Diagnosis and Prognosis of Retroperitoneal Liposarcoma: A Single Asian Center Cohort of 57 Cases

Recurrent Intrathoracic Liposarcoma: A Case Report and a Comprehensive Literature Review of a Rare Clinical Entity

Liposarcomas (LPSs) are rare malignant tumors of adipocytic origin, primarily occurring in the extremities and retroperitoneum, with thoracic involvement being exceptionally rare. This case report details the surgical management and outcomes of a recurrent intrathoracic LPS in a 65-year-old male with a history of previous mediastinal tumor resection. CT imaging revealed a recurrent tumor extending into the left pleura. The patient underwent a posterolateral thoracotomy for complete tumor excision and limited replacement of the descending aorta. Postoperative recovery was smooth, and histology confirmed dedifferentiated LPS (G2) with areas of highly differentiated LPS. LPSs encompass a heterogeneous group of tumors with various subtypes, including atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS), dedifferentiated liposarcoma (DDLPS), myxoid liposarcoma (MLPS), and pleomorphic liposarcoma (PLPS). Treatment primarily involves complete surgical resection, while the roles of radiotherapy and chemotherapy remain debated. Immunotherapy shows potential benefits, particularly for DDLPS patients expressing PD-L1. Prognosis varies significantly by subtype, with DDLPS and PLPS associated with poorer outcomes compared to MLPS and ALT/WDLPS. Long-term follow-up is crucial for managing LPSs due to their high recurrence rate. This case highlights the effectiveness of surgical intervention in recurrent intrathoracic LPSs and underlines the need for continued research into adjuvant therapies to improve patient outcomes.

Surgical management of giant retroperitoneal liposarcoma: Case report

Tumors originating from soft tissues are uncommon, among these tumors, liposarcomas are the most frequent. These tumors remain asymptomatic for a long time, and only revealing themselves when they reach an important size. In such cases, treatment is difficult, requiring extensive surgery procedures that can excise several adjacent structures, potentially completed by adjuvant radiotherapy. Despite successful treatment, the recurrence rate remains very high. We report the case of a giant liposarcoma requiring a monobloc extensive resection involving the removal of the tumor, left kidney, left adrenal gland, and a portion of the posterior abdominal wall.

Explainable machine learning predicts survival of retroperitoneal liposarcoma: A study based on the SEER database and external validation in China

OBJECTIVE

We have developed explainable machine learning models to predict the overall survival (OS) of retroperitoneal liposarcoma (RLPS) patients. This approach aims to enhance the explainability and transparency of our modeling results.

METHODS

We collected clinicopathological information of RLPS patients from The Surveillance, Epidemiology, and End Results (SEER) database and allocated them into training and validation sets with a 7:3 ratio. Simultaneously, we obtained an external validation cohort from The First Affiliated Hospital of Naval Medical University (Shanghai, China). We performed LASSO regression and multivariate Cox proportional hazards analysis to identify relevant risk factors, which were then combined to develop six machine learning (ML) models: Cox proportional hazards model (Coxph), random survival forest (RSF), ranger, gradient boosting with component-wise linear models (GBM), decision trees, and boosting trees. The predictive performance of these ML models was evaluated using the concordance index (C-index), the integrated cumulative/dynamic area under the curve (AUC), and the integrated Brier score, as well as the Cox-Snell residual plot. We also used time-dependent variable importance, analysis of partial dependence survival plots, and the generation of aggregated survival SHapley Additive exPlanations (SurvSHAP) plots to provide a global explanation of the optimal model. Additionally, SurvSHAP (t) and survival local interpretable model-agnostic explanations (SurvLIME) plots were used to provide a local explanation of the optimal model.

RESULTS

The final ML models are consisted of six factors: patient's age, gender, marital status, surgical history, as well as tumor's histopathological classification, histological grade, and SEER stage. Our prognostic model exhibits significant discriminative ability, particularly with the ranger model performing optimally. In the training set, validation set, and external validation set, the AUC for 1, 3, and 5 year OS are all above 0.83, and the integrated Brier scores are consistently below 0.15. The explainability analysis of the ranger model also indicates that histological grade, histopathological classification, and age are the most influential factors in predicting OS.

