Primary intrathoracic liposarcoma: a clinicopathologic study and prognostic analysis of 23 cases

Identification of CT Features to Differentiate Pulmonary Sarcoma from Carcinoma

Background  Primary lung sarcoma (PLS) differs in management protocols and prognosis from the more common primary lung carcinoma (PLC). It becomes imperative to raise a high index of suspicion on radiological and pathological features. Purpose  The aim of this study is to highlight the variable imaging appearances of PLS compared with PLC, which impacts radiologic - pathologic correlation. Materials and Methods  A retrospective observational study of 68 patients with biopsy-proven lung tumors who underwent baseline imaging at our tertiary care cancer hospital was conducted between January 2018 and March 2022. The patient details and imaging parameters of the mass on contrast-enhanced computed tomography (CECT) were recorded and analyzed for patients with PLS and compared with PLC. Follow-up imaging was available in 9/12 PLS and 52/56 PLC patients. Results  Among 12 patients with PLS, 5 patients had synovial sarcoma on histopathology. PLS was seen in patients with a mean age of 40.8 years; the mass showed a mean size of 13.2 cm, lower lobe (75%), parahilar (75%), hilar involvement (41.7%), oval shape (41.7%), circumscribed (25%) or lobulated (75%) margins, lower mean postcontrast attenuation of 57.3 HU, fissural extension (50%), calcification (50%), and no organ metastasis other than to the lung. PLC (56 patients) was seen in the elderly with a mean age of 54.8 years; the mass showed a mean size of 5.7 cm, irregular shape (83.9%), spiculated margins (73.2%), higher mean postcontrast attenuation (77.3 HU), chest wall infiltration (30.4%), and distant metastasis (58.9%) at baseline imaging. A statistically significant difference ( p  < 0.05) was seen between sarcoma and carcinoma in the mean age, size, site, shape, margins, postcontrast attenuation, presence of calcifications, fissural extension, and distant metastasis. Conclusion  The distinct imaging features of sarcoma help in differentiating it from carcinoma. This can also be used to corroborate with histopathology to achieve concordance and guide clinicians on further approach.

Metastatic Epithelioid Pleomorphic Liposarcoma in the Brain: A Case Report

Metastatic soft tissue sarcoma (STS) to the brain is rare, and metastatic pleomorphic liposarcoma (PLPS) to the brain is even rarer. We present the case of a 76-year-old male with an incidental finding of a brain mass on a brain magnetic resonance imaging (MRI) following a head injury. Additionally, multiple pulmonary nodules and a right gluteal mass were discovered. A core biopsy of the right gluteal mass revealed an epithelioid malignant neoplasm expressing transcription factor enhancer 3 (TFE3) by immunohistochemistry (IHC). Subsequently, the left middle fossa brain mass was removed and found to be an epithelioid PLPS, which was positive for TFE3 by IHC but lacked TFE3 rearrangement by fluorescence in situ hybridization (FISH), and negative for murine double minute (MDM2) amplification by FISH. The diagnosis of epithelioid PLPS mainly relies on histomorphology. This paper discusses the clinicopathological correlation of PLPS, including the epithelioid variant, with a focus on cases with brain metastases.

Giant primary liposarcoma of the mediastinum: A case report and review of the literature

Liposarcoma is a carcinomatous mesenchymal tumor with various histologic features and is the most common soft tissue sarcoma originating in adipose tissue. Liposarcoma commonly occurs in the lower extremities and retroperitoneum but rarely in the mediastinum, specially extending into the thoracic cavity. We report a giant primary liposarcoma of the posterior mediastinum in a 63-year-old female who complained of cough, sputum, and pain in the right chest wall. A computed tomography scan of the chest showed a giant mass of 24 × 15 × 24 cm in the posterior mediastinum of the right thoracic cavity. After a thorough examination, no suspected lipomatous lesions were found elsewhere in the patient's body. The patient underwent a thoracotomy to remove the mediastinal mass through a right thoracic approach. Subsequently, hematoxylin-eosin staining revealed dedifferentiated liposarcoma (DDL), immunohistochemistry showed positive expression of cyclin-dependent kinase 4, and murine double minute 2 (MDM2), in addition, fluorescence in situ hybridization for the MDM2 gene was also positive, which suggested DDL. The patient was discharged without any complications, and no metastasis or recurrence was observed after 19 months of follow-up. To provide a reference for clinical diagnosis and treatment, we reviewed and discussed the literature on primary liposarcoma of the mediastinum.

