Metastatic Patterns of Myxoid/Round Cell Liposarcoma: A Review of a 25-Year Experience

Abstract

Myxoid/round cell liposarcoma (MRCL), unlike other soft tissue sarcomas, has been associated with unusual pattern of metastasis to extrapulmonary sites. In an attempt to elucidate the clinical features of MRCL with metastatic lesions, 58 cases, from the medical database of Keio University Hospital were used for the evaluation. 47 patients (81%) had no metastases, whereas 11 patients (11%) had metastases during their clinical course. Among the 11 patients with metastatic lesions, 8 patients (73%) had extrapulmonary metastases and 3 patients (27%) had pulmonary metastases. Patients were further divided into three groups; without metastasis, with extrapulmonary metastasis, and with pulmonary metastasis. When the metastatic patterns were stratified according to tumor size, there was statistical significance between the three groups (P = 0.028). The 8 cases with extrapulmonary metastases were all larger than 10 cm. Similarly, histological grading had a significant impact on metastatic patterns (P = 0.027). 3 cases with pulmonary metastatic lesions were all diagnosed as high grade. In conclusion, large size and low histological grade were significantly associated with extrapulmonary metastasis.

Metastatic Pattern, Local Relapse, and Survival of Patients with Myxoid Liposarcoma: A Retrospective Study of 45 Patients

“…However, the distribution of the anatomic location of the distant metastases in these tumours was also mainly extrapulmonary [10, 16, 17], confirming the theory that the pure MLS and RCLS is now considered to represent a continuum of the same type, with the occurrence of areas with round cells considered to be a poor prognostic factor [4]. …”

“…Some of the previous studies also focused on the occurrence of round cells in the tumours, and in patients with tumours containing more than 5% of round cell areas, a significantly higher tendency towards distant metastases was found [10, 16, 17]. However, the distribution of the anatomic location of the distant metastases in these tumours was also mainly extrapulmonary [10, 16, 17], confirming the theory that the pure MLS and RCLS is now considered to represent a continuum of the same type, with the occurrence of areas with round cells considered to be a poor prognostic factor [4].…”

Prognostic factors for the recurrence of myxoid liposarcoma: 20 cases with up to 8 years follow-up

“…Atypical extrapulmonary localizations are common, and often multifocal [5,[14][15][16]21,26]. MRI has been shown to be superior at detecting secondary lesions [27,28].…”

Potential for immunotherapy in soft tissue sarcoma

“…In contrast, myxoid liposarcomas can metastasize to the lung, bones, as well as interestingly, other fat-bearing areas of the body; 12,13 however these tumors are generally very sensitive to chemotherapy and radiation therapy. Pleomorphic liposarcomas are almost uniformly high grade with aggressive clinical behavior and virtually no response to all forms of therapy.…”