Abstract
A 77-year-old woman who had undergone left nephrectomy for renal cell carcinoma at a neighboring hospital in 1997 was detected having a mass in the left lower abdomen by CT in 2005. She came to our hospital for further examination and treatment in January 2007. Abdominal CT scan showed a 5 cm round mass beside the small intestine. Fluorodeoxyglucose positron emission tomography (FDG-PET) revealed intense FDG uptake periphery (standard uptake value : 4.5) and little FDG uptake center of the tumor, showing a ring-shaped appearance. The most likely diagnosis was gastrointestinal stromal tumor of the small intestine, and thus the tumor was resected with the small intestine and the mesentery. The tumor was located in the mesentery of the small intestine, was hard, and had a thick capsule and central necrosis. Histopathological examination revealed artificial materials indicating retained gauze fragments with macrophage and giant-cell infiltration, confirming the diagnosis of foreign body granuloma. Accumulation morphology of FDG (ring-shaped appearance) should alert surgeons to make diagnosis of foreign body granuloma, in addition to patient's history, US and CT findings.
