Retroperitoneal liposarcoma: current insights in diagnosis and treatment

Retroperitoneal liposarcoma in older person - a rare case report

Retroperitoneal sarcoma is relatively uncommon, constituting only 10-15 percent of all soft tissue sarcomas. The most common histologic types of RPS are liposarcoma and leiomyosarcoma. Retroperitoneal sarcoma is classified based on the amount of lipid inside the cells, the mucoid lipid and the degree of cell differentiation. It is classified into the well-differentiated, myxoid, round cell, pleomorphic and dedifferentiated types and the commonest is the pleomorphic type. Dedifferentiated liposarcomas are defined by the presence of sharply demarcated regions of non-lipogenic sarcomatous tissue within a well-differentiated tumor. This type has a vague prognosis compared to other types of sarcoma and making the histological diagnosis can be difficult. Dedifferentiated liposarcoma commonly develops in the retroperitoneum, limbs, testis, and spermatic cord. Retro peritoneal sarcoma typically produces few symptoms until they are large enough to compress or invade surrounding structures. Most tumors are already large and locally advanced at the time they are first detected. Here, we reported a case that came to medical attention as an incidentally discovered large abdominal mass in an asymptomatic or minimally symptomatic, later the mass was successfully removed and free from symptoms.

Clinical features of multiply recurrent retroperitoneal liposarcoma: A single-center experience

BACKGROUND

To elucidate the clinicopathological features of multiply recurrent retroperitoneal liposarcoma referred to a tertiary center.

METHODS

We retrospectively analyzed the clinical data of 40 patients with pathologically proven primary retroperitoneal liposarcoma treated between January 2015 and June 2019.

RESULTS

The initial pathology was well-differentiated liposarcoma (WDLS) in 23 patients, dedifferentiated liposarcoma (DDLS) in 15 patients, and myxoid liposarcoma in two patients. Before and after referral to our hospital, the patients underwent 142 surgeries (median number of surgeries: 3) for initial and recurrent tumors. Of these, 35 (87.5%) patients underwent surgeries for recurrent tumors. In 11 (47.8%) of the 23 patients with initial WDLS, pathological progression (PP) to DDLS was observed in recurrent tumors at the median interval of 7.8 years. In eight patients (72.7%), the PP occurred at the first recurrence. In contrast, all 15 patients with DDLS recurred as DDLS. Distant metastases developed in eight patients (34.8%) with WDLS and five patients (29.4%) with DDLS/myxoid subtype. All eight WDLS patients who developed metastasis were alive with disease at the median interval of 3.6 years, whereas four of the five patients with primary diagnosis of DDLS/myxoid subtype died at the median interval of 5.6 months from the development of metastasis. The 5-year overall survival of the patients with initial WDLS and those with DDLS/myxoid subtype were 100% and 67.4% (p = 0.0006), respectively.

CONCLUSIONS

The prognosis of the initial-WDLS patients was favorable despite multiple recurrences. In WDLS patients, if distant metastases develop, it is possible to remain alive with disease for years.

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.

Concurrent minimal change disease and retroperitoneal liposarcoma successfully treated by tumor resection and steroid therapy

A 54-year-old Japanese woman developed simultaneous abdominal distension and bilateral leg edema. Her medical history and results of periodic medical check-up were unremarkable. Blood tests revealed severe hypoproteinemia and acute kidney injury, and urinalysis revealed 4+ proteinuria and 2+ hematuria. Abdominal computed tomography revealed a large intra-abdominal mass with fat tissue density. She underwent emergency tumor excision, splenectomy, and distal pancreatectomy. However, hypoproteinemia and acute kidney injury worsened. Therefore, she was transferred to the nephrology division for confirmation of diagnosis and for treatment of acute kidney injury and nephrotic syndrome. We conducted percutaneous kidney biopsy and diagnosed minimal change disease (MCD). Intravenous prednisolone was started, and heavy proteinuria and systemic edema were gradually alleviated. She achieved complete remission 2 months later, and oral prednisolone was tapered. Histopathological diagnosis of abdominal tumor was dedifferentiated liposarcoma of retroperitoneal origin. Immunohistochemical staining revealed strong expression of vascular endothelial growth factor in the tumor cells in the dedifferentiated component. Currently, her clinical course is stable without recurrence of liposarcoma and nephrotic syndrome. MCD develops in patients with Hodgkin's lymphoma, solid organ cancers, hematological malignancies, and thymoma, whereas concurrent MCD and liposarcoma are rare. Remission of nephrotic syndrome and normalized kidney function induced by steroid therapy are important for better management of patients with malignancy.

