Liposarcomas

Deciphering the roles of non-coding RNAs in liposarcoma development: Challenges and opportunities for translational therapeutic advances

Liposarcoma is one of the most prevalent forms of soft tissue sarcoma, and its prognosis is highly dependent on its molecular subtypes. Non-coding RNAs (ncRNAs) like microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) can bind various cellular targets to regulate carcinogenesis. By affecting the expressions and activities of their downstream targets post-transcriptionally, dysregulations of miRNAs can alter different oncogenic signalling pathways, mediating liposarcoma progression. On the contrary, lncRNAs can sponge miRNAs to spare their downstream targets from translational repression, indirectly affecting miRNA-regulated oncogenic activities. In the past 15 years, multiple fundamental and clinical research has shown that different ncRNAs play essential roles in modulating liposarcoma development. Yet, there is a lack of an effective review report that could summarize the findings from various studies. To narrow this literature gap, this review article aimed to compare the findings from different studies on the tumour-regulatory roles of ncRNAs in liposarcoma and to understand how ncRNAs control liposarcoma progression mechanistically. Additionally, the reported findings were critically reviewed to evaluate the translational potentials of various ncRNAs in clinical applications, including employing these ncRNAs as diagnostic and prognostic biomarkers or as therapeutic targets in the management of liposarcoma. Overall, over 15 ncRNAs were reported to play essential roles in modulating different cellular pathways, including apoptosis, WNT/β-catenin, TGF-β/SMAD4, EMT, interleukin, and YAP-associated pathways to influence liposarcoma development. 28 ncRNAs were reported to be upregulated in liposarcoma tissues or circulation, whereas 11 were downregulated, making them potential candidates as liposarcoma diagnostic biomarkers. Among these ncRNAs, measuring the tissues or circulating levels of miR-155 and miR-195 was reported to help detect liposarcoma, differentiate liposarcoma subtypes, and predict the survival and treatment response of liposarcoma patients. Overall, except for a few ncRNAs like miR-155 and miR-195, current evidence to support the use of discussed ncRNAs as biomarkers and therapeutic targets in managing liposarcoma is mainly based on a single-center study with relatively small sample sizes or cell-based studies. Hence, more large-scale multi-center studies should be conducted to further confirm the sensitivity, specificity, and safety of ncRNAs as biomarkers and therapeutic targets. Instead of furthering investigation to confirm the translational values of all the discussed ncRNAs, which can be time- and cost-consuming, it would be more practical to focus on a few ncRNAs, including miR-155 and miR-195, to evaluate if they are sensitive and safe to be used as liposarcoma biomarkers and therapeutic agents or targets.

Liposarcoma of the Spermatic Cord With Signs and Symptoms Mimicking the Inguinal Hernia: A Rare Case Report

Liposarcoma of the spermatic cord (LSC) is extremely rare; < 200 cases were reported in the medical literature. Because of the rarity of these tumors and their presentation as a painless inguinal or scrotal mass, preoperative diagnosis is uncertain and they are frequently misdiagnosed as inguinal hernias.

Liposarcoma of Maxilla- A Rare Case Report

Introduction

Sarcomas of the head and neck region account for less than 10% of soft tissue sarcomas, and comprise less than 1% of head and neck malignancies. Approximately 80% of sarcomas arise from soft tissue, with the remaining originating from bone or cartilage. Head and neck sarcomas typically occur more frequently in men.

Case report

Our patient was a 30 year old male who presented with a ulceroproliferative mass over the soft palate increasing in size over past 6 months. Punch biopsy of the lesion was suggestive of carcinosarcoma. MRI PNS was suggestive of 38 × 39 × 33 mm sized lobulated lesion involving soft palate on right side, crossing midline and displaces uvula. The lesion involved right side of hard palate, right retromolar trigone with abutment of right medial pterygoid. It was also suggestive of bilateral sub centimetric nodes involving bilateral level 2 neck nodes. The patient received 3 cycles neoadjuvant chemotherapy Ifosfamide and Doxorubicin and patient had no subjective response to chemotherapy with subjective increase in the size of lesion. MRI PNS post neoadjuvant chemotherapy was suggestive of 46 × 46 × 41 mm lobulated lesion involving right side of the soft palate crossing midline over to the left, involving right posterior hard palate and right retromolar trigone, tonsillar fossa and TL sulcus. CECT thorax was negative for lung metastasis. Our patient was a 30 year old male who presented with a ulceroproliferative mass over the soft palate increasing in size over past 6 months. Punch biopsy of the lesion was suggestive of carcinosarcoma. MRI PNS was suggestive of 38x39x33mm sized lobulated lesion involving soft palate on right side, crossing midline and displaces uvula. The lesion involved right side of hard palate, right retromolar trigone with abutment of right medial pterygoid. It was also suggestive of bilateral sub centimetric nodes involving bilateral level 2 neck nodes. The patient received 3 cycles neoadjuvant chemotherapy Ifosfamide and Doxorubicin and patient had no subjective response to chemotherapy with subjective increase in the size of lesion. MRI PNS post neoadjuvant chemotherapy was suggestive of 46 × 46 × 41 mm lobulated lesion involving right side of the soft palate crossing midline over to the left, involving right posterior hard palate and right retromolar trigone, tonsillar fossa and TL sulcus. CECT thorax was negative for lung metastasis.