CONCLUSIONS

The ranger ML prognostic model exhibits optimal performance and can be utilized to predict the OS of RLPS patients, offering valuable and crucial references for clinical physicians to make informed decisions in advance.

Recurrent retroperitoneal liposarcoma with multiple surgeries: a case report

Retroperitoneal liposarcoma (RPLPS) is a rare malignant tumor that is typically treated with surgical resection. However, RPLPS often has a high rate of local recurrence, making it crucial to explore new treatment options. In this report, we present the case of a middle-aged woman who experienced seven recurrences and underwent seven surgeries following the initial resection. Currently, the patient's condition remains stable after the eighth surgery. Although there have been numerous reports of RPLPS cases both domestically and internationally, instances of repeated recurrence like this are exceptionally rare. Therefore, we have gathered the patient's case data and conducted a retrospective analysis, incorporating relevant literature, to enhance the understanding of this disease among clinical practitioners.

Identification of predictors for short-term recurrence: comprehensive analysis of 296 retroperitoneal liposarcoma cases

BACKGROUND

The short-term (≤ 1 year) recurrence (STR) is the primary determinant impacting both the life quality and survival duration in patients who have undergone surgical resection for retroperitoneal liposarcoma (RPLS), a condition with intricate and ambiguous pathogenesis. The purpose of this study was to analyze the risk factors associated with STR in cases of RPLS and primary retroperitoneal liposarcoma (PRPLS).

METHODS

For this retrospective observational study, a total of 296 RPLS cases were selected as research subjects, who experienced tumor recurrence during the follow-up period. The Local recurrence-free survival (LRFS) rates were estimated using the Kaplan-Meier method and subsequently compared between groups utilizing the log-rank test. The subsequent analyses involved univariate and multivariate logistic regression to identify predictors of STR in RPLS cases. Additionally, a logistic regression model was constructed for PRPLS.

RESULTS

The 1-, 3-, and 5-year LRFS rates of the 296 RPLS cases were 51.7%, 16.9%, and 7.1%, respectively. In the univariate analysis, several factors were found to be associated with STR, including preoperative neutrophil/lymphocyte ratio (NLR), smoking history, surgical frequency, combined organ excision, operative time, intraoperative bleeding, transfer to the intensive care unit (ICU), multiple primary tumors, tumor shape and capsule characteristics, histological subtype, and presence of tumor necrosis. The elevated preoperative NLR, surgical frequency of ≥ 3 times, transfer to the ICU, presence of multiple primary tumors, and tumor necrosis were identified as independent risk factors for STR in surgically resected RPLS. Conversely, diabetes, intact tumor capsule, and well-differentiated histological subtype appeared to be independent protective factors. Analysis for PRPLS revealed that tumor capsule and tumor necrosis were independent predictors of STR.

CONCLUSIONS

The elevated preoperative NLR, surgical frequency of ≥ 3 times, transfer to the ICU, presence of multiple primary tumors, tumor necrosis, and tumor capsule were expected to serve as predictive factors of STR for surgical resected RPLS and PRPLS.

Giant dedifferentiated liposarcoma of the gastrocolic ligament: A case report

BACKGROUND

Dedifferentiated liposarcoma (DDLS) has a worse prognosis and occurs most commonly in the retroperitoneal region and rarely in the intraperitoneal region. Histological diagnosis was revolutionized by the combined contributions of histo-immuno-chemistry and molecular biology. Aside from surgery, there is no consensus on the optimal treatment for this chemoresistant cancer.

CASE SUMMARY

A thirty-year-old black female presented with a large painful abdominal mass occupying nearly the entire abdomen and progressive weight loss was admitted for surgery. Abdominal computed tomography showed a large heterogeneous mass of the mesentery that was sized 18 cm × 16 cm in size and had heterogeneous contrast enhancement. During laparotomy, en bloc excision of the large and multilobulated gastrocolic ligament mass was performed. The initial postoperative histopathological diagnosis was undifferentiated sarcoma. Finally, the results of immunohistochemistry and molecular biology allowed us to confirm the diagnosis of DDLS. The tumour followed an aggressive evolution with diffuse metastasis, causing the death of the patient less than 5 mo after the operation.

