Conclusions
Liposarcomas commonly occur in the extremities, however, primary pleural liposarcoma is extremely rare with very few reported cases1. We could only find 34 reported cases of pleural liposarcomas1-4.
The World Health Organization classifies liposarcoma into five types: atypical, well-differentiated, dedifferentiated, myxoid, and pleomorphic1. Of these, the dedifferentiated liposarcomas have a significantly poor prognosis with rates of local recurrence and metastasis of 41% and 17%, respectively, and 5-year survival rate of only 28%. Conversely, the 5-year survival rate for well-differentiated liposarcomas is 80% 5. The curative treatment for liposarcoma is surgical resection, with chemotherapy and/or radiotherapy. Adjuvant chemotherapy is selectively applied because the subtypes differ in chemosensitivity; it is not indicated in the resistant subtypes of dedifferentiated liposarcomas. Radiation therapy reportedly reduces the risk of local recurrence, especially in cases with myxoid liposarcoma3.
Regarding surgical resection of the tumor at the cavoatrial junction, Neves and Zincke classified venous tumor thrombus into four categories: level I–renal vein thrombus, level II– infrahepatic IVC thrombus, level III–retrohepatic IVC thrombus, and level IV–intraatrial IVC thrombus. In the presented case, the cavoatrial tumor thrombus can be classified as level IV. The standard surgical technique for level IV tumor thrombus is resection with CPB. However, the use of CPB in patients suffering from malignant diseases is controversial because CPB decreases the immunity of patients and potentially causes the spread of malignant cells to the whole body. Furthermore, CPB is associated with the release of inflammatory mediators, coagulopathy, platelet dysfunction, and increased bleeding. There have been contradictory reports on the use of CPB in cancer patients6, 7. Among 74 patients with metastatic cancer undergoing open-heart surgery with and without CPB, no significant difference was reportedly observed in cancer-specific mortality (patients with and without CPB: 26.7% and 24.1%, respectively, p=0.8)6. Conversely, another report demonstrated among 43,347 patients undergoing isolated CABG surgery, the adjusted relative risk of cancer-specific mortality caused by CPB was 1.16 (95% CI: 0.92–1.46, p=0.20)7. The lack of significant association between CPB and the progression of malignant diseases allowed us to perform aggressive surgical resection with CPB.
Similarly, there are no reports on HCA in cases with cavoatrial tumors, particularly liposarcoma. It was reported that CPB with HCA to treat level III or IV renal or adrenal tumors enabling complete tumor resection did not increase operative risks and was relatively safe8. The HCA proved useful in removing the cavoatrial tumor completely and in viewing the inside of the IVC clearly with endoscopy.
In conclusion, prompt complete resection of the cavoatrial metastatic dedifferentiated liposarcoma associated with poor prognosis was successfully performed using CPB with HCA, which resulted in satisfactory mid-term survival without recurrence.
Acknowledgements: I acknowledge Jun Matsubayashi, a professor at Tokyo Medical University, Department of Pathology, for assisting with the pathological analysis of this case.