• CD34
• CD34-positive stromal fibroblastic/fibrocytic cells (CD34+SFCs)
• dedifferentiated liposarcoma (DDLPS)

• Humans
• Male
• Liposarcoma/pathology
• Liposarcoma/metabolism
• Middle Aged
• Female
• Antigens, CD34/metabolism
• Aged
• Adult
• Biomarkers, Tumor/analysis
• Biomarkers, Tumor/metabolism
• Prognosis
• Aged, 80 and over
• Immunohistochemistry
• Neoplasm Recurrence, Local/pathology
• Neoplasm Recurrence, Local/metabolism
• Retroperitoneal Neoplasms/pathology
• Retroperitoneal Neoplasms/metabolism

• Liposarcoma
• Prognostic factors
• Retroperitoneum
• Surgical indications
• Surgical procedures

• Humans
• Liposarcoma/surgery
• Liposarcoma/pathology
• Liposarcoma/mortality
• Retroperitoneal Neoplasms/surgery
• Retroperitoneal Neoplasms/pathology
• Retroperitoneal Neoplasms/mortality
• Male
• Female
• Middle Aged
• Aged
• Adult
• Prognosis
• Follow-Up Studies
• Neoplasm Recurrence, Local/surgery
• Retrospective Studies
• Aged, 80 and over

• 12q
• CDK4
• GLI1
• MDM2
• amplification
• dedifferentiated liposarcoma
• well-differentiated liposarcoma

• Female
• Humans
• Male
• Middle Aged
• Biomarkers, Tumor/genetics
• Cyclin-Dependent Kinase 4/genetics
• Gene Amplification
• Liposarcoma/genetics
• Liposarcoma/pathology
• Proto-Oncogene Proteins c-mdm2/genetics
• Retrospective Studies
• Zinc Finger Protein GLI1/genetics

• P30 CA008748 NCI NIH HHS
• P50 CA217694 NCI NIH HHS

• cancer
• diseases
• oncology
• risk factors

• Male
• Female
• Adult
• Humans
• Middle Aged
• Retrospective Studies
• Fibrosarcoma/surgery
• Fibrosarcoma/pathology
• Extremities/pathology
• Prognosis
• Histiocytoma, Malignant Fibrous/pathology
• Neoplasm Recurrence, Local/pathology

• No. 82172446 China National Natural Science Funds

• genomics
• immunotherapy
• liposarcoma

• chemotherapy
• dedifferentiated
• excision
• mesenteric liposarcoma
• primary

• Amplificación MDM2
• Dedifferentiated liposarcoma
• FISH
• Histology
• Histología
• Immunohistochemistry
• Inmunohistoquímica
• Liposarcoma desdiferenciado
• MDM2 amplification

• Antigens, CD34
• Chromosome Aberrations
• Humans
• In Situ Hybridization, Fluorescence
• Lipoma
• Liposarcoma

The retroperitoneum can host a wide spectrum of soft tissue lesions. These tumours pose a challenge to the pathologist as the morphology is not of much help and immunohistochemistry becomes a necessity.

Sixty years old male presented with 2 months history of abdominal lump, pain and dyspepsia. The MRI revealed a heterogeneous mass in the retroperitoneum involving right para spinal muscle, right iliac fossa and right perinephric region with destruction of right transverse process and erosion of adjacent L3 vertebra. Trucut biopsy of the mass was reported as fibroliposarcoma at an outside lab. Patient underwent a wide local excision. Grossly the tumour gave an impression of a liposarcoma but the microscopy showed areas of spindle cells, epitheloid cells, focal areas of ganglion like cells and large areas of myxoid change. IHC panel of S-100, SMA, caldesmon, myogenin, myoglobin and Alk-1 was negative. MDM2, CDK4 and p16 IHC came positive proving it to be a dedifferentiated liposarcoma.

We report a curious case of retroperitoneal soft tissue tumour with complex morphology and IHC features diagnosed as dedifferentiated liposarcoma based on MDM2, CDK and p16 positivity.

• CDK4
• Dedifferentiated liposarcoma
• FISH
• IHC
• MDM2
• retroperitoneum

Dedifferentiated liposarcoma is a unique subtype of liposarcoma, which has obvious histological heterogeneity. In affected patients, the condition typically manifests as the dedifferentiation of high-grade histological morphology, but it may also manifest as the dedifferentiation of low-grade histological morphology. In some cases, unique histological or immunophenotypic characteristics are observed. We describe, herein, a rare case of dedifferentiated liposarcoma, in which the high-grade and low-grade dedifferentiated components coexisted with a relatively sharp transition in pathology.

