Thymus-related liposarcoma: report of a case and review of the literature

Enbloc resection of the largest thymic liposarcoma: A case report with literature review

Liposarcoma is the most common soft tissue tumor which is commonly found in the retroperitoneal region. This kind of tumor is usually well-differentiated with low to no potential to metastasize. Thymoliposarcomas are extremely rare tumors that are difficult to diagnose and differentiate from thymomas and other benign conditions.

Presentation of a case:This report presents a case of a 46-year-old male patient with dyspnea, generalized fatigue and non-specific chest pain caused by a giant anterior mediastinal mass. Computed tomography scan revealed a large mass in the anterior mediastinum. CT guided biopsy was consistent with thymolipoma. The tumor was surgically resected. The histological analysis of the tumor revealed thymoliposarcoma.

Discussion:Thymoliposarcoma usually presents with non-specific symptoms. The mean age of the diagnosis is 55.8 years old with a slight predominance in males. The corner stone of the treatment remains surgical excision of the tumor while the role of adjuvant therapy is not well documented.

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Thymoliposarcoma is an extremely rare diagnosis.

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The mean age of diagnosis is 55.8 years with a slight predominance in males.

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The mainstay of treatment remains surgical resection of the tumor.

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The role of adjuvant therapy is not well documented in the literature.

Mediastinal liposarcoma masquerading as penetrating aortic ulcer in the descending aorta: a case report

A 56-year-old woman with a history of hypertension and cerebral infarction was admitted to the hospital complaining of progressive and severe chest pain for 1 day. CT scan revealed a descending penetrating ulcer. Accordingly, she underwent an uneventful endovascular repair with a thoracic endograft. One month later the patient presented to our clinic with chest and back pain again. The contrast CT indicated that the periaortic mass grew larger, which interpreted as hematoma resulting from endoleak. But no endoleak was found by angiography. CT-guided needle biopsy was carried out, the histology of the mass revealed a pleomorphic liposarcoma. Liposarcomas are malignant fat-containing tumors derived from mesenchymal cells that typically occur in the extremities and retroperitoneum, mediastinal liposarcoma account for less than 1% in mediastinal malignancies; pleomorphic liposarcoma is the least common liposarcomas. Cases of liposarcoma invading vascular system are seldom, to our knowledge, it is the first case of mediastinal pleomorphic liposarcoma invaded the descending aorta. It is worth mentioning that in the modern endovascular era, the majority of aortic diseases are being repaired by endovascular techniques. When patients with growing periaortic mass post endovascular repair and endograft-related causes have been excluded, the rare possibility of mediastinal liposarcoma should arise as a differential diagnosis. Promptly CT-guided biopsy help establish an early diagnosis.

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.

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

BACKGROUND

Primary intrathoracic liposarcoma is an extremely rare malignancy as well as a rare histologic subtype of intrathoracic sarcoma. Relatively few reports appear in the world literatures. We explored the clinicopathologic features and prognostic factors of this tumor in this study.

METHODS

We retrospectively analyzed the clinicopathological data of 23 patients with primary intrathoracic liposarcoma who were treated in Shanghai chest Hospital affiliated to Jiao Tong University, from January 2003 to March 2013. These patients were classified into three groups according to the distinct tumor locations, including mediastinum, pleura and lung liposarcoma. Also, these patients could be divided into four types, including well-differentiated, myxoid, dedifferentiated and pleomorphic liposarcoma. The influences of age, sex, tumor size, tumor location, tumor histologic type and therapy on the prognosis of the patients were analyzed.

RESULTS

There were no significant difference for survival among distinct liposarcoma locations. However, significant difference for survival among distinct liposarcoma types were observed. Poor disease-free survival (DFS) was observed in the myxoid, pleomorphic and dedifferentiated types as compared to well-differentiated type (P = 0.038). Inferior overall-survival (OS) was observed in dedifferentiated, pleomorphic and myxoid types relative to well-differentiated type (P = 0.027). The radical surgery was a favorable prognostic factor for OS, as demonstrated by the better OS of the radical surgery group as compared to that of the non-radical surgery group ( P = 0.029). Notably, there were no significant differences for DFS and OS in other clinical parameters including tumor size, gender and age. In addition, radiotherapy and/or chemotherapy could not improve the prognosis of the patients receiving non-radical surgery or suffering from relapse.

CONCLUSIONS

The histological type and the radical surgery are the factors that influence the behavior and prognosis of liposarcoma. In general, radiotherapy and chemotherapy are believed to be ineffective therapeutic modalities for survival. So it is essential to completely resect the primary intrathoracic liposarcoma as radical cure of the disease.

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.

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.

Thymolipom

This report is on a 37-year-old female patient with an extraordinary large intrapleural tumor on the left, macroscopically originating from mediastinal structures. The tumor was completely removed via transpleural approach without compromising the left lung. It was identified as a thymolipoma with a weight of 2400 g.

Thymoliposarcoma

Thymoliposarcoma is an exceedingly rare thymic neoplasm with only five reports in English literature to date. We report another patient, a 36-year-old male, who developed local recurrences 4-years after initial resection. The clinicopathologic features of the present and previously reports were compared with particular emphasis on their morphologic spectrum and differential diagnosis.

Mediastinal liposarcoma appearing as a tumor arising in the esophageal wall

We report a case of mediastinal liposarcoma, a relatively uncommon neoplasm, in which the mass also appeared as a tumor arising in the esophageal wall. A 76-year-old man diagnosed with a posterior mediastinal mass had the tumor extirpated in local esophageal myectomy due to its unclear margin on the esophageal wall. The resected specimen was diagnosed as well-differentiated liposarcoma. Preoperative angiography showed the tumor received its blood supply from a branch of the left gastric artery, suggesting it arose in the lower esophageal segment close to the hiatus and extended to the mediastinum. Since this tumor's growth pattern differed completely from esophageal liposarcoma described in previous case reports, we concluded that it was mediastinal liposarcoma.