Pleomorphic liposarcoma of bone: a rare primary malignant bone tumour

Abstract

BackgroundLiposarcoma is an extremely rare primary bone sarcoma.Case presentationWe report a case of primary pleomorphic liposarcoma that arose in an 18 year old male in the metaphysis of the left tibia. Plain radiographs showed a partly sclerotic lesion and MR imaging a heterogeneous tumour predominantly isointense on T1- and high-signal on T2-weighted sequences with focal areas of increased T1 signal that suppressed with fat saturation. PET/CT showed marked FDG uptake (SUV = 17.1) in the primary tumour as well as a metastasis in the right distal femur and multiple small pulmonary metastases. Histologically, the tumour was a pleomorphic liposarcoma containing large tumour cells with vacuolated cytoplasm and hyperchromatic pleomorphic nuclei as well as numerous lipoblasts and scattered brown fat-like cells. Tumour cells strongly expressed FABP4/aP2, a marker of adipocyte differentiation, and UCP1, a marker of brown fat, but not S100. The case was treated with neoadjuvant MAP chemotherapy, resulting in extensive (> 95%) necrosis in the primary tumour and almost complete resolution of the femoral and pulmonary metastases.ConclusionsPleomorphic liposarcoma can present as a sclerotic primary malignant bone tumour; markers of adipose differentiation are useful in histological diagnosis and neoadjuvant MAP chemotherapy results in significant tumor necrosis.

Trabectedin arrests a doxorubicin-resistant PDGFRA-activated liposarcoma patient-derived orthotopic xenograft (PDOX) nude mouse model

“…All 6 patients underwent complete tumor resection and only one patient received chemotherapy with ifosfamide and epirubicin [ 8 ]. A primary PLPS in an 18-year-old male in the metaphysis of the left tibia was reported by Tiemeier et al [ 3 ]. The patient was treated with methotrexate, doxorubicin and cisplatinum (MAP).…”

“…PLPS consists of approximately 10% of liposarcomas. PLPS has been investigated in soft tissue sarcomas (STS) such as head and neck sarcoma as well as bone sarcoma [ 2 , 3 ] and has been demonstrated in patients of all ages [ 4 – 7 ]. Wang et al [ 8 ] reported 6 PLPS cases out of a total 89 liposarcoma cases between 2003 and 2017.…”

“…Pathology results demonstrated extensive (> 95%) tumor necrosis due to neoadjuvant chemotherapy. Chemotherapy and post-operative results after 12 months showed no sign of recurrence [ 3 ]. Yan et al [ 9 ] have shown an 81-year-old Chinese woman with advanced PLPS who was treated with apatinib after failure of chemotherapy had good efficacy and low toxicity.…”

Immunophenotypic expression of UCP1 in hibernoma and other adipose/non adipose soft tissue tumours

“…Four micrometre sections were cut and immunohistochemical staining was carried out using an Envision FLEX Minikit and the Dako Autostainer (Dako Agilent UK) as previously described [14, 19, 20]. The anti-UCP1 polyclonal rabbit antibody (diluted 1:250, 1: 500 (recommended dilution), 1:1000, 1:2000, 1:100000, 1:20000) employed in this study (ab10983) was obtained from Abcam, UK.…”

“…UCP1 is highly expressed in hibernoma, a tumour containing abundant BAT cells [14–17]. There are a few reports of UCP1 expression by tumour cells in liposarcoma [18, 19], but immunophenotypic expression of UCP1 in malignant adipose tumours has not been characterised. In this study, we have sought to determine whether UCP1 is expressed in specific benign and malignant adipose tumour subtypes.…”