Spindle cell thymoma and its histological mimickers

Spindle cell thymomas are the most common spindle cell neoplasms of the anterior mediastinum. These tumors belong to the group of thymic epithelial neoplasms and are known for their wide histomorphologic spectrum. This histological heterogeneity is the reason why unequivocal diagnosis can be challenging, especially when dealing with small biopsy material. Conversely, less conventional patterns of the tumor may also pose significant diagnostic problems in resected material and the differential diagnosis often includes other spindle cell neoplasms that are known to arise in the mediastinal cavity. These can be of variable origin and may share overlapping pathological features with spindle cell thymoma. Since spindle cell thymomas are tumors that primarily affect the adult population and predominantly arise from the thymic gland in the anterior mediastinum, this review will focus on the differential diagnosis with other spindle cell neoplasms that share similar demographic characteristics and, for the most part, originate from the anterior mediastinal compartment. These include other epithelial spindle cell tumors of thymic origin (sarcomatoid thymic carcinoma and spindle cell carcinoid tumor), mesenchymal neoplasms [solitary fibrous tumor (SFT), synovial sarcoma, and dedifferentiated liposarcoma] and various other tumors with spindle cell morphology, that may occasionally involve the anterior mediastinum. The clinical, pathological, immunohistochemical and molecular hallmarks of these lesions will be discussed and useful tips for the differential diagnosis with spindle cell thymoma will be provided.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The diagnostic value of magnetic resonance imaging compared to computed tomography in the evaluation of fat-containing thoracic lesions

Intrathoracic fat-containing lesions may arise in the mediastinum, lungs, pleura, or chest wall. While CT can be helpful in the detection and diagnosis of these lesions, it can only do so if the lesions contain macroscopic fat. Furthermore, because CT cannot demonstrate microscopic or intravoxel fat, it can fail to identify and diagnose microscopic fat-containing lesions. MRI, employing spectral and chemical shift fat suppression techniques, can identify both macroscopic and microscopic fat, with resultant enhanced capability to diagnose these intrathoracic lesions non-invasively and without ionizing radiation. This paper aims to review the CT and MRI findings of fat-containing lesions of the chest and describes the fat-suppression techniques utilized in their assessment.

Myxomatous Liposarcoma of the Mediastinum: A Review of the Literature

Myxomatous liposarcoma is an extremely rare type of mediastinal tumour that manifests in a manner comparable to other lung pathologies. Chest pain, shortness of breath, and dysphagia are the common presenting complaints. Radiological examinations or postoperative histological examinations provide the majority of the diagnostic evidence. The cornerstone of therapy consists of surgery and sometimes chemotherapy. Those who are afflicted have a better chance of experiencing favourable outcomes if they receive a diagnosis and treatment quickly.

Primary intrathoracic liposarcomas: A clinicopathologic and molecular study of 43 cases in one of the largest medical centers of China

Introduction

Primary intrathoracic liposarcoma is extremely rare, and most published series lack genetic analyses. The aim of our study is to better understand the clinicopathologic and genetic features of these rare lesions.

Materials and methods

Forty-three primary intrathoracic liposarcomas were identified and most cases were analyzed by systematic genetic studies, including fluorescence in situ hybridization (FISH), whole-exome sequencing (WES), and Sanger sequencing.

Results

This series included 27 males and 16 females (ratios, 1.68:1) aged 24-73 years (median, 53 years). Tumors mainly occurred in the mediastinum (n=23, 53.5%), followed by pleural cavity (n=16, 37.2%) and lung (n=4, 9.3%). The study included 21 well-differentiated liposarcomas (WDLs), 19 dedifferentiated liposarcomas (DDLs), 2 myxoid pleomorphic liposarcomas (MPLs) and 1 pleomorphic liposarcoma (PL), without identification of myxoid liposarcoma. FISH analysis identified MDM2 amplification in 17 of 18 WDLs (94.4%) and all DDLs (16/16, 100.0%). The MDM2-nonamplified WDL was CDK4-nonamplified but FRS2-amplified. WES and Sanger sequencing found somatic TP53 mutation in the 2 MPLs. Follow-up information was available for 33 of 38 cases (86.8%). Thirteen patients (39.4%) showed no evidence of disease, 10 patients (30.3%) were alive with disease, and 8 patients (24.2%) died of disease. Fourteen cases developed recurrence and 1 with metastasis.

Conclusions

WDL/DDL was the overwhelming subtype in this location, followed by MPL and PL. Analysis of the FRS2 gene, in combination with MDM2 and other genes of 12q13-15, may more precisely characterize WDL/DDLs. MPL is the most fatal subtype of this site. Further studies are needed to explore the role of TP53 in the pathogenesis of MPL.

Rare Case of Primary Pulmonary Pleomorphic Liposarcoma Treated With Multimodal Therapy

Background: Pleomorphic liposarcoma (PLS) is a very rare type of primary pulmonary sarcoma. Clinical data about these tumors are limited, and optimal treatment has not yet been defined.

Case Report: A 32-year-old male presented with pain and heaviness over the right chest. Contrast-enhanced computed tomography (CECT) of the chest showed a heterogeneous hypodense pleural-based mass and a mediastinal mass. The patient was treated with chemoradiotherapy, followed by excision and adjuvant chemotherapy. Seven months after completion of treatment, he presented with an abdominopelvic mass and soft tissue peritoneal deposits. The mass was resected, and second line chemotherapy resulted in a partial response. The patient was routinely followed. Six months after completion of the second round of chemotherapy, CECT showed multiple soft tissue deposits in the right lumbar region, right hemipelvis, and presacral region with no evidence of pulmonary disease. Chemotherapy elicited a partial response. Three years from the date of diagnosis, the patient was alive with stable disease.

