Clinicopathological and molecular diagnostic features of liposarcoma: A study of 27 cases.

Objective: Liposarcomas are rare tumors, and it is difficult to collect cases in less densely populated areas. Therefore, we aimed to document more cases over a relatively long period to provide more data about the characteristics of liposarcomas. In this study, the clinicopathological features of liposarcomas were investigated in 27 patients. Material and Methods: All cases were confirmed by diagnosis through hematoxylin and eosin staining, immunohistochemistry (IHC), and fluorescence Results: Seven cases of liposarcoma were located in the paratesticular region (25.9%, 7/27), 12 in the retroperitoneum (44.4%, 12/27), and eight in the limbs (29.6%, 8/27). Histological analysis showed that there were 13 cases of ALT/WDLPS (48.1%, 13/27), nine cases of DDLPS (33.3%, 9/27), three cases of MLPS (11.1%, 3/27), and two cases of pleomorphic liposarcoma (7.4%, 2/27). IHC analysis revealed that 26 cases were MDM2-positive (96.3%, 26/27), 22 were CDK4-positive (81.5%, 22/27), 26 were P16-positive (96.3%, 26/27), and 27 were cyclin D1-positive (100%, 27/27). FISH analysis revealed 20 cases of MDM2 positivity (90.9%, 20/22) and one case of DDIT3 positivity (50%, 1/2). The clinical outcomes were available for 21 patients. Four patients died (4/21, 19.0%), five experienced recurrence (5/21, 23.8%), and 12 (12/21, 57.1%) survived with no other disease. Conclusion: A combined IHC examination of the four indicators may be used to diagnose ALT/WDLPS and DDLPS, and FISH is recommended as an important supporting method.