Retrospective quality of life study in patients with retroperitoneal sarcoma in an Asian population

BACKGROUND

Retroperitoneal sarcoma represents 15% of sarcomas. The mainstay of treatment is surgery where a majority of patients require multi-visceral resections that may significantly impact their quality of life (QOL) following surgery. Studies in other cancers have shown that QOL may not be significantly impacted after radical or extensive surgery. However, there are limited studies examining the QOL specifically in patients with retroperitoneal sarcoma. In this pilot study, we retrospectively evaluated the QOL of patients with retroperitoneal sarcoma.

METHODS

32 out of 90 patients who underwent surgical intervention for retroperitoneal sarcoma in National Cancer Centre Singapore from January 1999 to August 2018 who were alive and on follow-up were included in this study. EORTC-QLQ-C30 was administered to the patients.

RESULTS

The median age of our patients was 59 years (range, 35-84), and median time from surgery to the implementation of questionnaire was 2.5 years (range, 0.05-9.6). Younger patients had significantly better differences in global health, physical and role functioning scores as compared to older individuals. Female patients reported higher global health, physical, emotional and social functioning scores than males. Patients who were more than 2 years post-surgery exhibited better QOL scores as compared to those who had more recent surgery. Our patients had comparable global health and functioning scores compared to a reference group of outpatient cancer patients at our institution.

CONCLUSIONS

Our pilot study investigating the QOL of patients with retroperitoneal sarcoma has shown that patients need to be followed up for at least 2 years following surgery to evaluate their QOL. In general, they achieved better functioning scores when compared with other cancer patients. These findings support the need for larger-scale prospective studies to further evaluate the QOL of these patients.

Perinephric myxoid pseudotumor of fat: A very rare entity that can mimic a renal cyst and retroperitoneal liposarcoma on imaging

We present a case of perinephric myxoid pseudotumor of fat, a rare benign entity that often occurs in patients with non-neoplastic renal disease. In our case, an 80 year old man with end-stage renal disease was imaged over the course of 5 years during evaluation for renal transplantation. Imaging identified a left perinephric mass whose appearance over time and on different imaging modalities variably suggested a simple cyst, cystic neoplasm, and liposarcoma. Contrast enhanced examination was necessary to discern the solid nature of this mass, and ultimately, tissue sampling with histopathologic evaluation and molecular testing were required to make the diagnosis of myxoid pseudotumor of fat and exclude the imaging mimics.

Retroperitoneal Sarcomas: Prognostic Factors and Outcomes of a Series of Patients Treated at a Single Institution

Retroperitoneal sarcomas (RPS) are rare heterogeneous tumors arising in the retroperitoneum with unique biological and behavioral patterns that are thought to be closely linked to histology. The aim of the study was to audit our results and analyze various clinico-pathological factors including surgical excision, histology, and their implications on the recurrences and survival outcomes in RPS. Retrospective analysis of patients treated at a tertiary referral center in India from March 2008 to July 2017 was performed. The clinico-pathological variables were analyzed for their association with tumor recurrence and survival with special emphasis on histological subtype. The primary outcome was overall survival (OS). One hundred consecutive patients operated for RPS were analyzed. Of these, 27 were operated for recurrent tumors. Liposarcomas (LPS) and leiomyosarcomas (LMS) constituted 50% (n = 50) and 30% (n = 30) of patients respectively. Complete tumor excision was achieved in 83%, with 43% patients undergoing adjacent organ resection. At a median follow-up of 25.3 months, the median disease-free survival (DFS) and overall survival (OS) were 30 months and 87.8 months respectively. On multivariate analysis, tumor grade was the only factor to significantly affect survival (p = 0.001 for DFS and 0.005 for OS). There was no difference in survival outcomes between infiltrative and adhesive tumors with respect to adjacent organ invasion (p = 0.361 for OS). Tumor grade remains an important prognostic factor affecting disease-free and overall survival in retroperitoneal sarcomas irrespective of tumor size, site, and histology.

Pelvic angiomyofibroblastoma: an unusual case report

Angiomyofibroblastoma is a rare mesenchymal benign tumor that frequently occurs in young- to middle-aged women, arising from the genital tract. There are many overlapping radiological and immunohistochemical features with other stromal cell lesions, making the diagnosis difficult. We report here a case of a 29-year-old woman admitted for a pelvic mass, in whom, the histopathological and immunohistochemical studies led to the diagnosis of angiomyofibroblastoma.

Soft Tissue Tumors of the Abdomen and Retroperitoneum

Soft tissue tumors of the abdomen and retroperitoneum encompass a wide range of benign and malignant neoplasms. Retroperitoneal sarcomas, the most common, are composed of rare malignancies with numerous histiotypes. Surgery remains the cornerstone of treatment and the only curative option for retroperitoneal sarcomas. With histiotype-dependent local and distant recurrences, it is imperative these cases are discussed in a multidisciplinary tumor board setting at specialized sarcoma centers. This review discusses the current evidence for the management of abdominal and retroperitoneal soft tissue tumors, with particular focus on retroperitoneal sarcomas and desmoid tumors.

