Retroperitoneal dedifferentiated liposarcoma: Analysis of 61 cases from a large institution

Survival and prognostic factors among different types of liposarcomas based on SEER database

The aim of this study is to elucidate the disparities in survival and risk factors among different subtypes of liposarcoma, through analysis of epidemiological and prognostic data. The study cohort consisted of 12,822 patients diagnosed with liposarcoma in the United States between 2000 and 2021, whose data were retrieved from the Surveillance, Epidemiology, and End Results (SEER) program. The prognosis for different subtypes of liposarcoma and the associated factors such as age, tumor stage, intervention, gender, tumor grade, location, size, chemotherapy and radiotherapy, were retrieved from the database. Well-differentiated liposarcoma demonstrated the most favorable prognosis, with 5-year and 10-year survival rates of 82% and 68%, respectively, followed by myxoid liposarcoma, pleomorphic liposarcoma and dedifferentiated liposarcoma, which exhibited the poorest prognosis. Advanced age, higher tumor stage, and the absence of surgical intervention were associated with inferior survival outcomes across all subtypes. Male gender, higher pathological grade, and primary tumor sites outside the extremities were identified as risk factors for the prognosis of subtypes other than pleomorphic liposarcoma. Larger tumor size was an indicator of a worse prognosis in subtypes other than well-differentiated liposarcoma. Chemotherapy was a risk factor for the prognosis of well-differentiated and myxoid liposarcomas but had no significant correlation with the prognosis of pleomorphic and dedifferentiated liposarcomas. Radiotherapy served as a protective factor for the prognosis of subtypes other than well-differentiated liposarcoma. Survival and prognostic factors vary among the major subtypes of liposarcoma, necessitating individualized analysis for each subtype. Poorer outcomes can be anticipated in the dedifferentiated and pleomorphic subtypes, while well-differentiated and myxoid liposarcomas exhibit relatively favorable prognoses.

A preliminary study of primary retroperitoneal sarcoma at a tertiary University Hospital in Bangkok, Thailand: a retrospective observational study

Background

Retroperitoneal sarcoma (RPS) is rare and difficult to treat with a high recurrent rate. Very little data regarding primary RPS exists in Thailand.

Objectives

To study the outcome of treatment of primary RPS at a tertiary University Hospital in Bangkok, Thailand.

Methods

All patients who had RPS undergoing the first surgical resection at King Chulalongkorn Memorial Hospital from June 2003 to December 2019 were retrospectively enrolled in the study. Perioperative management, results of treatment, postoperative complications, and outcome were analyzed.

Results

Thirty-eight patients entered the study. Large abdominal mass was the most common presentation (90%). Liposarcoma was the most common histology (58%). Twenty patients (53%) had preoperative core needle biopsy and 21 (55%) underwent preoperative radiotherapy (RT). The tumor size ranged from 3 cm to 48 cm (median 22 cm). Five patients (13%) had total mass removal only while 33 (87%) had complete gross resection with ≥1 visceral organ resection. Surgical margins classified as R0, R1, and R2 were 61%, 34%, and 5%, respectively. Five patients (16%) had postoperative complications. There was no 30-day postoperative mortality. The local recurrence rate was 34%. Survival analysis revealed a 5-year overall survival rate of 37% and 5-year disease-free survival rate of 29%. The 5-year and 10-year recurrent rates were 71% and 95%, respectively. Multivariate analysis showed that preoperative radiation was the only factor reducing recurrence (19% vs. 53%, OR: 0.21, P = 0.011).

Conclusion

The preliminary study of outcome of the treatment of primary RPS at our institution showed a fair prognosis of this rare malignancy despite our aggressive surgical approaches. Preoperative radiation may help reduce recurrence in selected primary RPS patients.

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

BACKGROUND

Retroperitoneal liposarcoma (RPLPS) is a relatively rare disease. Liposarcomas vary in size, but sizeable RPLPS larger than 30 cm in diameter are very rare, and their diagnosis and treatment present significant challenges.

