A Case of Solitary Fibrous Tumor of the Ileocecal Mesentery Presenting with Perforative Peritonitis

Abstract

A 33-year-old man was admitted with acute lower abdominal pain. A bulky tumor, ascites, and free air were indicated by abdominal computed tomography. We diagnosed the patient with perforative peritonitis and performed emergency surgery. Laparotomy showed that the tumor originated from the ileocecal mesentery and infiltrated the ileum. Ileocecal resection was performed. Pathological findings showed that spindle-shaped tumor cells grew proliferously with a patternless pattern. Immunohistochemistry findings showed that tumor cells were positive for CD34 and negative for c-kit, desmin, and S-100. Therefore, we diagnosed the patient with solitary fibrous tumor (SFT). Perforative peritonitis was thought to be caused by the penetrated ileum. SFTs are uncommon mesenchymal neoplasms of ubiquitous location, observed in middle-aged adults. This is the first report about a SFT presenting with perforative peritonitis.