Liposarcoma: Dedifferentiated or mixed-type?

Thin Thin WIN @ Safiya YUNUS ¹ and Mazita ISMAIL ²

¹ Pathology Department, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia and ² Pathology Department, Hospital Raja Permaisuri Bainun, Perak, Malaysia

ABSTRACT

Histopathological subtype of liposarcoma is one of the factors to assess biological behaviour of the tumour. It can be challenging for histopathologists if it is composed of more than one histological subtype or non-lipogenic dedifferentiated components. Two cases of liposarcoma with combined lipogenic and various non-lipogenic components were reported. Both cases were male patients in their fifties with deep seated soft tissue tumour in thigh. The first case was dedifferentiated liposarcoma; 30% of tumour showed features of atypical lipomatous tumour, and 70% of tumour showed dedifferentiated fibrosarcoma like pattern and malignant fibrous histiocytoma like pattern with abrupt transition in between. The second case was mixed-typed liposarcoma with combination of typical myxoid liposarcoma and dedifferentiated liposarcoma. Thorough sampling is necessary for identification of specific histological subtypes and its combination in liposarcoma. Ancillary immunohistochemistry, cytogenetic and molecular studies may be needed in difficult cases for histological subtyping which can guide the development of new therapeutic approach of targeted therapy.

Keywords: Liposarcoma, dedifferentiated liposarcoma, myxoid liposarcoma, mixed-typed liposarcoma

Correspondence: Thin Thin Win @ Safiya Yunus, Pathology Department, School of Medical Sciences Universiti Sains Malaysia,16150, Kubang Kerian, Kelantan, Malaysia.

Tel: 609 767 6445, Fax: 609 765 3370

E mail: drthinthinwin@gmail.com

Brunei Int Med J. 2013; 9 (5): 350-355