CONCLUSION

Dedifferentiated liposarcomas are rare tumours that typically originate in the retroperitoneum but may arise in unexpected locations.

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.

Correlation Analysis Between Demographic, Surgical, and Pathological Characteristics with Local Recurrence-Free Survival for Surgical Resected Retroperitoneal Liposarcoma

BACKGROUND

As the leading cause of mortality for retroperitoneal liposarcoma (RPLS) cases, postoperative recurrence has complicated and unclear risk factors. This study was conducted to explore the correlations between demographic, surgical, and pathological characteristics with local recurrence-free survival (LRFS) for surgical resected RPLS.

METHODS

RPLS cases that underwent radical operation were considered to be included in this analysis. LRFS rates were estimated based on the Kaplan-Meier method and were compared between groups by the log-rank test. Cox proportional hazard regression models were constructed to identified the predictors of LRFS. Subsequently, the independent predictors acquired from multivariate analyses were used to construct a nomogram.

RESULTS

348 RPLS cases who underwent radical operation were included. Of the 348 cases, 333 had tumor recurrence or with a follow-up period ≥5 years. Thus, 296 (88.9%) of the 333 cases had recurrent disease, and the median LRFS duration of 296 recurrence cases was 17.0 (95% confidence interval (CI) 13.2-20.8) months. Multivariate analysis identified the preoperative neutrophil/lymphocyte ratio (NLR), surgical frequency, operative time, tumor shape, histological subtype, and tumor necrosis as independent predictors of LRFS. Based on above independent predictors, a nomogram was constructed to predict the 1-, 3-, and 5-year LRFS of surgical resected RPLS.

CONCLUSION

Elevated preoperative NLR, ≥2nd time surgical frequency, extended operation time, irregular tumor shape, no well-differentiated histological subtype, and tumor necrosis could be used as predictors of LRFS for surgical resected RPLS.

Predictive factors and a novel nomogram for recurrence of primary retroperitoneal liposarcoma: Comprehensive analysis of 128 cases

Since primary retroperitoneal liposarcoma (PRPLS) is rare in the clinic, related clinical studies are lacking. The present study was designed to investigate the predictive factors of short-term (≤1 year) recurrence (STR) and construct a novel nomogram of local recurrence-free survival (LRFS) for surgically resected PRPLS. A total of 128 PRPLS cases who underwent radical surgery were retrospectively analyzed. Based on the interval from the operation to tumor recurrence, the predictors of STR were screened using univariate and multivariate logistic regression analyses. Cox proportional hazard regression models were applied to identify the predictors of LRFS. Furthermore, the independent predictors acquired from multivariate analyses were used to construct a nomogram. Multivariate logistic regression analysis revealed that age ≥55 years [odds ratio (OR)=5.607, P=0.010], operative time ≥260 min (OR=9.716, P=0.005) and tumor necrosis (OR=3.781, P=0.037) were independent risk factors of STR for PRPLS. In the Cox regression analysis, clinical symptoms [hazard ratio (HR)=1.746, P=0.017], resection method (OR=0.370, P=0.021) and de-differentiated histological subtype (HR=1.975, P=0.048) were identified as independent predictors of LRFS. Subsequently, the independent predictors acquired from multivariate analyses were used to construct a nomogram for LRFS. Age, operative time, tumor necrosis, clinical symptoms, resection method and histological subtype were related to recurrence for surgically resected PRPLS and a novel nomogram was constructed based on the above predictors.

Recurrent metastatic retroperitoneal dedifferentiated liposarcoma: a case report and literature review

BACKGROUND

Retroperitoneal liposarcoma (RPLPS), a rare tumor, is often treated using surgical procedures as the first choice for treatment. However, there is no consensus on the scope of surgical resection. In addition, the treatment outcomes of conventional radiotherapy and chemotherapy have not been satisfactory, particularly for specific types of LPS, such as dedifferentiated LPS. In this case study, we present a brief review of other cases of RPLPS, highlighting the selection of surgical scope for RPLPS and related adjuvant treatment for advanced RPLPS.