CASE PRESENTATION

We report a 58-year-old male patient who was admitted to the hospital with an increased abdominal circumference and was later diagnosed with a giant RPLPS. The liposarcoma was found to adhere to the right kidney and the entire ureter, invading the ascending colon. The patient underwent complete combined surgical resection. The tumor was removed intact, measured 55.0 cm × 30.0 cm × 18.0 cm, and weighed 19.8 kg. Histopathologic analysis revealed well-differentiated liposarcoma (WDLPS). The patient was successfully discharged from the hospital and followed up for 6 months with no signs of recurrence.

CONCLUSION

RPLPS is a rare tumor with atypical clinical presentation. Surgery remains the most effective method of treatment for retroperitoneal sarcomas, with complete removal if there is local invasion. Preoperative examination, including three-dimensional (3D) reconstruction, is essential for surgical success. The role of adjuvant radiotherapy or chemotherapy remains controversial. However, clinicians should not rule them out as viable options.

The association between CD34 expression status and the clinicopathological behavior of dedifferentiated liposarcoma

Lipogenic and fibrous tumors are thought to originate from CD34-positive stromal fibroblastic/fibrocystic cells. Well-differentiated lipogenic tumors typically express CD34, whereas dedifferentiated liposarcoma (DDLPS) often loses it. We conducted survival analyses involving 59 patients with DDLPS. Males comprised 53% of the cohort, and the median age at the time of wide resection of primary DDLPS was 60 years. Loss of CD34 expression was defined as when ≥50% of the dedifferentiated area was immunohistochemically negative for CD34. As a result, 39 of the 59 patients showed loss of CD34 expression during the initial operation for DDLPS. In the univariate analyses, the tumor site in the retroperitoneum/abdominal cavity and loss of CD34 expression were significantly associated with poor overall survival. In the multivariate analyses, loss of CD34 expression (HR = 2.26; 95% CI = 1.02-5.02; p = 0.04) and the tumor site in the retroperitoneum/abdominal cavity (HR = 3.11; 95% CI = 1.09-8.86; p = 0.03) were retained as independent prognostic factors. Six CD34-positive cases lost CD34 expression when they developed metastasis and/or local recurrence, suggesting that the loss was associated with the later stage of the tumor. Therefore, an association existed between the loss of CD34 expression and clinicopathological behaviors such as poorer prognoses and recurrence.

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

RATIONALE

Retroperitoneal dedifferentiated liposarcoma (RPDDL) is an uncommon malignancy, which often remains undetected for many years due to having adequate space in the retroperitoneal cavity and lacking clinical manifestations in the early stage of the disease. Surgical procedure is usually used as the first choice for treatment. However, it is prone to local recurrence after the operation, resulting in an unfavorable prognosis. Our aim is to draw useful lessons from the new case and provide some experience for management of the disease.

PATIENT CONCERNS

We describe a 55-year-old male patient who was admitted for a 3-week history of persistent dull ache of the left waist. A large mass of the left upper abdomen was palpated in physical examination. Moreover, the imaging examination revealed that the diameter of the mass was about 21 cm, and some adjacent vital organs were invaded, which brought great challenges to complete surgical resection.

DIAGNOSIS

The postoperative pathological results confirmed that the mass was RPDDL with invasion of the surrounding vital structures including pancreas, spleen, left adrenal gland, left kidney, and vasculature with tumor emboli.

INTERVENTIONS

Surgical resection of the mass was performed by our multidisciplinary team. The patient received chemotherapy 1 month after surgery.

OUTCOMES

The effect of chemotherapy seemed to be unsatisfactory. Local multifocal recurrence of the tumor was considered about 2 months after surgery. Finally, he gave up any treatments and died of the disease.