Discussion

The patient underwent wide local excision with medial maxillectomy via a bilateral Weber-Ferguson incision with Diffenbach extension and sent for frozen. The margins were negative and free of tumor. Bilateral modified neck dissection type 3 was done for lymph node clearance. A bilateral temporalis flap was done for reconstruction of the defect with a temporary obturator placement. Sarcomas of the sinonasal region may present a diagnostic challenge, as their location in the sinuses or nasal cavity may lead to presenting symptoms such as epistaxis, nasal congestion, or sinus pain and pressure that may be attributed to more benign causes such as chronic sinusitis, sinonasal polyposis, or allergic rhinitis. The less common sinonasal sarcoma subtypes may present a diagnostic challenge as their histopathological characteristics may overlap, especially with variations in tumor grade or with dedifferentiation. Additionally, the ideal treatment modality may present a therapeutic challenge, as the response to radiation and/or chemotherapy may vary according to the sarcoma subtype. Surgery is considered to be the mainstay in the management of carcinosarcomas of head and neck. Based on the evidence presented herein, elective neck dissection should be considered to treat squamous cell carcinomas of the maxillary palate, ginigiva, and alveolus.

Giant liposarcoma of the thigh: A case report

Liposarcoma is a tumor derived from primitive cells that undergo adipose differentiation. They comprise 10%-35% of all soft tissue sarcomas. We present a 46-year-old female patient with a 4-year history of a giant swelling on the lateral aspect of the left thigh. Wide local excision of the mass was performed and histopathological analysis revealed a well-differentiated liposarcoma. Liposarcomas commonly appear in the extremities and have distinct features on imaging studies. Surgical treatment and histology are the most important prognostic factors for patients with lipomatous tumors, as complete surgical excision reduces local recurrence rate.

The Conundrum of Dedifferentiation in a Liposarcoma at a Peculiar Location: A Case Report and Literature Review

Dedifferentiated liposarcoma of the deep soft tissue of the lower extremities is an infrequent finding. Myxoid liposarcoma is considered the most common soft tissue neoplasia arising in this anatomic region. Divergent differentiation usually occurs within well-differentiated liposarcoma and is exceedingly rare in a myxoid liposarcoma. We report a 32-year-old man who developed a dedifferentiated liposarcoma of the thigh on the background of a pre-existing myxoid liposarcoma. The gross examination of the surgical specimen showed a 11/7/2 cm tumour mass with solid tan-grey areas and focal myxoid degeneration. The microscopic examination revealed a malignant lipogenic proliferation, containing round cells with hyperchromatic nuclei and atypical lipoblasts, confined to the basophilic stroma with a myxoid aspect. Abrupt transition towards a hypercellular, non-lipogenic area consisting of highly pleomorphic spindle cells with atypical mitotic figures was also noted. Immunohistochemical staining was performed. Tumour cells in the lipogenic area were intensely positive for S100 and p16, and CD34 staining highlighted an arborizing capillary network. The dedifferentiated tumour areas showed positive MDM2 and CDK4 staining within neoplastic cells, with the Ki 67 proliferation marker expressed in approximately 10% of the cells. Wild-type TP53 protein expression pattern was documented. Thus, the diagnosis of a dedifferentiated liposarcoma was established. This paper aims to provide further knowledge about liposarcomas with divergent differentiation at peculiar locations, emphasizing the importance of histopathologic examination and immunohistochemical analysis for establishing the diagnosis and assessing the therapeutic response and prognosis of this condition.

Adrenal Liposarcoma: A Novel Presentation of Multiple Endocrine Neoplasia Type 1

Background/Objective

Multiple endocrine neoplasia type 1 (MEN1) syndrome results from genetic sequence variations of the tumor suppressor MEN1 gene, which codes for the protein menin. Individuals with MEN1 are prone to developing multiple tumors involving the endocrine and nonendocrine organs. MEN1 associated with liposarcomas has not been documented previously. We highlight a case of MEN1 presenting with a metastatic adrenal liposarcoma.

Case Report

A 41-year-old Hispanic man with a history of nephrolithiasis and skin lesions presented to the emergency department with abdominal pain. He was found to have a right adrenal mass measuring 7.9 cm with extension into the liver and primary hyperparathyroidism. He had multiple paternal first-degree relatives with similar skin lesions, hypercalcemia, and tumors of the brain, thoracic cavity, abdomen, and thyroid. The mass was identified as a metastatic pleiomorphic adrenal liposarcoma on surgical pathology. Genetic testing revealed a germline pathogenic sequence variation of the MEN1 gene.

Discussion

Liposarcomas are rare malignant tumors with an annual incidence of 2.5 cases per 1 million. Although lipoma formation is a commonly described manifestation of MEN1, liposarcomas have not been associated with MEN1 previously. A potential mechanism of this association is through the role of menin in inducing adipocyte differentiation via peroxisome proliferator-activated receptor-γ activation, a highly expressed protein in liposarcomas.

Conclusion

Liposarcomas should be included in the differential of MEN1-related tumors.

