prevalent subtype of soft tissue sarcomas, constituting less than 1% of all malignancies. Originating in the adipose tissue, they can manifest in various locations and are categorized by the World Health Organization into several subtypes: well-differentiated liposarcomas, dedifferentiated liposarcomas, myxoid liposarcomas, pleomorphic liposarcomas and mixed-type liposarcomas. These tumors typically affect middle-aged and older individuals, and their incidence has been progressively increasing over the years. As liposarcomas advance they tend to encase blood vessels and major organs, particularly in the retroperitoneal area. Often asymptomatic initially, symptoms arise as the tumor reaches a considerable size, exerting pressure on adjacent tissues and organs. This report features a 54-year-old patient incidentally diagnosed with a substantial retroperitoneal tumor extending to the antero-lateral abdominal wall and inner thigh via the right inguinal ligament. The patient, with a previous three-year history of a right inguinal mass, sought acute care for a perianal abscess The histological examination revealed morphological aspects consistent with a low-grade myxoid liposarcoma. While surgery remains the primary treatment for retroperitoneal liposarcomas, controversies exist regarding the role of radiotherapy and chemotherapy in improving survival rates. This case highlights the challenges in managing retroperitoneal tumors and underscores the importance of a personalized, multidisciplinary approach to optimize patient outcomes.

Anesthetic management of a huge retroperitoneal leiomyoma: a case report

BACKGROUND

Retroperitoneal leiomyomas are rare, with just over 100 cases reported in the literature. Perioperative management of retroperitoneal leiomyomas can be challenging due to the large tumor size and the risk of hemorrhage.

CASE PRESENTATION

We report a case of a 40-year-old Han woman with a 40-cm retroperitoneal leiomyoma. General anesthesia was performed for the surgical resection. Key flow parameters like cardiac output and stroke volume variation, as shown by the Vigileo™-FloTrac™ system, enabled the anesthesiologist to implement goal-directed fluid optimization. Acute normovolemic hemodilution and cell salvage technique were used resulting in a successful en bloc tumor resection with a 6000-mL estimated blood loss. Although the patient experienced postoperative bowel obstruction, no other significant complications were observed.

CONCLUSION

Advanced hemodynamic monitoring and modern patient blood management strategies are particularly helpful for anesthetic management of huge retroperitoneal leiomyomas.

Malignant peripheral nerve sheath tumor with hemophilic syndrome and bone marrow fibrosis: A rare case report

BACKGROUND

Malignant schwannoma is a rare tumor in the peripheral nervous system, accounting for approximately 5% to 10% of systemic soft tissue sarcomas. Especially, malignant schwannoma occurring in the broad ligament of the uterus with hemophilic syndrome and bone marrow fibrosis is extremely rare in clinical practice. Here, we report the first case of an patient diagnosed with malignant peripheral nerve sheath tumor (MPNST) of the broad ligament of the uterus with hemophilic syndrome and bone marrow fibrosis, and share our reference clinical diagnosis and treatment experience.

CASE SUMMARY

A patient was diagnosed with MPNST of the uterus harboring hemophilic syndrome and bone marrow fibrosis. She received combination, and repeated imaging revealed further encountered rare complications (hemophilia syndrome and bone marrow fibrosis) after two cycles of chemotherapy. Thereafter, combined treatment with pazopanib, gemcitabine, and dacarbazine was initiated. Unfortunately, the patient succumbed to death at hospital after two weeks.

CONCLUSION

This report firstly provided reference clinical practice for a patient with MPNST of the uterus harboring hemophilic syndrome and bone marrow fibrosis. Our case raises a reminder about the tolerance and safety of combination therapy, especially in young women.