• dedifferentiation
• histopathology
• liposarcoma
• magnetic resonance imaging
• neoplasm

• Dedifferentiation
• Gene fusion
• Genetics
• Immunohistochemistry
• Molecular pathology
• Spindle cell sarcoma
• Translocation
• Undifferentiated pleomorphic sarcoma
• Undifferentiated sarcoma

• Soft tissue perineurioma
• dedifferentiated liposarcoma
• kidney
• low-grade fibromyxoid sarcoma
• molecular genetics

• Dedifferentiated liposarcoma
• Multimodal treatment
• Oncologic emergency
• Small bowel mesentery

• Aged
• Humans
• Liposarcoma/diagnostic imaging
• Liposarcoma/surgery
• Male
• Mesentery/surgery
• Neoplasm Recurrence, Local
• Tomography, X-Ray Computed
• Vena Cava, Inferior/diagnostic imaging
• Vena Cava, Inferior/surgery

Primary retroperitoneal liposarcoma (PRPLS) is a rare soft tissue tumor with nonspecific clinical symptoms; it has different computed tomography (CT) image features according to pathological types. Some patients with a single tumor have been previously reported in the literature. We present an exceptional case of a PRPLS patient with multiple large tumors exhibiting different patterns of appearance on CT and confirmed as atypical lipomatous tumor/well-differentiated liposarcoma by postoperative pathology.

A 64-year-old man presented with abdominal distension for 1 year. The patient was diagnosed with PRPLS based on physical examination, laparotomy, ultrasonography, CT scan, and surgery. Both of the tumors were completely resected through surgery and confirmed as atypical lipomatous tumor/well-differentiated liposarcoma by postoperative pathology. The postoperative course was uneventful without recurrence or metastasis, as demonstrated by abdominal-pelvic CT during an 18 mo follow-up.

Multiple large Well-differentiated liposarcomas with different patterns of appearance on CT image can occur simultaneously in the same patient, to which more attention should be paid to make an effective differential diagnosis.

• Retroperitoneal liposarcoma
• Soft tissue tumor
• Complete resection
• Recurrence
• Case report

We present a resource‐efficient approach to fabricate and operate a micro‐nanofluidic device that uses cross‐flow filtration to isolate and capture liposarcoma derived extracellular vesicles (EVs). The isolated extracellular vesicles were captured using EV‐specific protein markers to obtain vesicle enriched media, which was then eluted for further analysis. Therefore, the micro‐nanofluidic device integrates the unit operations of size‐based separation with CD63 antibody immunoaffinity‐based capture of extracellular vesicles in the same device to evaluate EV‐cargo content for liposarcoma. The eluted media collected showed ∼76% extracellular vesicle recovery from the liposarcoma cell conditioned media and ∼32% extracellular vesicle recovery from dedifferentiated liposarcoma patient serum when compared against state‐of‐art extracellular vesicle isolation and subsequent quantification by ultracentrifugation. The results reported here also show a five‐fold increase in amount of critical liposarcoma‐relevant extracellular vesicle cargo obtained in 30 min presenting a significant advance over existing state‐of‐art.

• DNA
• MDM2
• cross flow filtration
• eEV
• extracellular vesicles
• lEV
• liposarcoma
• microfluidics
• nanofluidics
• tangential flow separation

• Desmoid-type fibromatosis
• Gastrointestinal stromal tumor
• Mesenteric vascular disease
• Sclerosing mesenteritis

• dedifferentiation
• liposarcoma
• meningothelial
• metaplastic bone
• whorls

• MDM2
• cutaneous
• dedifferentiated
• epithelioid
• liposarcoma
• metastasis

• CDK4
• MDM2
• dedifferentiated liposarcoma
• fluorescence in situ hybridization
• meningothelial-like whorls

• 12q13-15
• CDK4
• Chromosome 12q
• Dedifferentiated liposarcoma
• Genetics
• MDM2
• Pathology
• Sarcoma
• Targeted therapy
• Well-differentiated liposarcoma
• p16

• combination therapy
• lung metastasis
• retroperitoneal liposarcoma

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.