LESSONS

Regular physical examination and ultrasound screening may detect the disease as early as possible, especially for high-risk group aged 60 to 70, which should be popularized. Incomplete resection, vascular invasion, and interruption of postoperative treatment may lead to an unfavorable prognosis. Therefore, we think that patients with the disease may benefit from complete surgical resection and uninterrupted adjuvant therapy.

A large dedifferentiated retroperitoneal liposarcoma extended to the testis: a rare case report

Liposarcomas are neoplasms of mesodermal origin representing less than 1% of all malignant tumors and 1 to 2% of urogenital lesions. Primary retroperitoneal liposarcomas extending into the inguinal canal are rare. We present the case of a large retroperitoneal liposarcoma invading the left testicle and its spermatic cord. It was diagnosed by imaging as a large mass that compresses surrounding abdominal structures and communicating with the inguinal canal. A surgical intervention consisting of en bloc resection of the tumor and the left testicle with its cord was performed by 2 routes, intercostal and inguinal. Histology showed a dedifferentiated liposarcoma, which is a rare entity with a high rate of malignancy and a poor prognosis. The treatment of choice is wide surgical resection with clear margins; chemotherapy and radiotherapy are less sensitive. The patient did not manifest any particular complaints during the first six months after surgery.

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.

A Rare Case of Dedifferentiated Retroperitoneal Liposarcoma Presenting As Cardiac-Sounding Chest Pain

Retroperitoneal liposarcomas (RPL) are rare mesenchymal tumours with an annual incidence of 2.7 cases per million. Well-differentiated liposarcomas (WDLs) and dedifferentiated liposarcomas (DDLs) are the most common subtype. WDLs are widely known to be low-grade tumours that are less likely to metastasise and easily resected. In contrast, DDLs are high-grade aggressive metastatic tumours with mortality rates between 50% and 70%.

We present an unusual case of a 47-year-old male with a background of hypertension presenting with cardiac-sounding chest pain. Initially managed as an acute coronary syndrome (ACS), he eventually underwent a CT scan which revealed a 20x18x17cm retroperitoneal complex mass with possible infiltrates to the posterior wall of the greater curvature of the stomach. Ultrasound-guided biopsy and subsequent histopathology analysis revealed DDL consistent with MDM2 amplification.

This case highlights how RPL can present with diagnostic difficulties. Multidisciplinary input from haematology, surgery and specialist teams is vital to optimise patient management.

Surgical Diagnosis and Treatment of Primary Retroperitoneal Liposarcoma

Background: Primary retroperitoneal liposarcoma (PRPLS) is the most common soft tissue sarcoma of the retroperitoneum with high recurrence rate and short overall survival (OS).

Methods: A retrospective review of 51 patients with PRPLS, treated between September 1, 2009 and November 30, 2020, was conducted to evaluate clinical outcomes of PRPLS resection. Patient demographics, histopathologic subtypes, overall survival (OS), progression-free survival (PFS), disease recurrence rate, and tumor stage were reviewed and analyzed. Univariate analysis was done to identify factors potentially affecting OS and PFS of PRPLS patients. Multivariate Cox proportional hazards analysis was used to evaluate the impact of various clinicopathological factors on OS and PFS of PRPLS patients.

Results: Fifty-one PRPLS patients (28 Males, 23 Females; mean age 56.25 years) were evaluated. There was no significant effect of age, gender, contiguous organ resection, degree of differentiation and tumor size on the OS and PFS of the patients. Univariate analysis showed that negative surgical margin and early tumor stage significantly correlated with OS and PFS (all P < 0.001). Multivariate analysis showed that tumor stage [hazard ratio (HR) = 1.177, P = 0.001] was an independent predictors of poor progression-free survival, and surgical margins [HR = 4.0674 P = 0.038] and tumor stage [HR = 1.167 P = 0.001] were identified as independent predictors of poor overall survival.

Conclusion: Negative surgical margin is a prognostic factor of OS, and can prolong the postoperative survival time of PRPLS patients. Tumor stage is a prognostic factor for OS and PFS, and can influence the survival of PRPLS patients. Earlier tumor stages of PRPLS are associated with significantly better outcomes.