Pediatric retroperitoneal non-organ-originated malignancies: An analysis based on SEER database

Retroperitoneal non-organ-originated malignancies are rare pediatric tumors with challenging diagnosis and treatment. The present study aimed to analyze the clinicopathological characteristics, treatment, and prognosis of retroperitoneal non-organ-originated malignancies. In the study, we included the pathological diagnosis of pediatric retroperitoneal non-organ-originated malignant tumors between 2000 to 2019 through the updated Surveillance, Epidemiology, and End Results database. We use the Kaplan-Meier survival curve to calculate the overall survival (OS) and cancer-specific survival (CSS). The risk of all-cause death and disease-specific death were analyzed using Cox proportional hazard regression model and Fine-and-Grey competitive hazard model, respectively. In the study, a total of 443 pediatric retroperitoneal non-organ-originated malignancies were included. Of them, only 22.3% of patients had no metastatic disease, 42.9% had distant metastasis and 34.8% had locally advanced diseases. The primary pathological tumor was neuroblastoma followed by germ cell tumor. The overall 10-year OS and CSS were 70.7% and 73.1%, respectively, and the 10-year OS and CSS of metastatic diseases were 54.4% and 56.6%, respectively. Older children, worse tumor stage at diagnosis, incomplete resection, and prolonged time from diagnosis to treatment were significantly associated with worse survival outcomes. Radiotherapy and chemotherapy did not significantly improve the prognosis of patients without complete tumor resection. The study indicated that most pediatric retroperitoneal non-organ-originated malignancies diagnosed with metastatic diseases have plagued treatment. Radiotherapy and chemotherapy are the main treatment methods for children unable to undergo complete surgical treatment. However, these treatments do not reach the same therapeutic effect as complete tumor resection after early diagnosis. Hence, early diagnosis and surgery for complete tumor resection are of utmost importance.

Preoperative contrast-enhanced CT-based radiomics nomogram for differentiating benign and malignant primary retroperitoneal tumors

OBJECTIVES

This study evaluated the ability of a preoperative contrast-enhanced CT (CECT)-based radiomics nomogram to differentiate benign and malignant primary retroperitoneal tumors (PRT).

METHODS

Images and data from 340 patients with pathologically confirmed PRT were randomly placed into training (n = 239) and validation sets (n = 101). Two radiologists independently analyzed all CT images and made measurements. Key characteristics were identified through least absolute shrinkage selection combined with four machine-learning classifiers (support vector machine, generalized linear model, random forest, and artificial neural network back propagation) to create a radiomics signature. Demographic data and CECT characteristics were analyzed to formulate a clinico-radiological model. Independent clinical variables were merged with the best-performing radiomics signature to develop a radiomics nomogram. The discrimination capacity and clinical value of three models were quantified by the area under the receiver operating characteristics (AUC), accuracy, and decision curve analysis.

RESULTS

The radiomics nomogram was able to consistently differentiate between benign and malignant PRT in the training and validation datasets, with AUCs of 0.923 and 0.907, respectively. Decision curve analysis manifested that the nomogram achieved higher clinical net benefits than did separate use of the radiomics signature and clinico-radiological model.

CONCLUSIONS

The preoperative nomogram is valuable for differentiating between benign and malignant PRT; it can also aid in treatment planning.

KEY POINTS

• A noninvasive and accurate preoperative determination of benign and malignant PRT is crucial to identifying suitable treatments and predicting disease prognosis. • Associating the radiomics signature with clinical factors facilitates differentiation of malignant from benign PRT with improved diagnostic efficacy (AUC) and accuracy from 0.772 to 0.907 and from 0.723 to 0.842, respectively, compared with the clinico-radiological model alone. • For some PRT with anatomically special locations and when biopsy is extremely difficult and risky, a radiomics nomogram may provide a promising preoperative alternative for distinguishing benignity and malignancy.

MRI diagnosis of tumor‑like IgG4 masses in bilateral distal ureters: A case report

IgG4 masses in the bilateral distal ureters are rare and frequently misdiagnosed. The present study reported the case of a 55-year-old male patient with IgG4-related disease (IgG4-RD) who had symmetrical soft tissue masses of the bilateral distal ureters found on magnetic resonance imaging (MRI) with a significant increase in the serum levels of IL-6, IgG4 and IgE. Regarding treatment, this patient received prednisone acetate tablets (40 mg/day) and mycophenolate mofetil dispersible tablets (1 g/day). During the follow-up, significant reductions in the levels of IgG4 and IgE were found after 30 days. MRI after 6 months indicated complete disappearance of the masses. The prognosis has been good so far. In clinical practice, it is necessary to consider the possibility of IgG4-RD in cases with soft tissue masses surrounding both ureters and elevated levels of serum IgG4.

