Huge mediastinal liposarcoma resected by clamshell thoracotomy: a case report
© The Author(s). 2017
Received: 28 October 2016
Accepted: 14 January 2017
Published: 20 January 2017
Liposarcoma is the single most common soft tissue sarcoma. Because mediastinal liposarcomas often grow rapidly and frequently recur locally despite adjuvant chemotherapy and radiotherapy, they require complete excision. Therefore, the feasibility of achieving complete surgical excision must be carefully considered. We here report a case of a huge mediastinal liposarcoma resected via clamshell thoracotomy.
A 64-year-old man presented with dyspnea on effort. Cardiomegaly had been diagnosed 6 years previously, but had been left untreated. A computed tomography scan showed a huge (36 cm diameter) anterior mediastinal tumor expanding into the pleural cavities bilaterally. The tumor comprised mostly fatty tissue but contained two solid areas. Echo-guided needle biopsies were performed and a diagnosis of an atypical lipomatous tumor was established by pathological examination of the biopsy samples. Surgical resection was performed via a clamshell incision, enabling en bloc resection of this huge tumor. Although there was no invasion of surrounding organs, the left brachiocephalic vein was resected because it was circumferentially surrounded by tumor and could not be preserved. The tumor weighed 3500 g. Pathologic examination of the resected tumor resulted in a diagnosis of a biphasic tumor comprising dedifferentiated liposarcoma and non-adipocytic sarcoma with necrotic areas. The patient remains free of recurrent tumor 20 months postoperatively.
Clamshell incision provides an excellent surgical field and can be performed safely in patients with huge mediastinal liposarcomas.
KeywordsLiposarcoma Clamshell thoracotomy Huge mediastinal tumor
Liposarcoma, the single most common soft tissue sarcoma, comprises 9% of primary sarcomas of the mediastinum . Although the pattern of metastasis differs considerably between the histologic subtypes, mediastinal liposarcomas often grow rapidly and local recurrence (especially of myxoid and pleomorphic types) occurs frequently . Because liposarcomas often grow rapidly and frequently recur locally despite adjuvant chemotherapy and radiotherapy, they require complete excision . Therefore, the feasibility of achieving complete surgical excision must be carefully considered.
We here present a patient with a huge mediastinal liposarcoma that was resected by an extended surgical approach via clamshell thoracotomy.
Liposarcoma is the single most common soft tissue sarcoma, accounting for 20–35% of soft tissue sarcomas [2, 5]. The WHO defines four histologic liposarcoma subtypes, namely, well-differentiated, myxoid, dedifferentiated, and pleomorphic . Well-differentiated liposarcomas or atypical lipomatous tumors require complete excision because of the high risk of local recurrence . Two recent studies both reported that these tumors have 5-year local recurrence rates of approximately 50% [7, 8]. Because delayed dedifferentiation can occur, long-term surveillance of the operative site is recommended. En bloc resection is desirable; however, the optimal surgical technique remains controversial. Given the lack of more definitive data, we remain skeptical of the need for routine biopsies of lipomatous masses solely for the purpose of pre-operative identification of the subtype and advocate marginal excision regardless of tumor subtype. Wide local excision is also the treatment of choice for liposarcomas. In either case, an appropriate operative field is of paramount important because liposarcomas often have ill-defined borders: because they contain a high proportion of adipose-like tissue, it is sometimes difficult to distinguish tumor-related adipose tissue from normal adipose tissue . Though adjuvant radiation therapy is usually reserved for higher-grade tumors in the retroperitoneum where wide surgical margins are difficult to achieve, all subtypes of liposarcoma require complete resection to minimize recurrence [10, 11].
Because primary mediastinal liposarcomas grow slowly and are relatively unlikely to invade surrounding organs, many patients remain asymptomatic until their tumors are very large. Therefore, mediastinal liposarcomas can be huge when detected. Various surgical approaches should be considered. Median sternotomy is a common approach to resecting mediastinal tumors. However, it may not afford adequate exposure of mediastinal tumors that extend into the thoracic cavity. Clamshell incisions are used to resect bilateral pulmonary metastases and large mediastinal tumors, as well as for bilateral lung transplantation. Because a component of clamshell incisions is a large transverse incision, they provide good access to the intrapleural space bilaterally. In contrast, the median vertical incision for sternotomy provides better exposure of superior and anterior mediastinal lesions. In this case, we selected a clamshell incision because we expected it to provide good visualization of the bilateral extensions of the tumor into the thoracic cavity.
As in this case, sufficiently large surgical and visual fields are essential for complete resection of huge liposarcomas. By combining clamshell thoracotomy with the use of multiple thoracotomy retractors, we were able to obtain adequate surgical and visual fields to achieve complete excision.
In conclusion, we believe that clamshell incision provides an excellent surgical field and can be performed safely in patients with huge mediastinal liposarcomas.
No funding was received specifically for this case report.
MT, NI, and NN performed the operation. All authors designed and drafted the manuscript. MT and NN wrote and revised the manuscript. All authors have read and approved the final version of the manuscript.
The authors declare that they have no competing interests.
Consent for publication
The patient has consented to the publication of these features of his case, and his identity has been protected.
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