[Medicinal treatment of retroperitoneal soft tissue sarcomas]

Retroperitoneal soft tissue sarcomas represent extreme challenges for interdisciplinary treatment teams. The sarcoma-specific experience of surgeons has the greatest impact on the survival of patients; however, too many patients still die despite optimal local treatment. The role of chemotherapy is undisputed only for patients with highly malignant bone sarcomas or rhabdomyosarcomas. For soft tissue sarcomas in adult patients, especially liposarcomas and leiomyosarcomas, the evidence situation is very unsatisfactory. This overview article discusses the complex data situation and controversial aspects that are relevant for current treatment decisions in interdisciplinary treatment teams.

Role of FUS-CHOP in Myxoid Liposarcoma via miR-486/CDK4 Axis

This study aimed to explore the roles and relationship between FUsed in Sarcoma (FUS)-C/EBP HOmologous Protein (CHOP), microRNA (miR)-486 and cyclin dependent kinase 4 (CDK4) in myxoid liposarcoma, and determined whether FUS-CHOP can regulate proliferation and apoptosis of myxoid liposarcoma cells by regulating miR-486/CDK4 axis. The levels of miR-486, CDK4 and FUS-CHOP in myxoid liposarcoma samples/adjacent normal muscle tissues and myxoid liposarcoma/human adipose-derived stem cell line were evaluated using reverse transcription-quantitative polymerase chain reaction and western blotting. Cell proliferation and apoptosis were performed using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry, respectively. Furthermore, the apoptosis-related proteins were determined using Western blot assay. We found that miR-486 was down-regulated, FUS-CHOP and CDK4 were up-regulated in myxoid liposarcoma tissues and myxoid liposarcoma cell lines. Moreover, FUS-CHOP-siRNA distinctly suppressed FUS-CHOP level and increased miR-486 levels in 1955/91 cells. Our results demonstrated that knockdown of FUS-CHOP by siRNA inhibited 1955/91 growth, promoted cell apoptosis and enhanced cleaved Caspase3 protein expression. However, all these data were reversed by miR-486 inhibitor. Similarly, compared to mimic control, miR-486 mimic markedly reduced 1955/91 cells growth, induced cell apoptosis and fortified cleaved Caspase3 level, while these results were abolished by CDK4-plasmid. Collectively, our observations clearly suggested that FUS-CHOP regulated myxoid liposarcoma cell proliferation and apoptosis by the regulation of miR-486/CDK4 axis, indicating the potential use of FUS-CHOP-siRNA as a promising therapy for myxoid liposarcoma.

Postoperative recurrence of myxoid liposarcoma of left thigh with pericardial metastasis: A case report

Myxoid liposarcoma (MLS) is a common subtype of liposarcoma in children and adolescents and can occur anywhere in the body. Cardiac metastases from MLS are very rare. We report a rare case of postoperative recurrence of MLS in the left thigh with ectopic and metachronous pericardial metastases. Cardiac metastases from MLS are rare, the prognosis is poor, and long-term follow-up of patients after discharge is necessary.

Big and deep seated lipomatous tumours in children : results of surgical treatment

The objective of the study is aimed to evaluate results of our pediatric patients with big and deep-seated lipomatous tumors Results of 32 children who underwent resection for 5 cm or larger and deep-seated lipomas were evaluated. The mean age of the patients was 9.1 years (range, 0-16 ; 11 female/21 male), and median follow-up period was 3.21 years (range, 1-10 years). The median size of the excised tumour was 11 cm (range, 6-28 cm) in maximal dimension. Big lipomas in children can be treated with marginal resection procedures without biopsy with lower complication and local recurrence ratio compared to adult patients with similar tumours in similar size and location.

Big and deep seated lipomatous tumours in children : results of surgical treatment

The objective of the study is aimed to evaluate results of our pediatric patients with big and deep-seated lipomatous tumors Results of 32 children who underwent resection for 5 cm or larger and deep-seated lipomas were evaluated. The mean age of the patients was 9.1 years (range, 0-16 ; 11 female/21 male), and median follow-up period was 3.21 years (range, 1-10 years). The median size of the excised tumour was 11 cm (range, 6-28 cm) in maximal dimension. Big lipomas in children can be treated with marginal resection procedures without biopsy with lower complication and local recurrence ratio compared to adult patients with similar tumours in similar size and location.

Sarcomas of the sellar region: a systematic review

PURPOSE AND METHODS

Sarcomas of the sellar region are uncommon and unexpected tumors. Here, we review the cases reported in literature via a systematic search.

RESULTS

Ninety-four patients, 58.5% male with mean age of 39.2 ± 17.2 years were included. Fifty-seven (62%) had soft tissue sarcomas (STS) and 35 (38%) bone sarcomas (BS). Sarcoma was a primary tumor in 66%, developed after radiotherapy in 31.9% and 7.4% were metastatic. Median time between radiotherapy and sarcoma development was 10.5 (11) years. Main presentation symptoms were visual disorders (87.9%), headache (61.5%) and III cranial nerve palsy (24.1%). After surgery, sarcoma persisted or recurred in 82.3% and overall mortality reported was 44.6% with 6.5 (14) months of median survival. Tumor appeared earlier in BS compared to STS (34.4 ± 15.1 vs. 42.6 ± 17.6 years), p = 0.034 and complete tumor resection was achieved more often (41.3% vs. 4.4%), p =  < 0.001. Condrosarcoma and rhabdomyosarcoma were more frequent subtypes among primary tumors while fibrosarcoma was among post-radiation sarcomas. Tumor size was larger in radiation associated sarcomas (mean maximum diameter 46.3 ± 9.3 vs. 29.1 ± 8.0 mm, p = 0.004) and persistency/recurrence was similar in both groups (70.1 vs. 73.3%, p = 0.259).

