Successful resection of a primary liposarcoma in the anterior mediastinum in a child: report of a case

Primary Dedifferentiated Liposarcoma of the Posterior Mediastinum With a Positive Surgical Margin

Liposarcoma often occurs in the extremities and retroperitoneum. Primary mediastinal liposarcoma is uncommon, and there is no settled opinion regarding adjuvant therapy after surgery. We have recently experienced a relatively rare case of primary dedifferentiated liposarcoma of the posterior mediastinum. The patient was a 76-year-old woman. An abnormal shadow was noted in the posterior mediastinum. Esophageal submucosal tumor and gastrointestinal stromal tumor were suspected; endoscopic ultrasound-guided fine needle aspiration was performed, but a definitive diagnosis could not be obtained. As the tumor tended to slowly grow, surgical resection was performed. Based on histopathological findings, the patient was diagnosed with primary dedifferentiated liposarcoma of the posterior mediastinum. Owing to the presence of a positive surgical margin, postoperative radiotherapy (60 Gy/24 fr/6 w) was administered. No recurrence was observed after three and a half years of follow-up. The prognosis of primary dedifferentiated liposarcoma of the posterior mediastinum with a positive surgical margin is poor, but postoperative radiotherapy may be useful.

Surgical approaches, anaesthetic management and outcome in pediatric superior mediastinal tumors

BACKGROUND

Pediatric superior mediastinal tumors are a heterogeneous group of tumors with marked variation in pathology and extension. We reviewed our experience with different surgical approaches to tumors originating from or extending to superior mediastinum in pediatrics.

PATIENTS AND METHODS

The medical records of all patients who had undergone resection for superior mediastinal tumors in Children's Cancer Hospital - Egypt, between January 2008 to December 2015, were reviewed for demographic data, clinico-pathological features, radiologic findings, operative techniques and outcome.

RESULTS

The study included 20 patients. Diagnosis included: germ cell tumors (n=8), neuroblastoma (n=4), soft tissue sarcoma (n=3), thymolipoma (n=2), infantile fibromatosis (n=1), calcifying fibrous tumor (n=1), and thymic carcinoma (n=1). Tumor extension was divided into tumors extending unilaterally to one hemithorax (n=9), tumors extending bilaterally to both hemithoraces (n=4), and cervico thoracic junction tumors (n=7). Extended lateral thoracotomy was used in 8 patients. Other approaches included trapdoor (n=5), clamshell (n=4), cervical approach (n=2) and double level lateral thoracotomy (n=1). There was no perioperative mortality, and postoperative morbidity was 20%. At the end of December 2016, 15 patients were alive free of disease, 5 patients developed local and/ or distant relapse.

CONCLUSION

Pediatric superior mediastinal tumors could be divided into 3 groups according to tumor extension. Each group has an optimum surgical approach that achieves the best exposure for adequate resection. However, further research is needed to confirm the conclusion as this was a descriptive study and the sample size was too small for valid statistical analysis.

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.

Primary mediastinal pleomorphic liposarcoma involving the superior vena cava

Primary mediastinal liposarcomas are extremely rare. They are primarily diseases of adults; however, they may be encountered in children. They are characterized by their large size and variable histologic subtypes, which correlate with clinical behavior and prognosis. Although the overall prognosis is poor, it is dependent upon the histologic subtype and completeness of surgical excision. Herein we present a case of a primary mediastinal pleomorphic liposarcoma in a 49-year-old male who received an en-bloc resection and superior vena cava replacement with Gortex graft. The patient has been disease-free after surgery for over 14 months.