• SD rat
• lipoblasts
• liposarcoma
• spontaneous

• Spindle cell fatty tumours
• atypical lipomatous tumour
• atypical spindle cell lipomatous tumour
• cellular angiofibroma
• liposarcoma
• mammary-type myofibroblastoma
• spindle cell lipoma.

• Brain
• Liposarcoma
• Metastases
• Myxoid
• Parasellar
• Skull base

• MDM2
• colon cancer
• liposarcoma
• retroperitoneum
• sarcoma

Dedifferentiated liposarcoma is an uncommon variant of liposarcoma, with poor prognosis and higher preponderance to local recurrence. Only nine cases of dedifferentiated liposarcoma of small bowel mesentery have been reported till now. This is a case of giant dedifferentiated liposarcoma of the small bowel mesentery, weighing nearly 9 kg (19.8 lbs), with synchronous lesions in the extraperitoneal space, which is the first such case to be reported.

We report a case of a 62-year-old man, who presented with a huge abdominal mass occupying nearly the entire abdomen. A contrast enhanced computed tomography of abdomen and pelvis revealed a large, poorly enhancing, heterogeneous, lobulated mass of size 27 × 16 cm, displacing the bowel loops peripherally. At laparotomy, a large mass arising from the small bowel mesentery was found. In addition, many other smaller synchronous lesions were studded in the entire small bowel mesentery and a couple more in the extraperitoneal space. A palliative excision of the giant mass along with the adjacent small bowel was done. The other smaller swellings were not causing any mass effect and were left behind as they were numerous, virtually ruling out any possibility of a curative excision. The histopathological examination suggested the diagnosis of dedifferentiated liposarcoma. On immunohistochemistry, S-100 was positive in the well-differentiated sarcomatous areas. The CD 117 and SMA were strongly negative ruling out the possibility of a gastrointestinal stromal tumour. The CD 34 however was positive in the tumour cells.

Dedifferentiated liposarcoma of the small bowel mesentery is rare. Involvement of nearly whole of the small bowel mesentery in the disease process virtually rules out the possibility of a curative resection, the mainstay of management. This report would add to the knowledge of this rare disease and the possible therapeutic problem that may be encountered in case of multifocal disease.

• Dedifferentiated liposarcoma
• Mesentery
• Small bowel

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.

• Calcification
• Dedifferentiated liposarcoma
• Liposarcoma
• Ossification

• Atypical lipomatous tumor
• Follow-up
• Liposarcoma
• MRI
• Management
• Surveillance

• Aged
• Biomarkers, Tumor/analysis
• Cell Differentiation
• Chondrosarcoma/pathology
• Humans
• Immunohistochemistry
• Liposarcoma/pathology
• Male
• Neoplasms, Multiple Primary/pathology
• Soft Tissue Neoplasms/pathology
• Thigh/pathology
• Transforming Growth Factor beta/biosynthesis

• Small bowel
• Soft tissue sarcoma
• Surgery
• Synchronous

Liposarcoma (LS) is the second-most common type of soft-tissue sarcoma. Despite advances in knowledge and treatment of this disease, there remains a need for more effective LS therapy. Steroid hormone receptors regulate metabolism in adipocytes. Estrogen receptor alpha (ER), progesterone receptor (PR), and androgen receptor (AR) have been implicated in the pathophysiology of other cancer types. We sought to comprehensively determine temporal expression patterns of these receptors in LS.

We analyzed 561 histologically subtyped LS specimens from 354 patients for expression of ER, PR, and AR by immunohistochemistry (IHC) using diagnostic-grade reagents and protocols. The fractions of positively stained tumor cells were scored within each specimen. IHC scores were compared across LS subtypes using the Kruskal-Wallis test, and subtypes were compared using Dunn’s post-hoc test. Ages of patients with receptor-positive vs. -negative LS were compared by t-test. Genders and races were compared for hormone receptor positivity using Fisher’s exact test and Chi-square analysis, respectively. Recurrence-free survival was compared between receptor-positive and negative patients by log-rank test. p< 0.05 was considered significant.