CONCLUSION

Sarcomas appear as mass effect symptoms in the middle aged population, mainly as primary tumors, but one third is associated with radiotherapy. Surgery is commonly not curative, mortality rate is high and death ensues shortly after diagnosis.

Epidemiology and survival of liposarcoma and its subtypes: A dual database analysis

PURPOSE

Liposarcoma (LPS) is a one of the most commonly diagnosed soft tissue sarcomas. Little is known about the epidemiology and prognosis of each subtype. We present an analysis of epidemiology and survival of the subtypes of LPS using a national database.

METHODS

We queried the Survival Epidemiology, and End Results (SEER) and the Canadian Institute for Clinical Evaluative Sciences (ICES) databases for data on 7 types of LPS. Pearson's chi square was used to determine associations between variables and subtypes. Kaplan-Meier and Cox Regression analyses were performed for two tests: one using SEER data and the other using variables common to both SEER and ICES.

RESULTS

The well-differentiated subtype was the most common subtype identified. Metastatic disease was associated with decreased survival across all subtypes and age >35 was associated with decreased survival in well-differentiated and myxoid subtypes. Tumor grade was associated with decreased survival in the well-differentiated, myxoid, mixed, and round cell subtypes. In the secondary analysis, age >35 was associated with decreased survival in the myxoid subtype.

CONCLUSIONS

The prognosis of liposarcoma differs greatly by subtype. Clinicians should account for patient factors at the time of diagnosis to best navigate treatment of their patients.

Dedifferentiated liposarcoma with a rare presentation of disseminated intraperitoneal sarcomatosis: A case report

•

Dedifferentiated liposarcoma can present with disseminated intraperitoneal sarcomatosis.

•

Fluorescence in situ hybridization for MDM2 gene amplification is diagnostically discriminative.

•

Prognosis is poor and the benefit of chemotherapy remains uncertain.

•

Novel targeted therapies involving MDM2 and CKD4 inhibitors may emerge as viable systemic therapy options.

Introduction

Dedifferentiated liposarcoma is rare and tends to present with discrete tumors in the retroperitoneum, limbs and trunk. Majority of cases arise de-novo as primary tumors, while a minority occur as recurrences of well-differentiated liposarcomas. There has been no previous report of dedifferentiated liposarcoma presenting as disseminated intraperitoneal sarcomatosis.

Presentation of case

This report describes a young Asian female with disseminated intraperitoneal sarcomatosis arising from de-novo dedifferentiated liposarcoma, and discusses the diagnostic challenges faced in this highly unusual disease presentation. Initial biopsy was unconclusive, and considerations included sclerosing mesenteritis or an inflammatory myofibroblastic tumor. Fluorescence in situ hybridization was subsequently performed and showed amplification of the MDM2 gene. A diagnosis of dedifferentiated liposarcoma was then made.

Discussion

This was an extremely unusual presentation of advanced dedifferentiated liposarcoma that was eventually diagnosed using fluorescence in situ hybridization. Prognosis is poor and the only viable treatment options was palliative chemotherapy.

Conclusion

The diagnosis of dedifferentiated liposarcoma should be considered early and surgery carried out when still feasible.

Genomic Evolutionary Patterns of Leiomyosarcoma and Liposarcoma

PURPOSE

Leiomyosarcoma and liposarcoma are common subtypes of soft tissue sarcoma (STS). Patients with metastatic leiomyosarcoma or dedifferentiated liposarcoma (DDLPS) typically have worse outcomes compared with localized leiomyosarcoma or well-differentiated liposarcoma (WDLPS). A better understanding of genetic changes between primary/metastatic leiomyosarcoma and between WDLPS/DDLPS may provide insight into their genetic evolution.

EXPERIMENTAL DESIGN

We interrogated whole-exome sequencing (WES) from "trios" of normal tissue, primary tumor, and metastatic tumor from individual patients with leiomyosarcoma (n = 9), and trios of normal tissue, well-differentiated tumor, and dedifferentiated tumor from individual patients with liposarcoma (n = 19). Specifically, we performed mutational, copy number, and tumor evolution analyses on these cohorts and compared patterns among leiomyosarcoma and liposarcoma trios.

RESULTS

Leiomyosarcoma cases harbored shared drivers through a typical parent/child relationship where the metastatic tumor was derived from the primary tumor. In contrast, while all liposarcoma cases shared the characteristic focal chromosome 12 amplicon, most paired liposarcoma cases did not share additional mutations, suggesting a divergent evolutionary pattern from a common precursor. No highly recurrent genomic alterations from WES were identified that could be implicated as driving the progression of disease in either sarcoma subtype.

CONCLUSIONS

From a genomic perspective, leiomyosarcoma metastases contain genetic alterations that are also found in primary tumors. WDLPS and DDLPS, however, appear to divergently evolve from a common precursor harboring 12q amplification, rather than as a transformation to a higher-grade tumor. Further efforts to identify specific drivers of these distinct evolutionary patterns may inform future translational and clinical research in STS.