R0 surgical resection of giant dedifferentiated retroperitoneal liposarcomas in the COVID era with and without nephrectomy: A case report

Retroperitoneal sarcomas (RPSs) are rare findings that can grow into large masses without eliciting severe symptoms. At present, surgical resection is the only radical therapy, whenever it can be performed with the aim to achieve a complete removal of the tumor. The present report describes two consecutive cases of RPSs that resulted in dedifferentiated liposarcomas (DDLPSs) and these patients underwent R0 surgical resection with and without a nephron-sparing procedure. The diagnostic workup, the surgical approach, the impact of late surgical management due to the COVID pandemic and the latest literature on the topic are discussed and analyzed. The patients, who refused to undergo any medical examination during the prior 2 years due to the COVID pandemic, were admitted to Federico II University Hospital (Naples, Italy) complaining about weight loss and general abdominal discomfort. In the first case, a primitive giant abdominal right neoplasm of retroperitoneal origin enveloping and medializing the right kidney was observed. The second patient had a similar primitive retroperitoneal giant left neoplasm, which did not affect the kidney. Given the characteristics of the masses and the absence of distant metastases, after a multidisciplinary discussion, radical surgical removal was carried out for both patients. The lesions appeared well-defined from the surrounding tissues, and markedly compressed all the adjacent organs, without signs of infiltration. In the first patient, the right kidney was surrounded and undetachable from the tumor and it was removed en bloc with the mass. The second patient benefited from a nephron-sparing resection, due to the existence of a clear cleavage plane. The postoperative courses were uneventful. Both the histological examinations were oriented towards a DDLPS and both patients benefited from adjuvant chemotherapy. In conclusion, the treatment of giant RPS is still challenging and requires multidisciplinary treatment as well as, when possible, radical surgical removal. The lack of tissue infiltration and the avoidance of excision or reconstruction of major organs (including the kidney) could lead to an easier postoperative course and an improved prognosis. When possible, surgical management of recurrences or incompletely resected masses must be pursued. Since the COVID pandemic caused limited medicalization of a number of population groups and delayed diagnosis of other oncologic diseases, an increased number of DDLPSs could be expected in the near future.

Surgical approach for complete resection of giant retroperitoneal liposarcoma with diaphragmatic hernia via ninth rib thoracotomy

Background

Resection of a giant retroperitoneal liposarcoma is difficult and technically demanding, especially for large retroperitoneal tumors accompanied by a diaphragmatic hernia. Technically, the open abdominal approach can be time-consuming and difficult to perform, with possible intraoperative complications and other factors bringing psychological and physical difficulties to the patient. This study reports a safe and feasible approach for the complete resection of a large retroperitoneal tumor complicated by a diaphragmatic hernia.

Methods

A 58-year-old male patient with persistent upper abdominal pain and distension was treated at a local hospital on 4 July 2022. Computed tomography showed a mixed-density mass on the right retroperitoneum, and liposarcoma was considered. On 6 July 2022, the patient was transferred to our hospital for further treatment. Computed tomography showed a mass with low-density fatty shadow in the right adrenal region. The boundary with the right adrenal gland was unclear. The mass was 102 mm × 74 mm, and the right lobe of the liver was compressed. Insufficiency of the right middle lobe of the liver was seen due to a right diaphragmatic hernia and left mediastinal deviation. We considered the traditional approach for tumor resection via laparotomy, but we opted to perform a comprehensive evaluation first. The tumor was close to the back of the right kidney and liver, causing the diaphragm to rise because of its proximity to these organs. Exposing the tumor through laparotomy would be difficult, making it challenging to remove. The patient had a diaphragmatic hernia and moderate pulmonary dysfunction; therefore, we decided to enter the abdomen through a thoracotomy of the ninth rib.