Conclusion: This case is unique because of the rare primary site of PLS presentation and the rare presentation of peritoneal metastasis. Citing such cases would help us to define adequate treatment protocols for this aggressive tumor.

A successful trimodality therapy for difficult-to-diagnose primary mediastinal dedifferentiated liposarcoma, which originated from the perihilar fat and invaded the right lungs

A 40-year-old man with high fever, hemoptysis, and fatigue showed a 10-cm mass in the middle and lower lobes of the right lung on computed tomography. Histological examination of transbronchial biopsy specimens showed sheets of small round tumor cells and mild staining for CD99. Primary Ewing sarcoma was suspected, and a trimodality therapy consisting of chemotherapy, intensity-modulated radiation therapy, and right pneumonectomy with surrounding tissue resection was performed. In surgical specimens, negative outcome of NKX2.2 in immunostaining and EWSR1 rearrangement in fluorescence in situ hybridization did not support the diagnosis of Ewing sarcoma. Positive immunostaining for MDM2 and CDK4 led to a diagnosis of dedifferentiated liposarcoma, which probably originated from an adipose tissue of the right perihilar mediastinum, and then invaded the lungs. The postoperative course was uneventful, without recurrence for more than 16 months.

A liposarcoma arising in a pulmonary hamartoma, coexisting with benign metastasizing leiomyoma

Pulmonary hamartoma is a common benign tumor that rarely degenerates into malignancy. We document a unique case of pulmonary hamartoma with malignant transformation into well differentiated liposarcoma, coexisting in proximity to pulmonary nodules representing benign metastasizing leiomyoma in a sixty-year-old lady.

Myxomatous liposarcoma in giant pleural cavity: case report and literature review

Liposarcoma was mainly occurring in the lower extremities and deep retroperitoneal soft tissues, but rarely occurred in the thoracic cavity. Most cases were reported in the literature, and most of them were middle-aged and elderly people. It was even more rare in adolescents with tumors occupying the entire thoracic cavity. Recently, one case of myxomatous liposarcoma was admitted and treated in our hospital. This paper reports this case and discusses the diagnostic method, pathological type and treatment of giant liposarcoma in the chest, in order to provide a reference for the clinical diagnosis and treatment of this rare tumor.

Resection of a giant mediastinal atypical lipomatous tumor involving the esophagus

Liposarcoma is one of the common soft tissue tumors but barely arises from the mediastinum. Complete surgical resection with a negative surgical margin is required for the treatment; however, mediastinal liposarcomas tend to be large due to its slow-growing nature. A 57-year-old man was referred to us for having an abnormal mediastinal shadow in a chest X-ray. Computed tomography scanning revealed a giant posterior mediastinal tumor, completely involving the esophagus. Because of the unusual size and location of the tumor, we took a bilateral video-assisted thoracoscopic approach. First, the soft lipomatous compartment of the tumor was dissected from the esophagus and the descending aorta via the left thoracic cavity complete thoracoscopic procedure. Then, the patient was placed in the left lateral position, and the solid part of the tumor was completely resected using 13 cm of right-side thoracotomy. There was no complication or local recurrence in the first 26 months of follow-up.

A rare case of a giant anterior mediastinal liposarcoma

We report a case of a 53-year-old lady who was incidentally diagnosed to have giant anterior mediastinal mass while undergoing preoperative evaluation for another surgery. She came for surgery after 2 years when she became symptomatic. A large 6.7-lb (2800 g) tumor occupying both hemithoraces and engulfing heart was excised in its entirety through a clamshell thoracotomy under cardiopulmonary bypass standby. Histopathology revealed the final diagnosis as well as differentiated liposarcoma. She is now able to walk 2 km without any symptoms at the end of a 24-month follow-up.

Liposarcomas of the mediastinum

Liposarcoma is a malignant tumor of adipocytic differentiation that rarely arises within the mediastinum. Most of the existing data available comes from scattered case reports and a few small series. The World Health Organization (WHO) recognizes four basic types of liposarcoma: well-differentiated/atypical lipomatous tumor (ALT), dedifferentiated, myxoid and pleomorphic liposarcoma (PLS). All of these liposarcoma subtypes have been recorded to occur within the mediastinum. On morphologic grounds liposarcoma can present a challenge for diagnosis as it can be difficult to distinguish from benign adipocytic neoplasms, or in the case of dedifferentiated liposarcoma (DDLS), from virtually any other type of sarcoma. Molecularly the most common subtypes of liposarcoma are characterized by specific, recurrent genetic alterations involving amplification events of MDM2 and CDK4 in well-differentiated liposarcoma (WDL) and a recurrent t(12;16)(q13;p11) in myxoid liposarcoma (MLS). MDM2 and CDK4 amplification can be assessed by immunohistochemistry, fluorescence in situ hybridization, or molecular techniques that evaluate copy number alterations and amplifications such as array based assays and next generation sequencing (NGS). In addition to WDL and MLS, a few additional rare subtypes of liposarcoma may occur in the mediastinum including PLS, myxoid WDL, thymoliposarcoma, and sclerosing high-grade liposarcoma. The present review will focus on the clinicopathologic features of the various histologic types of liposarcoma described in the mediastinum and their differential diagnosis. Data is derived from review of the largest series published in the more recent literature on these tumors.