Solitary pancreatic metastasis of extremity myxoid liposarcoma: a case report and literature review

BACKGROUND

Myxoid liposarcoma has a distinct migration aptitude; however, pancreatic metastasis is rare.

CASE PRESENTATION

We report on the case of a 40-year-old female patient who suffered solitary pancreatic metastasis of myxoid liposarcoma and had a right thigh myxoid liposarcoma radical resection 5 years ago. The patient underwent a medial pancreatectomy and pancreaticojejunostomy for solitary pancreatic metastasis of myxoid liposarcoma. After 12 months of disease-free survival, the patient underwent an extended radical resection for the recurrence of the right thigh primary myxoid liposarcoma and received postoperative radiotherapy. Currently, the disease-free survival time after the last operation has been 22 months.

CONCLUSIONS

We reviewed the relevant literature and suggest that radical surgery might result in a good prognosis for patients with solitary pancreatic metastasis of myxoid liposarcoma.

Influence of age and subtype in outcome of operable liposarcoma

AIM

Liposarcoma (LPS) is rare tumor deriving from adipocytes. LPS is classified into histological subtypes: well-differentiated (WDLPS), dedifferentiated (DDLPS), myxoid (MLPS) and pleomorphic (PLPS). A tailored approach taking into account the specificity of disease subtype and age at presentation could be helpful in delineating therapeutic management of liposarcoma. In this paper, we report a retrospective series of a single-institution cohort of patients with LPS, undergoing surgery and radiotherapy and/or chemotherapy. The aim of this study is to evaluate whether clinical characteristics, tumor- and treatment-related features affect clinical outcome in patients treated with curative intent for non-metastatic liposarcoma.

METHODS

Data of patients with locally advanced, non-metastatic liposarcoma treated between 1990 and 2015 were retrospectively reviewed. Data about patient, tumor and treatment features were collected. Two patients subgroups were identified according to age (cutoff: age < 65 years or > 65 years). Statistical analysis was performed to assess correlation between the above-cited variables and local recurrence-free survival (DFS-LR), distant metastasis-free survival, overall survival (OS) and disease-specific survival (DSS); moreover, differences in clinical outcome between the two age groups were identified.

RESULTS

Data of 186 patients were collected. At diagnosis, 27.4% of patients were 65 years or older. At a median follow-up of 8.6 years (range 0.1-27.3 years), Kaplan-Meier (KM) survival analysis showed that LR, DM, OS and DSS were 75.5%, 76.6%, 48.1% and 72.1%, respectively. KM analysis showed that age > 65, DDLPS and lower limb localization were related to LR (p = 0.001, p = 0.0001 and p = 0.0001, respectively). Association between LR, age and DDLPS persisted both at univariate (p = 0.003 and p = 0.0001, respectively) and multivariate Cox regression (CR) analysis (p = 0.024 and p = 0.002). Age, tumor depth and grading influenced distant recurrence, both at KM (p = 0.023, p = 0.026 and p = 0.016) and univariate CR (p = 0.026, p = 0.042 and p = 0.012). Age and grading were confirmed at multivariate analysis (p = 0.009 and p = 0.017). Patients with WDLPS and wide excision had significantly better OS (p = 0.001 and p = 0.03, respectively), while histological G3 and age > 65 were related with worse OS (p = 0.008 and p = 0.0001, respectively). Age, DDLPS and grade were related to OS at univariate (p = 0.0001, p = 0.0001 and p = 0.03, respectively) and multivariate CR analysis (p = 0.031, p = 0.0001 and p = 0.001, respectively). However, analyzing the specific causes of death, female died less often for tumor-related causes, with a DSS of 91.0% compared to 57.4% of male counterpart (p = 0.005). At Kaplan-Meier analysis, postoperative radiotherapy resulted in a statistically significant better disease-specific survival than postoperative radiotherapy (82.9% vs. 46.2%, p = 0.045). High grade correlated with poorer disease-specific survival (59.3%) than intermediate and low grade (73.4% and 91.6%, respectively) (p = 0.008). Association between DSS, sex and grade persisted both at univariate (p = 0.008 and p = 0.022, respectively) and multivariate Cox regression (CR) analysis (p = 0.014 and p = 0.038). Histotype-driven schedules of treatment should be developed to take into account biological heterogeneity of this disease. Further studies are needed to stratify patients subgroup and develop tailored treatment strategies (i.e., altered fractionations and different chemotherapy regimens in aggressive subtypes), in particular more prospective trials are needed to develop treatment guidelines in elderly STS, taking into account the frailty and the peculiarity of this subgroup.

Liposarcoma of the Thyroid: A Case Report with a Review of the Literature

BACKGROUND

Liposarcomas of the thyroid gland are extremely rare tumors, and, to our knowledge, only 12 cases have been reported in the English literature. An accurate diagnosis is challenging due to the nonspecific clinical presentation of this cancer, frequently defined just by a swelling of the neck.

PATIENT FINDINGS

We present an 82-year-old woman with liposarcoma of the thyroid, complaining of a fast-growing neck mass. MRI and neck ultrasound showed a large lipomatous mass, which corresponded to a cold nodule in the thyroid scan. After performing a total thyroidectomy, the diagnosis of a well-differentiated liposarcoma of the thyroid gland was made, showing an MDM2 amplification in fluorescence in situ hybridization. Since neither a metastasis nor a residual tumor was found, no further adjuvant therapy was needed.