Non-adrenal tumors of the adrenal area; what are the pitfalls?

Discovery of an adrenal mass is nowadays a frequent situation. While adrenal tumors can cause a variety of symptoms, more often than not they are diagnosed incidentally on imaging exams such as CT-scan or MRI performed for another purpose. However, any retroperitoneal supra-renal mass can have an extra-adrenal origin. Indeed, operated non-adrenal masses initially but wrongly diagnosed as an adrenal disease represent about 3.5% of adrenalectomies. These differential diagnoses principally include retroperitoneal tumors that are malignant in two thirds of cases (lymphomas, sarcomas, neurogenic or germinal tumors), and more rarely vascular anomalies or congenital malformations, which are most frequently left-sided due to the wide variety of anatomical structures surrounding the left adrenal gland. Several lesions can originate from the adrenal gland or be located near the gland (paraganglioma, ganglioneuroma). Even though unilateral adrenalectomy is associated with low morbidity, ignorance of these differential diagnoses can cause ill-adapted management; overly conservative surgery in case of sarcoma is one example. Some of these lesions have characteristic clinical or imaging features (cystic lymphangioma, angiomyolipoma…). In other cases, assessment of hormonal secretion is required and additional exams (MRI, percutaneous biopsy, PET-scan with 18-Fluorodeoxyglucose) can correct an erroneous diagnosis. The above diagnostic approach allows appropriate management (with or without surgery). The purpose of this review was to highlight the main differential diagnoses of adrenal masses, to describe their characteristics, and to discuss their therapeutic management.

The Role of Tc-99m DTPA Renal Dynamic Scintigraphy in Retroperitoneal Liposarcoma

Purpose

Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) renal dynamic scintigraphy is a widely used imaging technique that evaluates renal function of patients with extrarenal abnormalities, but its clinical value in potentially offering us information on proliferation of liposarcoma has not yet been reported.

Methods

We retrospectively reviewed 7 patients with histopathologically confirmed retroperitoneal liposarcoma who underwent Tc-99m DTPA renal dynamic scintigraphy. The clinical data, histopathological findings, Glomerular Filtration Rate (GFR), and Tc-99m DTPA uptake were recorded.

Results

Dedifferentiated liposarcoma and well-differentiated liposarcoma showed dissimilar degrees of Tc-99m DTPA uptake, an observation that correlated with Ki-67 expression (p < 0.01). 4 of the 7 patients were diagnosed with dedifferentiated liposarcoma, showing a moderate uptake of Tc-99m DTPA and greater than 20% Ki-67 expression on histological slides. Meanwhile, the remaining 3 patients, diagnosed with well-differentiated liposarcoma, showed no uptake of Tc-99m DTPA and Ki-67 expression of less than 5%.

Conclusions

This study suggests that Tc-99m DTPA renal dynamic scintigraphy provides diagnostic value in patients with retroperitoneal liposarcoma, not only in evaluating renal function but also in visualizing lesion-related radionuclide uptake, which may potentially offer further clinical insights into tumor proliferation and provide prognostic value for clinical outcomes in patients with retroperitoneal liposarcoma.

Giant retroperitoneal liposarcoma: A case report and literature review

Retroperitoneal liposarcomas are a heterogeneous group of mesenchymal tumours that have a wide spectrum of histological subtypes and vague clinical presentations. Herein, we present the case of a 75-year-old man with anorexia, weight loss of 7 kg, and a growing abdominal circumference within a span of 6 weeks. Computed tomography of the abdomen and pelvis showed a large mass that filled almost the entire abdominal cavity. After consultation with a multidisciplinary tumour board, en bloc resection of the tumour was performed. In addition, the left kidney and a part of the left diaphragm were removed. The tumour measured 35 × 29 × 20.5 cm and weighed 11.6 kg. The histological report confirmed low-grade dedifferentiated liposarcoma with scarce atypical adipocytes, lipoblasts containing spindle cell, pleomorphic, and chondroid components. The patient had uneventful recovery and remained stable during the follow-up period. We report this case to highlight the need for customized surgical oncological measures in the treatment of solid abdominal tumours due to locoregional invasion that usually necessitates en bloc resection.

