RETROPERITONEAL FIBROSARCOMA WITH DISTINCTIVE CHARACTERISTICS ON GROWTH P ATTERN AND FINDINGS IN DIAGNOSTIC IMAGING

Abstract

A 47-year-old man with lumbago had been found to have a perirenal hematoma at the lower pole of the left kidney on CT. MR imaging also demonstrated a hematoma，8 X8X9αn in size. After 1-month observation，the mass had very rapidly increased in size，suggesting it to be a neoplasm. Consequent surgery resulted in noncurative tumor extirpation，because of invasion to the descending colon，left kidney and surrounding tissues. Histlogically，the tumor consisted of uniform spindle-shaped cells with interlacing solid and bundle forms，showing a herring-bone pattern. Immunohistochemical studies finally led to the diagnosis of fibrosarcoma with markedly high malignant potential. Additional therapy was not performed. Rapid local spread of the tumor was demonstrated when bowel obstruction developed 2 months later. The patient died of the disease 3 months after surgery. No distant metastasis was observed throughout the clinical course.