CASE PRESENTATION

A case study is reported regarding an extremely rare recurrent and metastatic retroperitoneal dedifferentiated LPS. The primary RPLPS tumor, with a diameter of 20 cm and a weight of 2.5 kg, occupied the whole left abdomen and adhered to the left kidney. A surgical tumor resection combined with a left nephrectomy is performed. During the 6th -month postoperative follow-up examination, we observed the local recurrence of the tumor in the operation area, in addition to multiple metastatic tumors in both lungs. Further, the prescribed 3-month targeted treatment with anlotinib significantly reduced the size of the metastatic pulmonary tumors. However, the recurrent retroperitoneal tumors showed no significant change in size. Eventually, we observed no substantial evidence of tumor progression, with the patient's condition under control.

CONCLUSION

The case demonstrated that the postoperative recurrence of widespread RPLPS required R0 resection to cure the disease, considering targeted therapy for advanced RPLPS control.

Myxoid Pseudotumor Involving the Renal Sinus: Clinicopathologic Study of 33 Cases Supporting a Distinct Benign Non-neoplastic Lesion

We describe 33 cases of myxoid pseudotumor involving the renal sinus from 31 patients. Patients included 21 men and 10 women, ages 30 to 95 years. Twenty-seven cases (82%) had an associated malignancy, including urothelial carcinoma of the renal pelvis (22 cases), clear cell renal cell carcinoma (3 cases), urothelial carcinoma of the bladder (1 case), and poorly differentiated carcinoma of uncertain lineage (1 case). The remaining 6 (18%) had no associated malignancy and included 3 nephrectomies for ureteral stricture, 2 ureteropelvic junction repairs, and 1 resection of a "periureteral mass" (subsequently shown to be myxoid pseudotumor). Myxoid pseudotumor was identified by preoperative computed tomography imaging in 2 patients (6%) and identified by the gross dissector in 9 cases (27%). The mean size was 14 mm (range: 5 to 38 mm). All cases had an admixture of adipocytes, myxoid stromal matrix, variable collagenization, and a hypocellular population of bland spindled and stellate stromal cells. No multilobated atypical stromal cells were present. Clinical follow-up was available for 28 patients (90%), ranging from 1 to 132 months (mean: 24.6 mo). No patients had adverse events related to the myxoid pseudotumor. Myxoid pseudotumor of the renal sinus is often associated with a variety of adjacent neoplastic and non-neoplastic conditions and may present as a mass lesion detectable by imaging and/or gross inspection. Awareness of this benign process is important to avoid confusion with a neoplasm, especially liposarcoma.

Clinicopathological Features of Intrathoracic Liposarcoma-A Systematic Review with an Illustrative Case

BACKGROUND

Liposarcoma (LPS) is one of the most common soft-tissue sarcomas. However, intrathoracic LPS is rare, as only 1% of all LPS cases are found in the thorax.

METHODS

A systematic literature review through PubMed and Embase databases was performed. Only eligible case reports and case series reporting intrathoracic LPS in adult patients were included. Kaplan-Meier curves were calculated to evaluate the survival rate of included patients based on the histological subtype of LPS.

RESULTS

123 studies reporting 197 patients were included. We added a case of a 69-year-old female patient with recurrent giant intrathoracic LPS. The primary tumor measured 15.1cm × 22.9 cm × 21.9 cm and weighed 3100 g. Six months later, the patient was admitted to the hospital with another intrathoracic tumor measuring 9.5 cm × 9 cm× 1.4 cm. The immunohistochemical studies showed expression of murine double minute 2 (MDM2) antigen in both primary and recurrent tumor cells.

CONCLUSIONS

Dyspnea, chest pain, and cough were the most common symptoms reported in included studies. Overall, the 5-year survival rate was 62%. The highest survival was observed in well-differentiated LPS patients (80%) and the lowest in myxoid LPS (31%).