Giant atypical lipomatous tumor/well-differentiated liposarcoma affects lower limb activity: A case report

RATIONALE

Liposarcomas are locally invasive mesenchymal soft tissue tumors; most deep liposarcomas are large. Liposarcomas have heterogeneous histomorphology, molecular and genetic characteristics, and clinical prognosis, making the diagnosis and treatment of giant liposarcomas difficult for bone tumor surgeons.

PATIENT CONCERNS

A 70-year-old man presented with a mass in the posterior part of his left lower extremity that was first noticed 3 years prior. The mass was initially fist sized but continued to grow and had been affecting lower limb mobility on presentation.

DIAGNOSES

Computed tomography and magnetic resonance imaging revealed a large space-occupying lesion in the left thigh muscles, which was identified as a low-grade malignant tumor. Postoperative pathology results confirmed the diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS).

INTERVENTIONS

The patient underwent open surgery to completely remove the tumor tissue and relieve pain.

OUTCOMES

At the 10-month follow-up appointment, the patient had recovered well, function of the lower extremities had returned to normal, and no signs of recurrence or metastasis were noted.

LESSONS

Although ALT/WDLPS is a locally invasive tumor with good prognosis, delayed treatment is associated with increased tumor size, which can affect lower limb mobility. Therefore, we believe that extensive surgical resection of tumor tissue is a suitable treatment for all ALT/WDLPS cases in order to avoid possible local recurrence. In addition, for ALT/WDLPS tumors that are difficult to extensively excise, long-term follow-ups are necessary due to the possibility of recurrence.

Recurrent abdominal liposarcoma presenting with intestinal obstruction

Liposarcoma is the most common retroperitoneal sarcoma and mesenchymal tumor in the abdomen. Usually, it presents with vague symptoms due to its large size and slow growth at the time of diagnosis. Liposarcoma is associated with a high local recurrence rate according to its histology, size and growth rate. Up till now, surgical resection is the only effective treatment for primary and recurrent abdominal liposarcoma. Secondary mesenteric liposarcoma is an extremely rare entity and so far a small number of cases have been reported in the literature. In this article, we present a rare case of a 63-year-old female patient who was diagnosed with mesenteric liposarcoma after 3 years of complete excision of retroperitoneal liposarcoma, presenting primarily as abdominal mass causing mechanical intestinal obstruction.

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.

Primary retroperitoneal liposarcoma with extensive ossification: A case report

RATIONALE

Primary retroperitoneal liposarcoma, which originates from mesenchymal tissues, can rarely present with extensive ossification.

PATIENT CONCERNS

A 41-year-old male patient presented with a chief complaint of discomfort around the waist for 2 months.

DIAGNOSES

Computerized tomography (CT) and magnetic resonance imaging suggested a lesion of approximately 5.6 × 5.1 × 8.7 cm in front of the psoas major muscle, which was considered to be a mesenchymal or neurogenic tumor.

INTERVENTIONS

The hard mass was removed by laparotomy, and the pathological investigation revealed that this was an atypical lipomatous tumor/well-differentiated liposarcoma, with extensive ossification.

OUTCOMES

The patient was discharged from the hospital after surgery. There was no sign of reoccurrence after 1 year of follow-up.

LESSONS

Retroperitoneal liposarcomas with extensive ossification are rare tumors that can present with nonspecific symptoms, and are difficult to diagnose. CT is the most common imaging technique, and surgical resection has been considered to be the most effective treatment. This rare case can be challenging for diagnosis and treatment.

A contemporary review of myxoid adipocytic tumors

Myxoid adipocytic tumors encompass a broad heterogeneous group of benign and malignant adipocytic tumors, which are typically myxoid (e.g. myxoid liposarcoma, lipoblastoma and lipoblastoma-like tumor of the vulva) or may occasionally appear predominantly myxoid (e.g. pleomorphic liposarcoma, atypical lipomatous tumor, dedifferentiated liposarcoma, chondroid lipoma, spindle cell/pleomorphic lipoma, atypical spindle cell lipomatous tumor and atypical pleomorphic lipomatous tumor). There have been significant advances in recent years in classification and understanding the pathogenesis of adipocytic tumors, based on the correlation of histologic, immunohistochemical, and cytogenetic/molecular findings. Despite these advances, the morphologic diagnosis and accurate classification of a myxoid adipocytic tumor can be challenging due to major morphologic overlap between myxoid adipocytic and non-adipocytic tumors. This article will provide a review on the currently known morphological, immunohistochemical and molecular features of myxoid adipocytic tumors and their differential diagnosis.