Pictorial Review of Mediastinal Masses with an Emphasis on Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) has become a crucial tool for evaluating mediastinal masses considering that several lesions that appear indeterminate on computed tomography and radiography can be differentiated on MRI. Using a three-compartment model to localize the mass and employing a basic knowledge of MRI, radiologists can easily diagnose mediastinal masses. Here, we review the use of MRI in evaluating mediastinal masses and present the images of various mediastinal masses categorized using the International Thymic Malignancy Interest Group's three-compartment classification system. These masses include thymic hyperplasia, thymic cyst, pericardial cyst, thymoma, mediastinal hemangioma, lymphoma, mature teratoma, bronchogenic cyst, esophageal duplication cyst, mediastinal thyroid carcinoma originating from ectopic thyroid tissue, mediastinal liposarcoma, mediastinal pancreatic pseudocyst, neurogenic tumor, meningocele, and plasmacytoma.

An extremely rare case of rapidly growing mediastinal well-differentiated liposarcoma with a sclerosing variant: a case report

Background

Liposarcoma arising from the mediastinum is rare, accounting for less than 1% of mediastinal tumors. Furthermore, a rapidly growing well-differentiated liposarcoma is extremely rare. A well-differentiated liposarcoma is usually considered a low-grade malignancy. However, we present an extremely rare case of a sclerosing variant of well-differentiated liposarcoma that grew rapidly within a year.

Case presentation

A 77-year-old man with a giant mass in the left thoracic cavity was referred to our hospital. This mass measured about 10 cm and occupied the left-sided mediastinum on a chest radiography; however, there was no abnormal finding on the previous year’s chest radiography. Chest-enhanced computed tomography revealed a well-circumscribed 11-cm mass in the left-sided anterior mediastinum. Positron emission tomography showed accumulation of fluorodeoxyglucose uptake in this tumor (maximum standard uptake value = 3.3). The radiological findings of computed tomography and positron emission tomography indicated that this tumor was a benign or low-grade malignancy; therefore, the chest radiographic findings were difficult to explain. To explain this discrepancy and establish the diagnosis, tumor resection was performed via left posterolateral thoracotomy. Intraoperatively, the left phrenic nerve and pericardium were adhered tightly to the tumor, so we resected them. The tumor was well-circumscribed and fibrous; therefore, the initial diagnosis was solitary fibrous tumor. However, based on its histopathological and immunohistochemical patterns, the tumor was diagnosed as a sclerosing variant of well-differentiated liposarcoma. Five years postoperatively, the patient remains alive with no evidence of disease recurrence.

Conclusions

A well-differentiated liposarcoma is usually considered a low-grade malignancy. Nevertheless, the giant tumor in the present case appeared within 1 year. Thus, this was an extremely rare case of a sclerosing variant of well-differentiated liposarcoma with rapid growth.

Primary pleural liposarcoma combined spindle cell lipoma of the lung

Liposarcoma is a malignant adipose tissue tumor which mainly originates from the extremities and retroperitoneum. Primary pleural liposarcoma is very rare. Spindle cell lipoma is a rare benign adipose tissue tumor. A 66‐year‐old male was referred to our hospital for the evaluation of a mass‐like opacity visible on chest X‐ray. Computed tomography (CT) scan revealed a well‐defined soft tissue mass with internal low attenuations and adjacent multiple nodules in the upper lobe of the left lung, and surgical excision was subsequently performed. Histopathological findings revealed adipose tissue with lipoblasts and spindle cells and immunohistochemical staining (IHC) revealed the tumor cells were strongly positive for CDK4 and MDM2. Histopathological examination of the small lung nodules showed spindle cell proliferation and adipose tissue without positivity for MDM2. Here, we report a rare case of primary pleural liposarcoma combined adjacent spindle cell lipoma of the lung.

Combining surgery with 125I brachytherapy for recurrent mediastinal dedifferentiated liposarcoma: A case report and review of literature

BACKGROUND

Dedifferentiated liposarcoma in the mediastinum is an extremely rare malignant neoplasm. A few previous case reports indicate that surgical resection is the major treatment, but frequent recurrence occurs locally. Due to its rarity, its clinical characteristics, optimal treatment and clinical outcomes remain unclear. Here, we report a case of multifocal recurrent dedifferentiated liposarcoma in the posterior mediastinum treated by combining surgery with ¹²⁵I brachytherapy, and summarize its clinical features, treatment and prognosis.

CASE SUMMARY

A 75-year-old man was admitted to our hospital with a history of gradual dysphagia for one year and aggravated dysphagia for 3 mo. Contrast-enhanced computed tomography (CT) revealed several large cystic-solid masses with lipomatous density, and calcification in the posterior-inferior mediastinum. The patient received a wide excision by video-assisted thoracoscopic surgery. Pathological analysis confirmed the tumors were dedifferentiated liposarcomas. The tumor locally relapsed 24 mo later, and another operation was performed by video-assisted thoracoscopic surgery. Fifteen months after the second surgery, the tumor recurred again, and the patient received CT-guided radioactive seeds ¹²⁵I implantation. After 8 mo, follow-up chest CT showed an enlarged tumor. Finally, his condition exacerbated with severe dysphagia and dyspnea, and he died of respiratory failure in July 2018.