Tumor grade and symptoms at presentation are survival risk factors in Chinese patients with primary retroperitoneal sarcoma

Background and Aim

No cohort studies have been performed on Chinese primary retroperitoneal sarcoma (RPS) patients. Data derived from western cohort studies may not be directly superimposable on Asian counterparts. Furthermore, the risk factors for survival of RPS are currently unknown for Chinese patients. The objectives were therefore to (1) gain insight into RPS incidence and patient demographics and clinical details; (2) determine the risk factors for overall survival (OS) and disease-free survival (DFS); and (3) critically appraise the Asian cohort data in relation to information obtained in western cohort studies.

Methods

In this retrospective cohort study, the health records of patients that had been diagnosed with primary localized RPS with curative intent between 2009 and 2020 were analyzed. Cox proportional hazards analysis was conducted to evaluate the risk factors for OS and DFS.

Results

A total of 261 patients met the inclusion criteria. Ninety-six (36.8%) patients had been diagnosed with well-differentiated liposarcoma, 63 patients (24.1%) with dedifferentiated liposarcoma, 41 patients (15.7%) with leiomyosarcoma (LMS), 22 patients (8.4%) with solitary fibroma, 7 patients (2.7%) with malignant peripheral nerve sheath tumor (MPNST), and 32 patients (12.3%) with another type of RPS. The study further revealed that (1) the 5-y OS and DFS in RPS patients was 67.8% and 51.3%, respectively, with the highest OS and DFS observed in MPNST (100% and 100%, respectively) and the lowest 5-y OS and DFS attributed to LMS (42.6% and 28.9%, respectively); (2) symptoms at presentation, Federal National Cancer Center (FNCLCC) grade, and number of combined resections are independent risk factors in OS; (3) symptoms at presentation, FNCLCC grade, chemotherapy, and hospital length of stay are independent risk factors for DFS; and (4) patients at high risk (symptoms at presentation and high-grade tumors) have less than half the chance of survival at 5 y post-diagnosis than patients with a low-risk profile.

Conclusions

Symptoms at presentation constitute a risk factor for OS and DFS. When combined with tumor grade - another risk factor for both OS and DFS - patients can be classified into a high-risk and low-risk category to gauge a patient's prognosis and, accordingly, frame an optimal clinical trajectory. Moreover, the clinicopathology and overall prognosis of RPS in Asian and Western populations are comparable and hence superimposable.

Relevance for Patients

The present study identifies the risk factors of survival in RPS and suggests symptoms at presentation should be considered in the preoperative consultation and added in prognostic grouping.

Giant retroperitoneal dedifferentiated liposarcoma mimicking ovarian cancer: A case report

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Clinical features of the dedifferentiated subtype of LPS that has a diameter of >30 cm remains unknown.

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Surgical resection entails a high risk due to the size and anatomical location and difficulty in preoperative diagnosis.

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CT is the most useful imaging method for evaluating tumor location, size, origin, and relationship to adjacent organs.

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Retroperitoneal LPS should be considered in the case of a giant intra-abdominal tumor with a fatty component.

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Surgical resection is the mainstay of treatment for retroperitoneal LPS.

Retroperitoneal liposarcoma is a rare tumor, and its dedifferentiated subtype and a larger diameter are associated with a poor prognosis. However, there are few reports of retroperitoneal liposarcomas, both with a dedifferentiated subtype and a diameter of >30 cm. We report a case of a giant retroperitoneal liposarcoma with a dedifferentiated subtype. A 78-year-old woman presented to our hospital with abdominal distension and loss of appetite. Computed tomography and magnetic resonance imaging findings revealed a 35-cm-diameter solid tumor in the peritoneal cavity. CA125 (64.8 U/mL) and HE4 (229.0 pmol/L) were elevated preoperatively raising suspicion for ovarian malignancy. However, intraoperative findings revealed that the tumor originated in the retroperitoneal cavity. Reductive surgery for the tumor and partial resection of the sigmoid colon and left ureter were performed, and pathological examination confirmed a retroperitoneal dedifferentiated liposarcoma. Although her symptoms improved postoperatively, she died 11 months after surgery due to disease progression.