RESULTS

We searched the literature for previous case reports and identified only 12 cases worldwide to form our database. A demographic as well as clinical and histopathological analysis was made. In most cases, the liposarcoma occurred in patients >60 years of age. All histological subtypes, such as well-differentiated and myxoid liposarcomas, and pleomorphic and dedifferentiated liposarcomas, were found in the literature. In only 38.46% of the cases, an infiltration of the adjacent organs was observed. Surgery was the most common treatment chosen.

CONCLUSIONS

Our review provides clinical and histopathological features of a primary liposarcoma of the thyroid to enable the identifi-cation of this rare tumor entity and assist in the decision-making process regarding therapeutic options and tumor follow-up.

Preclinical evaluation of the Aurora kinase inhibitors AMG 900, AZD1152-HQPA, and MK-5108 on SW-872 and 93T449 human liposarcoma cells

Liposarcoma is a malignant soft tissue tumor that originates from adipose tissue and is one of the most frequently diagnosed soft tissue sarcomas in humans. There is great interest in identifying novel chemotherapeutic options for treating liposarcoma based upon molecular alterations in the cancer cells. The Aurora kinases have been identified as promising chemotherapeutic targets based on their altered expression in many human cancers and cellular roles in mitosis and cytokinesis. In this study, we investigated the effects of an Aurora kinase A inhibitor (MK-5108), an Aurora kinase B inhibitor (AZD1152-HQPA), and a pan-Aurora kinase inhibitor (AMG 900) on undifferentiated SW-872 and well-differentiated 93T449 human liposarcoma cells. Treatment of the SW-872 and 93T449 cells with MK-5108 (0-1000 nM), AZD1152-HQPA (0-1000 nM), and AMG 900 (0-1000 nM) for 72 h resulted in a dose-dependent decrease in the total viable cell number. Based upon the EC₅₀ values, the potency of the three Aurora kinase inhibitors in the SW-872 cells was as follows: AMG 900 (EC₅₀ = 3.7 nM) > AZD1152-HQPA (EC₅₀ = 43.4 nM) > MK-5108 (EC₅₀ = 309.0 nM), while the potency in the 93T449 cells was as follows: AMG 900 (EC₅₀ = 6.5 nM) > AZD1152-HQPA (EC₅₀ = 74.5 nM) > MK-5108 (EC₅₀ = 283.6 nM). The percentage of polyploidy after 72 h of drug treatment (0-1000 nM) was determined by propidium iodide staining and flow cytometric analysis. AMG 900 caused a significant increase in polyploidy starting at 25 nM in the SW-872 and 93T449 cells, and AZD1152-HQPA caused a significant increase starting at 100 nM in the SW-872 cells and 250 nM in the 93T449 cells. The Aurora kinase A inhibitor MK-5108 did not significantly increase the percentage of polyploid cells at any of the doses tested in either cell line. The expression of Aurora kinase A and B was evaluated in the SW-872 cells versus differentiated adipocytes and human mesenchymal stem cells by real-time RT-PCR and Western blot analysis. Aurora kinase A and B mRNA expression was significantly increased in the SW-872 cells versus the differentiated adipocytes and human mesenchymal stem cells. Western blot analysis revealed a ~ 48 kDa immunoreactive band for Aurora kinase A that was not present in the differentiated adipocytes or the human mesenchymal stem cells. A ~ 39 kDa immunoreactive band for Aurora kinase B was detected in the SW-872 cells, differentiated adipocytes, and human mesenchymal stem cells. A smaller immunoreactive band for Aurora kinase B was detected in the SW-872 cells but not in the differentiated adipocytes and human mesenchymal stem cells, and this may reflect the expression of a truncated splice variant of Aurora kinase B that has been associated with poor patient prognosis. The 93T449 cells demonstrated decreased expression of Aurora kinase A and B mRNA and protein compared to the SW-872 cells, and also expressed the truncated form of Aurora kinase B. The results of these in vitro studies indicate that Aurora kinase inhibitors should be further investigated as possible chemotherapeutic agents for human liposarcoma.

Giant atypical lipoma

Liposarcomas correspond to the most common histological subtype of soft tissue sarcomas. They can be subdivided into: well differentiated or atypical lipoma, undifferentiated, myxoid, round, and pleomorphic cells. Atypical lipomas are the most prevalent and usually appear as asymptomatic softened tumors. They are locally aggressive but rarely lead to distant metastases. The diagnosis of this tumor is based on the imaging and histopathologic findings. Treatment consists of excision surgery with complete tumor removal. It has a good prognosis due to the low percentage of distant metastases. We report a rare case of giant atypical lipoma as well as the adopted therapy and evolution.