CONCLUSION

We reviewed the literature, and suggest that surgical resection provides beneficial effects for dedifferentiated liposarcoma in the mediastinum, even in cases with local recurrence. ¹²⁵I brachytherapy may be beneficial for recurrent unresectable patients.

Primary pulmonary myxoid sarcoma with EWSR1-CREB1 fusion: a case report and review of the literature

BACKGROUND

Primary pulmonary myxoid sarcoma (PPMS) is an extremely rare lung sarcoma that is characterized in most cases by recurrent balanced chromosomal translocation t(2;22)(q33;q12) leading to the oncogenic fusion gene EWSR1-CREB1.

CASE PRESENTATION

We report a case of PPMS with molecular confirmation using fluorescence in situ hybridization (FISH) and DNA sequencing in a 45-year-old female patient. Computer tomography (CT) scanning revealed a peripheral circumscribed solid mass of 2.1 × 2 cm in the right lung superior lobe. Histologically, the tumor cells ranged from stellate, polygonal to chondrocyte-like or physaliferous-like, forming reticular network of delicate lace-like cellular strands and cords in abundant myxoid stroma. The tumor cell immunophenotype was positive for vimentin, EMA and negative for CK-pan, TTF-1, CAM5.2, S-100, calponin, SMA, desmin, ALK, CD31 and CD34. Molecular analysis demonstrated EWSR1-CREB1 gene fusion in this tumor. During 38 months of follow-up, the patient was alive with no clinical or radiological evidence of recurrence or metastasis.

CONCLUSION

PPMS is a rare low-grade sarcoma with distinct histological and genetic features. We add another case to the literature of this rare tumor and report for the first time occurrence of chondrocyte-like and physaliferous-like tumor cells in this tumor, thus enriching its morphologic and cytologic spectrum.

Atypical lipomatous tumour/well-differentiated liposarcoma and de-differentiated liposarcoma in patients aged ≤ 40 years: a study of 116 patients

AIMS

Limited data exist on atypical lipomatous tumour (ALT)/well-differentiated liposarcoma (WDL) and de-differentiated liposarcoma (DDLPS) in children and young adults.

METHODS AND RESULTS

Cases of ALT/WDL/DDLPS arising in patients aged ≤ 40 years were collected from multiple institutional and consultation archives. A total of 116 cases of ALT/WDL (75) and DDLPS (41) were identified, representing fewer than 5% of these tumours seen at our institutions during this time-period. The patients (59 male/57 female) ranged in age from 8 to 40 years. Sites included deep central (abdomen/retroperitoneum/pelvis/groin) (n = 60), extremity (n = 42), trunk (n = 5), head/neck (n = 8) and mediastinum (n = 1). De-differentiated patterns included: high-grade pleomorphic sarcoma, myxofibrosarcoma-like, heterologous rhabdomyoblastic differentiation, low-grade spindle cell sarcoma and homologous lipoblastic differentiation. Forty-one patients experienced a local recurrence and 11 patients with DDLPS developed metastasis. ALT arising in the extremities had lower recurrence rates than deep central WDL (5-year recurrence-free survival 88.9% versus 59.0%; P = 0.002), while patients with deep central DDLPS experienced significantly more adverse events compared to WDL at this site (5-year event-free survival 11.9% versus 59.0%) (P < 0.0001). Seven (of eight) head/neck tumours had follow-up available; five recurred, and one patient (DDLPS) with recurrence also experienced a metastasis. The single mediastinal tumour (DDLPS) recurred and metastasised.

CONCLUSION

ALT/WDL and DDLPS occurring in patients aged ≤ 40 years is rare, but exhibits similar morphological features to its counterparts in older adults, including potential for heterologous and homologous de-differentiation in the latter. Although case numbers are limited, tumours arising in the head and neck exhibit high rates of adverse events, suggesting that classification as WDL rather than ALT is more appropriate.

Primary pleural liposarcoma: A rare entity

Primary pleural liposarcoma (PPL) is a rare malignant tumor of the pleura. The diagnosis of PPL may be suspected on chest imaging based on radiologic features such as large pleural mass showing areas of fat with or without calcification. Herein, we present the case of a 32-year-old male whose contrast-enhanced computed tomography scan of the chest revealed a large, heterogeneous, hypodense, right pleural-based mass with small areas of fat and calcification within it. An ultrasound-guided biopsy was performed, which confirmed the diagnosis of a myxoid variant of pleural liposarcoma.

Radiation Therapy in Resectable Intrathoracic Sarcomas. A Rare Cancer Network Study

PURPOSE

Intrathoracic sarcomas (ITS) are considered rare tumors and have a dismal prognosis. We investigated outcomes and risk factors for local control (LC), disease-free survival (DFS), and overall survival (OS) in patients with resected nonmetastatic ITS treated with or without adjuvant radiation therapy (RT) and/or chemotherapy.

