Giant retroperitoneal liposarcoma

A 71-year-old man presented with a history of progressive abdominal distention during the previous two years, accompanied by increasing difficulty in moving his lower extremities and a recurrent right scrotal mass on standing in the past two months. Physical examination revealed that the patient had prominent abdominal distention and a soft mass in the right scrotum (Figure 1). Computed tomography (CT) scan of the abdomen and pelvis revealed a large, wellencapsulated mass that filled the entire abdominal cavity (Figure 2), which caused left anterior compression of the right kidney (arrowhead) and compression of the bowels (arrow). The scan also showed that a part of the mass herniated into the right scrotum through the inguinal canal. Exploratory operation revealed a lobulated fatty tumour covered by a layer of transparent membrane (Figure 3). Ninety percent of the tumour which weighed about 13 kg, was resected; the unresectable part was bound tightly to the mesenteric vessels. Pathological examination revealed a welldifferentiated liposarcoma (lipoma-like subtype), composed of fat cells of various sizes, univacuolated (signet-ring cells, arrowhead) and multivacuolated (arrow) lipoblasts (Figure 4) and stromal cells with heteromorphous hyperchromatic nuclei (arrow) (Figure 5). The patient recovered and was discharged within a week after surgery. At a follow-up visit 5 months later, he remained free of symptoms.