A case of perinephric liposarcoma which recurred ten years later from the initial operation

A 58-year old man was referred to our hospital for treatment of an abdominal
mass. As for him, tumor resection with right nephrectomy had been performed ten years
ago for a giant well-differentiated perinephric liposarcoma. CT examination showed a
huge tumor shadow in the abdominal cavity. Abdominal MRI examination showed a 15 8
cm tumor with almost high signal intensity on the T2 weighted images. At lapalotomy, a
large bulky retroperitoneal tumor pointed out before an operation was found. Surgical
extirpation of the tumor was performed. Besides, several tumors of the thumb head size
were detected into right retroperitoneal fatty tissue. The right side mesocolon and the
tumors were not able to exfoliate, therefore right hemicolectomy was performed. Histological
features showed dedifferentiated liposarcoma. The postoperative course was uneventful.
But eight months after surgery, he was admitted again for treatment of a 4 3
cm retroperitoneal tumor. Extirpation of the tumor was performed. Histological finding
of this tumor also showed dedifferentiated liposarcoma. Dedifferentiation, occurring in
15% of the well-differentiated liposarcomas, sometimes may develop later. Long-term detailed
follow-up is necessary for well-differentiated liposarcoma.

The journal of medical investigation : http://medical.med.tokushima-u.ac.jp/jmi/index.html