Results

Using our technique, the tumor was easily visualized and completely removed in approximately 30 min. The intraoperative blood loss was 100 ml, and no postoperative bleeding, pneumothorax, intestinal fistula, infection, or other complications occurred.

Conclusion

The transthoracic approach may be a safer and more feasible resection method than the traditional open approach for patients with giant retroperitoneal liposarcoma with a diaphragmatic hernia.

Practical Management of Adult Ultra-Rare Primary Retroperitoneal Soft Tissue Sarcoma: A Focus on Perivascular Epithelioid Tumours and Extraosseous Ewing Sarcoma

With the exception of well-differentiated liposarcoma, dedifferentiated liposarcoma, leiomyosarcoma, solitary fibrous tumour, malignant peripheral nerve sheath tumour, and undifferentiated pleomorphic sarcoma, the majority of the ≈70 histologic subtypes of retroperitoneal sarcoma are defined as 'ultra-rare' sarcomas, with an incidence of ≤1-5/1,000,000 persons/year. For most of these ultra-rare RPS subtypes, diagnosis and treatment follows international guidelines for the management of more common RPS histologies, with en bloc surgical resection as the mainstay of curative treatment, and enrolment in clinical trials where possible. Because the treatment of RPS is heavily driven by histology, the surgeon must be familiar with specific issues related to the diagnosis and management of ultra-rare sarcoma subtypes. Expert radiological and surgeon reviews are required to differentiate similarly presenting tumours where surgery can be avoided (e.g., angiomyolipoma), or where upfront systemic therapy is indicated (e.g., extraosseous Ewing's sarcoma). Thus, the management of all retroperitoneal sarcomas should occur at a sarcoma referral centre, with a multidisciplinary team of experts dedicated to the surgical and medical management of these rare tumours. In this focused review, we highlight how diagnosis and management of the ultra-rare primary RPS histologies of malignant perivascular epithelioid cell tumour (PEComa), extraosseous Ewing sarcoma (EES), extraosseous osteosarcoma (EOS), and rhabdomyosarcoma (RMS) critically diverge from the management of more common RPS subtypes.

Histology-tailored multidisciplinary management of primary retroperitoneal sarcomas

Until recently, the recommendation for primary retroperitoneal sarcomas (RPS) was to perform a complete en-bloc gross excision, (neo) adjuvant treatments being options which were not validated by randomized studies, with a large discrepancy of use between centers. The heterogeneity of RPS, with their different biological behaviour, renders a homogenous therapeutic and surgical approach probably inappropriate. Recent studies, both surgical and dedicated to adjuvant treatments, allow refining these recommendations. This review summarizes recent advances and directions.

Extrauterine Retroperitoneal Leiomyomas: 3 Case Reports and Review of the Literature

Leiomyomas are benign mesenchymal tumors which originate from smooth muscle cells. Extrauterine leiomyomas are rare and they may arise where smooth muscle cells are found. Their diagnosis is challenging due to their heterogeneous ways of presentation. Histological analysis may reveal areas of sarcomatous differentiation; therefore, complete resection of the entire tumor is the only curative treatment. There is no adjuvant therapy proved to increase overall survival. It is essential to develop a standardized protocol, detailing how to follow up these patients since it is not reported in the literature to date; however, it is advisable to follow them because the local recurrence rate is high if small implants remain. In this review, we present 3 cases of extrauterine leiomyomas diagnosed and treated in our hospital. The management was different in each case, highlighting the heterogeneity of this condition. According to the literature, there are no solid guidelines on their management. We compare our experience with the data available to date in order to support the existing knowledge and provide our expertise for future studies.