Huge retroperitoneal liposarcoma encasing right kidney: A case report from Nepal

Introduction and importance

Retroperitoneal liposarcoma is a rare entity originating from adipocytes. Before showing any symptoms, it can grow hugely and envelop nearby structures. Surgery is the optimum course of treatment, however, well-differentiated liposarcomas make it challenging to discern between malignant and normal adipocytes during surgery.

Case presentation

We report a case of a 62-year-old male referred to evaluate his abdominal distention presented for four years. Recently he had developed loin pain for six months. A computerized tomography scan showed extensive tumor encompassing the right kidney and ureter, colon, and duodenum, however, exploratory laparotomy revealed free colon and duodenum. Complete resection of the mass with a right nephrectomy was performed. Subsequently, a histopathological assessment of the resected specimen confirmed the diagnosis of well-differentiated liposarcoma. Adjuvant chemotherapy was initiated as the tumor was a high-risk sarcoma but local recurrence was observed after 2 years despite surgery and chemotherapy.

Clinical discussion

Imaging modalities are the mainstay of preoperative diagnosis. Preferably, surgical resection with a tumor-free margin is recommended to avoid tumor recurrence which remains the primary challenge. This, along with the grade of the tumor, multifocal disease, and invasion of adjacent structure dictate the prognosis of the disease. Adjuvant chemotherapy and radiotherapy are not regarded as standard therapies for resectable retroperitoneal liposarcoma, although further research is still needed to determine their value in the case of high-risk sarcoma.

Conclusion

Retroperitoneal liposarcoma has the potential to present as huge asymptomatic masses which with an added predilection for recurrence poses a huge challenge to any surgeon.

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Due to lack of early signs, retroperitoneal liposarcoma is challenging to diagnose.

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Surgery is the standard treatment, with repeat surgery required to treat recurrence.

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The common cause of treatment failure is local recurrence from the residual tumor.

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Efficacy of chemotherapy and radiotherapy is still controversial.

Updates in Pathology for Retroperitoneal Soft Tissue Sarcoma

Retroperitoneal tumors are extremely rare. More than 70% of primary retroperitoneal soft tissue tumors are malignant. The most common sarcomas in the retroperitoneum include liposarcomas and leiomyosarcoma, however other sarcomas, along with benign mesenchymal tumors, can occur. Sarcomas are a heterogenous group of tumors with overlapping microscopic features, posing a diagnostic challenge for the pathologist. Correct tumor classification has become important for prognostication and the evolving targeted therapies for sarcoma subtypes. In this review, the pathology of retroperitoneal soft tissue sarcomas is discussed, which is important to the surgical oncologist. In addition, less common sarcomas and benign mesenchymal tumors of the retroperitoneum, which may mimic sarcoma clinically and pathologically, are also discussed.

Giant retroperitoneal liposarcoma treated with radical conservative surgery: A case report and review of literature

BACKGROUND

Retroperitoneal liposarcoma (RLPS) is a rare malignant tumor of the connective tissue and usually grows to a large size, undetected. Diagnosis is currently based on collective findings from clinical examinations and computed tomography (CT) and magnetic resonance imaging, the latter of which show a fat density mass and possible surrounding organ involvement. Surgical resection is the main therapeutic strategy. The efficacy and safety of further therapeutic choices, such as chemotherapy and radiotherapy, are still controversial.

CASE SUMMARY

A 61-year-old man presented with complaint of a large left inguinal mass that had appeared suddenly, after a slight exertion. Ultrasonography revealed an omental inguinal hernia. During further clinical examination, an enormous palpable abdominal mass, continuing from the left inguinal location, was observed. CT revealed a giant RLPS, with remarkable mass effect and wide visceral dislocation. After multidisciplinary consultation, surgical intervention was performed. Subsequent neoadjuvant chemotherapy and radiotherapy were precluded by the mass’ large size and retroperitoneal localization, features typically associated with non-response to these types of treatment. Instead, the patient underwent conservative treatment via radical surgical excision. After 1 year, his clinical condition remained good, with no radiological signs of recurrence.

