Follicular Dendritic Cell Sarcoma of the Omentum: Multidetector Computed Tomography Findings
A 47-year-old woman had had epigastralgia, acid regurgitation, and fatigue over the two prior months. Her body weight had increased 10 kg over one month and a physical examination revealed a large, bulging, movable hard mass in the umbilical area. No bowel obstruction, anorexia, fever, or tarry stool was noted. A colonoscopy showed hyperplastic polyps, while a gastroduodenoscopy revealed a gastric polyp and erosive gastritis. CT of the abdomen showed a 14 × 8 × 7-cm mass with calcification in the abdomen and pelvis at the umbilical level (). The mass was inferior to the stomach, anterior to the transverse colon, and extended downward to pelvic level (). We could trace the engorged right gastroepiploic artery and vein at the uppermost part of the tumor (). All of these landmarks revealed that the exact anatomical location was the greater omentum. The tumor showed complex internal architecture, such as heterogeneous enhancement, central necrosis, hemorrhage, and focal calcification. The possibility of sarcoma and primary gastrointestinal stromal tumor (GIST) were considered. Under the impression of sarcoma of the greater omentum or primary GIST of the greater omentum, an operation was performed.\nThe surgery revealed a huge solid encapsulated mass in the omentum, with central necrosis and hemorrhage within the tumor (). No invasion to adjacent organs was observed and a histological diagnosis revealed a follicular dendritic cell sarcoma of the greater omentum ().