Aggressive and frequent resection of recurrences in retroperitoneal sarcoma contributes to long-term survival

PURPOSE

Retroperitoneal sarcoma (RPS) is a rare tumor with a poor prognosis and is often undetected until it is significantly enlarged. While surgical resection remains the primary treatment, there is little research on its benefits, especially that concerning the reoperation of recurrent disease. This study investigated the impact of surgical procedures, especially reoperation of recurrent RPS, on prognosis.

METHODS

This retrospective study included 51 patients who underwent radical resection surgery (R0 status) for primary or recurrent RPS without distant metastasis. Patient outcomes and prognosis were defined in terms of the clinicopathologic factors and surgical techniques performed.

RESULTS

In all cases, the 5-year disease-free survival (DFS) rate was 28.2%, 5-year overall survival rate was 89.9%, and 5-year no residual liposarcoma rate was 54.3% after operation and re-reoperation. There was a statistically significant difference between the 5-year DFS rate and 5-year no residual liposarcoma rate due to frequent re-reoperation (p = 0.011). On univariate analysis of primary and recurrent lesions, the histological type and the number of organs involved were identified as statistically significant prognostic factors. Patients with well-differentiated liposarcomas had a statistically better prognosis than those with other cancer types (primary RPS, p = 0.028; recurrence, p = 0.024).

CONCLUSIONS

Aggressive and frequent resection of recurrent RPS with combined resection of adjacent organs contributes to long-term survival. The establishment of a surgical strategy for RPS will require a prospective study.

A Proposed Staging System for Improved Prognostication of MDM2-amplified Liposarcoma

Despite the release of anatomic site-specific staging systems for soft tissue sarcomas in the eighth edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual, the algorithms for sarcomas arising in the extremities/trunk and retroperitoneum differ only in the staging of lymph node metastasis. The retroperitoneum not only provides a larger potential space for tumor growth before the clinical presentation, but its anatomic complexities complicate surgical resection and adversely affect disease-free survival. Here, we propose a new staging system for MDM2-amplified liposarcomas (well-differentiated and dedifferentiated subtypes) that properly emphasizes retroperitoneal localization, degree of differentiation (histologic subtype), and presence of distant metastasis. A retrospective cohort of 4146 adult patients with surgically resected liposarcoma was extracted from the SEER database to compare the natural history of MDM2-amplified liposarcomas arising in the extremities/trunk or retroperitoneum. Separate training and validation datasets were created, and Cox proportional hazard regression, multivariable nonlinear regression, and nomographic analyses determined the most significant parameters in predicting sarcoma-specific death. A new staging system was derived and its predictive accuracy was compared with the AJCC, eighth edition system using areas under receiver operating characteristic curves and multiple concordance indices. Multivariable analysis showed that dedifferentiation (hazard ratio [HR]=3.7±0.5; P<0.0005), retroperitoneal location (HR=3.2±0.5; P<0.0005), and distant metastasis (HR=2.4±0.6; P=0.002), but not categorized tumor size (pT category), had the largest effects on sarcoma-specific survival. A new staging system based on these predictive factors demonstrated better discrimination between tumor stages, higher concordance with clinical outcomes, and greater predictive accuracy than the AJCC eighth edition staging system (86±1% vs. 83±2%; P=0.005). Statistical analysis of a large national cohort failed to confirm that categorized tumor size is a useful criterion by which to stage MDM2-amplified liposarcoma. A simplified staging system based on anatomic location and dedifferentiation outperforms the current AJCC staging system. Anatomic localization and histologic grade, and not tumor size, should be included in any future liposarcoma-specific staging system.

Resection outcomes for primary and local recurrent retroperitoneal liposarcoma patients

Background

The clinical characteristics of primary retroperitoneal liposarcoma (PR RPLPS) and local recurrent retroperitoneal liposarcoma (LR RPLPS) cases were compared to determine the related factors involved in postoperative survival.