ER and AR were frequently expressed in LS, while few tumors expressed PR. Most of the ER + and AR + samples were of the well-differentiated LS subtype. A smaller fraction of de-differentiated LS expressed ER or AR, but expression was common within well-differentiated regions of tumors histologically classified as de-differentiated LS. In LS specimens from patients who underwent multiple surgeries over time, receptor expression frequently changed over time, which may be attributable in part to intratumor heterogeneity, varying degrees of de-differentiation, and biopsy bias. ER and AR were frequently co-expressed. Receptor status was not significantly associated with gender or race, but AR and PR expression were associated with earlier age at diagnosis. Receptor expression was not associated with altered recurrence-free survival.

ER and AR are commonly expressed in LS, particularly in well-differentiated tumors. These data warrant further functional study to determine receptor function in LS, and the potential efficacy of anti-hormone therapies for the treatment of patients with LS.

• PLAG1
• desmin
• immunohistochemistry
• lipoblastoma
• lipomatous tumor
• spindle cells

Liposarcoma is the most common type of soft tissue sarcoma (STS). It is divided into five groups according to histological pattern: well-differentiated, myxoid, round cell, pleomorphic, and dedifferentiated. Dedifferentiated liposarcoma most commonly occurs in the retroperitoneum, while an intraperitoneal location is extremely rare. Only seven cases have been reported in literature. Many pathologists recognize that a large number of intra-abdominal poorly differentiated sarcomas are dedifferentiated liposarcomas. We report a case initially diagnosed as undifferentiated sarcoma that was reclassified as intraperitoneal dedifferentiated liposarcoma showing an amplification of the MDM2 gene.

A 59-year-old woman with abdominal pain and constipation was referred to the Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy, in November 2012. On physical examination, a very large firm mass was palpable in the meso-hypogastrium. Computed tomography (CT) scan showed a heterogeneous density mass (measuring 10 × 19 cm) that was contiguous with the mesentery and compressed the third part of the duodenum and jejunum.

At laparotomy, a large mass occupying the entire abdomen was found, adhering to the first jejunal loop and involving the mesentery. Surgical removal of the tumor along with a jejunal resection was performed because the first jejunal loop was firmly attached to the tumor.

Macroscopic examination showed a solid, whitish, cerebroid, and myxoid mass, with variable hemorrhage and cystic degeneration, measuring 26 × 19 × 5 cm. Microscopic examination revealed two main different morphologic patterns: areas with spindle cells in a myxoid matrix and areas with pleomorphic cells. The case was initially diagnosed as undifferentiated pleomorphic sarcoma. Histological review showed areas of well-differentiated liposarcoma. Fluorescence in situ hybridization (FISH) analysis was performed and demonstrated an amplification of the MDM2 gene. Definitive diagnosis was intraperitoneal dedifferentiated liposarcoma.

No adjuvant therapy was given, but 5 months after laparotomy, the patient presented with a locoregional recurrence and chemotherapy with high-dose ifosfamide was started.

No guidelines are available for the management of intraperitoneal dedifferentiated liposarcoma. We report this case to permit the collection of a larger number of cases to improve understanding and management of this tumor. Moreover, this study strongly suggests that poorly differentiated sarcomas should prompt extensive sampling to demonstrate a well-differentiated liposarcoma component and, if possible, FISH analysis.

Background. Liposarcoma is the second most common soft tissue sarcoma affecting predominantly the retroperitoneal space and extremities. Mesenteric liposarcoma is uncommon and occurs in the small bowel mesentery. In this paper we report the case of a recurrent mesocolon myxoid liposarcoma manifesting 6 years from the initial right hemicolectomy for the primary tumour. Case Report. A 41-year-old female presented with a 4-day history of signs and symptoms indicative of small bowel obstruction, subsequently confirmed on plain abdominal X-ray. In 2006 she underwent a right hemicolectomy for a myxoid liposarcoma of the mesentery. The patient was initially managed conservatively; however she showed no signs of improvement and was taken to theatre for an exploratory laparotomy and division of adhesional bands. During this procedure an incidental finding of a dark purple, smooth pelvic mass was identified with similar macroscopic appearance to that of splenic tissue. Histological examination revealed a recurrent mesocolon myxoid liposarcoma. Conclusion. Mesocolon myxoid liposarcoma is a rare soft tissue neoplastic pathology and carries a high risk of recurrence. Therefore, a symptomatic patient with a previous history of primary liposarcoma excision should be treated with a high index of suspicion and a longer period of followup should be considered.

• Yondelis®
• complete remission
• dedifferentiation
• leiomyosarcoma
• mesenteric liposarcoma
• trabectedin