CT and MR Imaging of Retroperitoneal Sarcomas: A Practical Guide for the Radiologist

Primary retroperitoneal sarcomas (RPS) represent around 10-16% of all sarcomas, with liposarcomas and leiomyosarcomas being the most common subtypes. RPS have some peculiar characteristics, imaging appearances, worse prognosis, and complications compared to other locations of sarcoma. Commonly, RPS primarily present as large masses, progressively encasing adjacent structures, causing mass effect, and complications. RPS diagnosis is often challenging, and these tumors may be overlooked; however, failure to recognize RPS characteristics leads to a worse prognosis for the patients. Surgery is the only recognized curative treatment, but the anatomical constraints of the retroperitoneum limit the ability to achieve wide resection margins; therefore, these tumors have a high rate of recurrence, and require long-term follow-up. The radiologist has an important role in the diagnosis of RPS, the definition of their extent, and their follow-up. Specific knowledge of the main imaging findings is required to reach an early diagnosis, and, ultimately, to guarantee the best patient management. This article provides an overview of the current knowledge regarding cross-sectional imaging features of patients with retroperitoneal sarcomas, presenting tips and tricks to improve imaging diagnosis of RPS.

The Role of Surgery in Oligometastatic Retroperitoneal Sarcoma

Retroperitoneal sarcomas are extremely rare, comprising <15% of primary sarcomas. Distant metastasis occurs in about 20% of cases, with pulmonary and hepatic metastasis as the most common sites of hematogenous spread. Although surgical resection is well established as the main treatment of localized primary disease, there are limited guidelines for the surgical treatment of intra-abdominal and distant metastases. There are inadequate systemic treatment options for patients with metastatic sarcoma, thereby necessitating the consideration of surgical options in carefully selected patients. Key points to consider include tumor biology, patient fitness and co-morbidities, overall prognosis, and goals of care. Multidisciplinary sarcoma tumor board discussion for each case is an essential practice in order to deliver the best care to these patients. The purpose of this review is to summarize the published literature on the past and present role of surgery in the treatment of oligometastatic retroperitoneal sarcoma in order to inform the management of this difficult disease.

Diagnostic accuracy of biopsy after neoadjuvant treatment for well-differentiated and dedifferentiated retroperitoneal liposarcoma

PURPOSE

Accurate histopathological grading of percutaneous biopsies is essential to guide adequate management of patients with suspected retroperitoneal liposarcoma. In this regard, however, limited reliability has been described. Therefore, we conducted a retrospective study to assess the diagnostic accuracy in retroperitoneal soft tissue sarcomas and simultaneously investigate its impact on patients' survival.

MATERIALS AND METHODS

Reports of an interdisciplinary sarcoma tumor board between 2012 and 2022 were systematically screened for patients with well-differentiated (WDLPS) and dedifferentiated retroperitoneal liposarcoma (DDLPS). Histopathological grading on pre-operative biopsy was correlated with corresponding postoperative histology. Additionally, patients' survival outcomes were examined. All analyses were performed in two subgroups: patients with primary surgery and patients with neoadjuvant treatment.

RESULTS

A total of 82 patients met our inclusion criteria. Diagnostic accuracy of patients who underwent upfront resection (n = 32) was significantly inferior to patients with neoadjuvant treatment (n = 50) (66% versus 97% for WDLPS, p < 0.001; 59% versus 97% for DDLPS, p < 0.001). For patients with primary surgery, histopathological grading on biopsy and surgery was concordant in only 47% of cases. Sensitivity for detecting WDLPS was higher than for DDLPS (70% versus 41%). Higher histopathological grading in surgical specimens correlated with worse survival outcomes (p = 0.01).

CONCLUSION

Histopathological grading of RPS may no longer be reliable after neoadjuvant treatment. The true accuracy of the percutaneous biopsy may need to be studied in patients who do not receive neoadjuvant treatment. Future biopsy strategies should aim to improve identification of DDLPS to inform patient management.

Giant Adrenal Cyst: A Case Report

Giant adrenal cysts are rare lesions, most often discovered incidentally. In this case report, a patient presenting with nonspecific abdominal distension is described. Imaging studies revealed a vast cystic mass closely attached to the left adrenal gland. Neither routine laboratory tests nor endocrine function tests revealed abnormalities. By performing open surgery, the cystic mass was completely removed. According to the pathological results, the wall of the cystic mass has an endothelial structure and some vascular components. Comprehensive analysis indicated that this case was an angiomatous adrenal endothelial cyst which was an extremely uncommon form of an adrenal cyst. Over a one-year follow-up, no evidence of recurrence was observed in the patient postoperatively. Through this case, we wish to raise awareness of this disease.