CONCLUSION

Conservative treatment via surgery resulted in a successful outcome for a large RLPS.

Effects of marital status on survival of retroperitoneal liposarcomas stratified by age and sex: A population-based study

BACKGROUND

Previous studies have shown that marital status is associated with survival in patients with a variety of cancer types, including lung cancer, prostate cancer, and bladder cancer. However, to date, the impact of marital status on the survival of patients with retroperitoneal liposarcomas (RPLs) has not been established.

METHODS

A total of 1211 eligible patients diagnosed with RPLs were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The relationships between marital status and survival in patients with RPLs were assessed. Patients were stratified by age to determine whether an association exists between marital status and age. We also probed the association between marital status and survival in males and females.

RESULTS

Our findings suggest that divorced, separated, or widowed patients have more advanced cancer stages, and more of these patients do not undergo surgery. Meanwhile, divorced, separated, or widowed patients have worse survival outcomes than married patients (overall survival (OS): HR = 1.66 (95% CI, 1.12, 2.46)); cancer-specific survival (CSS): HR = 1.90 (95% CI, 1.13, 3.19)). OS does not differ between single patients and married patients (HR = 1.21 [95% CI, 0.81, 1.81]) or CSS (HR = 1.36 [95% CI, 0.80, 2.29]). In addition, these results demonstrate that being divorced, separated, or widowed can play a significant detrimental role in mortality in older and female patients.

CONCLUSION

Married patients have earlier disease stages at diagnosis and better survival outcomes than divorced, separated, or widowed patients with RPLs. In addition, this effect is especially pronounced in older people and females.

Development and Validation of a Prognostic Model to Predict the Prognosis of Patients With Retroperitoneal Liposarcoma: A Large International Population-Based Cohort Study

Background

Retroperitoneal liposarcomas (RPLs), sarcoma of mesenchymal origin, are the most common soft tissue sarcomas (STS) of the retroperitoneum. Given the rarity of RPLs, the prognostic values of clinicopathological features in the patients remain unclear. The nomogram can provide a visual interface to aid in calculating the predicted probability that a patient will achieve a particular clinical endpoint and communication with patients.

Methods

We included a total of 1,392 RPLs patients diagnosed between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. For nomogram construction and validation, patients in the SEER database were divided randomly into the training cohort and internal validation cohort at a ratio of 7:3, while 65 patients with RPLs from our center between 2010 and 2016 served as the external validation cohort. The OS curves were drawn using the Kaplan-Meier method and assessed using the log-rank test. Moreover, Fine and Gray's competing-risk regression models were conducted to assess CSS. Univariate and multivariate analyses were performed to select the prognostic factors for survival time. We constructed a predictive nomogram based on the results of the multivariate analyses.

Results

Through univariate and multivariate analyses, it is found that age, histological grade, classification, SEER stage, surgery constitute significant risk factors for OS, and age, classification, SEER stage, AJCC M stage, surgery, and tumor size constitute risk factors for CSS. We found that the nomogram provided a good assessment of OS and CSS at 1, 3, and 5 years in patients with RPLs (1-year OS: (training cohort: AUC = 0.755 (95% CI, 0.714, 0.796); internal validation cohort: AUC = 0.754 (95% CI, 0.681, 0.827); external validation cohort: AUC = 0.793 (95% CI, 0.651, 0.935)); 3-year OS: (training cohort: AUC = 0.782 (95% CI, 0.752, 0.811); internal validation cohort: AUC = 0.788 (95% CI, 0.736, 0.841); external validation cohort: AUC = 0.863 (95% CI, 0.773, 0.954)); 5-year OS: (training cohort: AUC = 0.780 (95% CI, 0.752, 0.808); internal validation cohort: AUC = 0.783 (95% CI, 0.732, 0.834); external validation cohort: AUC = 0.854 (95% CI, 0.762, 0.945)); 1-year CSS: (training cohort: AUC = 0.769 (95% CI, 0.717, 0.821); internal validation cohort: AUC = 0.753 (95% CI, 0.668, 0.838); external validation cohort: AUC = 0.799 (95% CI, 0.616, 0.981)); 3-year CSS: (training cohort: AUC = 0.777 (95% CI, 0.742, 0.811); internal validation cohort: AUC = 0.787 (95% CI, 0.726, 0.849); external validation cohort: AUC = 0.808 (95% CI, 0.673, 0.943)); 5-year CSS: (training cohort: AUC = 0.773 (95% CI, 0.741, 0.805); internal validation cohort: AUC = 0.768 (95% CI, 0.709, 0.827); external validation cohort: AUC = 0.829 (95% CI, 0.712, 0.945))). The calibration plots for the training, internal validation, and external validation cohorts at 1-, 3-, and 5-year OS and CSS indicated that the predicted survival rates closely correspond to the actual survival rates.