Practical approach to primary retroperitoneal masses in adults

Primary retroperitoneal masses constitute a heterogeneous group of uncommon lesions and represent a challenge due to overlapping imaging findings. Most are malignant lesions. Although they are more prevalent in adults, they can occur at any age. Such lesions are classified as primary when they do not originate from a specific retroperitoneal organ and are divided, according to the image findings, into two major groups: solid and cystic. The clinical findings are nonspecific and vary depending on the location of the lesion in relation to adjacent structures, as well as on its behavior. The main imaging methods used for staging and surgical planning, as well as for selecting the biopsy site and guiding the biopsy procedure, are computed tomography and magnetic resonance imaging. In most cases, the treatment is challenging, because of the size of the lesions, vascular involvement, or involvement of adjacent organs. In this article, we present a review of the retroperitoneal anatomy and a practical approach to the main imaging features to be evaluated, with a view to the differential diagnosis, which can guide the clinical management.

Massive retroperitoneal dedifferentiated liposarcoma in a young patient

Liposarcomas are rare malignant tumors that mostly develop in the retroperitoneum. They have a broad behavioral spectrum, from small masses of tissue to highly aggressive tumors. The dedifferentiation process occurs in up to 10% and it's most likely to occur in the retroperitoneum, a process that not only changes its components but also its prognosis. These tumors can grow to a massive size since most of them do not give any symptoms until they invade the adjacent structures. Timely detection and surgery could avoid all these potentially lethal scenarios. We present a case of a 34-year-old patient, who reported a growing mass in her abdomen that reached massive proportions but remained untreated due to lack of sufficient access to healthcare facilities in her geographic location. After complete removal of the mass the patient underwent complete recovery, dedifferentiated liposarcoma was the final diagnosis.

Imaging appearance of well-differentiated liposarcomas with myxoid stroma

OBJECTIVE

Describe the imaging appearance of well-differentiated liposarcoma with myxoid stroma (WDLMS) and correlate with histopathology.

MATERIALS AND METHODS

A keyword search of the institution medical records was performed from 1 January 2000 to 30 June 2017. The histopathology slides of cases identified in this fashion were then reviewed by a pathologist. Additional cases were prospectively collected from extramural referrals and tumor boards. Diagnostic imaging studies of pathologically proven cases of WDLMS were then reviewed in consensus and correlated with pathology.

RESULTS

Ten cases of pathologically proven WDLMS were identified (7 men, 3 women, ages 26-81). Tumor location included the retroperitoneum (n = 5), thigh (n = 4), and the shin (n = 1). Nine patients had macroscopic fat on imaging. The nonlipomatous components had a variable appearance, including septal, nodular, and lacelike patterns. Two cases included two distinct areas that were predominantly myxoid or lipomatous ("bi-morphic"). One tumor had no macroscopic fat on imaging. On CT, the nonlipomatous nodular components were hypodense/had hypodense areas. On MRI, the nodular components had intermediate/bright T2W signal. Interval nonlipomatous nodular growth was identified in 3 cases.

CONCLUSION

WDLMS may present on imaging as a mass with variable morphology and amounts of nonlipomatous components. Histopathological diagnosis of WDLMS is challenging and imaging correlation may be helpful, as this tumor may have ≥50% fatty volume, may have a myxoid nodular component or bi-morphic appearance, or may be located in the retroperitoneum, features that are unusual for myxoid liposarcoma. WDLMS with a nodular component cannot be distinguished from dedifferentiated liposarcoma based on imaging alone.

Dedifferentiated retroperitoneal liposarcoma spontaneously occurring in an aged SD rat

Liposarcoma is a rare neoplasm in rats and is characterized by the presence of lipoblasts containing multiple cytoplasmic vacuoles. We encountered a rare type of liposarcoma in a male SD (Crj:CD(SD)IGS) rat during a long-term study to gather background data. At necropsy at 105 weeks of age, there was a large amount of fatty tissue covering the mesentery, pancreas, and retroperitoneum; a white nodule in the right kidney; and paleness of the liver. Microscopically, the tumor had a well-differentiated component and dedifferentiated high-grade component. Immunohistochemical and electron microscopic examinations revealed that the pleomorphic tumor cells retained the characteristics of lipoblasts. Distant or disseminated metastasis was also confirmed in various organs. A liposarcoma with these histological features is extremely rare in rats, and this is the first report of a highly metastatic dedifferentiated type of liposarcoma originating from the abdominal fat tissue in a rat.

A retroperitoneal dedifferentiated liposarcoma mimicking an ovarian tumor

A 74-year-old postmenopausal woman visited our gynecology clinic complaining of a palpable abdominal mass. Physical and radiological evaluation indicated that the mass exhibited features of a left ovarian neoplasm showing heterogeneous enhancement. Surgical resection was performed to confirm this suspicion. During surgery, a mass was observed only in the left ovary with no invasive growth, but adhesions to the surrounding peritoneum were seen. Given the patient's age, large mass size, and accompanying uterine myoma and right ovarian cyst, total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. The final pathologic diagnosis was dedifferentiated liposarcoma. The liposarcoma was suspected to originate from retroperitoneal adipose tissue rather than the ovary. Radiotherapy was planned if a gross lesion indicating recurrence followed 6 months later. This case required a considerable multi-disciplinary approach for diagnosis and treatment because of its ambiguous clinical and radiological findings.