Liposarcomas of the mediastinum and thorax: a clinicopathologic and molecular cytogenetic study of 24 cases, emphasizing unusual and diverse histologic features

Liposarcoma rarely occurs in the mediastinum, and most reports predate the current genetically based classification system. We report the clinicopathologic and molecular genetic features of a series of thoracic liposarcomas identified over a 60-year period. Twenty-four confirmed cases were reclassified using the most recent World Health Organization classification. Fluorescent in situ hybridization for CPM amplification and/or DDIT3 rearrangement was performed on selected cases. The 24 cases occurred in 13 men and 11 women (mean age, 53 y; range, 15 to 73 y) and arose in all mediastinal compartments. All subtypes were encountered with 8 well-differentiated liposarcomas, 6 dedifferentiated liposarcomas (3 of 6 confirmed CPM+), 7 pleomorphic liposarcomas (2 of 7 confirmed CPM-, 1 of 7 confirmed DDIT3-), 2 myxoid liposarcomas, and 1 unclassifiable liposarcoma (CPM- and DDIT3-). Unusual histologic features included myxoid well-differentiated liposarcoma mimicking myxoid liposarcoma (2 cases), lipoleiomyosarcoma (1 case), dedifferentiated liposarcoma with "meningothelial"-like dedifferentiation, differentiated myxoid liposarcoma mimicking well-differentiated liposarcoma (CPM-), and pleomorphic liposarcoma with epithelioid and myxoid change. Follow-up information was available for 19 patients (mean, 55 mo; range, 8 to 252 mo). Outcome was strongly associated with histologic subtype, with death from disease occurring in 1 of 6 well-differentiated, 1 of 4 dedifferentiated, 5 of 7 pleomorphic, and 2 of 2 myxoid liposarcomas. The mediastinum shows a preponderance of uncommon subtypes and unusual morphologic variants. Correct classification has important implications, with most patients with well-differentiated/dedifferentiated liposarcoma having a protracted clinical course, in contrast to the more rapid disease progression seen in patients with myxoid and pleomorphic liposarcoma.

[Recurrent primary mediastinal liposarcoma with histological change]

INTRODUCTION

Primary mediastinal liposarcomas are rare tumours with various histological features. Local recurrence is frequent.

CASE REPORT

We report the case of a 70-year-old patient, in whom a mediastinal mass was resected surgically and identified as a mediastinal, "lipoma-like" liposarcoma on histopathological examination. Nine years later, the patient complained of dyspnoea with cough. The chest X-ray showed anterior mediastinal enlargement and the chest CT scan revealed a heterogeneous mass containing both solid tissue and fat. The patient underwent a successful surgical resection of the mass and the histopathological examination confirmed the diagnosis of a recurrent, mixed-type liposarcoma of the mediastinum (well-differentiated and myxoid).

CONCLUSION

This report discusses the epidemiological, clinical and therapeutic features of this tumour.

Liposarcomas in young patients: a study of 82 cases occurring in patients younger than 22 years of age

Liposarcomas typically occur in middle aged to older adults. Altogether, approximately 50 bona fide liposarcomas have been reported in children and adolescents, most of which have represented myxoid liposarcomas, with a good prognosis. We undertook a retrospective study of 82 liposarcomas occurring in patients below 22 years of age. Clinicopathologic and follow-up information was obtained. Fluorescence in situ hybridization for FUS, EWSR1, CHOP (DDIT3), and MDM2 was performed in 30 cases. The tumors occurred in 28 males and 54 females (5 to 22 y of age) and involved many locations. Fifty-six cases were typical myxoid liposarcomas, including 2 with round cell areas. The tumors were grade 1 (56 cases) and grade 3 (2 cases). Thirty-seven of 38 patients with follow-up are alive without disease and 1 is alive with disease (median 59 mo follow-up duration, range: 8 to 108 mo). Six cases showed myxoid liposarcoma with spindled growth ("spindle cell myxoid liposarcoma"); these arose in 5 females and 1 male (median age 14 y) and involved the thigh in 40% of cases. All were grade 1. Follow-up (4 of 6 patients) showed local recurrences in 2 cases and metastases in 1 case. Twelve tumors consisted of conventional myxoid liposarcoma and pleomorphic liposarcoma ("pleomorphic myxoid liposarcoma"); these arose in 4 males and 8 females (10 to 22 y of age) and often involved the mediastinum. Tumor grades were 2 (4 cases) and 3 (8 cases). Follow-up (10 patients) showed 7 dead of disease, 1 alive with disease, and 2 disease free. Four atypical lipomatous tumors were seen including 2 with low-grade dedifferentiation. Two local recurrences were seen; all patients are disease free. Two conventional pleomorphic liposarcomas were seen; 1 patient with follow-up is disease free. FUS-CHOP and EWSR1-CHOP rearrangements were identified by fluorescence in situ hybridization in 15/23 and 2/23 conventional myxoid liposarcomas, respectively, and in no other tumors. Amplification for MDM2 was absent in all cases. We conclude that conventional myxoid liposarcoma is by far the most common subtype of liposarcoma in young patients, with an excellent prognosis. Two apparently novel subtypes of liposarcoma, termed pleomorphic myxoid liposarcoma and spindle cell myxoid liposarcoma comprise considerable percentages of liposarcomas in this age group and should be distinguished from conventional myxoid liposarcoma and conventional pleomorphic liposarcoma. Pleomorphic myxoid liposarcoma and spindle cell myxoid liposarcoma most likely represent high-grade and low-grade variants of myxoid liposarcoma, respectively. Additional study of such cases will be necessary for definitive classification.