METHODS AND MATERIALS

Patients from the Rare Cancer Network database were studied. A Kaplan-Meier estimate was used to assess survival curves, and Cox proportional hazards regression was used to assess risk factors for LC, DFS, and OS.

RESULTS

Between 2000 and 2017, 121 patients met inclusion criteria. The primary site was lung in 30%, mediastinum in 34%, and pleura in 36%. Thirty-nine percent and 32% received RT and chemotherapy. Median follow-up was 34 months (range, 2-141). LC, DFS, and OS at 10 years were 52%, 18.7%, and 7.2%, respectively. In multivariate analysis, RT (P = .003) and R1 margin status (P = .041) retained a significant association with LC. Only R1 resection (P = .002) remained associated with an increased risk of death in multivariate analysis. Overall, 7 patients (6%) developed grade 3 treatment-related chronic toxicity events.

CONCLUSIONS

This joint analysis revealed that OS remains modest in this group of patients, mainly given by the high risk of local and distant failure. Our results suggest that resected ITS can benefit from adjuvant RT.

Recurrent intrathoracic dedifferentiated liposarcoma: A case report and literature review

Background

Liposarcoma (LPS) is the second most common type of soft tissue sarcoma, accounting for approximately 15–20% of all the sarcomas. Primary intrathoracic LPS, however, is quite rare. LPS is a malignant mesenchymal tumor, comprised of lipogenic tissue with varying degrees of atypia. It can be subclassified into well-differentiated LPS (WDLPS), myxoid LPS (MLPS)/round cell LPS, pleomorphic LPS (PLPs), and dedifferentiated LPS (DDLPS), based on the histology.

Case presentation

A 76-year-old male patient initially presented to the emergency room with a complaint of precordial chest pain for one month. Computed tomography (CT) of his chest showed a large, 8 cm × 8 cm x 10 cm, supradiaphragmatic, complex solid mass in the lower left hemithorax, along the anterior chest wall. Chest wall mass excision revealed dedifferentiated LPS, with excision of margins. Positron emission tomography (PET) scan did not show metastatic disease. Seven months later, he presented with shortness of breath, and CT of the chest showed large, left pleural-based masses, causing compression of surrounding structures. He was not a candidate for surgical resection. This patient subsequently failed chemotherapy and opted for hospice.

Conclusion

Intrathoracic LPS is a rare tumor. Recurrence is higher with dedifferentiated histology forms. Radical surgery with excision of margins is the primary recommended treatment.

Pleural dedifferentiated liposarcoma: A case report

The present case report describes a rare case of pleural liposarcoma. A 45-year-old Japanese man was hospitalized for increasing left chest pain. Imaging revealed a 10-cm pleural tumor and a 1.7-cm contralateral right pulmonary nodule. Biopsy specimens of the pleural tumor showed undifferentiated spindle-shaped and/or rounded sarcomatous features with myxoid stroma. The patient underwent embolization of the arteries feeding the left pleural tumor and palliative partial resection of the pleural tumor. The surgically removed specimens exhibited similar undifferentiated sarcomatous features. The left pleural tumor regrew aggressively, and the patient succumbed to mortality ~4.2 months following hospitalization. Autopsy demonstrated a 35-cm left pleural tumor, metastasizing to both adrenal glands and lumbar vertebral bones, and a 2.2-cm primary adenocarcinoma of the right lung. The majority of the left pleural tumor and its metastases consisted of undifferentiated sarcomatous elements, however, scattered or aggregated lipoblasts were identified in localized areas adjacent to the diaphragm. Immunohistochemically, these lipoblasts were diffusely positive for MDM2 and focally positive for S-100 protein. Undifferentiated sarcomatous tumor cells were focally positive for MDM2 but negative for S-100 protein. This case was diagnosed as pleural dedifferentiated liposarcoma. The local aggressiveness of the pleural liposarcoma directly contributed to the patient's mortality. A review of the literature indicated that the dedifferentiated subtype may serve as a factor that is indicative of a poor prognosis for pleural liposarcoma.

Rapidly growing pleural liposarcoma masquerading as extrapleural hematoma

Intrathoracic liposarcoma can occur in the lung, mediastinum, pleura, and chest wall, and tends to remain clinically silent until becoming large enough to displace adjacent structures. Treatment usually includes sufficient surgical resection followed when necessary by adjuvant chemoradiotherapy. We report a case of an uncommon presentation of a rapidly growing pleural liposarcoma, the diagnosis of which may have been obscured by coexisting thoracic trauma with suspected extrapleural hematoma.

Primary mediastinal dedifferentiated liposarcoma: Five case reports and a review

Background

Liposarcoma has been subclassified histologically into well‐differentiated, myxoid, pleomorphic, and dedifferentiated types. The dedifferentiated type generally shows poorer prognosis than the well‐differentiated type. Because of its rarity, the clinicopathological features and clinical outcomes of primary mediastinal dedifferentiated liposarcoma remain unclear.