Historical perspectives and future directions in the surgical management of retroperitoneal sarcoma

Retroperitoneal sarcomas (RPS) have fascinated and intrigued physicians both past and present. Operative mortality rates were historically very high and complete resection was not possible for the majority of patients until only the last 2 decades. More recently, changes to the surgical approach and clinical decision-making in RPS have improved patient outcomes. With select integration of nonsurgical therapies, continued RPS-specific research, and ongoing collaborative efforts among major referral centers, the future appears promising.

A novel long noncoding RNA PILRLS promote proliferation through TCL1A by activing MDM2 in Retroperitoneal liposarcoma

It is becoming evident that lncRNAs may be an important class of pervasive genes involved in carcinogenesis and metastasis. However, the biological and molecular mechanisms of lncRNAs in retroperitoneal liposarcoma have never been reported. In our study, we found a novel lncRNA PILRLS (Proliferation Interacting LncRNA in Retroperitoneal Liposarcoma), which as an oncogene significantly overexpressed in retroperitoneal liposarcoma. Functions of PILRLS on tumor progression both in vitro and in vivo have verified in this study which PILRLS knockdown significantly inhibited cell proliferation and colony formation. RNA pull-down assay found PILRLS can specific binding with TCL1A which also regulate the expression level of TCL1A. Our work for the first time demonstrated PILRLS can activating the MDM2 by binding with TCL1A which suppress the P53 pathway to promote the unlimited growth of retroperitoneal Liposarcoma cells. It suggests that PILRLS may be an important targets for retroperitoneal liposarcoma therapy.

Giant Retroperitoneal Sarcoma

Retroperitoneal sarcomas are rare tumors, having an annual incidence of 0.3 to 0.4 new cases per 100,000 occupants. R0 resection is the cornerstone of therapy, with local control being integral for a favorable prognosis. We present a case of giant retroperitoneal liposarcoma treated with complete surgical resection.

Lipomatous tumours in adrenal gland: WHO updates and clinical implications

Adrenal lipomatous tumour is a group of adrenal tumours with a significant component of adipose tissue. According to the current World Health Organization (WHO) classification of tumours of endocrine organs, adrenal myelolipoma is the only entity amongst the group of tumours being described. In the literature, other more recently documented adrenal lipomatous tumours included 24 lipomas, 32 teratomas and 16 angiomyolipomas. Rare fatty tumours of the adrenal gland comprised liposarcoma, hibernoma, adrenocortical tumours with fat component and rare adrenal tumours with fat component. Myelolipoma comprises approximately 3% of primary adrenal tumour. It is noted more commonly in females and in the right adrenal gland. Approximately 40 bilateral myelolipomas were reported. The tumour is most frequently recorded in patients between fifth and seventh decades of life. Adrenal lipomas are often seen in males and in the right adrenal gland. They were commonly noted in patients in the sixth decade of life. The diagnosis could only be possible on examination of the surgically removed specimen. Adrenal teratomas were more common in females and with a bimodal age distribution. Slightly over 60% of the patients with adrenal teratoma are symptomatic. Adrenal angiomyolipomas were often symptomatic, more common in females and in the fifth decades of life. To conclude, adrenal lipomatous tumour is uncommon. They are often benign and non-functional. It is important to recognize the features of this group of lipomatous tumours in the adrenal gland as they are being detected on increasing incidence as a result of the wide-spread use of modern imaging modalities.

Huge mediastinal liposarcoma resected by clamshell thoracotomy: a case report

BACKGROUND

Liposarcoma is the single most common soft tissue sarcoma. Because mediastinal liposarcomas often grow rapidly and frequently recur locally despite adjuvant chemotherapy and radiotherapy, they require complete excision. Therefore, the feasibility of achieving complete surgical excision must be carefully considered. We here report a case of a huge mediastinal liposarcoma resected via clamshell thoracotomy.

