Myxoid liposarcoma with cartilagenous differentiation

Myxoid liposarcoma (MLPS) is an adipocytic tumour and second commonest among the types of liposarcoma. It exhibits a wide histological spectrum. It is important to be aware of this diversity of morphology in this tumour to prevent a wrong diagnosis. Heterologous differentiation in myxoid liposarcoma is reported; however, this is rare. To date, seven cases of MLPS with cartilaginous differentiation have been reported. Only five of these were further confirmed by cytogenetic analysis. We are reporting the 8th case of MLPS with cartilaginous differentiation. A 66-year female presented with posterior left thigh mass. Excision was done. Microscopic examination showed sheets of bland spindle cells containing round to oval nuclei and fine, delicate chicken-wire vessels. The firm blue appearing areas, which accounted for about 20% of the tumor volume, were characterised by mature hyaline cartilage. The final diagnosis was MLPS, showing prominent cartilaginous differentiation. Anterior and lateral margins were involved. Tumour was very close to the rest of the resection margins. FNCLCC grade was 1. Provisional pathological stage, as per staging system of the Union for International Cancer Control for extremity, was pT2. Patient was examined by oncologists. Wide local excision is in plan as two margins were involved by the tumour, while rest of the margins were very close to tumour. (author)