Rapid and Progressive Transformation of Well-Differentiated Retroperitoneal Liposarcoma to Poorly Differentiated Type: A Case Report

Abstract

Background and Aim: Retroperitoneal liposarcoma (LS) is a rare neoplasm. Well-differentiated LS is a slow-growing subtype with a high rate of recurrence. Despite the high recurrence rate after complete surgical resection, tumor transformation to poorly-differentiated LS is very rare. Case: A 45-year-old man with a primary retroperitoneal tumor and the final pathology of well-differentiated LS underwent tumor resection surgery. Local recurrence was detected nine months after surgery. Second surgical resection revealed a poorly-differentiated subtype of LS which was treated with adjuvant radiation therapy. No local recurrence and distant metastasis were detected in a three years follow-up period. Conclusion: Tumor transformation of well-differentiated retroperitoneal LS to poorly-differentiated subtype is extremely rare. Nevertheless, this rare case was successfully managed in a multi-disciplinary setting using surgical resection and adjuvant radiation therapy.

Keywords

• liposarcoma
• retroperitoneal sarcoma
• retroperitoneal tumor
• radiation therapy.