Methods

Five patients with primary mediastinal dedifferentiated liposarcoma were treated at Shinshu University Hospital between January 2012 and August 2017. We investigated the clinical characteristics, including age, gender, radiographic findings, pathological status, and clinical and treatment outcomes.

Results

Four of the five patients initially underwent radical surgical resection. One patient was disease‐free after surgery, but the remaining three patients developed local recurrence in the mediastinum after surgical resection. Two of these patients underwent repeat surgical resection, resulting in long survival (60 and 40 months, respectively), while the other underwent proton beam therapy and showed no evidence of recurrence as of 17 months after treatment. The remaining patient was treated with chemotherapy using doxorubicin because of advanced inoperable disease, but failed to show a response and died within a month of the initiation of chemotherapy. Although the maximum standardized uptake values on fluorodeoxyglucose‐computed tomography were relatively low, there was a slight positive relation between these values and the Ki‐67‐positive ratio in the tumor.

Conclusion

Aggressive treatment by surgical resection should be considered for mediastinal dedifferentiated liposarcoma, even in cases with local recurrence.

Giant primary liposarcoma of the anterior mediastinum: A case report

RATIONALE

Liposarcoma is a cancerous mesenchymal tumor and the most common soft-tissue sarcoma that starts in the adipose tissue. Liposarcoma is commonly found in lower extremities and retroperitoneum, but rarely occurs in the mediastinum.

PATIENT CONCERNS

A 63-year-old male was referred to our clinic with a 6-month history of chronic cough and dyspnea.

DIAGNOSE

Chest x-rays demonstrated a large mass occupying the left hemithorax. Contrast-enhanced computed tomography (CT) revealed a large mass in the anterior mediastinum, which caused the extrinsic compression of the main and left pulmonary artery and the right shift of mediastinum. Diagnosis of liposarcoma was confirmed by microscopic examination and immunohistochemistry analysis.

INTERVENTIONS

The patient underwent a thoracotomy for resection of the mediastinal lesion via left thoracic approach.

OUTCOMES

The patient discharged without any complications and has been continuing to follow up in clinic without any complaints.

LESSONS

The primary mediastinal liposarcoma is rare, and we recommend that the liposarcoma should be considered in the differential diagnosis of a patient presenting with a mediastinal mass.

Refractory bleeding from a giant de-differentiated liposarcoma of the chest wall: An indication for neoadjuvant chemotherapy and palliative resection? - A case report

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Dedifferentiated Liposarcoma (DDLPS) occur rarely in the chest.

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Response to chemotherapy is believed to be minimal.

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Neoadjuvant chemotherapy plays a role in stopping refractory bleeding from a chest wall DDLPS.

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Palliative resection may be used to improve quality of life even in the face of incurable disease.

Introduction

Dedifferentiated liposarcoma (DDLPS) is a heterogenous neoplasm of variable histological grade. DDLPS uncommonly arises from the chest wall. There are limited data available about the tumor’s response to chemotherapy and accessible reports indicate minimal benefits. Surgery is thus the cornerstone of management. Here, we demonstrate an uncommon situation where chemotherapy was used to arrest bleeding from a giant DDLPS that was refractory to all available hemostatic agents. This case also presents an uncommon indication for palliative chest wall resection and reconstruction (CWRR).

Presentation of case

A 55-year old woman presented with refractory bleeding from an ulcerated and foul-smelling mass on the anterior chest wall, confirmed histologically to be DDLPS. Chemotherapy with Doxorubicin and Ifosfamide was used to control the bleeding. She subsequently had CWRR to improve her quality of life. The patient made an uneventful recovery but later died from pulmonary embolism.

Discussion

The dedifferentiated component of DDLPS is vascular and may account for why we were able to exhibit a hemostatic response to chemotherapy. CWRR was then employed to improve the quality of life in an advanced, ulcerated and infected tumor of the chest wall.

Conclusion

We were able to demonstrate a hemostatic response of DDLPS to neoadjuvant chemotherapy and anticipate that this report may serve as a reference for further studies. Furthermore, we believe that palliative resection may be carried out to improve a patient’s quality of life even in the face of advanced disease.

Giant Mediastinal Liposarcoma: A Rare Yet Distinct Clinical Entity

Mediastinal liposarcomas are rare tumors that occasionally present as unusually large and rapidly growing mediastinal masses resulting in compressive symptoms. We present a case of a 48-year-old woman undergoing resection of a mediastinal liposarcoma of massive proportion and propose that "giant mediastinal liposarcomas" be identified as a distinct clinical entity.

A novel sclerosing atypical lipomatous tumor/well-differentiated liposarcoma in a 7-year-old girl: report of a case with molecular confirmation

Atypical lipomatous tumor (ALT)/well-differentiated liposarcoma (WDL)/dedifferentiated liposarcoma (DDL) is a common type of liposarcoma in late adulthood. However, pediatric ALT/WDL/DDL is extremely rare, and only 3 cases have been described in children younger than 10 years of age. Notably, none of these cases harbored MDM2 gene amplification. Here, we reported a sclerosing ALT/WDL in a 7-year-old Chinese girl. Histologically, in most areas, the neoplastic cells were embedded within the collagenous background, and typical lipogenic areas were inconspicuous throughout the sclerotic areas. In addition, scattered small foci of atypical osseous/chondrous elements were identified. Notably, a small typical lipoma-like ALT/WDL area was detected in the periphery of the mass. Immunohistochemically, all the neoplastic components demonstrated positivity for MDM2, CDK4, and p16. Fluorescence in situ hybridization revealed MDM2 gene amplification in all the tumor components. To the best of our knowledge, this is the first example of MDM2-amplified ALT/WDL in this age group.