Conclusion

We constructed and externally validated an unprecedented nomogram prognostic model for patients with RPLs. The nomogram can be used as a potential, objective, and supplementary tool for clinicians to predict the prognosis of RPLs patients around the world.

Giant Retroperitoneal Mass: Case Report in a Primary Hospital and Review of the Literature

Retroperitoneal liposarcoma (RPLS) is a rare form of cancer that mostly affects adults. Symptoms may be undetected unless the tumor begins to grow. Diagnosis is made when the tumor is large and puts vital organs such as the pancreas, liver, kidneys at risk. Symptoms of a liposarcoma depend on tumor location. Liposarcoma in the arms, legs, particularly thighs may be painful, swollen, with patients citing weakness in the affected area; 15% of soft tissue sarcomas are retroperitoneal, with two of the most common types being the well-differentiated liposarcoma (WDLPS) and high-grade dedifferentiated liposarcoma (DDLPS). The tumor can weigh between 15 kg and 20 kg, with 20 to 25 cm in diameter (4). Surgery is the main form of treatment provided along with adjuvant therapies. We present the case of a 60-year-old woman who was referred to the Emergency Department with acute onset of abdominal distension, nausea, vomiting, right back pain, lipothymia and a giant abdominal mass.

Prognostic Factor Analysis and Nomogram Construction of Primary Retroperitoneal Liposarcoma: A Review of 10 Years of Treatment Experience in a Single Asian Cohort of 211 Cases

Objective

This study intended to retrospectively analyze the data of patients with primary retroperitoneal liposarcoma in a single Asian large-volume sarcoma center and to establish nomograms focused on PRLPS for predicting progression-free survival (PFS) and overall survival (OS).

Methods

A total of 211 patients treated surgically for primary, non-metastatic retroperitoneal liposarcoma during 2009–2021 were identified, and clinicopathologic variables were analyzed. PFS and OS nomograms were built based on variables selected by multivariable analysis. The discriminative and predictive ability of the nomogram was assessed by concordance index and calibration curve.

Results

The median follow-up time was 25 months. A total of 117 (56%) were well-differentiated, 78 (37%) were dedifferentiated, 13 (6%) were myxoid, and 3 (1%) were pleomorphic morphology. Compared to the western population cohort reported by the Memorial Sloan-Kettering Cancer Center, the median age of patients in this cohort was younger (57 vs. 63 years), the tumor burden was lower (20 vs. 26 cm), and the proportion of patients with R0 or R1 resection was higher (97% vs. 81%). The 5-year PFS rate was 49%, and factors independently associated with PFS were symptoms at visit, preoperative needle biopsy, histologic subtypes, and postoperative hospital stay. The 5-year OS rate was 72%. American Society of Anesthesiologists Physical Status and Clavien-Dindo classification were independently associated with OS. The concordance indexes for PFS and OS nomograms were 0.702 and 0.757, respectively. The calibration plots were excellent.

Conclusions

The proposed nomogram provided a favorable reference for the treatment of primary retroperitoneal liposarcoma patients.