Spectrum of Fat-containing Soft-Tissue Masses at MR Imaging: The Common, the Uncommon, the Characteristic, and the Sometimes Confusing

Fat-containing tumors are the most common soft-tissue tumors encountered clinically. The vast majority of fat-containing soft-tissue masses are benign. Lipomas are the most common benign fat-containing masses and demonstrate a characteristic appearance at magnetic resonance (MR) imaging. Less common benign soft-tissue masses include lipoblastoma, angiolipoma, spindle cell lipoma/pleomorphic lipoma, myolipoma, chondroid lipoma, lipomatosis of nerve, lipomatosis, hibernoma, and fat necrosis. Well-differentiated liposarcomas (WDLPSs)/atypical lipomatous tumors (ALTs) are locally aggressive soft-tissue masses that do not metastasize. Biologically more aggressive liposarcomas include myxoid, pleomorphic, and dedifferentiated liposarcomas. At MR imaging, lipomas typically resemble subcutaneous fat but may contain a few thin septa. The presence of thick, irregular, enhancing septa and nonfatty soft-tissue mass components suggests liposarcoma rather than lipoma. However, benign lipomatous lesions and WDLPS/ALT often have overlapping MR imaging findings. Distinguishing WDLPS/ALT from a benign lipomatous lesion or from fat necrosis at imaging can be challenging and often requires histologic evaluation. We present the spectrum of fat-containing masses, using the World Health Organization classification of adipocytic tumors, with an emphasis on commonly encountered lesions, characteristic MR imaging findings associated with specific tumors, and overlapping MR imaging findings of certain tumors that may require histologic sampling. We also briefly discuss the role of molecular markers in proper characterization and classification of fat-containing soft-tissue masses. (©)RSNA, 2016.

Primary liposarcoma of the diaphragm: a rare intra-abdominal mass

Primary malignant tumors of the diaphragm are rare, and primary liposarcoma of the diaphragm is extremely rare. The role of imaging is description of the anatomic relationships of the tumor as well as a suggestion of histologic diagnosis based on the presence of fatty and/or nonfatty components.

Liposarcoma of the thigh with mixed calcification and ossification

Liposarcoma is one of the most common soft-tissue sarcomas. Calcification and ossification can occur in liposarcoma; however, the presence of both ossification and calcification is a very rare entity. We present a case of a partially calcified and ossified dedifferentiated liposarcoma of the thigh in a 76-year-old woman, which contained heterologous elements of chondrosarcoma and rhabdomyosarcoma.

Retroperitoneal liposarcomas: a representative literature review occasioned by a rare case of laterelapse abdominal liposarcoma

Soft tissue sarcomas (STS) are rare and heterogeneous tumours representing approximately 0.7%-1% of all adult tumours. In the adults and among the retroperitoneal sarcomas (RPS), Liposarcoma (LS) is the most common variant accounting for 12% -20% of all sarcomas and up to 45% of sarcomas at retroperitoneal localization. A rare case of LS relapsed after 15 years is giving the occasion to review the published literature and emphasise the followings concepts: 1) Despite extensive surgery remains the mainstay of treatment for localized STS at present, anatomical complexity and occult localization result in local recurrence in the majority of patients; 2) The role of imaging and tumour markers is still limited; 3) Indefinite prolonged surveillance is a key point of treatment; 4) Referral to tertiary centres with dedicated Retroperitonal Surgeons and Oncology expertise is mandatory.

Myxoid liposarcoma of the hand - A rare entity

Hand liposarcomas are not well recognized in common practice, which leads to erroneous diagnostics and delayed proper treatment. We reported a case of a myxoid liposarcoma classified as stage IIb, and developed in the palmar side of the left hand in a 38-year-old man. There was an initial tumor reduction by a sclerosing agent injection that proved to be a failure. An open excisional biopsy confirmed the diagnostic after pathology examination. Recurrence occurred after 2 years, followed by a second resection and an adjunctive radiotherapy. At 5 years follow-up, the patient was recurrence free. Although myxoid liposarcoma is rare in the hand, it should be considered in the differential diagnosis of a painless soft tissue mass in this region.

Myxoid Liposarcoma of the Thigh with Metastasis to the Left Ventricle of the Heart: A Case Report

CASE

This report describes a sixty-one-year old man who was diagnosed with a myxoid liposarcoma of the left thigh that was resected and then treated with radiation therapy. He underwent yearly surveillance imaging but presented seventeen years after initial resection with symptoms of heart failure. He was found to have a cardiac abnormality that was first thought to be a pseudoaneurysm but was later shown to be a myxoid liposarcoma, presumably metastatic.

CONCLUSION

Myxoid liposarcoma can present with late metastasis, including to the heart.

Multiple spinal metastases from a well-differentiated liposarcoma of the iliac wing: a case report

STUDY DESIGN

A case report.

OBJECTIVES

To report an unusual case of multiple spinal metastases from an undiagnosed well-differentiated liposarcoma (WDLPS) of the iliac wing and to stress the need of a meticulous clinical examination and further screening of patients with chronic and asymptomatic bony lesions.

SETTING

University of medicine of Monastir, Department of neurological surgery, Fattouma Bourguiba University Hospital, Monastir, Tunisia and University of Medicine of Tunis EL Manar, Department of neurological surgery, Tunisian National Institute of Neurology, Tunis, Tunisia.

METHODS

A 39-year-old man presented with signs of spinal cord compression for the past 2 weeks. His medical history was consistent for an asymptomatic right iliac wing mass that appeared 3 years ago and for which he has not consulted. Magnetic resonance imaging revealed multiple bony lesions of the thoraco-lumbar spine associated with a 6-cm right paravertebral mass at the T4 level extending posteriorly through the intervertebral foramina to the spinal canal causing major spinal cord compression. An emergent T2-T6 laminectomy allowed for a complete resection of the epidural mass. Pathological examination confirmed the diagnosis of well-differentiated liposarcoma. Adjunctive radiation therapy was administered.