[Relapsed Pleomorphic Liposarcoma with Mediastinal Metastasis: A Case Report and Review of the Literature]

纵隔内转移性多形性脂肪肉瘤为纵隔内肿瘤的罕见病种，目前总体治疗效果欠佳。本文介绍腰大肌旁多形性脂肪肉瘤复发伴纵隔转移1例，探讨多形性脂肪肉瘤的临床特点和治疗策略。回顾性分析我院收治的1例转移性多形性脂肪肉瘤患者，基于影像学诊断与手术病理诊断，对患者进行针对性的多学科综合治疗。一名41岁女性患者，诊断腰大肌旁多形性脂肪肉瘤伴纵隔转移。经手术、靶向及化疗等多学科治疗，随访至今已65个月。对于多形性脂肪肉瘤治疗策略，应以外科完整切除为首选，术后辅助相关内科治疗，多学科综合治疗以延缓患者病情进展及复发。

Primary mediastinal dedifferentiated liposarcoma resected by lateral thoracotomy with video-assisted thoracoscopic surgery

Primary dedifferentiated liposarcoma originating in the mediastinum is extremely uncommon. Here, we report a case of mediastinal dedifferentiated liposarcoma. A 74-year-old man was admitted to our hospital with a left intrathoracic tumor ∼10 cm in diameter. Computed tomography that was taken in another hospital 2 years before the initial visit to our hospital had shown a lipomatous tumor ∼3 cm in diameter adjacent to the left lower pulmonary vein. The tumor was resected by left lateral thoracotomy with video-assisted thoracoscopic surgery. Pathological examination revealed primary mediastinal dedifferentiated liposarcoma. No evidence of recurrence has been seen as of 8 months postoperatively.

Primary Diaphragmatic Dedifferentiated Liposarcoma in a Young Female Patient after Delivery

A 26-year-old woman was admitted with the chief complaint of chest pain. She had delivered her first child 9 months before admission. Computed tomography showed a bulky mass in her left chest, and histopathological analysis revealed it to be dedifferentiated liposarcoma. We initiated doxorubicin chemotherapy, and the tumor mass reduced. After that, we performed vascular embolization along with chemotherapy, but tumor size did not reduce. On the 160th day of illness, the patient died. This is the first report of a primary diaphragmatic dedifferentiated liposarcoma diagnosed after delivery. Establishment of a regimen of chemotherapy for bulky unresectable liposarcoma is necessary.

Surgical resection of a giant primary liposarcoma of the anterior mediastinum

This case describes the incidental finding and surgical removal of an 1.8-kg liposarcoma in the anterior mediastinum. These tumors are very rare and would normally present with symptoms of intrathoracic compression; however, this patient was completely asymptomatic. The case presentation and treatment rationale are described along with a brief review of existing literature.

Mesenchymal tumours of the mediastinum--part I

The mediastinum is an anatomically defined space in which organs and major blood vessels reside with surrounding soft tissue elements. The thymus is an important organ in the mediastinum, and many of the masses encountered in the mediastinum are related to this organ. Most neoplasms diagnosed in the mediastinum are epithelial tumours (thymomas and thymic carcinomas), lymphomas or germ cell tumours. In contrast, soft tissue tumours of the mediastinum are rare. In 1963, Pachter and Lattes systematically reviewed soft tissue pathology of the mediastinum, covering the hitherto described [2, 226, 227] In this review, based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart, we provide an updated overview of mesenchymal tumours that may be encountered in the mediastinum.

[Myxoid primitive liposarcoma of the middle mediastinum]

Les liposarcomes “LPS” myxoïdes sont des tumeurs rares, notamment dans leur localisation médiastinale. Nous rapportons un cas d'un liposarcome myxoïde du médiastin moyen, chez un patient de 69 ans, sans passé pathologique particulier et sans signes d'appels respiratoires. Une radiographie thoracique faite lors d'un bilan préopératoire montre un élargissement médiastinal dont le scanner thoracique le rattache à une tumeur hétéro dense, siège de quelques zones de densité graisseuse au niveau du médiastin moyen. Malgré son volume, cette masse parait de contours nets, sans envahissement ni compression des structures adjacentes. La ponction biopsie transpariétale scanno-guidée est compatible avec un liposarcome myxoïde; Une exérèse chirurgicale complète est réalisée. Après 24 mois de surveillance, le patient ne présente pas de signe de récidive. Le LPS myxoïde du médiastin est une entité rarissime et quelques cas sporadiques ont été reportés dans la littérature. La chirurgie parait être le traitement de choix. La radiothérapie et la chimiothérapie gardent leur place dans des indications bien particulières.