Surgical excision of a large retroperitoneal lymphangioma: A case report

BACKGROUND

Lymphangiomas are rare benign tumors most commonly found in children under 2 years of age; adult cases are extremely rare. Retroperitoneal lymphangiomas represent less than 1% of all lymphangiomas. Because of their benign nature and possibility of spontaneous resolution, lymphangiomas are sometimes left untreated for long periods of time. However, if they grow large enough to compress surrounding structures, retroperitoneal lymphangiomas may cause symptoms such as abdominal pain, nausea or vomiting. We report a case of a rapidly growing retroperitoneal lymphangioma in an adult, treated with complete surgical excision.

CASE SUMMARY

A 60-year-old female who was diagnosed with an intra-abdominal cystic mass (11 cm × 9.5 cm) seven years ago presented to our hospital with symptoms of early satiety, nausea, and intermittent abdominal pain. Computed tomography (CT) scan confirmed interval enlargement to a 24 cm × 22 cm-sized huge left retroperitoneal mass, causing left hydronephrosis by external compression. Laparotomy was done via long midline incision. Due to severe adhesion between the aorta and the medial border of the mass, the cyst was intentionally opened for fluid aspiration and size reduction. After suture closure of the opening, we proceeded carefully with dissection. Aspiration showed light yellowish serous fluid. The mass was excised completely, and the pathology was consistent with cystic lymphangioma. The post-operative period was uneventful, and the patient was discharged without complications. Follow-up CT scan one month after surgery confirmed complete removal of the mass and decreased left hydronephrosis.

CONCLUSION

Excision of the huge retroperitoneal cystic mass resulted in relief of the patient’s symptoms, originally caused by external compression, and also ruled out the possibility of malignancy.

Microsurgical treatment of lumbar paravertebral tumors via lateral retroperitoneal approach: operative technique and a series of 6 patients

OBJECTIVE

To investigate the surgical techniques and postoperative therapeutic effectiveness of microsurgical treatment of lumbar paravertebral tumors via lateral retroperitoneal approach.

METHODS

The clinical data of 6 cases with lumbar paravertebral tumors treated by lateral retroperitoneal approach in the Neurosurgery department of Xuanwu Hospital, Capital Medical University were analyzed retrospectively. The mean operation time, blood loss, incision length, length of hospital stay, and the resection rate of paravertebral tumors were collected, and the score of The Ability to Perform Activities of Daily Living (ADL) and incidence of postoperative complications was recorded.

RESULTS

The operation time ranged from 56 to 181 min, with an average of (94.8 ± 48.3) minutes. The blood loss was between 5 and 100 ml, with an average of (31.7 ± 37.5) ml. The incision length was 6-7 cm, with an average of (6.7 ± 0.5) cm. The hospitalization length was between 5 and 11 days, with an average of (8.7 ± 2.6) days. The resection rate of paravertebral tumors was 100%. Postoperative pathological diagnosis results revealed 4 cases of schwannoma, 1 case of ganglioneuroma, and 1 case of malignant small round cell tumor. During the 3-month follow-up, there were no tumor recurrence, abdominal infection, incision infection, incisional hernia, or death, and there was no significant decrease in the ADL score compared with that before the operation.

CONCLUSION

The surgical treatment of lumbar paravertebral tumors via the lateral retroperitoneal approach has the advantages of the short operation time, minimally invasive procedures, quick postoperative recovery, and fewer complications.

Challenging surgical treatment of giant retroperitoneal liposarcoma: A case report

Liposarcoma is a rare malignant tumor type and surgical resection is the gold standard treatment. The present study reported on the case of a 51-year-old woman who presented with a mass in the left upper abdomen. Computed tomography revealed a 32-cm giant retroperitoneal liposarcoma. Complete tumor resection was performed without the removal of other organs. Postoperative pathological examination indicated retroperitoneal well-differentiated liposarcoma and immunohistochemistry revealed S-100(−), MDM2(+), vimentin(+), CDK4(+), p16(+) and STAT6(+) results. The patient recovered well after the surgery. Complete tumor resection during the first surgery is key to cure liposarcoma. The present case report will be helpful for clinical oncologists to fully understand giant retroperitoneal liposarcoma and treat it accordingly.

