Acute life-threatening portal venous dilatation induced by a huge solitary fibrous tumor of the omentum.

An 85-year-old woman was referred to the medical oncology department because of a hypogastric mass. Contrast-enhanced CT showed a large hypervascular mass in the lower abdomen. CT angiography with volume rendering imaging revealed a vascular pedicle with an arborizing pattern of vessels. Many thick, early draining veins shunting into the portal vein were detected. Before surgery, the maximum size of the portal vein was 22 mm in diameter. Laparotomy revealed a huge, encapsulated, well-defined, hard tumor with hypervascularization, which was appended to the omentum. The mass with the omentum was curatively resected; it was 19 cm x 17 cm x 13 cm in size and 1915 g in weight. Histological features were consistent with a benign solitary fibrous tumor of the omentum, despite the tumor size and necrotic area found in the specimen. q Ultrasonography and CT performed at a 28-month follow-up revealed no evidence of tumor recurrence. Venous dilatation including that of the portal veins had diminished.