Methods

A total of 90 patients who underwent surgery between 2006 and 2013 were included in this study. Clinicopathological data that was prospectively gathered was analyzed to identify factors associated with overall survival (OS) and progression-free survival (PFS).

Results

The PR cases showed a higher complete resection rate when compared to the LR group. The LR group showed a greater number that were poorly differentiated and highly malignant. More blood loss was observed in the LR compared to the PR group. Multivariate analysis suggested that blood loss and tumor grade were prognostic factors for OS and PFS of the PR group, but extent of resection was a prognostic factor only for OS. In the LR group, the extent of resection was a significant prognostic factor associated with OS, whereas tumor grade was associated with PFS.

Conclusions

Complete surgical resection is the most important factor for the survival of RPLPS patients. Tumor grade is an independent prognostic factor for PFS. In PR RPLPS, poor tumor classification and increased intraoperative bleeding are associated with a poor prognosis.

Outcome of patients with primary retroperitoneal solitary fibrous sarcoma

BACKGROUND

To describe the clinicopathological features of primary retroperitoneal solitary fibrous tumor (RSFT) and define the prognostic factors.

METHODS

The comprehensive data of 35 primary RSFT patients who got curative surgery at a tertiary cancer center from April 2004 to October 2018 were retrospectively analyzed.

RESULTS

Male patients outnumbered female patients (19 vs. 16), with the age ranging from 19 to 73 years (median, 51 years). 7 (20%) patients had tumors located in special parts, including three in kidney, one in renal pelvis, one in bladder, one in prostate, and one in mesentery. Tumor sizes ranged from 2.5 to 25 cm (median, 9 cm). Microscopic negative margin was reached in 33 (94.3%) cases. 13 (37.1%) were classified as atypical/malignant, while 22 (62.9%) were benign. Concomitant organ excision was performed on 11 (31.4%) patients, with kidney (n = 5) being the most frequent organ. Multifocality was only found in 4 (11.4%) cases. The majority of the patients (31, 88.6%) did not get adjuvant treatment. The median follow-up time was 46 months (range 4-153 months). The 5-year DSS rate and DFS rate were 100% and 63.6%, respectively. In univariate analysis, tumor size ≥ 10 cm (P = 0.002) and atypical/malignant pathology (P = 0.024) were associated with decreased DFS. Multivariate analysis revealed that tumor size was the only independent prognostic factor for DFS (HR 6.03, 95% CI 1.18-30.77, P = 0.031).

CONCLUSION

RSFT is uncommon, slow-growing, and recrudescent tumors. Large tumor size and malignant pathology are associated with decreased DFS. Tumor size ≥ 10 cm independently predicts shortened DFS.

A Multi-Modality Treatment of Retroperitoneal De-Differentiated Liposarcoma

BACKGROUND Retroperitoneal sarcomas are rare tumors, only affecting 2 to 5 people per million population and accounting for 0.1% of all malignancies. Liposarcoma is the most common of all retroperitoneal sarcomas, responsible for approximately 20% of all sarcomas in adults. The most important prognostic factors are tumor grade, the presence of positive margins, tumor integrity, and degree of resection. CASE REPORT Our patient was a 73-year-old man with abdominal pain whose CT scan of the abdomen and pelvis demonstrated a 15×15 cm heterogeneous, left-sided intra-abdominal mass. He underwent resection of the retroperitoneal tumor, left colectomy, and left nephrectomy. Final pathology demonstrated a high-grade, de-differentiated liposarcoma with a rhabdosarcomatous component. The postoperative course was complicated by a small intra-abdominal abscess and abdominal dehiscence. a CT scan after surgery showed a residual tumor of the retroperitoneal posterior margin. Re-exploration to resect the residual tumor and repair the fascial dehiscence were performed. The patient underwent an initial chemotherapy regimen with doxorubicin, then moved to targeted therapy with Palbociclib, and is now on chemotherapy using Eribulin. CONCLUSIONS Achieving complete resection and the grade of the tumor at diagnosis are the 2 most important prognostic factors for patient survival in retroperitoneal liposarcoma, as survival rates are inversely proportional to the grade of the tumor. Even with the best resection attempts, there is always a risk of residual tumor cells within the tumor bed, which contribute to recurrence and need for additional surgical interventions. It is important to approach this disease process with a multidisciplinary team that includes surgical, medical, and radiation oncology to ensure the best survival outcomes. Retroperitoneal sarcoma recurrence and survival are directly related to the ability to achieve negative margins of resection, as well as the grade and size of the primary tumor. Adjuvant therapies that include radiation and immunotherapy may be effective in treating recurrent disease.