Clinical Experience and Management Strategy of Retroperitoneal Tumor With Venous Tumor Thrombus Involvement

Background

This study aims to report the surgical management, complications, and outcomes for patients with retroperitoneal tumor and venous thrombus.

Methods

We retrospectively analyzed 19 cases of retroperitoneal tumor with venous tumor thrombus from August 2015 to March 2021. A new tumor thrombus PUTH-RT grading system was proposed on the basis of the characteristics of the surgical techniques.

Results

Two cases of PUTH-RT-1a, two cases of PUTH-RT-1b, six cases of PUTH-RT-2, six cases of PUTH-RT-3, and three cases of PUTH-RT-4 were included. Surgeries were successfully performed in all 19 patients. Among them, five cases (26.3%) were operated via a completely laparoscopic approach and 13 cases (68.4%) via an open approach. One case (5.3%) was converted from laparoscopic to open approach. Five cases (26.3%) experienced postoperative complications. All patients were followed for a median of 14 months. Cancer-associated death occurred in three cases. Distant metastases occurred in seven cases.

Conclusions

We propose a new tumor thrombus grading system based on the anatomical characteristics of retroperitoneal tumors with venous tumor thrombus. Retroperitoneal tumor resection and removal of venous tumor thrombi are safe and effective for the treatment of such diseases.

Intradiaphragmatic bronchogenic cyst: report of a rare new case

Bronchogenic cysts (BCs) are congenital abnormalities commonly found within the mediastinum. Diaphragmatic location is extremely rare. We present a woman in her 60s with an asymptomatic intradiaphragmatic BC. The patient underwent complete surgical resection with primary closure of the left hemidiaphragm. BCs should remain a differential diagnosis of any soft-tissue mass in the region of the diaphragm. Complete surgical resection is recommended even in asymptomatic patients to avoid complications such as infection, rupture, bleeding or malignant transformation.

Transcriptome analysis of tumor-derived mesenchymal progenitor cells shows that CHST15 is a fibrosis regulator of retroperitoneal liposarcoma

Background

Retroperitoneal liposarcoma (RPLS) is a rare, biologically heterogeneous tumor with distinct clinical characteristics, such as frequent local recurrence, repeated relapse, and rare distant metastasis. No effective targeted therapy is available for RPLS. Here, we aim to determine the pathological functions and therapeutic potential of carbohydrate sulfotransferase 15 (CHST15) in RPLS.

Methods

Tumor-derived mesenchymal progenitor cells (MPCs) and normal adipose derived mesenchymal stem cells (MSCs) were obtained from patients with RPLS. MPCs and MSCs were isolated and characterized based on surface markers, proliferation, and differentiation using flow cytometry and molecular staining. Transcriptome analysis was performed to decipher expression profile of differentiation-related genes in 3 paired MSCs and MPCs. Further confirmation of genes were performed using quantitative real-time polymerase chain reaction (qRT-PCR). Plasmids overexpressing CHST15 were transfected into adipose MSCs to examine fibrosis-related gene expression at mRNA level by real-time PCR.

Results

The tumor stromal-derived MPCs expressed CD105, CD73, and CD90, and exhibited osteogenic and adipogenic differentiation potential in vitro. The proliferation of tumor-derived MPCs was significantly lower than that of normal adipose-derived MSCs (P<0.001). Transcriptome analysis revealed upregulation of IL-7R, ALPL, PKNOX2, and CHST15 in tumor-derived MPCs. CHST15 was highly expressed in tumor-derived MPCs (P<0.001). CHST15 mediated fibrosis-related FGF2 gene expression in MSCs (P<0.05) and MPCs (P<0.001).

Conclusions

CHST15 is upregulated in tumor-derived MPCs and regulates fibrosis in RPLS. This provides clues for development of novel therapeutic strategies by targeting CHST15-induced MPC activation in RPLS.

