Dedifferentiated Retroperitoneal Liposarcoma Presenting with Intra-Tumoral Hemorrhage：A Case Report

Abstract

We present a rare case of a patient with dedifferentiated retroperitoneal liposarcoma（DDLPS）who presented with intra-tumoral hemorrhage. The patient, a 75-year-old woman, was diagnosed as having a retroperitoneal tumor located above the left kidney. While waiting for surgery, she presented with symptomatic anemia（hemoglobin 7.6 g/dL）. A plain CT of the abdomen showed a high-density area in the tumor, and we made the diagnosis of intra-tumoral hemorrhage within the retroperitoneal tumor. As the patient was hemodynamically stable, we opted for elective surgery after blood transfusion. At laparotomy, there was no bloody ascites. The tumor was resected with the mesocolon, left adrenal grand, Gerota’s fascia, and suprarenal capsule. Macroscopic examination of the resected specimen showed a white yellowish and solid mass with a subcapsular hematoma. On histological examination, the tumor was composed of proliferating spindle-shaped cells with prominent small vessels. The findings were similar to those of a solitary fibrous tumor, however, immunohistochemical staining showed positive staining of the tumor cells for MDM2, CDK4 and CD34. On the basis of the above findings, the tumor was diagnosed as a DDLPS. The patient died of local recurrence and lung metastases 23 months after the surgery. Intra-tumoral hemorrhage within a DDLPS is rather rare. Although preoperative diagnosis is difficult, curative resection must be attempted considering the possibility of DDLPS.