Unusual subcutaneous dedifferentiated liposarcoma exhibiting coexistence of meningothelial-like whorls and inflammatory myofibroblastic tumor-like structures

To explore the clinicopathological features of a rare dedifferentiated liposarcoma (DDLPS) with meningothelial-like whorls, we retrospectively analyzed 46 reported cases and 1 case that we encountered. Fluorescence in situ hybridization (FISH) analysis of the MDM2 amplification status of our case was also performed. Our case involved a 73-year-old male patient who had a mass in the upper part of his left arm for 10 years and was treated by surgical ablation of the tumor because of the mass' recent rapid enlargement. Microscopically, the tumor tissues showed coexistence of well-differentiated and dedifferentiated components, the latter of which included meningothelial-like whorls and inflammatory myofibroblastic tumor-like structures. The dedifferentiated components diffusely expressed vimentin, MDM2, CDK4, p16, and smooth muscle actin. They were also focally positive for desmin but negative for S-100, CD117, CD34, ALK, EMA, SOX-10, p53, and β-catenin. FISH detection showed MDM2 amplification. In conclusion, subcutaneous DDLPS with meningothelial-like whorls and inflammatory myofibroblastic tumor-like features is rare. This case broadens the histopathological lineage of DDLPS, and confirms DDLPS with myogenic differentiation. The use of the combination of MDM2, CDK4, p16, and FISH to detect MDM2 amplification is a reliable basis for the diagnosis of DDLPS with meningothelial-like whorls.

Dedifferentiated retroperitoneal large liposarcoma and laparoscopic treatment: Is it possible and safe? The first literature case report

INTRODUCTION

Soft tissue sarcomas are rare neoplasms often characterized by local invasiveness and distant metastasis with poor prognosis for affected patients. Among the most frequent sarcomas we find well-differentiated and dedifferentiated liposarcomas characterized by a better survival compared to the other histological types. When it is possible the only curative treatment for these neoplasms is surgical resection.

CASE REPORT

We report a case of a 62-year-old caucasian woman with CT abdominal scan that demonstrated a voluminous solid oval mass in the left perirenal space with dislocation of the kidney and in continuity with the anterior renal fascia. After a percutaneous CT-guided biopsy of the mass the histopathological diagnosis was a dedifferentiated retroperitoneal liposarcoma. We performed a laparoscopic surgical resection of the retroperitoneal mass in block with kidney and left adrenal gland.

DISCUSSION

When possible, surgical resection with adequate margins represents the only curative therapeutic option for this pathology. Only a few papers are available in literature which take into consideration the possibility of laparoscopic approach for retroperitoneal masses with better vision of surgical field, reduction of post-operative pain and better cosmesis.

CONCLUSION

A retroperitoneal mass represents a serious diagnostic challenge. The choice of the best surgical procedure can benefit to the patient prognosis. To our opinion laparoscopy can be a safe and successful treatment and it can represent a valid alternative to open surgery. However, we have no randomized controlled trials that compare laparoscopic versus open resection for retroperitoneal liposarcomas.