An Analysis of Computed Tomography Imaging Features and Predictive Factors for Postoperative Recurrence and Metastasis of Abdominal Paragangliomas

Methods

We studied 51 abdominal PGL patients at the First Affiliated Hospital of Bengbu Medical College, Tongde Hospital, and Sir Run Shaw Hospital, Hangzhou, Zhejiang Province, China, from June 2009 to May 2019. Thereafter, the clinical research data, tumor biomarkers, and CT features were compared between the aggressive PGLs and the nonaggressive PGLs using independent-samples t-tests and chi-square tests.

Results

Of the 51 cases, 43 were benign and 8 had malignant tendencies. Postoperative recurrence and metastasis were more likely to occur when the tumor diameter was >8 cm or/and the enhancement degree was not obvious. Clinical symptoms, tumor markers, sex, age, and CT image characteristics including morphology, presence of cystic degeneration, "pointed peach" sign, calcification, hemorrhage, enlarged lymph nodes, and peritumor and intratumor blood vessels were not significantly different between the two groups (p > 0.05).

Conclusion

Our findings suggest that CT features, including size >8 cm and enhancement degree, could provide important evidence to assess risk factors for aggressive PGLs.

Reconstruction of three‐dimensional models for complex female pelvic tumors

3D reconstructed models appear to be a very reliable method for assessing complex female pelvic tumors prior to surgery.

Two Different Types of Sarcoma Occurring Synchronously: The Impact of Molecular Biology on Therapeutic Strategy

Sarcoma is a rare type of tumor that can arise in the different types of connective tissues. Symptoms vary depending on the size, type, and location of the tumor. Management and surgery should be performed in a referral sarcoma center with a molecular biology platform and a dedicated medical staff. A preoperative percutaneous core needle biopsy (CNB) is required to tailor the medical and surgical strategies. In this report, we describe the case of a well-differentiated retroperitoneal liposarcoma (WD LPS) discovered in the context of recurrent cystitis on an abdominal CT scan, synchronously occurring, with another different type of sarcoma, undifferentiated pleomorphic sarcoma (UPS) developing in the thigh, discovered because of sciatic pain. This extremely rare condition was confirmed by the molecular analysis and justifies a specific strategy taking account of the differential risk. This event should also encourage genetic counseling.

Predictive Value of Preoperative Controlling Nutritional Status Score Combined with Fibrinogen-Albumin Ratio in Postoperative Local Recurrence-Free Survival of Patients with Retroperitoneal Liposarcoma

Background

Previous studies have shown that nutrition and systemic inflammation plays an essential role in the development of soft tissue sarcoma. However, few studies have explored the association of clinicopathologic features and local recurrence with nutritional and inflammatory markers in retroperitoneal liposarcoma (RPLS). This study sought to evaluate the prognostic value of the preoperative nutritional and inflammatory markers for local recurrence-free survival (LRFS) among surgical RPLS patients.

Methods

The study included 111 RPLS patients who underwent surgery between May 2010 and June 2019 at the Peking University Cancer Hospital Sarcoma Center. Time-dependent receiver operating characteristic (time-ROC) curve analysis was conducted to evaluate the ability of markers to predict LRFS. The associations of the CONUT-FAR score with clinicopathological variables and LRFS were evaluated.

Results

In the time-ROC curve analysis, the CONUT-FAR score was superior to other nutritional and inflammatory markers in predicting LRFS. The CONUT-FAR score was the only nutritional and inflammatory marker that independently predicted LRFS in the multivariate analysis, and patients with a high CONUT-FAR score (> 11) showed significantly decreased LRFS. Although the CONUT-FAR score failed to discriminate patients with low grade (G1) (p = 0.327) or undergoing incomplete (R2) resection (p = 0.072), it stratified patients with high grade (G2 and G3) or undergoing complete resection (R0/R1) into subgroups with significantly distinct LRFS (p < 0.001). The CONUT-FAR score also showed good clinical utility among patients with different clinical characteristics.

Conclusion

The preoperative CONUT-FAR score reflects both nutritional and inflammatory factors and is an effective predictor of LRFS for surgical RPLS patients.