Dedifferentiated liposarcoma of the pleura mimicking a malignant solitary fibrous tumor and associated with dedifferentiated liposarcoma of the mediastinum: usefulness of cytogenetic and molecular genetic analyses

Dedifferentiated liposarcoma of the pleura is an extremely rare malignancy mimicking a variety of tumors, such as other sarcomas, mesothelioma, and malignant solitary fibrous tumor of the pleura. Liposarcoma of the pleura can be combined with mediastinal involvement, and in most cases it may be impossible to be certain where the primary tumor originated. In this report, we describe a very rare occurence of a dedifferentiated liposarcoma of the pleura in a 76-year-old woman associated with a distinct second dedifferentiated liposarcoma of the mediastinum. Histologically, the pleural tumor demonstrated spindle cells arranged in a fascicular pattern, whereas the mediastinal tumor was mostly adipocytic with small areas of spindle cells. Vimentin and protein S100 were focally expressed by the tumor cells. The differential diagnosis of the pleural mass included malignant solitary fibrous tumor. Cytogenetic analysis showed supernumerary ring chromosomes in the pleural tumor, as well as strong amplification of MDM2 and CDK4 genes in both tumors. Array comparative genomic hybridization showed amplifications of chromosome arms 6q, 12q, and 15q, shared by both tumors and strongly pointing to a common origin.

Successful resection of a giant primary liposarcoma of the posterior mediastinum

Primary liposarcomas of the mediastinum are extremely rare neoplasms, comprising less than 1% of all mediastinal tumors. These tumors occur most commonly in the lower extremities (75%) and less frequently in the retroperitoneum. We present a case involving a successful radical resection of a large myxoid liposarcoma and its recurrence, both located in the posterior mediastinum.

Progressively enlarging paracardial lipoma in a child

Mediastinal lipomas are slowly growing tumours. Only very few cases have been reported in children. None of these included a rapidly enlarging lipoma. We present an 8-year-old severely adipose girl with an incidentally diagnosed mediastinal lipoma that showed rapid enlargement within 7 weeks.

Primary liposarcoma of the mediastinum

Primary mediastinal liposarcomas are extremely rare malignancies that remain asymptomatic until large and, even then, initial symptoms are nonspecific. We report a 48-year-old man followed up for asymptomatic multiple bullae who suffered progressive weight loss and dyspnea on exertion. Radiography and computed tomography of the chest showed a large mass with calcified nodules in the left pleural cavity and giant bullae in the right pleural cavity. Previous computed tomography of the chest showed a small tumor of mediastinal adipose tissue with calcified nodules. Tumor growth was calculated at about 500 times the tumor volume per 3.6 years. We completely resected the mediastinal tumor and conducted a bullectomy through a median sternotomy. The microscopic pathological diagnosis was well-differentiated/sclerosing liposarcoma. The man underwent no postoperative adjunctive irradiation and remains well 8 months after surgery.