CASE PRESENTATION

A 64-year-old man presented with dyspnea on effort. Cardiomegaly had been diagnosed 6 years previously, but had been left untreated. A computed tomography scan showed a huge (36 cm diameter) anterior mediastinal tumor expanding into the pleural cavities bilaterally. The tumor comprised mostly fatty tissue but contained two solid areas. Echo-guided needle biopsies were performed and a diagnosis of an atypical lipomatous tumor was established by pathological examination of the biopsy samples. Surgical resection was performed via a clamshell incision, enabling en bloc resection of this huge tumor. Although there was no invasion of surrounding organs, the left brachiocephalic vein was resected because it was circumferentially surrounded by tumor and could not be preserved. The tumor weighed 3500 g. Pathologic examination of the resected tumor resulted in a diagnosis of a biphasic tumor comprising dedifferentiated liposarcoma and non-adipocytic sarcoma with necrotic areas. The patient remains free of recurrent tumor 20 months postoperatively.

CONCLUSIONS

Clamshell incision provides an excellent surgical field and can be performed safely in patients with huge mediastinal liposarcomas.

Recent advances in the management of liposarcoma

Liposarcoma is the most common soft tissue sarcoma. With its various subtypes, the natural history of this disease can vary significantly from a locally recurrent tumor to a highly malignant one carrying a poor prognosis. Progress in the understanding of the specific molecular abnormalities in liposarcoma provides greater opportunity for new treatment modalities. Although surgical resection and radiation therapy remain the keystones for the management of primary liposarcoma, the inclusion of novel agents that target known abnormalities in advanced liposarcoma enhances the potential for improved outcomes.

Verticillin A Inhibits Leiomyosarcoma and Malignant Peripheral Nerve Sheath Tumor Growth via Induction of Apoptosis

Objective

The heterogeneity of soft tissue sarcoma (STS) represents a major challenge for the development of effective therapeutics. Comprised of over 50 different histology subtypes of various etiologies, STS subsets are further characterized as either karyotypically simple or complex. Due to the number of genetic anomalies associated with genetically complex STS, development of therapies demonstrating potency against this STS cluster is especially challenging and yet greatly needed. Verticillin A is a small molecule natural product with demonstrated anticancer activity; however, the efficacy of this agent has never been evaluated in STS. Therefore, the goal of this study was to explore verticillin A as a potential STS therapeutic.

Methods

We performed survival (MTS) and clonogenic analyses to measure the impact of this agent on the viability and colony formation capability of karyotypically complex STS cell lines: malignant peripheral nerve sheath tumor (MPNST) and leiomyosarcoma (LMS). The in vitro effects of verticillin A on apoptosis were investigated through annexin V/PI flow cytometry analysis and by measuring fluorescently-labeled cleaved caspase 3/7 activity. The impact on cell cycle progression was assessed via cytometric measurement of propidium iodide intercalation. In vivo studies were performed using MPNST xenograft models. Tumors were processed and analyzed using immunohistochemistry (IHC) for verticillin A effects on growth (Ki67) and apoptosis (cleaved caspase 3).

Results

Treatment with verticillin A resulted in decreased STS growth and an increase in apoptotic levels after 24 h. 100 nM verticillin A induced significant cellular growth abrogation after 24 h (96.7, 88.7, 72.7, 57, and 39.7% reduction in LMS1, S462, ST88, SKLMS1, and MPNST724, respectively). We observed no arrest in cell cycle, elevated annexin, and a nearly two-fold increase in cleaved caspase 3/7 activity in all MPNST and LMS cell lines. Control normal human Schwann (HSC) and aortic smooth muscle (HASMC) cells displayed higher tolerance to verticillin A treatment compared to sarcoma cell lines, although toxicity was seen in HSC at the highest treatment dose. In vivo studies mirrored the in vitro results: by day 11, tumor size was significantly reduced in MPNST724 xenograft models with treatment of 0.25 and 0.5 mg/kg verticillin A. Additionally, IHC assessment of tumors demonstrated increased cleaved caspase 3 and decreased proliferation (Ki67) following treatment with verticillin A.

Conclusion

Advancement in the treatment of karyotypically complex STS is confounded by the high level of genetic abnormalities found in these diseases. Consequently, the identification and investigation of novel therapies is greatly needed. Our data suggest that verticillin A selectively inhibits MPNST and LMS growth via induction of apoptosis while exhibiting minimal to moderate effects on normal cells, pointing to verticillin A as a potential treatment for MPNST and LMS, after additional preclinical validation.