RESULTS

The patient's neurological status improved remarkably under an intensive care and rehabilitation program. He was ambulatory without assistance in the second postoperative week.

CONCLUSION

The case reported in this paper represents a genuine example of the possible metastatic potential of WDLPSs of the bone and underscores the importance of examining patients thoroughly, especially when they have chronic and asymptomatic lesions.

Association of FPGS genetic polymorphisms with primary retroperitoneal liposarcoma

Primary retroperitoneal liposarcoma is generally regarded as a genetic disorder. We have retrospectively genotyped 8 single nucleotide polymorphisms (SNPs) in 6 candidate genes (MDM2, CDK4, CDC27, FPGS, IGFN1, and PRAMEF13) in 138 patients and 131 healthy control subjects to evaluate the effects of genetic factors on individual susceptibility to primary retroperitoneal liposarcoma in Chinese population. Three SNPs (rs2870820, rs1695147, rs3730536) of MDM2 showed significant differences in single-loci genotypes and allele frequencies between case and control groups (p < 0.05). The minor allele G of SNP rs10760502 in FPGS (folylpolyglutamate synthase) gene was significantly associated with increased risk for primary retroperitoneal liposarcoma, compared with major allele A. Our data suggest that FPGS variant in Chinese population may affect individual susceptibility to primary retroperitoneal liposarcoma.

Treatment for intramuscular lipoma frequently confused with sarcoma: a 6-year restrospective study and literature review

Introduction. Intramuscular lipoma is a very rare form of lipoma, known to be categorized as an infiltrating lipoma due to its tendencies to infiltrate the muscle or the synovium. Contrary to other subcutaneous lipomas, even after surgical removal, the rate of local recurrence ranges at a high rate from 50∼80% and differential diagnosis with liposarcoma is very difficult. Patients and Methods. A retrospective chart review was conducted for a total of 27 patients. Before performing a surgery based on the types of mass, a radiologic imaging study was performed. An intraoperative frozen biopsy was performed on every patient and the results were compared. The progress was monitored every 3 to 6 months for recurrence or struggles with rehabilitation. Results. There were 13 male and 14 female patients with an average age of 54.6. The average tumor size was 8.2 cm (1.1 cm∼31.6 cm). Excision was performed using a wide excision. All 27 individuals were initially diagnosed as intramuscular lipoma; however, 1 of the patients was rediagnosed as liposarcoma in the final checkup. The patients had an average of 3 years and 1 month of follow-up and did not suffer recurrences. Conclusion. Thus, it is essential that a frozen biopsy is performed during the surgery in order to identify its malignancy. And a wide excision like malignant tumor operation is a principle of treatment.

Soft tissue sarcomas

Sarcoma is a cancer that arises from cells of mesenchymal origin, such as bone, cartilage, muscle, fat, vascular, or hematopoietic tissue. It is a very rare form of cancer with over 50 histologic subtypes. This chapter discusses selected individual subtypes of sarcomas and characteristics specific to each one. It will broadly go over molecular biology, etiology, risk factors, and the clinical features of this disease. It discusses diagnostic evaluation and the principles of management including imaging, biopsy, staging, treatment, follow-up, and the importance of a multidisciplinary approach.

Antiproliferative effects of CDK4/6 inhibition in CDK4-amplified human liposarcoma in vitro and in vivo

Well-differentiated/dedifferentiated liposarcomas (WD/DDLPS) are among the most common subtypes of soft tissue sarcomas. Conventional systemic chemotherapy has limited efficacy and novel therapeutic strategies are needed to achieve better outcomes for patients. The cyclin-dependent kinase 4 (CDK4) gene is highly amplified in more than 95% of WD/DDLPS. In this study, we explored the role of CDK4 and the effects of NVP-LEE011 (LEE011), a novel selective inhibitor of CDK4/CDK6, on a panel of human liposarcoma cell lines and primary tumor xenografts. We found that both CDK4 knockdown by siRNA and inhibition by LEE011 diminished retinoblastoma (RB) phosphorylation and dramatically decreased liposarcoma cell growth. Cell-cycle analysis demonstrated arrest at G0-G1. siRNA-mediated knockdown of RB rescued the inhibitory effects of LEE011, demonstrating that LEE011 decreased proliferation through RB. Oral administration of LEE011 to mice bearing human liposarcoma xenografts resulted in approximately 50% reduction in tumor (18)F-fluorodeoxyglucose uptake with decreased tumor biomarkers, including RB phosphorylation and bromodeoxyuridine incorporation in vivo. Continued treatment inhibited tumor growth or induced regression without detrimental effects on mouse weight. After prolonged continuous dosing, reestablishment of RB phosphorylation and cell-cycle progression was noted. These findings validate the critical role of CDK4 in maintaining liposarcoma proliferation through its ability to inactivate RB function, and suggest its potential function in the regulation of survival and metabolism of liposarcoma, supporting the rationale for clinical development of LEE011 for the treatment of WD/DDLPS.