Current classification, treatment options, and new perspectives in the management of adipocytic sarcomas

Sarcomas are a heterogeneous group of mesenchymal tumors arising from soft tissue or bone, with an uncertain etiology and difficult classification. Soft tissue sarcomas (STSs) account for around 1% of all adult cancers. Till date, more than 50 histologic subtypes have been identified. Adipocyte sarcoma or liposarcoma (LPS) is one of the most common STS subtypes, accounting for 15% of all sarcomas, with an incidence of 24% of all extremity STSs and 45% of all retroperitoneal STSs. The new World Health Organization classification system has divided LPS into four different subgroups: atypical lipomatous tumor/well-differentiated LPS, dedifferentiated LPS, myxoid LPS, and pleomorphic LPS. These lesions can develop at any location and exhibit different aggressive potentials reflecting their morphologic diversity and clinical behavior. Patients affected by LPS should be managed in specialized multidisciplinary cancer centers. Whereas surgical resection is the mainstay of treatment for localized disease, the benefits of adjuvant and neoadjuvant chemotherapy are still unclear. Systemic treatment, particularly chemotherapy, is still limited in metastatic disease. Despite the efforts toward a better understanding of the biology of LPS, the outcome of advanced and metastatic patients remains poor. The advent of targeted therapies may lead to an improvement of treatment options and clinical outcomes. A larger patient enrollment into translational and clinical studies will help increase the knowledge of the biological behavior of LPSs, test new drugs, and introduce new methodological studies, that is, on treatment response.

Practical Issues for Retroperitoneal Sarcoma

Background

Retroperitoneal sarcoma is rare. Using initial specimens on biopsy, a definitive diagnosis of histological subtypes is ideal but not always achievable.

Methods

A retrospective institutional review was performed for all cases of adult retroperitoneal sarcoma from 1996 to 2015. A review of the literature was also performed related to the distribution of retroperitoneal sarcoma subtypes. A meta-analysis was performed.

Results

Liposarcoma is the most common subtype (45%), followed by leiomyosarcoma (21%), not otherwise specified (8%), and undifferentiated pleomorphic sarcoma (6%) by literature review. Data from Moffitt Cancer Center demonstrate the same general distribution for subtypes of retroperitoneal sarcoma. A pathology-based algorithm for the diagnosis of retroperitoneal sarcoma is illustrated, and common pitfalls in the pathology of retroperitoneal sarcoma are discussed.

Conclusions

An informative diagnosis of retroperitoneal sarcoma via specimens on biopsy is achievable and meaningful to guide effective therapy. A practical and multidisciplinary algorithm focused on the histopathology is helpful for the management of retroperitoneal sarcoma.

Hypothesis: The Intratumoral Immune Response against a Cancer Progenitor Cell Impacts the Development of Well-Differentiated versus Dedifferentiated Disease in Liposarcoma

Well-differentiated/dedifferentiated (WD/DD) liposarcoma is a rare malignancy of adipocyte origin (“fat cancer”). Tumors may be entirely WD, WD with a DD component, or rarely DD without a clear WD component. WD tumors are low grade and generally indolent, while tumors with a DD component are high grade and behave much more aggressively, with a modest potential for distant metastasis. The presence of cancer progenitor cells in WD/DD liposarcoma is suggested by clinical evidence and reported research findings. In addition, there are emerging data to support the existence of a naturally occurring, antigen-driven, and adaptive immune response within the tumor microenvironment. We hypothesize that the intratumoral immune response is directed against a cancer progenitor cell and that the outcome of this response impacts the development of WD versus DD disease. Further study will likely provide interesting insights into the disease biology of WD/DD liposarcoma that may be readily translated to other more common cancers.

Prognostic Model to Predict Survival Outcome for Curatively Resected Liposarcoma: A Multi-Institutional Experience

Purpose: We performed this study to analyze the clinical features and prognosis of Korean patients with liposarcoma.

Patients & Methods: Between October 1986 and April 2013, 231 patients who were diagnosed with liposarcoma by histologic examination were enrolled in this study.

Results: The distribution of histologic subtypes was well-differentiated (n = 97, 42%), myxoid (n = 74, 32%), dedifferentiated (n = 32, 13.9%), pleomorphic (n = 15, 6.5%), and round-cell liposarcoma (n = 13, 5.6%). The majority of liposarcomas were located in the lower extremities (35.5%) and retroperitoneum (34.2%). Prognosis was worse for the trunk group compared with the extremity group (median disease-free survival [DFS] 3.3 vs. 9.9 years, respectively, P <0.001). Median DFS was significantly worse in patients with high grade histology compared to those with low grade histology (16.9% vs. 65.7%, P <0.001). The independent prognostic factors associated with survival were histology (hazard ratio [HR] 3.01; 95% confidence interval [CI], 1.82-4.97; P <0.001) and primary site (HR 1.80; 95% CI, 1.12-2.89; P = 0.015). Three risk groups with different survival outcomes were identified: group 1 (n = 98), no risk factors; group 2 (n = 92), one risk factor; and group 3 (n = 41), two risk factors.

Conclusions: Histologic subtype and primary site were independent prognostic factors for curatively resected liposarcoma. A prognostic model for patients with liposarcoma clarified distinct groups of patients with good prognostic discrimination.